Support semver metadata in plugin version

Permission errors aren't reported since I'm not sure what the user could do about them.
Some properties can be set in the model format but not in live-sync mode, like HttpEnabled.

.editorconfig

@@ -3,13 +3,16 @@ root = true
 [*]
 end_of_line = lf
 charset = utf-8
-
-[*.json]
-indent_style = space
-indent_size = 2
+insert_final_newline = false
 trim_trailing_whitespace = true
 
-[*.md]
+[*.{json,js,css}]
+indent_style = space
+indent_size = 2
+
+[*.{md,rs}]
 indent_style = space
 indent_size = 4
-trim_trailing_whitespace = true
+
+[*.lua]
+indent_style = tab

.gitignore

@@ -1 +1,5 @@
 /site
+/target
+/server/scratch
+**/*.rs.bk
+/generate-docs.run

.travis.yml

@@ -29,11 +29,10 @@ matrix:
       rust: stable
 
       script:
-        - cd server
         - cargo test --verbose
+
     - language: rust
       rust: beta
 
       script:
-        - cd server
-        - cargo test --verbose
+        - cargo test --verbose

CHANGES.md

@@ -1,7 +1,51 @@
 # Rojo Change Log
 
 ## Current master
-* *No changes*
+* "Epiphany" rewrite, in progress since the beginning of time
+* New live sync protocol
+    * Uses HTTP long polling to reduce request count and improve responsiveness
+* New project format
+    * Hierarchical, preventing overlapping partitions
+* Added `rojo build` command
+    * Generates `rbxm`, `rbxmx`, `rbxl`, or `rbxlx` files out of your project
+    * Usage: `rojo build <PROJECT> --output <OUTPUT>.rbxm`
+* Added `rojo upload` command
+    * Generates and uploads a place or model to roblox.com out of your project
+    * Usage: `rojo upload <PROJECT> --cookie "<ROBLOSECURITY>" --asset_id <PLACE_ID>`
+* New plugin
+    * Only one button now, "Connect"
+    * New UI to pick server address and port
+    * Better error reporting
+* Added support for `.csv` files turning into `LocalizationTable` instances
+* Added support for `.txt` files turning into `StringValue` instances
+* Added debug visualization code to diagnose problems
+    * `/visualize/rbx` and `/visualize/imfs` show instance and file state respectively; they require GraphViz to be installed on your machine.
+* Added optional place ID restrictions to project files
+    * This helps prevent syncing in content to the wrong place
+    * Multiple places can be specified, like when building a multi-place game
+* Added support for specifying properties on services in project files
+
+## 0.4.13 (November 12, 2018)
+* When `rojo.json` points to a file or directory that does not exist, Rojo now issues a warning instead of throwing an error and exiting
+
+## 0.4.12 (June 21, 2018)
+* Fixed obscure assertion failure when renaming or deleting files ([#78](https://github.com/LPGhatguy/rojo/issues/78))
+* Added a `PluginAction` for the sync in command, which should help with some automation scripts ([#80](https://github.com/LPGhatguy/rojo/pull/80))
+
+## 0.4.11 (June 10, 2018)
+* Defensively insert existing instances into RouteMap; should fix most duplication cases when syncing into existing trees.
+* Fixed incorrect synchronization from `Plugin:_pull` that would cause polling to create issues
+* Fixed incorrect file routes being assigned to `init.lua` and `init.model.json` files
+* Untangled route handling-internals slightly
+
+## 0.4.10 (June 2, 2018)
+* Added support for `init.model.json` files, which enable versioning `Tool` instances (among other things) with Rojo. ([#66](https://github.com/LPGhatguy/rojo/issues/66))
+* Fixed obscure error when syncing into an invalid service.
+* Fixed multiple sync processes occurring when a server ID mismatch is detected.
+
+## 0.4.9 (May 26, 2018)
+* Fixed warning when renaming or removing files that would sometimes corrupt the instance cache ([#72](https://github.com/LPGhatguy/rojo/pull/72))
+* JSON models are no longer as strict -- `Children` and `Properties` are now optional.
 
 ## 0.4.8 (May 26, 2018)
 * Hotfix to prevent errors from being thrown when objects managed by Rojo are deleted
@@ -32,11 +76,11 @@
 ## 0.4.3 (April 7, 2018)
 * Plugin now automatically selects `HttpService` if it determines that HTTP isn't enabled ([#58](https://github.com/LPGhatguy/rojo/pull/58))
 * Plugin now has much more robust handling and will wipe all state when the server changes.
-	* This should fix issues that would otherwise be solved by restarting Roblox Studio.
+    * This should fix issues that would otherwise be solved by restarting Roblox Studio.
 
 ## 0.4.2 (April 4, 2018)
 * Fixed final case of duplicated instance insertion, caused by reconciled instances not being inserted into `RouteMap`.
-	* The reconciler is still not a perfect solution, especially if script instances get moved around without being destroyed. I don't think this can be fixed before a big refactor.
+    * The reconciler is still not a perfect solution, especially if script instances get moved around without being destroyed. I don't think this can be fixed before a big refactor.
 
 ## 0.4.1 (April 1, 2018)
 * Merged plugin repository into main Rojo repository for easier tracking.
@@ -44,9 +88,9 @@
 
 ## 0.4.0 (March 27, 2018)
 * Protocol version 1, which shifts more responsibility onto the server
-	* This is a **major breaking** change!
-	* The server now has a content of 'filter plugins', which transform data at various stages in the pipeline
-	* The server now exposes Roblox instance objects instead of file contents, which lines up with how `rojo pack` will work, and paves the way for more robust syncing.
+    * This is a **major breaking** change!
+    * The server now has a content of 'filter plugins', which transform data at various stages in the pipeline
+    * The server now exposes Roblox instance objects instead of file contents, which lines up with how `rojo pack` will work, and paves the way for more robust syncing.
 * Added `*.model.json` files, which let you embed small Roblox objects into your Rojo tree.
 * Improved error messages in some cases ([#46](https://github.com/LPGhatguy/rojo/issues/46))
 
@@ -56,18 +100,18 @@
 
 ## 0.3.1 (December 14, 2017)
 * Improved error reporting when invalid JSON is found in a `rojo.json` project
-	* These messages are passed on from Serde
+    * These messages are passed on from Serde
 
 ## 0.3.0 (December 12, 2017)
 * Factored out the plugin into a separate repository
 * Fixed server when using a file as a partition
-	* Previously, trailing slashes were put on the end of a partition even if the read request was an empty string. This broke file reading on Windows when a partition pointed to a file instead of a directory!
+    * Previously, trailing slashes were put on the end of a partition even if the read request was an empty string. This broke file reading on Windows when a partition pointed to a file instead of a directory!
 * Started running automatic tests on Travis CI (#9)
 
 ## 0.2.3 (December 4, 2017)
 * Plugin only release
 * Tightened `init` file rules to only match script files
-	* Previously, Rojo would sometimes pick up the wrong file when syncing
+    * Previously, Rojo would sometimes pick up the wrong file when syncing
 
 ## 0.2.2 (December 1, 2017)
 * Plugin only release

Cargo.toml

@@ -0,0 +1,5 @@
+[workspace]
+members = [
+	"server",
+	"rojo-e2e",
+]

DESIGN.md

@@ -1,49 +0,0 @@
-# Rojo Design - Protocol Version 1
-This is a super rough draft that I'm trying to use to lay out some of my thoughts.
-
-## API
-
-### POST `/read`
-Accepts a `Vec<Route>` of items to read.
-
-Returns `Vec<Option<RbxInstance>>`, in the same order as the request.
-
-### POST `/write`
-Accepts a `Vec<{ Route, RbxInstance }>` of items to write.
-
-I imagine that the `Name` attribute of the top-level `RbxInstance` would be ignored in favor of the route name?
-
-## CLI
-The `rojo serve` command uses three major components:
-* A Virtual Filesystem (VFS), which exposes the filesystem as `VfsItem` objects
-* A VFS watcher, which tracks changes to the filesystem and logs them
-* An HTTP API, which exposes an interface to the Roblox Studio plugin
-
-### Transform Plugins
-Transform plugins (or filter plugins?) can interject in three places:
-* Transform a `VfsItem` that's being read into an `RbxInstance` in the VFS
-* Transform an `RbxInstance` that's being written into a `VfsItem` in the VFS
-* Transform a file change into paths that need to be updated in the VFS watcher
-
-The plan is to have several built-in plugins that can be rearranged/configured in project settings:
-
-* Base plugin
-	* Transforms all unhandled files to/from StringValue objects
-* Script plugin
-	* Transforms `*.lua` files to their appropriate file types
-* JSON/rbxmx/rbxlx model plugin
-* External binary plugin
-	* User passes a binary name (like `moonc`) that modifies file contents
-
-## Roblox Studio Plugin
-With the protocol version 1 change, the Roblox Studio plugin got a lot simpler. Notably, the plugin doesn't need to be aware of anything about the filesystem's semantics, which is super handy.
-
-## Bi-directional syncing
-Quenty laid out a good way to handle bi-directional syncing.
-
-When receiving a change from the plugin:
-1. Hash the new contents of the file, store it in a map from routes to hashes
-2. Write the new file contents to the filesystem
-3. Later down the line, receive a change event from the filesystem watcher
-4. When receiving a change, if the item is in the hash map, read it and hash those contents
-5. If the hash matches the last noted hash, discard the change, else continue as normal

README.md

@@ -8,9 +8,11 @@
     <a href="https://travis-ci.org/LPGhatguy/rojo">
         <img src="https://api.travis-ci.org/LPGhatguy/rojo.svg?branch=master" alt="Travis-CI Build Status" />
     </a>
-    <img src="https://img.shields.io/badge/latest_version-0.4.8-brightgreen.svg" alt="Current server version" />
-    <a href="https://lpghatguy.github.io/rojo">
-        <img src="https://img.shields.io/badge/documentation-website-brightgreen.svg" alt="Rojo Documentation" />
+    <a href="https://crates.io/crates/rojo">
+        <img src="https://img.shields.io/crates/v/rojo.svg?label=version" alt="Latest server version" />
+    </a>
+    <a href="https://lpghatguy.github.io/rojo/0.4.x">
+        <img src="https://img.shields.io/badge/documentation-0.4.x-brightgreen.svg" alt="Rojo Documentation" />
     </a>
 </div>
 
@@ -18,7 +20,9 @@
 
 **Rojo** is a flexible multi-tool designed for creating robust Roblox projects.
 
-It's designed for power users who want to use the **best tools available** for building games, libraries, and plugins.
+It lets Roblox developers use industry-leading tools like Git and VS Code, and crucial utilities like Luacheck.
+
+Rojo is designed for **power users** who want to use the **best tools available** for building games, libraries, and plugins.
 
 ## Features
 Rojo lets you:
@@ -27,31 +31,35 @@ Rojo lets you:
 * Version your place, library, or plugin using Git or another VCS
 * Sync JSON-format models from the filesystem into your game
 
-Later this year, Rojo will be able to:
+Soon, Rojo will be able to:
 
+* Sync scripts from Roblox Studio to the filesystem
+* Compile MoonScript and sync it into Roblox Studio
 * Sync `rbxmx` models between the filesystem and Roblox Studio
 * Package projects into `rbxmx` files from the command line
 
-## [Documentation Website](https://lpghatguy.github.io/rojo)
-You can also view the documentation by browsing the [docs folder of the repository](https://github.com/LPGhatguy/rojo/tree/master/docs), but because it uses a number of Markdown extensions, it may not be very readable.
+## [Documentation](https://lpghatguy.github.io/rojo/0.4.x)
+You can also view the documentation by browsing the [docs](https://github.com/LPGhatguy/rojo/tree/master/docs) folder of the repository, but because it uses a number of Markdown extensions, it may not be very readable.
 
-## Inspiration
+## Inspiration and Alternatives
 There are lots of other tools that sync scripts into Roblox or provide other tools for working with Roblox places.
 
 Here are a few, if you're looking for alternatives or supplements to Rojo:
 
-* [Studio Bridge by Vocksel](https://github.com/vocksel/studio-bridge)
-* [RbxRefresh by Osyris](https://github.com/osyrisrblx/RbxRefresh)
-* [RbxSync by evaera](https://github.com/evaera/RbxSync)
-* [CodeSync](https://github.com/MemoryPenguin/CodeSync) and [rbx-exteditor](https://github.com/MemoryPenguin/rbx-exteditor) by [MemoryPenguin](https://github.com/MemoryPenguin)
 * [rbxmk by Anaminus](https://github.com/anaminus/rbxmk)
+* [Rofresh by Osyris](https://github.com/osyrisrblx/rofresh)
+* [RbxRefresh by Osyris](https://github.com/osyrisrblx/RbxRefresh)
+* [Studio Bridge by Vocksel](https://github.com/vocksel/studio-bridge)
+* [Elixir by Vocksel](https://github.com/vocksel/elixir)
+* [RbxSync by evaera](https://github.com/evaera/RbxSync)
+* [CodeSync by MemoryPenguin](https://github.com/MemoryPenguin/CodeSync)
+* [rbx-exteditor by MemoryPenguin](https://github.com/MemoryPenguin/rbx-exteditor)
 
-I also have a couple tools that Rojo intends to replace:
-
-* [rbxfs](https://github.com/LPGhatguy/rbxfs), which has been deprecated by Rojo
-* [rbxpacker](https://github.com/LPGhatguy/rbxpacker), which is still useful
+If you use a plugin that _isn't_ Rojo for syncing code, open an issue and let me know why! I'd like Rojo to be the end-all tool so that people stop reinventing solutions to this problem.
 
 ## Contributing
+The `master` branch is a rewrite known as **Epiphany**. It includes a breaking change to the project configuration format and an infrastructure overhaul.
+
 Pull requests are welcome!
 
 All pull requests are run against a test suite on Travis CI. That test suite should always pass!

assets/kenney-ui-gray-sheet.xml

@@ -0,0 +1,41 @@
+<TextureAtlas imagePath="sheet.png">
+	<SubTexture name="grey_arrowDownGrey.png" x="78" y="498" width="15" height="10"/>
+	<SubTexture name="grey_arrowDownWhite.png" x="123" y="496" width="15" height="10"/>
+	<SubTexture name="grey_arrowUpGrey.png" x="108" y="498" width="15" height="10"/>
+	<SubTexture name="grey_arrowUpWhite.png" x="93" y="498" width="15" height="10"/>
+	<SubTexture name="grey_box.png" x="147" y="433" width="38" height="36"/>
+	<SubTexture name="grey_boxCheckmark.png" x="147" y="469" width="38" height="36"/>
+	<SubTexture name="grey_boxCross.png" x="185" y="433" width="38" height="36"/>
+	<SubTexture name="grey_boxTick.png" x="190" y="198" width="36" height="36"/>
+	<SubTexture name="grey_button00.png" x="0" y="143" width="190" height="45"/>
+	<SubTexture name="grey_button01.png" x="0" y="188" width="190" height="49"/>
+	<SubTexture name="grey_button02.png" x="0" y="98" width="190" height="45"/>
+	<SubTexture name="grey_button03.png" x="0" y="331" width="190" height="49"/>
+	<SubTexture name="grey_button04.png" x="0" y="286" width="190" height="45"/>
+	<SubTexture name="grey_button05.png" x="0" y="0" width="195" height="49"/>
+	<SubTexture name="grey_button06.png" x="0" y="49" width="191" height="49"/>
+	<SubTexture name="grey_button07.png" x="195" y="0" width="49" height="49"/>
+	<SubTexture name="grey_button08.png" x="240" y="49" width="49" height="49"/>
+	<SubTexture name="grey_button09.png" x="98" y="433" width="49" height="45"/>
+	<SubTexture name="grey_button10.png" x="191" y="49" width="49" height="49"/>
+	<SubTexture name="grey_button11.png" x="0" y="433" width="49" height="45"/>
+	<SubTexture name="grey_button12.png" x="244" y="0" width="49" height="49"/>
+	<SubTexture name="grey_button13.png" x="49" y="433" width="49" height="45"/>
+	<SubTexture name="grey_button14.png" x="0" y="384" width="190" height="49"/>
+	<SubTexture name="grey_button15.png" x="0" y="237" width="190" height="49"/>
+	<SubTexture name="grey_checkmarkGrey.png" x="99" y="478" width="21" height="20"/>
+	<SubTexture name="grey_checkmarkWhite.png" x="78" y="478" width="21" height="20"/>
+	<SubTexture name="grey_circle.png" x="185" y="469" width="36" height="36"/>
+	<SubTexture name="grey_crossGrey.png" x="120" y="478" width="18" height="18"/>
+	<SubTexture name="grey_crossWhite.png" x="190" y="318" width="18" height="18"/>
+	<SubTexture name="grey_panel.png" x="190" y="98" width="100" height="100"/>
+	<SubTexture name="grey_sliderDown.png" x="190" y="234" width="28" height="42"/>
+	<SubTexture name="grey_sliderEnd.png" x="138" y="478" width="8" height="10"/>
+	<SubTexture name="grey_sliderHorizontal.png" x="0" y="380" width="190" height="4"/>
+	<SubTexture name="grey_sliderLeft.png" x="0" y="478" width="39" height="31"/>
+	<SubTexture name="grey_sliderRight.png" x="39" y="478" width="39" height="31"/>
+	<SubTexture name="grey_sliderUp.png" x="190" y="276" width="28" height="42"/>
+	<SubTexture name="grey_sliderVertical.png" x="208" y="318" width="4" height="100"/>
+	<SubTexture name="grey_tickGrey.png" x="190" y="336" width="17" height="17"/>
+	<SubTexture name="grey_tickWhite.png" x="190" y="353" width="17" height="17"/>
+</TextureAtlas>

design.gv

@@ -0,0 +1,39 @@
+digraph G {
+	graph [
+		ranksep = "0.7",
+		nodesep = "1.0",
+	];
+	node [
+		fontname = "Hack",
+		shape = "record",
+	];
+
+	roblox_studio -> plugin [dir = "both"];
+	plugin -> web_server [style = "dashed", dir = "both"];
+
+	web_server -> session;
+
+	session -> rbx_session;
+	session -> fs_watcher;
+	session -> message_queue;
+
+	fs_watcher -> imfs [weight = "10"];
+	fs_watcher -> rbx_session [constraint = "false"];
+
+	imfs -> fs;
+
+	rbx_session -> imfs;
+	rbx_session -> middlewares [weight = "10"];
+	rbx_session -> message_queue [constraint = "false"];
+
+	plugin [label = "Studio Plugin"];
+	roblox_studio [label = "Roblox Studio"];
+	fs [label = "Filesystem"];
+	fs_watcher [label = "Filesystem Watcher"];
+	session [label = "Session"];
+	web_server [label = "Web API"];
+	imfs [label = "In-Memory Filesystem"];
+	rbx_session [label = "RbxSession"];
+	message_queue [label = "MessageQueue"];
+	middlewares [label = "Middlewares"];
+}

docs/getting-started/creating-a-place.md

@@ -0,0 +1,64 @@
+To use Rojo to build a place, you'll need to create a new project file, which tells Rojo how your project is structured on-disk and in Roblox.
+
+Create a new folder, then run `rojo init` inside that folder to initialize an empty project.
+
+```sh
+mkdir my-new-project
+cd my-new-project
+
+rojo init
+```
+
+Rojo will make a small project file in your directory, named `roblox-project.json`. It'll make sure that any code in the directory `src` will get put into `ReplicatedStorage.Source`.
+
+Speaking of, let's make sure we create a directory named `src`, and maybe a Lua file inside of it:
+
+```sh
+mkdir src
+echo 'print("Hello, world!")' > src/hello.lua
+```
+
+## Building Your Place
+Now that we have a project, one thing we can do is build a Roblox place file for our project. This is a great way to get started with a project quickly with no fuss.
+
+All we have to do is call `rojo build`:
+
+```sh
+rojo build -o MyNewProject.rbxl
+```
+
+If you open `MyNewProject.rbxl` in Roblox Studio now, you should see a `Folder` containing a `ModuleScript` under `ReplicatedStorage`!
+
+!!! info
+    To generate an XML place file instead, like if you're checking the place file into version control, just use `rbxlx` as the extension on the output file instead.
+
+## Live-Syncing into Studio
+Building a place file is great for the initial build, but for actively working on your place, you'll want something quicker.
+
+In Roblox Studio, make sure the Rojo plugin is installed. If you need it, check out [the installation guide](installation) to learn how to install it.
+
+To expose your project to the plugin, you'll need to _serve_ it from the command line:
+
+```sh
+rojo serve
+```
+
+This will start up a web server that tells Roblox Studio what instances are in your project and sends notifications if any of them change.
+
+Note the port number, then switch into Roblox Studio and press the Rojo **Connect** button in the plugins tab. Type in the port number, if necessary, and press **Start**.
+
+If everything went well, you should now be able to change files in the `src` directory and watch them sync into Roblox Studio in real time!
+
+## Uploading Your Place
+Aimed at teams that want serious levels of automation, Rojo can upload places to Roblox.com automatically.
+
+You'll need an existing place on Roblox.com as well as the `.ROBLOSECURITY` cookie of an account that has write access to that place.
+
+!!! warning
+    It's recommended that you set up a Roblox account dedicated to deploying your place instead of your personal account in case your security cookie is compromised.
+
+Generating and uploading your place file is as simple as:
+
+```sh
+rojo upload --asset_id [PLACE ID] --cookie "[SECURITY COOKIE]"
+```

docs/getting-started/creating-a-project.md

@@ -1,77 +0,0 @@
-# Creating a Project
-To use Rojo, you'll need to create a new project file, which tells Rojo what your project is, and how to load it into Roblox Studio.
-
-## New Project
-Create a new folder, then run `rojo init` inside that folder to initialize an empty project.
-
-```sh
-mkdir my-new-project
-cd my-new-project
-
-rojo init
-```
-
-Rojo will create an empty project file named `rojo.json` in the directory.
-
-The default configuration doesn't do anything. We need to tell Rojo where our code is on the filesystem, and where we want to put it in the Roblox tree.
-
-To do that, open up `rojo.json` and add an entry to the `partitions` table:
-
-```json
-{
-    "name": "your-project-name-here",
-    "servePort": 8000,
-    "partitions": {
-        "src": {
-            "path": "src",
-            "target": "ReplicatedStorage.Project"
-        }
-    }
-}
-```
-
-!!! warning
-    Make sure that the `src` directory exists in your project, or Rojo will throw an error!
-
-!!! warning
-    Any objects contained in the `target` of a partition will be destroyed by Rojo if not found on the filesystem!
-
-A Rojo project has one or more *partitions*. Partitions define how code should be transferred between the filesystem and Roblox by mapping directories and files to Roblox objects.
-
-Each partition has:
-
-* A name (the key in the `partitions` object), which is used for debugging
-* `path`, the location on the filesystem relative to `rojo.json`
-* `target`, the location in Roblox relative to `game`
-
-## Syncing into Studio
-
-Once you've added your partition to the project file, you can start the Rojo dev server by running a command in your project's directory:
-
-```sh
-rojo serve
-```
-
-If your project is in the right place, Rojo will let you know that it was found and start an HTTP server that the plugin can connect to.
-
-In Roblox Studio, open the plugins tab and find Rojo's buttons.
-
-![Location of Rojo's plugin buttons in Roblox Studio](/images/plugin-buttons.png)
-{: align="center" }
-
-Press **Test Connection** to verify that the plugin can communicate with the dev server. Watch the Output panel for the results.
-
-!!! info
-    If you see an error message, return to the previous steps and make sure that the Rojo dev server is running.
-
-    ![Rojo error in Roblox Studio Output](/images/connection-error.png)
-    {: align="center" }
-
-After your connection was successful, press **Sync In** to move code from the filesystem into Studio, or use **Toggle Polling** to have Rojo automatically sync in changes as they happen.
-
-## Importing an Existing Project
-Rojo will eventually support importing an existing Roblox project onto the filesystem for use with Rojo.
-
-Rojo doesn't currently support converting an existing project or syncing files from Roblox Studio onto the filesystem. In the mean time, you can manually copy your files into the structure that Rojo expects.
-
-Up-to-date information will be available on [issue #5](https://github.com/LPGhatguy/rojo/issues/5) as this is worked on.

docs/getting-started/installation.md

@@ -1,4 +1,3 @@
-# Installation
 Rojo has two components:
 
 * The server, a binary written in Rust
@@ -20,4 +19,7 @@ To install the plugin, either:
 * Install the plugin from the [Roblox plugin page](https://www.roblox.com/library/1211549683/Rojo).
   * This gives you less control over what version you install -- you will always have the latest version.
 * Or, download the latest release from [the GitHub releases section](https://github.com/LPGhatguy/rojo/releases) and install it into your Roblox plugins folder
-  * You can open this folder by clicking the "Plugins Folder" button from the Plugins toolbar in Roblox Studio
+  * You can open this folder by clicking the "Plugins Folder" button from the Plugins toolbar in Roblox Studio
+
+## Visual Studio Code Extension
+If you use Visual Studio Code on Windows, you can install [Evaera's unofficial Rojo extension](https://marketplace.visualstudio.com/items?itemName=evaera.vscode-rojo), which will install both halves of Rojo for you. It even has a nifty UI to add partitions and start/stop the Rojo server!

docs/index.md

@@ -1,6 +1,11 @@
-# Home
 This is the documentation home for Rojo.
 
+Available versions of these docs:
+
+* [0.5.x](https://lpghatguy.github.io/rojo/0.5.x)
+* [0.4.x](https://lpghatguy.github.io/rojo/0.4.x)
+* [`master` branch](https://lpghatguy.github.io/rojo/master)
+
 **Rojo** is a flexible multi-tool designed for creating robust Roblox projects.
 
-This documentation is a work in progress, and is incomplete.
+This documentation is a continual work in progress. If you find any issues, please file an issue on [Rojo's issue tracker](https://github.com/LPGhatguy/rojo/issues)!

docs/migrating-to-epiphany.md

@@ -0,0 +1,59 @@
+Rojo underwent a large refactor during most of 2018 to enable a bunch of new features and lay groundwork for lots more in 2019. As such, Rojo **0.5.x** projects are not compatible with Rojo **0.4.x** projects.
+
+## Supporting Both 0.4.x and 0.5.x
+Rojo 0.5.x uses a different name for its project format. While 0.4.x used `rojo.json`, 0.5.x uses `roblox-project.json`, which allows them to coexist.
+
+If you aren't sure about upgrading or want to upgrade gradually, it's possible to keep both files in the same project without causing problems.
+
+## Upgrading Your Project File
+Project files in 0.5.x are more explicit and flexible than they were in 0.4.x. Project files can now describe models and plugins in addition to places.
+
+This new project file format also guards against two of the biggest pitfalls when writing a config file:
+
+* Using a service as a partition target directly, which often wiped away extra instances
+* Defining two partitions that overlapped, which made Rojo act unpredictably
+
+The biggest change is that the `partitions` field has been replaced with a new field, `tree`, that describes the entire hierarchy of your project from the top-down.
+
+A project for 0.4.x that syncs from the `src` directory into `ReplicatedStorage.Source` would look like this:
+
+```json
+{
+    "name": "Rojo 0.4.x Example",
+    "partitions": {
+        "path": "src",
+        "target": "ReplicatedStorage.Source"
+    }
+}
+```
+
+In 0.5.x, the project format is more explicit:
+
+```json
+{
+    "name": "Rojo 0.5.x Example",
+    "tree": {
+        "$className": "DataModel",
+        "ReplicatedStorage": {
+            "$className": "ReplicatedStorage",
+            "Source": {
+                "$path": "src"
+            }
+        }
+    }
+}
+```
+
+For each object in the tree, we define *metadata* and *children*.
+
+Metadata begins with a dollar sign (`$`), like `$className`. This is so that children and metadata can coexist without creating too many nested layers.
+
+All other values are considered children, where the key is the instance's name, and the value is an object, repeating the process.
+
+## Migrating `.model.json` Files
+No upgrade path yet, stay tuned.
+
+## Migrating Unknown Files
+If you used Rojo to sync in files as `StringValue` objects, you'll need to make sure those files end with the `txt` extension to preserve this in Rojo 0.5.x.
+
+Unknown files are now ignored in Rojo instead of being converted to `StringValue` objects.

docs/sync-details.md

@@ -1,21 +1,24 @@
-# Sync Details
 This page aims to describe how Rojo turns files on the filesystem into Roblox objects.
 
+## Overview
+| File Name      | Instance Type       |
+| -------------- | ------------------- |
+| any directory  | `Folder`            |
+| `*.server.lua` | `Script`            |
+| `*.client.lua` | `LocalScript`       |
+| `*.lua`        | `ModuleScript`      |
+| `*.csv`        | `LocalizationTable` |
+| `*.txt`        | `StringValue`       |
+
 ## Folders
-Any directory on the filesystem will turn into a `Folder` instance in Roblox, unless that folder matches the name of a service or other existing instance. In those cases, that instance will be preserved.
+Any directory on the filesystem will turn into a `Folder` instance unless it contains an 'init' script, described below.
 
 ## Scripts
-Rojo can represent `ModuleScript`, `Script`, and `LocalScript` objects. The default script type is `ModuleScript`, since most scripts in well-structued Roblox projects will be modules.
+The default script type in Rojo projects is `ModuleScript`, since most scripts in well-structued Roblox projects will be modules.
 
-| File Name      | Instance Type  |
-| -------------- | -------------- |
-| `*.server.lua` | `Script`       |
-| `*.client.lua` | `LocalScript`  |
-| `*.lua`        | `ModuleScript` |
+If a directory contains a file named `init.server.lua`, `init.client.lua`, or `init.lua`, that folder will be transformed into a `*Script` instance with the contents of the 'init' file. This can be used to create scripts inside of scripts.
 
-If a directory contains a file named `init.server.lua`, `init.client.lua`, or `init.lua`, that folder will be transformed into a `*Script` instance with the conents of the `init` file. This can be used to create scripts inside of scripts.
-
-For example, this file tree:
+For example, these files:
 
 * my-game
     * init.client.lua
@@ -25,37 +28,8 @@ Will turn into these instances in Roblox:
 
 ![Example of Roblox instances](/images/sync-example.png)
 
-## Models
-Rojo supports a JSON model format for representing simple models. It's designed for instance types like `BindableEvent` or `*Value` objects, and is not suitable for larger models.
+## Localization Tables
+Any CSV files are transformed into `LocalizationTable` instances. Rojo expects these files to follow the same format that Roblox does when importing and exporting localization information.
 
-!!! info
-    In the future, Rojo will support `.rbxmx` models. See [issue #7](https://github.com/LPGhatguy/rojo/issues/7) for more details and updates on this feature.
-
-JSON model files are strict, with every property being required. They look like this:
-
-```json
-{
-    "Name": "hello",
-    "ClassName": "Model",
-    "Children": [
-        {
-            "Name": "Some Part",
-            "ClassName": "Part",
-            "Children": [],
-            "Properties": {}
-        },
-        {
-            "Name": "Some StringValue",
-            "ClassName": "StringValue",
-            "Children": [],
-            "Properties": {
-                "Value": {
-                    "Type": "String",
-                    "Value": "Hello, world!"
-                }
-            }
-        }
-    ],
-    "Properties": {}
-}
-```
+## Plain Text Files
+Plain text files (`.txt`) files are transformed into `StringValue` instances. This is useful for bringing in text data that can be read by scripts at runtime.

docs/why-rojo.md

@@ -1,4 +1,3 @@
-# Why Rojo?
 There are a number of existing plugins for Roblox that move code from the filesystem into Roblox.
 
 Besides Rojo, there is:

generate-docs

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# Kludged documentation generator to support multiple versions.
+# Make sure the `site` folder is a checkout of this repository's `gh-pages`
+# branch.
+# To use, copy this file to `generate-docs.run` so that Git will leave it alone,
+# then run `generate-docs.run` in the root of the repository.
+
+set -e
+
+CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
+
+echo "Building 0.4.x"
+git checkout v0.4.x
+git pull
+mkdocs build --site-dir site/0.4.x
+
+echo "Building master"
+git checkout master
+mkdocs build --site-dir site/master
+
+echo "Building 0.5.x"
+mkdocs build --site-dir site/0.5.x
+
+git checkout "$CURRENT_BRANCH"

mkdocs.yml

@@ -1,5 +1,4 @@
 site_name: Rojo Documentation
-site_url: https://lpghatguy.github.io/rojo/
 repo_name: LPGhatguy/rojo
 repo_url: https://github.com/LPGhatguy/rojo
 
@@ -9,13 +8,14 @@ theme:
     primary: 'Red'
     accent: 'Red'
 
-pages:
+nav:
   - Home: index.md
   - Why Rojo?: why-rojo.md
   - Getting Started:
     - Installation: getting-started/installation.md
-    - Creating a Project: getting-started/creating-a-project.md
+    - Creating a Place with Rojo: getting-started/creating-a-place.md
   - Sync Details: sync-details.md
+  - Migrating from 0.4.x to 0.5.x: migrating-to-epiphany.md
 
 markdown_extensions:
   - attr_list

plugin/.editorconfig

@@ -1,4 +0,0 @@
-[*.lua]
-indent_style = tab
-trim_trailing_whitespace = true
-insert_final_newline = true

plugin/README.md

@@ -0,0 +1,5 @@
+# Rojo Plugin
+
+This is the source to the Rojo Roblox Studio plugin.
+
+Documentation is WIP.

plugin/loadEnvironment.lua

@@ -0,0 +1,37 @@
+--[[
+	Loads the Rojo plugin and all of its dependencies.
+]]
+
+local function loadEnvironment()
+	-- If you add any dependencies, add them to this table so they'll be loaded!
+	local LOAD_MODULES = {
+		{"src", "Rojo"},
+		{"modules/promise/lib", "Promise"},
+		{"modules/testez/lib", "TestEZ"},
+	}
+
+	-- This makes sure we can load Lemur and other libraries that depend on init.lua
+	package.path = package.path .. ";?/init.lua"
+
+	-- If this fails, make sure you've run `lua bin/install-dependencies.lua` first!
+	local lemur = require("modules.lemur")
+
+	-- Create a virtual Roblox tree
+	local habitat = lemur.Habitat.new()
+
+	-- We'll put all of our library code and dependencies here
+	local modules = lemur.Instance.new("Folder")
+	modules.Name = "Modules"
+	modules.Parent = habitat.game:GetService("ReplicatedStorage")
+
+	-- Load all of the modules specified above
+	for _, module in ipairs(LOAD_MODULES) do
+		local container = habitat:loadFromFs(module[1])
+		container.Name = module[2]
+		container.Parent = modules
+	end
+
+	return habitat, modules
+end
+
+return loadEnvironment

plugin/roblox-project.json

@@ -0,0 +1,21 @@
+{
+  "name": "Rojo",
+  "tree": {
+    "$className": "Folder",
+    "Plugin": {
+      "$path": "src"
+    },
+    "Roact": {
+      "$path": "modules/roact/lib"
+    },
+    "Rodux": {
+      "$path": "modules/rodux/lib"
+    },
+    "RoactRodux": {
+      "$path": "modules/roact-rodux/lib"
+    },
+    "Promise": {
+      "$path": "modules/promise/lib"
+    }
+  }
+}

plugin/rojo.json

@@ -4,31 +4,31 @@
   "partitions": {
     "plugin": {
       "path": "src",
-      "target": "ReplicatedStorage.Rojo.plugin"
+      "target": "ReplicatedStorage.Rojo.Plugin"
     },
     "modules/roact": {
       "path": "modules/roact/lib",
-      "target": "ReplicatedStorage.Rojo.modules.Roact"
+      "target": "ReplicatedStorage.Rojo.Roact"
     },
     "modules/rodux": {
       "path": "modules/rodux/lib",
-      "target": "ReplicatedStorage.Rojo.modules.Rodux"
+      "target": "ReplicatedStorage.Rojo.Rodux"
     },
     "modules/roact-rodux": {
       "path": "modules/roact-rodux/lib",
-      "target": "ReplicatedStorage.Rojo.modules.RoactRodux"
+      "target": "ReplicatedStorage.Rojo.RoactRodux"
     },
     "modules/promise": {
       "path": "modules/promise/lib",
-      "target": "ReplicatedStorage.Rojo.modules.Promise"
+      "target": "ReplicatedStorage.Rojo.Promise"
     },
     "modules/testez": {
       "path": "modules/testez/lib",
       "target": "ReplicatedStorage.TestEZ"
     },
     "tests": {
-      "path": "tests",
-      "target": "TestService"
+      "path": "testBootstrap.server.lua",
+      "target": "TestService.testBootstrap"
     }
   }
 }

plugin/runTest.lua

@@ -0,0 +1,15 @@
+local loadEnvironment = require("loadEnvironment")
+
+local testPath = assert((...), "Please specify a path to a test file.")
+
+local habitat = loadEnvironment()
+
+local testModule = habitat:loadFromFs(testPath)
+
+if testModule == nil then
+	error("Couldn't find test file at " .. testPath)
+end
+
+print("Starting test module.")
+
+habitat:require(testModule)

plugin/spec.lua

@@ -2,68 +2,16 @@
 	Loads our library and all of its dependencies, then runs tests using TestEZ.
 ]]
 
--- If you add any dependencies, add them to this table so they'll be loaded!
-local LOAD_MODULES = {
-	{"src", "Plugin"},
-	{"modules/testez/lib", "TestEZ"},
-}
+local loadEnvironment = require("loadEnvironment")
 
--- This makes sure we can load Lemur and other libraries that depend on init.lua
-package.path = package.path .. ";?/init.lua"
-
--- If this fails, make sure you've run `lua bin/install-dependencies.lua` first!
-local lemur = require("modules.lemur")
-
---[[
-	Collapses ModuleScripts named 'init' into their parent folders.
-
-	This is the same result as the collapsing mechanism from Rojo.
-]]
-local function collapse(root)
-	local init = root:FindFirstChild("init")
-	if init then
-		init.Name = root.Name
-		init.Parent = root.Parent
-
-		for _, child in ipairs(root:GetChildren()) do
-			child.Parent = init
-		end
-
-		root:Destroy()
-		root = init
-	end
-
-	for _, child in ipairs(root:GetChildren()) do
-		if child:IsA("Folder") then
-			collapse(child)
-		end
-	end
-
-	return root
-end
-
--- Create a virtual Roblox tree
-local habitat = lemur.Habitat.new()
-
--- We'll put all of our library code and dependencies here
-local Root = lemur.Instance.new("Folder")
-Root.Name = "Root"
-
--- Load all of the modules specified above
-for _, module in ipairs(LOAD_MODULES) do
-	local container = lemur.Instance.new("Folder", Root)
-	container.Name = module[2]
-	habitat:loadFromFs(module[1], container)
-end
-
-collapse(Root)
+local habitat, modules = loadEnvironment()
 
 -- Load TestEZ and run our tests
-local TestEZ = habitat:require(Root.TestEZ)
+local TestEZ = habitat:require(modules.TestEZ)
 
-local results = TestEZ.TestBootstrap:run(Root.Plugin, TestEZ.Reporters.TextReporter)
+local results = TestEZ.TestBootstrap:run({modules.Rojo}, TestEZ.Reporters.TextReporter)
 
 -- Did something go wrong?
 if results.failureCount > 0 then
 	os.exit(1)
-end
+end

plugin/src/Api.lua

@@ -1,113 +0,0 @@
-local HttpService = game:GetService("HttpService")
-
-local Promise = require(script.Parent.Parent.modules.Promise)
-
-local Config = require(script.Parent.Config)
-local Version = require(script.Parent.Version)
-
-local Api = {}
-Api.__index = Api
-
-Api.Error = {
-	ServerIdMismatch = "ServerIdMismatch",
-}
-
-setmetatable(Api.Error, {
-	__index = function(_, key)
-		error("Invalid API.Error name " .. key, 2)
-	end
-})
-
---[[
-	Api.connect(Http) -> Promise<Api>
-
-	Create a new Api using the given HTTP implementation.
-
-	Attempting to invoke methods on an invalid conext will throw errors!
-]]
-function Api.connect(http)
-	local context = {
-		http = http,
-		serverId = nil,
-		currentTime = 0,
-	}
-
-	setmetatable(context, Api)
-
-	return context:_start()
-end
-
-function Api:_start()
-	return self.http:get("/")
-		:andThen(function(response)
-			response = response:json()
-
-			if response.protocolVersion ~= Config.protocolVersion then
-				local message = (
-					"Found a Rojo dev server, but it's using a different protocol version, and is incompatible." ..
-					"\nMake sure you have matching versions of both the Rojo plugin and server!" ..
-					"\n\nYour client is version %s, with protocol version %s. It expects server version %s." ..
-					"\nYour server is version %s, with protocol version %s." ..
-					"\n\nGo to https://github.com/LPGhatguy/rojo for more details."
-				):format(
-					Version.display(Config.version), Config.protocolVersion,
-					Config.expectedApiVersionString,
-					response.serverVersion, response.protocolVersion
-				)
-
-				return Promise.reject(message)
-			end
-
-			self.serverId = response.serverId
-			self.currentTime = response.currentTime
-
-			return self
-		end)
-end
-
-function Api:getInfo()
-	return self.http:get("/")
-		:andThen(function(response)
-			response = response:json()
-
-			if response.serverId ~= self.serverId then
-				return Promise.reject(Api.Error.ServerIdMismatch)
-			end
-
-			return response
-		end)
-end
-
-function Api:read(paths)
-	local body = HttpService:JSONEncode(paths)
-
-	return self.http:post("/read", body)
-		:andThen(function(response)
-			response = response:json()
-
-			if response.serverId ~= self.serverId then
-				return Promise.reject(Api.Error.ServerIdMismatch)
-			end
-
-			return response.items
-		end)
-end
-
-function Api:getChanges()
-	local url = ("/changes/%f"):format(self.currentTime)
-
-	return self.http:get(url)
-		:andThen(function(response)
-			response = response:json()
-
-			if response.serverId ~= self.serverId then
-				return Promise.reject(Api.Error.ServerIdMismatch)
-			end
-
-			self.currentTime = response.currentTime
-
-			return response.changes
-		end)
-end
-
-return Api

plugin/src/ApiContext.lua

@@ -0,0 +1,145 @@
+local Promise = require(script.Parent.Parent.Promise)
+
+local Config = require(script.Parent.Config)
+local Version = require(script.Parent.Version)
+local Http = require(script.Parent.Http)
+local HttpError = require(script.Parent.HttpError)
+
+local ApiContext = {}
+ApiContext.__index = ApiContext
+
+-- TODO: Audit cases of errors and create enum values for each of them.
+ApiContext.Error = {
+	ServerIdMismatch = "ServerIdMismatch",
+}
+
+setmetatable(ApiContext.Error, {
+	__index = function(_, key)
+		error("Invalid ApiContext.Error name " .. key, 2)
+	end
+})
+
+function ApiContext.new(baseUrl)
+	assert(type(baseUrl) == "string")
+
+	local self = {
+		baseUrl = baseUrl,
+		serverId = nil,
+		rootInstanceId = nil,
+		messageCursor = -1,
+		partitionRoutes = nil,
+	}
+
+	setmetatable(self, ApiContext)
+
+	return self
+end
+
+function ApiContext:onMessage(callback)
+	self.onMessageCallback = callback
+end
+
+function ApiContext:connect()
+	local url = ("%s/api/rojo"):format(self.baseUrl)
+
+	return Http.get(url)
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.protocolVersion ~= Config.protocolVersion then
+				local message = (
+					"Found a Rojo dev server, but it's using a different protocol version, and is incompatible." ..
+					"\nMake sure you have matching versions of both the Rojo plugin and server!" ..
+					"\n\nYour client is version %s, with protocol version %s. It expects server version %s." ..
+					"\nYour server is version %s, with protocol version %s." ..
+					"\n\nGo to https://github.com/LPGhatguy/rojo for more details."
+				):format(
+					Version.display(Config.version), Config.protocolVersion,
+					Config.expectedApiContextVersionString,
+					body.serverVersion, body.protocolVersion
+				)
+
+				return Promise.reject(message)
+			end
+
+			if body.expectedPlaceIds ~= nil then
+				local foundId = false
+
+				for _, id in ipairs(body.expectedPlaceIds) do
+					if id == game.PlaceId then
+						foundId = true
+						break
+					end
+				end
+
+				if not foundId then
+					local idList = {}
+					for _, id in ipairs(body.expectedPlaceIds) do
+						table.insert(idList, "- " .. tostring(id))
+					end
+
+					local message = (
+						"Found a Rojo server, but its project is set to only be used with a specific list of places." ..
+						"\nYour place ID is %s, but needs to be one of these:" ..
+						"\n%s" ..
+						"\n\nTo change this list, edit 'servePlaceIds' in roblox-project.json"
+					):format(
+						tostring(game.PlaceId),
+						table.concat(idList, "\n")
+					)
+
+					return Promise.reject(message)
+				end
+			end
+
+			self.serverId = body.serverId
+			self.partitionRoutes = body.partitions
+			self.rootInstanceId = body.rootInstanceId
+		end)
+end
+
+function ApiContext:read(ids)
+	local url = ("%s/api/read/%s"):format(self.baseUrl, table.concat(ids, ","))
+
+	return Http.get(url)
+		:catch(function(err)
+			return Promise.reject(err)
+		end)
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.serverId ~= self.serverId then
+				return Promise.reject("Server changed ID")
+			end
+
+			self.messageCursor = body.messageCursor
+
+			return body
+		end)
+end
+
+function ApiContext:retrieveMessages()
+	local url = ("%s/api/subscribe/%s"):format(self.baseUrl, self.messageCursor)
+
+	return Http.get(url)
+		:catch(function(err)
+			if err.type == HttpError.Error.Timeout then
+				return self:retrieveMessages()
+			end
+
+			return Promise.reject(err)
+		end)
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.serverId ~= self.serverId then
+				return Promise.reject("Server changed ID")
+			end
+
+			self.messageCursor = body.messageCursor
+
+			return body.messages
+		end)
+end
+
+return ApiContext

plugin/src/Assets.lua

@@ -0,0 +1,52 @@
+local sheetAsset = "rbxassetid://2738712459"
+
+local Assets = {
+	Sprites = {
+		WhiteCross = {
+			asset = sheetAsset,
+			offset = Vector2.new(190, 318),
+			size = Vector2.new(18, 18),
+		},
+	},
+	Slices = {
+		GrayBox = {
+			asset = sheetAsset,
+			offset = Vector2.new(147, 433),
+			size = Vector2.new(38, 36),
+			center = Rect.new(8, 8, 9, 9),
+		},
+		GrayButton02 = {
+			asset = sheetAsset,
+			offset = Vector2.new(0, 98),
+			size = Vector2.new(190, 45),
+			center = Rect.new(16, 16, 17, 17),
+		},
+		GrayButton07 = {
+			asset = sheetAsset,
+			offset = Vector2.new(195, 0),
+			size = Vector2.new(49, 49),
+			center = Rect.new(16, 16, 17, 17),
+		},
+	},
+	StartSession = "",
+	SessionActive = "",
+	Configure = "",
+}
+
+local function guardForTypos(name, map)
+	setmetatable(map, {
+		__index = function(_, key)
+			error(("%q is not a valid member of %s"):format(tostring(key), name), 2)
+		end
+	})
+
+	for key, child in pairs(map) do
+		if type(child) == "table" then
+			guardForTypos(("%s.%s"):format(name, key), child)
+		end
+	end
+end
+
+guardForTypos("Assets", Assets)
+
+return Assets

plugin/src/Components/App.lua

@@ -0,0 +1,194 @@
+local Roact = require(script:FindFirstAncestor("Rojo").Roact)
+
+local Plugin = script:FindFirstAncestor("Plugin")
+
+local Assets = require(Plugin.Assets)
+local Session = require(Plugin.Session)
+local Config = require(Plugin.Config)
+local Version = require(Plugin.Version)
+local Logging = require(Plugin.Logging)
+local DevSettings = require(Plugin.DevSettings)
+
+local ConnectPanel = require(Plugin.Components.ConnectPanel)
+local ConnectionActivePanel = require(Plugin.Components.ConnectionActivePanel)
+
+local e = Roact.createElement
+
+local function showUpgradeMessage(lastVersion)
+	local message = (
+		"Rojo detected an upgrade from version %s to version %s." ..
+		"\nMake sure you have also upgraded your server!" ..
+		"\n\nRojo plugin version %s is intended for use with server version %s."
+	):format(
+		Version.display(lastVersion), Version.display(Config.version),
+		Version.display(Config.version), Config.expectedServerVersionString
+	)
+
+	Logging.info(message)
+end
+
+--[[
+	Check if the user is using a newer version of Rojo than last time. If they
+	are, show them a reminder to make sure they check their server version.
+]]
+local function checkUpgrade(plugin)
+	-- When developing Rojo, there's no use in doing version checks
+	if DevSettings:isEnabled() then
+		return
+	end
+
+	local lastVersion = plugin:GetSetting("LastRojoVersion")
+
+	if lastVersion then
+		local wasUpgraded = Version.compare(Config.version, lastVersion) == 1
+
+		if wasUpgraded then
+			showUpgradeMessage(lastVersion)
+		end
+	end
+
+	plugin:SetSetting("LastRojoVersion", Config.version)
+end
+
+local SessionStatus = {
+	Disconnected = "Disconnected",
+	Connected = "Connected",
+	ConfiguringSession = "ConfiguringSession",
+	-- TODO: Error?
+}
+
+setmetatable(SessionStatus, {
+	__index = function(_, key)
+		error(("%q is not a valid member of SessionStatus"):format(tostring(key)), 2)
+	end,
+})
+
+local App = Roact.Component:extend("App")
+
+function App:init()
+	self:setState({
+		sessionStatus = SessionStatus.Disconnected,
+	})
+
+	self.connectButton = nil
+	self.configButton = nil
+	self.currentSession = nil
+
+	self.displayedVersion = DevSettings:isEnabled()
+		and Config.codename
+		or Version.display(Config.version)
+end
+
+function App:render()
+	local children
+
+	if self.state.sessionStatus == SessionStatus.Connected then
+		children = {
+			ConnectionActivePanel = e(ConnectionActivePanel),
+		}
+	elseif self.state.sessionStatus == SessionStatus.ConfiguringSession then
+		children = {
+			ConnectPanel = e(ConnectPanel, {
+				startSession = function(address, port)
+					Logging.trace("Starting new session")
+
+					local success, session = Session.new({
+						address = address,
+						port = port,
+						onError = function(message)
+							Logging.warn("%s", tostring(message))
+							Logging.trace("Session terminated due to error")
+							self.currentSession = nil
+
+							self:setState({
+								sessionStatus = SessionStatus.Disconnected,
+							})
+						end
+					})
+
+					if success then
+						self.currentSession = session
+						self:setState({
+							sessionStatus = SessionStatus.Connected,
+						})
+					end
+				end,
+				cancel = function()
+					Logging.trace("Canceling session configuration")
+
+					self:setState({
+						sessionStatus = SessionStatus.Disconnected,
+					})
+				end,
+			}),
+		}
+	end
+
+	return e("ScreenGui", {
+		AutoLocalize = false,
+		ZIndexBehavior = Enum.ZIndexBehavior.Sibling,
+	}, children)
+end
+
+function App:didMount()
+	Logging.trace("Rojo %s initializing", self.displayedVersion)
+
+	local toolbar = self.props.plugin:CreateToolbar("Rojo " .. self.displayedVersion)
+
+	self.connectButton = toolbar:CreateButton(
+		"Connect",
+		"Connect to a running Rojo session",
+		Assets.StartSession)
+	self.connectButton.ClickableWhenViewportHidden = false
+	self.connectButton.Click:Connect(function()
+		checkUpgrade(self.props.plugin)
+
+		if self.state.sessionStatus == SessionStatus.Connected then
+			Logging.trace("Disconnecting session")
+
+			self.currentSession:disconnect()
+			self.currentSession = nil
+			self:setState({
+				sessionStatus = SessionStatus.Disconnected,
+			})
+
+			Logging.trace("Session terminated by user")
+		elseif self.state.sessionStatus == SessionStatus.Disconnected then
+			Logging.trace("Starting session configuration")
+
+			self:setState({
+				sessionStatus = SessionStatus.ConfiguringSession,
+			})
+		elseif self.state.sessionStatus == SessionStatus.ConfiguringSession then
+			Logging.trace("Canceling session configuration")
+
+			self:setState({
+				sessionStatus = SessionStatus.Disconnected,
+			})
+		end
+	end)
+
+	self.configButton = toolbar:CreateButton(
+		"Configure",
+		"Configure the Rojo plugin",
+		Assets.Configure)
+	self.configButton.ClickableWhenViewportHidden = false
+	self.configButton.Click:Connect(function()
+		self.configButton:SetActive(false)
+	end)
+end
+
+function App:didUpdate()
+	local connectActive = self.state.sessionStatus == SessionStatus.ConfiguringSession
+		or self.state.sessionStatus == SessionStatus.Connected
+
+	self.connectButton:SetActive(connectActive)
+
+	if self.state.sessionStatus == SessionStatus.Connected then
+		self.connectButton.Icon = Assets.SessionActive
+	else
+		self.connectButton.Icon = Assets.StartSession
+	end
+end
+
+return App

plugin/src/Components/ConnectPanel.lua

@@ -0,0 +1,243 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+
+local Roact = require(Rojo.Roact)
+
+local Config = require(Plugin.Config)
+local Assets = require(Plugin.Assets)
+
+local FitList = require(Plugin.Components.FitList)
+local FitText = require(Plugin.Components.FitText)
+local FormButton = require(Plugin.Components.FormButton)
+local FormTextInput = require(Plugin.Components.FormTextInput)
+
+local WhiteCross = Assets.Sprites.WhiteCross
+local GrayBox = Assets.Slices.GrayBox
+
+local e = Roact.createElement
+
+local TEXT_COLOR = Color3.new(0.05, 0.05, 0.05)
+local FORM_TEXT_SIZE = 20
+
+local ConnectPanel = Roact.Component:extend("ConnectPanel")
+
+function ConnectPanel:init()
+	self.labelSizes = {}
+	self.labelSize, self.setLabelSize = Roact.createBinding(Vector2.new())
+
+	self:setState({
+		address = Config.defaultHost,
+		port = Config.defaultPort,
+	})
+end
+
+function ConnectPanel:updateLabelSize(name, size)
+	self.labelSizes[name] = size
+
+	local x = 0
+	local y = 0
+
+	for _, size in pairs(self.labelSizes) do
+		x = math.max(x, size.X)
+		y = math.max(y, size.Y)
+	end
+
+	self.setLabelSize(Vector2.new(x, y))
+end
+
+function ConnectPanel:render()
+	local startSession = self.props.startSession
+	local cancel = self.props.cancel
+
+	return e(FitList, {
+		containerKind = "ImageLabel",
+		containerProps = {
+			Image = GrayBox.asset,
+			ImageRectOffset = GrayBox.offset,
+			ImageRectSize = GrayBox.size,
+			ScaleType = Enum.ScaleType.Slice,
+			SliceCenter = GrayBox.center,
+			BackgroundTransparency = 1,
+			Position = UDim2.new(0.5, 0, 0.5, 0),
+			AnchorPoint = Vector2.new(0.5, 0.5),
+		},
+		layoutProps = {
+			HorizontalAlignment = Enum.HorizontalAlignment.Center,
+		},
+	}, {
+		Head = e("Frame", {
+			LayoutOrder = 1,
+			Size = UDim2.new(1, 0, 0, 36),
+			BackgroundTransparency = 1,
+		}, {
+			Padding = e("UIPadding", {
+				PaddingTop = UDim.new(0, 8),
+				PaddingBottom = UDim.new(0, 8),
+				PaddingLeft = UDim.new(0, 8),
+				PaddingRight = UDim.new(0, 8),
+			}),
+
+			Title = e("TextLabel", {
+				Font = Enum.Font.SourceSansBold,
+				TextSize = 22,
+				Text = "Start New Rojo Session",
+				Size = UDim2.new(1, 0, 1, 0),
+				TextXAlignment = Enum.TextXAlignment.Left,
+				BackgroundTransparency = 1,
+				TextColor3 = TEXT_COLOR,
+			}),
+
+			Close = e("ImageButton", {
+				Image = WhiteCross.asset,
+				ImageRectOffset = WhiteCross.offset,
+				ImageRectSize = WhiteCross.size,
+				Size = UDim2.new(0, 18, 0, 18),
+				Position = UDim2.new(1, 0, 0.5, 0),
+				AnchorPoint = Vector2.new(1, 0.5),
+				ImageColor3 = TEXT_COLOR,
+				BackgroundTransparency = 1,
+				[Roact.Event.Activated] = function()
+					cancel()
+				end,
+			}),
+		}),
+
+		Border = e("Frame", {
+			BorderSizePixel = 0,
+			BackgroundColor3 = Color3.new(0.7, 0.7, 0.7),
+			Size = UDim2.new(1, -4, 0, 2),
+			LayoutOrder = 2,
+		}),
+
+		Body = e(FitList, {
+			containerProps = {
+				BackgroundTransparency = 1,
+				LayoutOrder = 3,
+			},
+			layoutProps = {
+				Padding = UDim.new(0, 8),
+			},
+			paddingProps = {
+				PaddingTop = UDim.new(0, 8),
+				PaddingBottom = UDim.new(0, 8),
+				PaddingLeft = UDim.new(0, 8),
+				PaddingRight = UDim.new(0, 8),
+			},
+		}, {
+			Address = e(FitList, {
+				containerProps = {
+					LayoutOrder = 1,
+					BackgroundTransparency = 1,
+				},
+				layoutProps = {
+					FillDirection = Enum.FillDirection.Horizontal,
+					Padding = UDim.new(0, 8),
+				},
+			}, {
+				Label = e(FitText, {
+					MinSize = Vector2.new(0, 24),
+					Kind = "TextLabel",
+					LayoutOrder = 1,
+					BackgroundTransparency = 1,
+					TextXAlignment = Enum.TextXAlignment.Left,
+					Font = Enum.Font.SourceSansBold,
+					TextSize = FORM_TEXT_SIZE,
+					Text = "Address",
+					TextColor3 = TEXT_COLOR,
+
+					[Roact.Change.AbsoluteSize] = function(rbx)
+						self:updateLabelSize("address", rbx.AbsoluteSize)
+					end,
+				}, {
+					Sizing = e("UISizeConstraint", {
+						MinSize = self.labelSize,
+					}),
+				}),
+
+				Input = e(FormTextInput, {
+					layoutOrder = 2,
+					size = UDim2.new(0, 300, 0, 24),
+					value = self.state.address,
+					onValueChange = function(newValue)
+						self:setState({
+							address = newValue,
+						})
+					end,
+				}),
+			}),
+
+			Port = e(FitList, {
+				containerProps = {
+					LayoutOrder = 2,
+					BackgroundTransparency = 1,
+				},
+				layoutProps = {
+					FillDirection = Enum.FillDirection.Horizontal,
+					Padding = UDim.new(0, 8),
+				},
+			}, {
+				Label = e(FitText, {
+					MinSize = Vector2.new(0, 24),
+					Kind = "TextLabel",
+					LayoutOrder = 1,
+					BackgroundTransparency = 1,
+					TextXAlignment = Enum.TextXAlignment.Left,
+					Font = Enum.Font.SourceSansBold,
+					TextSize = FORM_TEXT_SIZE,
+					Text = "Port",
+					TextColor3 = TEXT_COLOR,
+
+					[Roact.Change.AbsoluteSize] = function(rbx)
+						self:updateLabelSize("port", rbx.AbsoluteSize)
+					end,
+				}, {
+					Sizing = e("UISizeConstraint", {
+						MinSize = self.labelSize,
+					}),
+				}),
+
+				Input = e(FormTextInput, {
+					layoutOrder = 2,
+					size = UDim2.new(0, 300, 0, 24),
+					value = self.state.port,
+					onValueChange = function(newValue)
+						self:setState({
+							port = newValue,
+						})
+					end,
+				}),
+			}),
+
+			Buttons = e(FitList, {
+				containerProps = {
+					LayoutOrder = 3,
+					BackgroundTransparency = 1,
+				},
+				layoutProps = {
+					FillDirection = Enum.FillDirection.Horizontal,
+					Padding = UDim.new(0, 8),
+				},
+			}, {
+				e(FormButton, {
+					text = "Start",
+					onClick = function()
+						if startSession ~= nil then
+							startSession(self.state.address, self.state.port)
+						end
+					end,
+				}),
+
+				e(FormButton, {
+					text = "Cancel",
+					onClick = function()
+						if cancel ~= nil then
+							cancel()
+						end
+					end,
+				}),
+			})
+		})
+	})
+end
+
+return ConnectPanel

plugin/src/Components/ConnectionActivePanel.lua

@@ -0,0 +1,39 @@
+local Roact = require(script:FindFirstAncestor("Rojo").Roact)
+
+local Assets = require(script.Parent.Parent.Assets)
+
+local FitList = require(script.Parent.FitList)
+local FitText = require(script.Parent.FitText)
+
+local e = Roact.createElement
+
+local GrayBox = Assets.Slices.GrayBox
+
+local ConnectionActivePanel = Roact.Component:extend("ConnectionActivePanel")
+
+function ConnectionActivePanel:render()
+	return e(FitList, {
+		containerKind = "ImageButton",
+		containerProps = {
+			Image = GrayBox.asset,
+			ImageRectOffset = GrayBox.offset,
+			ImageRectSize = GrayBox.size,
+			SliceCenter = GrayBox.center,
+			ScaleType = Enum.ScaleType.Slice,
+			BackgroundTransparency = 1,
+			Position = UDim2.new(0.5, 0, 0, 0),
+			AnchorPoint = Vector2.new(0.5, 0),
+		},
+	}, {
+		Text = e(FitText, {
+			Padding = Vector2.new(12, 6),
+			Font = Enum.Font.SourceSans,
+			TextSize = 18,
+			Text = "Rojo Connected",
+			TextColor3 = Color3.new(0.05, 0.05, 0.05),
+			BackgroundTransparency = 1,
+		}),
+	})
+end
+
+return ConnectionActivePanel

plugin/src/Components/FitList.lua

@@ -0,0 +1,50 @@
+local Roact = require(script:FindFirstAncestor("Rojo").Roact)
+
+local Dictionary = require(script.Parent.Parent.Dictionary)
+
+local e = Roact.createElement
+
+local FitList = Roact.Component:extend("FitList")
+
+function FitList:init()
+	self.sizeBinding, self.setSize = Roact.createBinding(UDim2.new())
+end
+
+function FitList:render()
+	local containerKind = self.props.containerKind or "Frame"
+	local containerProps = self.props.containerProps
+	local layoutProps = self.props.layoutProps
+	local paddingProps = self.props.paddingProps
+
+	local padding
+	if paddingProps ~= nil then
+		padding = e("UIPadding", paddingProps)
+	end
+
+	local children = Dictionary.merge(self.props[Roact.Children], {
+		["$Layout"] = e("UIListLayout", Dictionary.merge({
+			SortOrder = Enum.SortOrder.LayoutOrder,
+			[Roact.Change.AbsoluteContentSize] = function(instance)
+				local size = instance.AbsoluteContentSize
+
+				if paddingProps ~= nil then
+					size = size + Vector2.new(
+						paddingProps.PaddingLeft.Offset + paddingProps.PaddingRight.Offset,
+						paddingProps.PaddingTop.Offset + paddingProps.PaddingBottom.Offset)
+				end
+
+				self.setSize(UDim2.new(0, size.X, 0, size.Y))
+			end,
+		}, layoutProps)),
+
+		["$Padding"] = padding,
+	})
+
+	local fullContainerProps = Dictionary.merge(containerProps, {
+		Size = self.sizeBinding,
+	})
+
+	return e(containerKind, fullContainerProps, children)
+end
+
+return FitList

plugin/src/Components/FitText.lua

@@ -0,0 +1,52 @@
+local TextService = game:GetService("TextService")
+
+local Roact = require(script:FindFirstAncestor("Rojo").Roact)
+
+local Dictionary = require(script.Parent.Parent.Dictionary)
+
+local e = Roact.createElement
+
+local FitText = Roact.Component:extend("FitText")
+
+function FitText:init()
+	self.sizeBinding, self.setSize = Roact.createBinding(UDim2.new())
+end
+
+function FitText:render()
+	local kind = self.props.Kind or "TextLabel"
+
+	local containerProps = Dictionary.merge(self.props, {
+		Kind = Dictionary.None,
+		Padding = Dictionary.None,
+		MinSize = Dictionary.None,
+		Size = self.sizeBinding
+	})
+
+	return e(kind, containerProps)
+end
+
+function FitText:didMount()
+	self:updateTextMeasurements()
+end
+
+function FitText:didUpdate()
+	self:updateTextMeasurements()
+end
+
+function FitText:updateTextMeasurements()
+	local minSize = self.props.MinSize or Vector2.new(0, 0)
+	local padding = self.props.Padding or Vector2.new(0, 0)
+
+	local text = self.props.Text or ""
+	local font = self.props.Font or Enum.Font.Legacy
+	local textSize = self.props.TextSize or 12
+
+	local measuredText = TextService:GetTextSize(text, textSize, font, Vector2.new(9e6, 9e6))
+	local totalSize = UDim2.new(
+		0, math.max(minSize.X, padding.X * 2 + measuredText.X),
+		0, math.max(minSize.Y, padding.Y * 2 + measuredText.Y))
+
+	self.setSize(totalSize)
+end
+
+return FitText

plugin/src/Components/FormButton.lua

@@ -0,0 +1,49 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+
+local Roact = require(Rojo.Roact)
+
+local Assets = require(Plugin.Assets)
+local FitList = require(Plugin.Components.FitList)
+local FitText = require(Plugin.Components.FitText)
+
+local e = Roact.createElement
+
+local GrayButton07 = Assets.Slices.GrayButton07
+
+local function FormButton(props)
+	local text = props.text
+	local layoutOrder = props.layoutOrder
+	local onClick = props.onClick
+
+	return e(FitList, {
+		containerKind = "ImageButton",
+		containerProps = {
+			LayoutOrder = layoutOrder,
+			BackgroundTransparency = 1,
+			Image = GrayButton07.asset,
+			ImageRectOffset = GrayButton07.offset,
+			ImageRectSize = GrayButton07.size,
+			ScaleType = Enum.ScaleType.Slice,
+			SliceCenter = GrayButton07.center,
+
+			[Roact.Event.Activated] = function()
+				if onClick ~= nil then
+					onClick()
+				end
+			end,
+		},
+	}, {
+		Text = e(FitText, {
+			Kind = "TextLabel",
+			Text = text,
+			TextSize = 22,
+			Font = Enum.Font.SourceSansBold,
+			Padding = Vector2.new(14, 6),
+			TextColor3 = Color3.new(0.05, 0.05, 0.05),
+			BackgroundTransparency = 1,
+		}),
+	})
+end
+
+return FormButton

plugin/src/Components/FormTextInput.lua

@@ -0,0 +1,47 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+
+local Roact = require(Rojo.Roact)
+
+local Assets = require(Plugin.Assets)
+
+local e = Roact.createElement
+
+local GrayBox = Assets.Slices.GrayBox
+
+local function FormTextInput(props)
+	local value = props.value
+	local onValueChange = props.onValueChange
+	local layoutOrder = props.layoutOrder
+	local size = props.size
+
+	return e("ImageLabel", {
+		LayoutOrder = layoutOrder,
+		Image = GrayBox.asset,
+		ImageRectOffset = GrayBox.offset,
+		ImageRectSize = GrayBox.size,
+		ScaleType = Enum.ScaleType.Slice,
+		SliceCenter = GrayBox.center,
+		Size = size,
+		BackgroundTransparency = 1,
+	}, {
+		InputInner = e("TextBox", {
+			BackgroundTransparency = 1,
+			Size = UDim2.new(1, -8, 1, -8),
+			Position = UDim2.new(0.5, 0, 0.5, 0),
+			AnchorPoint = Vector2.new(0.5, 0.5),
+			Font = Enum.Font.SourceSans,
+			ClearTextOnFocus = false,
+			TextXAlignment = Enum.TextXAlignment.Left,
+			TextSize = 20,
+			Text = value,
+			TextColor3 = Color3.new(0.05, 0.05, 0.05),
+
+			[Roact.Change.Text] = function(rbx)
+				onValueChange(rbx.Text)
+			end,
+		}),
+	})
+end
+
+return FormTextInput

plugin/src/Config.lua

@@ -1,12 +1,8 @@
 return {
-	pollingRate = 0.2,
-	version = {0, 4, 8},
-	expectedServerVersionString = "0.4.x",
-	protocolVersion = 1,
-	icons = {
-		syncIn = "rbxassetid://1820320573",
-		togglePolling = "rbxassetid://1820320064",
-		testConnection = "rbxassetid://1820320989",
-	},
-	dev = false,
-}
+	codename = "Epiphany",
+	version = {0, 5, 0, "-alpha.0"},
+	expectedServerVersionString = "0.5.0 or newer",
+	protocolVersion = 2,
+	defaultHost = "localhost",
+	defaultPort = 34872,
+}

plugin/src/Config.spec.lua

@@ -1,7 +0,0 @@
-return function()
-	local Config = require(script.Parent.Config)
-
-	it("should have 'dev' disabled", function()
-		expect(Config.dev).to.equal(false)
-	end)
-end

plugin/src/DevSettings.lua

@@ -0,0 +1,59 @@
+local Config = require(script.Parent.Config)
+
+local function getValueContainer()
+	return game:FindFirstChild("RojoDev-" .. Config.codename)
+end
+
+local valueContainer = getValueContainer()
+
+local function getValue(name)
+	if valueContainer == nil then
+		return nil
+	end
+
+	local valueObject = valueContainer:FindFirstChild(name)
+
+	if valueObject == nil then
+		return nil
+	end
+
+	return valueObject.Value
+end
+
+local function setValue(name, kind, value)
+	local object = valueContainer:FindFirstChild(name)
+
+	if object == nil then
+		object = Instance.new(kind)
+		object.Name = name
+		object.Parent = valueContainer
+	end
+
+	object.Value = value
+end
+
+local function createAllValues()
+	valueContainer = getValueContainer()
+
+	if valueContainer == nil then
+		valueContainer = Instance.new("Folder")
+		valueContainer.Name = "RojoDev-" .. Config.codename
+		valueContainer.Parent = game
+	end
+
+	setValue("LogLevel", "IntValue", getValue("LogLevel") or 2)
+end
+
+_G[("ROJO_%s_DEV_CREATE"):format(Config.codename:upper())] = createAllValues
+
+local DevSettings = {}
+
+function DevSettings:isEnabled()
+	return valueContainer ~= nil
+end
+
+function DevSettings:getLogLevel()
+	return getValue("LogLevel")
+end
+
+return DevSettings

plugin/src/Dictionary.lua

@@ -0,0 +1,33 @@
+--[[
+	This is a placeholder module waiting for Cryo to become available.
+]]
+
+local None = newproxy(true)
+getmetatable(None).__tostring = function()
+	return "None"
+end
+
+local function merge(...)
+	local output = {}
+
+	for i = 1, select("#", ...) do
+		local source = select(i, ...)
+
+		if source ~= nil then
+			for key, value in pairs(source) do
+				if value == None then
+					output[key] = nil
+				else
+					output[key] = value
+				end
+			end
+		end
+	end
+
+	return output
+end
+
+return {
+	None = None,
+	merge = merge,
+}

plugin/src/Http.lua

@@ -1,68 +1,75 @@
 local HttpService = game:GetService("HttpService")
 
-local HTTP_DEBUG = false
-
-local Promise = require(script.Parent.Parent.modules.Promise)
+local Promise = require(script.Parent.Parent.Promise)
 
+local Logging = require(script.Parent.Logging)
 local HttpError = require(script.Parent.HttpError)
 local HttpResponse = require(script.Parent.HttpResponse)
 
-local function dprint(...)
-	if HTTP_DEBUG then
-		print(...)
-	end
-end
+local lastRequestId = 0
 
+-- TODO: Factor out into separate library, especially error handling
 local Http = {}
-Http.__index = Http
 
-function Http.new(baseUrl)
-	assert(type(baseUrl) == "string", "Http.new needs a baseUrl!")
+function Http.get(url)
+	local requestId = lastRequestId + 1
+	lastRequestId = requestId
 
-	local http = {
-		baseUrl = baseUrl
-	}
+	Logging.trace("GET(%d) %s", requestId, url)
 
-	setmetatable(http, Http)
-
-	return http
-end
-
-function Http:get(endpoint)
-	dprint("\nGET", endpoint)
 	return Promise.new(function(resolve, reject)
-		spawn(function()
-			local ok, result = pcall(function()
-				return HttpService:GetAsync(self.baseUrl .. endpoint, true)
+		coroutine.wrap(function()
+			local success, response = pcall(function()
+				return HttpService:RequestAsync({
+					Url = url,
+					Method = "GET",
+				})
 			end)
 
-			if ok then
-				dprint("\t", result, "\n")
-				resolve(HttpResponse.new(result))
+			if success then
+				Logging.trace("Request %d success: status code %s", requestId, response.StatusCode)
+				resolve(HttpResponse.fromRobloxResponse(response))
 			else
-				reject(HttpError.fromErrorString(result))
+				Logging.trace("Request %d failure: %s", requestId, response)
+				reject(HttpError.fromErrorString(response))
 			end
-		end)
+		end)()
 	end)
 end
 
-function Http:post(endpoint, body)
-	dprint("\nPOST", endpoint)
-	dprint(body)
+function Http.post(url, body)
+	local requestId = lastRequestId + 1
+	lastRequestId = requestId
+
+	Logging.trace("POST(%d) %s\n%s", requestId, url, body)
+
 	return Promise.new(function(resolve, reject)
-		spawn(function()
-			local ok, result = pcall(function()
-				return HttpService:PostAsync(self.baseUrl .. endpoint, body)
+		coroutine.wrap(function()
+			local success, response = pcall(function()
+				return HttpService:RequestAsync({
+					Url = url,
+					Method = "POST",
+					Body = body,
+				})
 			end)
 
-			if ok then
-				dprint("\t", result, "\n")
-				resolve(HttpResponse.new(result))
+			if success then
+				Logging.trace("Request %d success: status code %s", requestId, response.StatusCode)
+				resolve(HttpResponse.fromRobloxResponse(response))
 			else
-				reject(HttpError.fromErrorString(result))
+				Logging.trace("Request %d failure: %s", requestId, response)
+				reject(HttpError.fromErrorString(response))
 			end
-		end)
+		end)()
 	end)
 end
 
-return Http
+function Http.jsonEncode(object)
+	return HttpService:JSONEncode(object)
+end
+
+function Http.jsonDecode(source)
+	return HttpService:JSONDecode(source)
+end
+
+return Http

plugin/src/HttpError.lua

@@ -1,3 +1,5 @@
+local Logging = require(script.Parent.Logging)
+
 local HttpError = {}
 HttpError.__index = HttpError
 
@@ -7,14 +9,23 @@ HttpError.Error = {
 			"Check your game settings, located in the 'Home' tab of Studio.",
 	},
 	ConnectFailed = {
-		message = "Rojo plugin couldn't connect to the Rojo server.\n" ..
-			"Make sure the server is running -- use 'Rojo serve' to run it!",
+		message = "Couldn't connect to the Rojo server.\n" ..
+			"Make sure the server is running -- use 'rojo serve' to run it!",
+	},
+	Timeout = {
+		message = "Request timed out.",
 	},
 	Unknown = {
-		message = "Rojo encountered an unknown error: {{message}}",
+		message = "Unknown error: {{message}}",
 	},
 }
 
+setmetatable(HttpError.Error, {
+	__index = function(_, key)
+		error(("%q is not a valid member of HttpError.Error"):format(tostring(key)), 2)
+	end,
+})
+
 function HttpError.new(type, extraMessage)
 	extraMessage = extraMessage or ""
 	local message = type.message:gsub("{{message}}", extraMessage)
@@ -36,25 +47,26 @@ end
 --[[
 	This method shouldn't have to exist. Ugh.
 ]]
-function HttpError.fromErrorString(err)
-	err = err:lower()
+function HttpError.fromErrorString(message)
+	local lower = message:lower()
 
-	if err:find("^http requests are not enabled") then
+	if lower:find("^http requests are not enabled") then
 		return HttpError.new(HttpError.Error.HttpNotEnabled)
 	end
 
-	if err:find("^curl error") then
+	if lower:find("^httperror: timedout") then
+		return HttpError.new(HttpError.Error.Timeout)
+	end
+
+	if lower:find("^httperror: connectfail") then
 		return HttpError.new(HttpError.Error.ConnectFailed)
 	end
 
-	return HttpError.new(HttpError.Error.Unknown, err)
+	return HttpError.new(HttpError.Error.Unknown, message)
 end
 
 function HttpError:report()
-	warn(self.message)
-	if self.type == HttpError.Error.HttpNotEnabled then
-		game:GetService("Selection"):Set{game:GetService("HttpService")}
-	end
+	Logging.warn(self.message)
 end
 
-return HttpError
+return HttpError

plugin/src/HttpResponse.lua

@@ -1,16 +1,30 @@
 local HttpService = game:GetService("HttpService")
 
+local stringTemplate = [[
+HttpResponse {
+	code: %d
+	body: %s
+}]]
+
 local HttpResponse = {}
 HttpResponse.__index = HttpResponse
 
-function HttpResponse.new(body)
-	local response = {
-		body = body,
+function HttpResponse:__tostring()
+	return stringTemplate:format(self.code, self.body)
+end
+
+function HttpResponse.fromRobloxResponse(response)
+	local self = {
+		body = response.Body,
+		code = response.StatusCode,
+		headers = response.Headers,
 	}
 
-	setmetatable(response, HttpResponse)
+	return setmetatable(self, HttpResponse)
+end
 
-	return response
+function HttpResponse:isSuccess()
+	return self.code >= 200 and self.code < 300
 end
 
 function HttpResponse:json()

plugin/src/Logging.lua

@@ -0,0 +1,55 @@
+local DevSettings = require(script.Parent.DevSettings)
+
+local testLogLevel = nil
+
+local Level = {
+	Error = 0,
+	Warning = 1,
+	Info = 2,
+	Trace = 3,
+}
+
+local function getLogLevel()
+	if testLogLevel ~= nil then
+		return testLogLevel
+	end
+
+	local devValue = DevSettings:getLogLevel()
+	if devValue ~= nil then
+		return devValue
+	end
+
+	return Level.Info
+end
+
+local function addTags(tag, message)
+	return tag .. message:gsub("\n", "\n" .. tag)
+end
+
+local INFO_TAG = (" "):rep(15) .. "[Rojo-Info] "
+local TRACE_TAG = (" "):rep(15) .. "[Rojo-Trace] "
+local WARN_TAG = "[Rojo-Warn] "
+
+local Log = {}
+
+Log.Level = Level
+
+function Log.trace(template, ...)
+	if getLogLevel() >= Level.Trace then
+		print(addTags(TRACE_TAG, string.format(template, ...)))
+	end
+end
+
+function Log.info(template, ...)
+	if getLogLevel() >= Level.Info then
+		print(addTags(INFO_TAG, string.format(template, ...)))
+	end
+end
+
+function Log.warn(template, ...)
+	if getLogLevel() >= Level.Warning then
+		warn(addTags(WARN_TAG, string.format(template, ...)))
+	end
+end
+
+return Log

plugin/src/Main.server.lua

@@ -1,79 +0,0 @@
-if not plugin then
-	return
-end
-
-local Plugin = require(script.Parent.Plugin)
-local Config = require(script.Parent.Config)
-local Version = require(script.Parent.Version)
-
---[[
-	Check if the user is using a newer version of Rojo than last time. If they
-	are, show them a reminder to make sure they check their server version.
-]]
-local function checkUpgrade()
-	-- When developing Rojo, there's no use in doing version checks
-	if Config.dev then
-		return
-	end
-
-	local lastVersion = plugin:GetSetting("LastRojoVersion")
-
-	if lastVersion then
-		local wasUpgraded = Version.compare(Config.version, lastVersion) == 1
-
-		if wasUpgraded then
-			local message = (
-				"\nRojo detected an upgrade from version %s to version %s." ..
-				"\nMake sure you have also upgraded your server!" ..
-				"\n\nRojo version %s is intended for use with server version %s.\n"
-			):format(
-				Version.display(lastVersion), Version.display(Config.version),
-				Version.display(Config.version), Config.expectedServerVersionString
-			)
-
-			print(message)
-		end
-	end
-
-	plugin:SetSetting("LastRojoVersion", Config.version)
-end
-
-local function main()
-	local pluginInstance = Plugin.new()
-
-	local displayedVersion = Config.dev and "DEV" or Version.display(Config.version)
-
-	local toolbar = plugin:CreateToolbar("Rojo Plugin " .. displayedVersion)
-
-	toolbar:CreateButton("Test Connection", "Connect to Rojo Server", Config.icons.testConnection)
-		.Click:Connect(function()
-			checkUpgrade()
-
-			pluginInstance:connect()
-				:catch(function(err)
-					warn(err)
-				end)
-		end)
-
-	toolbar:CreateButton("Sync In", "Sync into Roblox Studio", Config.icons.syncIn)
-		.Click:Connect(function()
-			checkUpgrade()
-
-			pluginInstance:syncIn()
-				:catch(function(err)
-					warn(err)
-				end)
-		end)
-
-	toolbar:CreateButton("Toggle Polling", "Poll server for changes", Config.icons.togglePolling)
-		.Click:Connect(function()
-			checkUpgrade()
-
-			pluginInstance:togglePolling()
-				:catch(function(err)
-					warn(err)
-				end)
-		end)
-end
-
-main()

plugin/src/Plugin.lua

@@ -1,303 +0,0 @@
-local CoreGui = game:GetService("CoreGui")
-
-local Promise = require(script.Parent.Parent.modules.Promise)
-
-local Config = require(script.Parent.Config)
-local Http = require(script.Parent.Http)
-local Api = require(script.Parent.Api)
-local Reconciler = require(script.Parent.Reconciler)
-local Version = require(script.Parent.Version)
-
-local function collectMatch(source, pattern)
-	local result = {}
-
-	for match in source:gmatch(pattern) do
-		table.insert(result, match)
-	end
-
-	return result
-end
-
-local Plugin = {}
-Plugin.__index = Plugin
-
-function Plugin.new()
-	local address = "localhost"
-	local port = Config.dev and 8001 or 8000
-
-	local remote = ("http://%s:%d"):format(address, port)
-
-	local self = {
-		_http = Http.new(remote),
-		_reconciler = Reconciler.new(),
-		_api = nil,
-		_polling = false,
-		_syncInProgress = false,
-	}
-
-	setmetatable(self, Plugin)
-
-	do
-		local uiName = ("Rojo %s UI"):format(Version.display(Config.version))
-
-		if Config.dev then
-			uiName = "Rojo Dev UI"
-		end
-
-		-- If there's an existing Rojo UI, like from a Roblox plugin upgrade
-		-- that wasn't Rojo, make sure we clean it up.
-		local existingUi = CoreGui:FindFirstChild(uiName)
-
-		if existingUi ~= nil then
-			existingUi:Destroy()
-		end
-
-		local screenGui = Instance.new("ScreenGui")
-		screenGui.Name = uiName
-		screenGui.Parent = CoreGui
-		screenGui.DisplayOrder = -1
-		screenGui.Enabled = false
-
-		local label = Instance.new("TextLabel")
-		label.Font = Enum.Font.SourceSans
-		label.TextSize = 20
-		label.Text = "Rojo polling..."
-		label.BackgroundColor3 = Color3.fromRGB(31, 31, 31)
-		label.BackgroundTransparency = 0.5
-		label.BorderSizePixel = 0
-		label.TextColor3 = Color3.new(1, 1, 1)
-		label.Size = UDim2.new(0, 120, 0, 28)
-		label.Position = UDim2.new(0, 0, 0, 0)
-		label.Parent = screenGui
-
-		self._label = screenGui
-
-		-- If our UI was destroyed, we assume it was from another instance of
-		-- the Rojo plugin coming online.
-		--
-		-- Roblox doesn't notify plugins when they get unloaded, so this is the
-		-- best trigger we have right now unless we create a dedicated event
-		-- object.
-		screenGui.AncestryChanged:Connect(function(_, parent)
-			if parent == nil then
-				self:restart()
-			end
-		end)
-	end
-
-	return self
-end
-
---[[
-	Clears all state and issues a notice to the user that the plugin has
-	restarted.
-]]
-function Plugin:restart()
-	warn("Rojo: The server has changed since the last request, reloading plugin...")
-
-	self:stopPolling()
-
-	self._reconciler:destruct()
-	self._reconciler = Reconciler.new()
-
-	self._api = nil
-	self._polling = false
-	self._syncInProgress = false
-end
-
-function Plugin:api()
-	if not self._api then
-		self._api = Api.connect(self._http)
-			:catch(function(err)
-				self._api = nil
-				return Promise.reject(err)
-			end)
-	end
-
-	return self._api
-end
-
-function Plugin:connect()
-	print("Rojo: Testing connection...")
-
-	return self:api()
-		:andThen(function(api)
-			local ok, info = api:getInfo():await()
-
-			if not ok then
-				return Promise.reject(info)
-			end
-
-			print("Rojo: Server found!")
-			print("Rojo: Protocol version:", info.protocolVersion)
-			print("Rojo: Server version:", info.serverVersion)
-		end)
-		:catch(function(err)
-			if err == Api.Error.ServerIdMismatch then
-				self:restart()
-				return self:connect()
-			else
-				return Promise.reject(err)
-			end
-		end)
-end
-
-function Plugin:togglePolling()
-	if self._polling then
-		return self:stopPolling()
-	else
-		return self:startPolling()
-	end
-end
-
-function Plugin:stopPolling()
-	if not self._polling then
-		return Promise.resolve(false)
-	end
-
-	print("Rojo: Stopped polling server for changes.")
-
-	self._polling = false
-	self._label.Enabled = false
-
-	return Promise.resolve(true)
-end
-
-function Plugin:_pull(api, project, routes)
-	return api:read(routes)
-		:andThen(function(items)
-			for index = 1, #routes do
-				local itemRoute = routes[index]
-				local partitionName = itemRoute[1]
-				local partition = project.partitions[partitionName]
-				local item = items[index]
-
-				local partitionRoute = collectMatch(partition.target, "[^.]+")
-
-				-- If the item route's length was 1, we need to rename the instance to
-				-- line up with the partition's root object name.
-				--
-				-- This is a HACK!
-				if #itemRoute == 1 then
-					if item then
-						local objectName = partition.target:match("[^.]+$")
-						item.Name = objectName
-					end
-				end
-
-				local fullRoute = {}
-				for _, piece in ipairs(partitionRoute) do
-					table.insert(fullRoute, piece)
-				end
-
-				for i = 2, #itemRoute do
-					table.insert(fullRoute, itemRoute[i])
-				end
-
-				self._reconciler:reconcileRoute(fullRoute, item, itemRoute)
-			end
-		end)
-end
-
-function Plugin:startPolling()
-	if self._polling then
-		return
-	end
-
-	print("Rojo: Polling server for changes...")
-
-	self._polling = true
-	self._label.Enabled = true
-
-	return self:api()
-		:andThen(function(api)
-			local syncOk, result = self:syncIn():await()
-
-			if not syncOk then
-				return Promise.reject(result)
-			end
-
-			local infoOk, info = api:getInfo():await()
-
-			if not infoOk then
-				return Promise.reject(info)
-			end
-
-			while self._polling do
-				local changesOk, changes = api:getChanges():await()
-
-				if not changesOk then
-					return Promise.reject(changes)
-				end
-
-				if #changes > 0 then
-					local routes = {}
-
-					for _, change in ipairs(changes) do
-						table.insert(routes, change.route)
-					end
-
-					local pullOk, pullResult = self:_pull(api, info.project, routes):await()
-
-					if not pullOk then
-						return Promise.reject(pullResult)
-					end
-				end
-
-				wait(Config.pollingRate)
-			end
-		end)
-		:catch(function(err)
-			self:stopPolling()
-
-			if err == Api.Error.ServerIdMismatch then
-				self:restart()
-				return self:startPolling()
-			else
-				return Promise.reject(err)
-			end
-		end)
-end
-
-function Plugin:syncIn()
-	if self._syncInProgress then
-		warn("Rojo: Can't sync right now, because a sync is already in progress.")
-
-		return Promise.resolve()
-	end
-
-	self._syncInProgress = true
-	print("Rojo: Syncing from server...")
-
-	return self:api()
-		:andThen(function(api)
-			local ok, info = api:getInfo():await()
-
-			if not ok then
-				return Promise.reject(info)
-			end
-
-			local routes = {}
-
-			for name in pairs(info.project.partitions) do
-				table.insert(routes, {name})
-			end
-
-			self:_pull(api, info.project, routes)
-
-			self._syncInProgress = false
-			print("Rojo: Sync successful!")
-		end)
-		:catch(function(err)
-			self._syncInProgress = false
-
-			if err == Api.Error.ServerIdMismatch then
-				self:restart()
-				return self:syncIn()
-			else
-				return Promise.reject(err)
-			end
-		end)
-end
-
-return Plugin

plugin/src/Reconciler.lua

@@ -1,220 +1,281 @@
-local RouteMap = require(script.Parent.RouteMap)
+local Logging = require(script.Parent.Logging)
 
-local function classEqual(a, b)
-	if a == "*" or b == "*" then
-		return true
+local function makeInstanceMap()
+	local self = {
+		fromIds = {},
+		fromInstances = {},
+	}
+
+	function self:insert(id, instance)
+		self.fromIds[id] = instance
+		self.fromInstances[instance] = id
 	end
 
-	return a == b
-end
+	function self:removeId(id)
+		local instance = self.fromIds[id]
 
-local function applyProperties(target, properties)
-	for key, property in pairs(properties) do
-		-- TODO: Transform property value based on property.Type
-		-- Right now, we assume that 'value' is primitive!
-		target[key] = property.Value
-	end
-end
-
---[[
-	Attempt to parent `rbx` to `parent`, doing nothing if:
-	* parent is already `parent`
-	* Changing parent threw an error
-]]
-local function reparent(rbx, parent)
-	if rbx then
-		if rbx.Parent == parent then
-			return
+		if instance ~= nil then
+			self.fromIds[id] = nil
+			self.fromInstances[instance] = nil
+		else
+			Logging.warn("Attempted to remove nonexistant ID %s", tostring(id))
 		end
-
-		-- It's possible that 'rbx' is a service or some other object that we
-		-- can't change the parent of. That's the only reason why Parent would
-		-- fail except for rbx being previously destroyed!
-		pcall(function()
-			rbx.Parent = parent
-		end)
 	end
-end
 
---[[
-	Attempts to match up Roblox instances and object specifiers for
-	reconciliation.
+	function self:removeInstance(instance)
+		local id = self.fromInstances[instance]
 
-	An object is considered a match if they have the same Name and ClassName.
+		if id ~= nil then
+			self.fromInstances[instance] = nil
+			self.fromIds[id] = nil
+		else
+			Logging.warn("Attempted to remove nonexistant instance %s", tostring(instance))
+		end
+	end
 
-	primaryChildren and secondaryChildren can each be either a list of Roblox
-	instances or object specifiers. Since they share a common shape, switching
-	the two around isn't problematic!
+	function self:destroyId(id)
+		local instance = self.fromIds[id]
+		self:removeId(id)
 
-	visited is expected to be an empty table initially. It will be filled with
-	the set of children that have been visited so far.
-]]
-local function findNextChildPair(primaryChildren, secondaryChildren, visited)
-	for _, primaryChild in ipairs(primaryChildren) do
-		if not visited[primaryChild] then
-			visited[primaryChild] = true
+		if instance ~= nil then
+			local descendantsToDestroy = {}
 
-			for _, secondaryChild in ipairs(secondaryChildren) do
-				if classEqual(primaryChild.ClassName, secondaryChild.ClassName) and primaryChild.Name == secondaryChild.Name then
-					visited[secondaryChild] = true
-
-					return primaryChild, secondaryChild
+			for otherInstance in pairs(self.fromInstances) do
+				if otherInstance:IsDescendantOf(instance) then
+					table.insert(descendantsToDestroy, otherInstance)
 				end
 			end
 
-			return primaryChild, nil
+			for _, otherInstance in ipairs(descendantsToDestroy) do
+				self:removeInstance(otherInstance)
+			end
+
+			instance:Destroy()
+		else
+			Logging.warn("Attempted to destroy nonexistant ID %s", tostring(id))
 		end
 	end
 
-	return nil, nil
+	return self
+end
+
+local function setProperty(instance, key, value)
+	-- The 'Contents' property of LocalizationTable isn't directly exposed, but
+	-- has corresponding (deprecated) getters and setters.
+	if key == "Contents" and instance.ClassName == "LocalizationTable" then
+		instance:SetContents(value)
+		return
+	end
+
+	-- If we don't have permissions to access this value at all, we can skip it.
+	local readSuccess, existingValue = pcall(function()
+		return instance[key]
+	end)
+
+	if not readSuccess then
+		-- An error will be thrown if there was a permission issue or if the
+		-- property doesn't exist. In the latter case, we should tell the user
+		-- because it's probably their fault.
+		if existingValue:find("lacking permission") then
+			Logging.trace("Permission error reading property %s on class %s", tostring(key), instance.ClassName)
+			return
+		else
+			error(("Invalid property %s on class %s: %s"):format(tostring(key), instance.ClassName, existingValue), 2)
+		end
+	end
+
+	local writeSuccess, err = pcall(function()
+		if existingValue ~= value then
+			instance[key] = value
+		end
+	end)
+
+	if not writeSuccess then
+		error(("Cannot set property %s on class %s: %s"):format(tostring(key), instance.ClassName, err), 2)
+	end
+
+	return true
 end
 
 local Reconciler = {}
 Reconciler.__index = Reconciler
 
 function Reconciler.new()
-	local reconciler = {
-		_routeMap = RouteMap.new(),
+	local self = {
+		instanceMap = makeInstanceMap(),
 	}
 
-	setmetatable(reconciler, Reconciler)
-
-	return reconciler
+	return setmetatable(self, Reconciler)
 end
 
---[[
-	A semi-smart algorithm that attempts to apply the given item's children to
-	an existing Roblox object.
-]]
-function Reconciler:_reconcileChildren(rbx, item)
-	local visited = {}
-	local rbxChildren = rbx:GetChildren()
+function Reconciler:applyUpdate(requestedIds, virtualInstancesById)
+	-- This function may eventually be asynchronous; it will require calls to
+	-- the server to resolve instances that don't exist yet.
+	local visitedIds = {}
 
-	-- Reconcile any children that were added or updated
-	while true do
-		local itemChild, rbxChild = findNextChildPair(item.Children, rbxChildren, visited)
-
-		if not itemChild then
-			break
-		end
-
-		reparent(self:reconcile(rbxChild, itemChild), rbx)
-	end
-
-	-- Reconcile any children that were deleted
-	while true do
-		local rbxChild, itemChild = findNextChildPair(rbxChildren, item.Children, visited)
-
-		if not rbxChild then
-			break
-		end
-
-		reparent(self:reconcile(rbxChild, itemChild), rbx)
+	for _, id in ipairs(requestedIds) do
+		self:__applyUpdatePiece(id, visitedIds, virtualInstancesById)
 	end
 end
 
 --[[
-	Construct a new Roblox object from the given item.
+	Update an existing instance, including its properties and children, to match
+	the given information.
 ]]
-function Reconciler:_reify(item)
-	local className = item.ClassName
+function Reconciler:reconcile(virtualInstancesById, id, instance)
+	local virtualInstance = virtualInstancesById[id]
 
-	-- "*" represents a match of any class. It reifies as a folder!
-	if className == "*" then
-		className = "Folder"
+	-- If an instance changes ClassName, we assume it's very different. That's
+	-- not always the case!
+	if virtualInstance.ClassName ~= instance.ClassName then
+		-- TODO: Preserve existing children instead?
+		local parent = instance.Parent
+		self.instanceMap:destroyId(id)
+		return self:__reify(virtualInstancesById, id, parent)
 	end
 
-	local rbx = Instance.new(className)
-	rbx.Name = item.Name
+	self.instanceMap:insert(id, instance)
 
-	applyProperties(rbx, item.Properties)
+	-- Some instances don't like being named, even if their name already matches
+	setProperty(instance, "Name", virtualInstance.Name)
 
-	for _, child in ipairs(item.Children) do
-		reparent(self:_reify(child), rbx)
+	for key, value in pairs(virtualInstance.Properties) do
+		setProperty(instance, key, value.Value)
 	end
 
-	if item.Route then
-		self._routeMap:insert(item.Route, rbx)
+	local existingChildren = instance:GetChildren()
+
+	local unvisitedExistingChildren = {}
+	for _, child in ipairs(existingChildren) do
+		unvisitedExistingChildren[child] = true
 	end
 
-	return rbx
-end
+	for _, childId in ipairs(virtualInstance.Children) do
+		local childData = virtualInstancesById[childId]
 
---[[
-	Clears any state that the Reconciler has, stopping it completely.
-]]
-function Reconciler:destruct()
-	self._routeMap:destruct()
-end
+		local existingChildInstance
+		for instance in pairs(unvisitedExistingChildren) do
+			local ok, name, className = pcall(function()
+				return instance.Name, instance.ClassName
+			end)
 
---[[
-	Apply the changes represented by the given item to a Roblox object that's a
-	child of the given instance.
-]]
-function Reconciler:reconcile(rbx, item)
-	-- Item was deleted
-	if not item then
-		if rbx then
-			self._routeMap:removeByRbx(rbx)
-			rbx:Destroy()
+			if ok then
+				if name == childData.Name and className == childData.ClassName then
+					existingChildInstance = instance
+					break
+				end
+			end
 		end
 
-		return nil
+		if existingChildInstance ~= nil then
+			unvisitedExistingChildren[existingChildInstance] = nil
+			self:reconcile(virtualInstancesById, childId, existingChildInstance)
+		else
+			self:__reify(virtualInstancesById, childId, instance)
+		end
 	end
 
-	-- Item was created!
-	if not rbx then
-		return self:_reify(item)
+	if self:__shouldClearUnknownInstances(virtualInstance) then
+		for existingChildInstance in pairs(unvisitedExistingChildren) do
+			self.instanceMap:removeInstance(existingChildInstance)
+			existingChildInstance:Destroy()
+		end
 	end
 
-	-- Item changed type!
-	if not classEqual(rbx.ClassName, item.ClassName) then
-		self._routeMap:removeByRbx(rbx)
-		rbx:Destroy()
+	-- The root instance of a project won't have a parent, like the DataModel,
+	-- so we need to be careful here.
+	if virtualInstance.Parent ~= nil then
+		local parent = self.instanceMap.fromIds[virtualInstance.Parent]
 
-		return self:_reify(item)
-	end
-
-	applyProperties(rbx, item.Properties)
-	self:_reconcileChildren(rbx, item)
-
-	return rbx
-end
-
-function Reconciler:reconcileRoute(route, item, itemRoute)
-	local parent
-	local rbx = game
-
-	for i = 1, #route do
-		local piece = route[i]
-
-		local child = rbx:FindFirstChild(piece)
-
-		-- We should get services instead of making folders here.
-		if rbx == game and not child then
-			local _
-			_, child = pcall(game.GetService, game, piece)
+		if parent == nil then
+			Logging.info("Instance %s wanted parent of %s", tostring(id), tostring(virtualInstance.Parent))
+			error("Rojo bug: During reconciliation, an instance referred to an instance ID as parent that does not exist.")
 		end
 
-		-- We don't want to create a folder if we're reaching our target item!
-		if not child and i ~= #route then
-			child = Instance.new("Folder")
-			child.Parent = rbx
-			child.Name = piece
+		-- Some instances, like services, don't like having their Parent
+		-- property poked, even if we're setting it to the same value.
+		setProperty(instance, "Parent", parent)
+		if instance.Parent ~= parent then
+			instance.Parent = parent
 		end
-
-		parent = rbx
-		rbx = child
 	end
 
-	-- Let's check the route map!
-	if not rbx then
-		rbx = self._routeMap:get(itemRoute)
-	end
-
-	rbx = self:reconcile(rbx, item)
-
-	reparent(rbx, parent)
+	return instance
 end
 
-return Reconciler
+function Reconciler:__shouldClearUnknownInstances(virtualInstance)
+	if virtualInstance.Metadata ~= nil then
+		return not virtualInstance.Metadata.ignoreUnknownInstances
+	else
+		return true
+	end
+end
+
+function Reconciler:__reify(virtualInstancesById, id, parent)
+	local virtualInstance = virtualInstancesById[id]
+
+	local instance = Instance.new(virtualInstance.ClassName)
+
+	for key, value in pairs(virtualInstance.Properties) do
+		-- TODO: Branch on value.Type
+		setProperty(instance, key, value.Value)
+	end
+
+	instance.Name = virtualInstance.Name
+
+	for _, childId in ipairs(virtualInstance.Children) do
+		self:__reify(virtualInstancesById, childId, instance)
+	end
+
+	setProperty(instance, "Parent", parent)
+	self.instanceMap:insert(id, instance)
+
+	return instance
+end
+
+function Reconciler:__applyUpdatePiece(id, visitedIds, virtualInstancesById)
+	if visitedIds[id] then
+		return
+	end
+
+	visitedIds[id] = true
+
+	local virtualInstance = virtualInstancesById[id]
+	local instance = self.instanceMap.fromIds[id]
+
+	-- The instance was deleted in this update
+	if virtualInstance == nil then
+		self.instanceMap:destroyId(id)
+		return
+	end
+
+	-- An instance we know about was updated
+	if instance ~= nil then
+		self:reconcile(virtualInstancesById, id, instance)
+		return instance
+	end
+
+	-- If the instance's parent already exists, we can stick it there
+	local parentInstance = self.instanceMap.fromIds[virtualInstance.Parent]
+	if parentInstance ~= nil then
+		self:__reify(virtualInstancesById, id, parentInstance)
+		return
+	end
+
+	-- Otherwise, we can check if this response payload contained the parent and
+	-- work from there instead.
+	local parentData = virtualInstancesById[virtualInstance.Parent]
+	if parentData ~= nil then
+		if visitedIds[virtualInstance.Parent] then
+			error("Rojo bug: An instance was present and marked as visited but its instance was missing")
+		end
+
+		self:__applyUpdatePiece(virtualInstance.Parent, visitedIds, virtualInstancesById)
+		return
+	end
+
+	Logging.trace("Instance ID %s, parent ID %s", tostring(id), tostring(virtualInstance.Parent))
+	error("Rojo NYI: Instances with parents that weren't mentioned in an update payload")
+end
+
+return Reconciler

plugin/src/RouteMap.lua

@@ -1,123 +0,0 @@
---[[
-	A map from Route objects (given by the server) to Roblox instances (created
-	by the plugin).
-]]
-
-local function hashRoute(route)
-	return table.concat(route, "/")
-end
-
-local RouteMap = {}
-RouteMap.__index = RouteMap
-
-function RouteMap.new()
-	local self = {
-		_map = {},
-		_reverseMap = {},
-		_connectionsByRbx = {},
-	}
-
-	setmetatable(self, RouteMap)
-
-	return self
-end
-
-function RouteMap:insert(route, rbx)
-	local hashed = hashRoute(route)
-
-	-- Make sure that each route and instance are only present in RouteMap once.
-	self:removeByRoute(route)
-	self:removeByRbx(rbx)
-
-	self._map[hashed] = rbx
-	self._reverseMap[rbx] = hashed
-	self._connectionsByRbx[rbx] = rbx.AncestryChanged:Connect(function(_, parent)
-		if parent == nil then
-			self:removeByRbx(rbx)
-		end
-	end)
-end
-
-function RouteMap:get(route)
-	return self._map[hashRoute(route)]
-end
-
-function RouteMap:removeByRoute(route)
-	local hashedRoute = hashRoute(route)
-	local rbx = self._map[hashedRoute]
-
-	if rbx ~= nil then
-		self:_removeInternal(rbx, hashedRoute)
-	end
-end
-
-function RouteMap:removeByRbx(rbx)
-	local hashedRoute = self._reverseMap[rbx]
-
-	if hashedRoute ~= nil then
-		self:_removeInternal(rbx, hashedRoute)
-	end
-end
-
---[[
-	Correcly removes the given Roblox Instance/Route pair from the RouteMap.
-]]
-function RouteMap:_removeInternal(rbx, hashedRoute)
-	self._map[hashedRoute] = nil
-	self._reverseMap[rbx] = nil
-	self._connectionsByRbx[rbx]:Disconnect()
-	self._connectionsByRbx[rbx] = nil
-
-	self:removeRbxDescendants(rbx)
-end
-
---[[
-	Ensure that there are no descendants of the given Roblox Instance still
-	present in the map, guaranteeing that it has been cleaned out.
-]]
-function RouteMap:_removeRbxDescendants(parentRbx)
-	for rbx in pairs(self._reverseMap) do
-		if rbx:IsDescendantOf(parentRbx) then
-			self:removeByRbx(rbx)
-		end
-	end
-end
-
---[[
-	Remove all items from the map and disconnect all connections, cleaning up
-	the RouteMap.
-]]
-function RouteMap:destruct()
-	self._map = {}
-	self._reverseMap = {}
-
-	for _, connection in pairs(self._connectionsByRbx) do
-		connection:Disconnect()
-	end
-
-	self._connectionsByRbx = {}
-end
-
-function RouteMap:visualize()
-	-- Log all of our keys so that the visualization has a stable order.
-	local keys = {}
-
-	for key in pairs(self._map) do
-		table.insert(keys, key)
-	end
-
-	table.sort(keys)
-
-	local buffer = {}
-	for _, key in ipairs(keys) do
-		local visualized = ("- %s: %s"):format(
-			key,
-			self._map[key]:GetFullName()
-		)
-		table.insert(buffer, visualized)
-	end
-
-	return table.concat(buffer, "\n")
-end
-
-return RouteMap

plugin/src/Session.lua

@@ -0,0 +1,97 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+
+local Promise = require(Rojo.Promise)
+
+local ApiContext = require(script.Parent.ApiContext)
+local Reconciler = require(script.Parent.Reconciler)
+
+local Session = {}
+Session.__index = Session
+
+function Session.new(config)
+	local remoteUrl = ("http://%s:%s"):format(config.address, config.port)
+	local api = ApiContext.new(remoteUrl)
+
+	local self = {
+		onError = config.onError,
+		disconnected = false,
+		reconciler = Reconciler.new(),
+		api = api,
+	}
+
+	api:connect()
+		:andThen(function()
+			if self.disconnected then
+				return Promise.resolve()
+			end
+
+			return api:read({api.rootInstanceId})
+				:andThen(function(response)
+					if self.disconnected then
+						return Promise.resolve()
+					end
+
+					self.reconciler:reconcile(response.instances, api.rootInstanceId, game)
+					return self:__processMessages()
+				end)
+		end)
+		:catch(function(message)
+			self.disconnected = true
+			self.onError(message)
+		end)
+
+	return not self.disconnected, setmetatable(self, Session)
+end
+
+function Session:__processMessages()
+	if self.disconnected then
+		return Promise.resolve()
+	end
+
+	return self.api:retrieveMessages()
+		:andThen(function(messages)
+			local promise = Promise.resolve(nil)
+
+			for _, message in ipairs(messages) do
+				promise = promise:andThen(function()
+					return self:__onMessage(message)
+				end)
+			end
+
+			return promise
+		end)
+		:andThen(function()
+			return self:__processMessages()
+		end)
+end
+
+function Session:__onMessage(message)
+	if self.disconnected then
+		return Promise.resolve()
+	end
+
+	local requestedIds = {}
+
+	for _, id in ipairs(message.added) do
+		table.insert(requestedIds, id)
+	end
+
+	for _, id in ipairs(message.updated) do
+		table.insert(requestedIds, id)
+	end
+
+	for _, id in ipairs(message.removed) do
+		table.insert(requestedIds, id)
+	end
+
+	return self.api:read(requestedIds)
+		:andThen(function(response)
+			return self.reconciler:applyUpdate(requestedIds, response.instances)
+		end)
+end
+
+function Session:disconnect()
+	self.disconnected = true
+end
+
+return Session

plugin/src/Version.lua

@@ -34,7 +34,13 @@ function Version.compare(a, b)
 end
 
 function Version.display(version)
-	return table.concat(version, ".")
+	local output = ("%d.%d.%d"):format(version[1], version[2], version[3])
+
+	if version[4] ~= nil then
+		output = output .. version[4]
+	end
+
+	return output
 end
 
-return Version
+return Version

plugin/src/init.server.lua

@@ -0,0 +1,19 @@
+if not plugin then
+	return
+end
+
+local Roact = require(script.Parent.Roact)
+
+Roact.setGlobalConfig({
+	elementTracing = true,
+})
+
+local App = require(script.Components.App)
+
+local app = Roact.createElement(App, {
+	plugin = plugin,
+})
+
+Roact.mount(app, game:GetService("CoreGui"), "Rojo UI")
+
+-- TODO: Detect another instance of Rojo coming online and shut down this one.

plugin/test-plugin-project.json

@@ -0,0 +1,38 @@
+{
+  "name": "rojo",
+  "tree": {
+    "$className": "DataModel",
+
+    "ReplicatedStorage": {
+      "$className": "ReplicatedStorage",
+      "Rojo": {
+        "$className": "Folder",
+        "Plugin": {
+          "$path": "src"
+        },
+        "Roact": {
+          "$path": "modules/roact/lib"
+        },
+        "Rodux": {
+          "$path": "modules/rodux/lib"
+        },
+        "RoactRodux": {
+          "$path": "modules/roact-rodux/lib"
+        },
+        "Promise": {
+          "$path": "modules/promise/lib"
+        }
+      },
+      "TestEZ": {
+        "$path": "modules/testez/lib"
+      }
+    },
+
+    "TestService": {
+      "$className": "TestService",
+      "TestBootstrap": {
+        "$path": "testBootstrap.server.lua"
+      }
+    }
+  }
+}

plugin/testBootstrap.server.lua

@@ -0,0 +1,2 @@
+local TestEZ = require(game.ReplicatedStorage.TestEZ)
+TestEZ.TestBootstrap:run(game.ReplicatedStorage.Rojo.plugin)

plugin/tests/empty.lua

@@ -0,0 +1,5 @@
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+
+local Session = require(ReplicatedStorage.Modules.Rojo.Session)
+
+Session.new()

plugin/tests/runTests.server.lua

@@ -1,2 +0,0 @@
-local TestEZ = require(game.ReplicatedStorage.TestEZ)
-TestEZ.TestBootstrap:run(game.ReplicatedStorage.Rojo.plugin)

rojo-e2e/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "rojo-e2e"
+version = "0.1.0"
+authors = ["Lucien Greathouse <me@lpghatguy.com>"]
+
+[dependencies]

rojo-e2e/README.md

@@ -0,0 +1,2 @@
+# Rojo End-to-End
+This is a WIP test runner designed for Rojo. It will eventually start up the Rojo server and plugin and test functionality end-to-end.

rojo-e2e/src/lib.rs

@@ -0,0 +1,32 @@
+use std::{
+    path::Path,
+    process::Command,
+    thread,
+    time::Duration,
+};
+
+fn main() {
+    let plugin_path = Path::new("../plugin");
+    let server_path = Path::new("../server");
+    let tests_path = Path::new("../tests");
+
+    let server = Command::new("cargo")
+        .args(&["run", "--", "serve", "../test-projects/empty"])
+        .current_dir(server_path)
+        .spawn();
+
+    thread::sleep(Duration::from_millis(1000));
+
+    // TODO: Wait for server to start responding on the right port
+
+    let test_client = Command::new("lua")
+        .args(&["runTest.lua", "tests/empty.lua"])
+        .current_dir(plugin_path)
+        .spawn();
+
+    thread::sleep(Duration::from_millis(300));
+
+    // TODO: Collect output from the client for success/failure?
+
+    println!("Dying!");
+}

server/.editorconfig

@@ -1,5 +0,0 @@
-[*.rs]
-indent_style = space
-indent_size = 4
-trim_trailing_whitespace = true
-insert_final_newline = true

server/.gitignore

@@ -1,2 +0,0 @@
-/target/
-**/*.rs.bk

server/Cargo.toml

@@ -1,22 +1,45 @@
 [package]
 name = "rojo"
-version = "0.4.8"
+version = "0.5.0-alpha.0"
 authors = ["Lucien Greathouse <me@lpghatguy.com>"]
 description = "A tool to create robust Roblox projects"
 license = "MIT"
 repository = "https://github.com/LPGhatguy/rojo"
+edition = "2018"
+
+[lib]
+name = "librojo"
+path = "src/lib.rs"
 
 [[bin]]
 name = "rojo"
 path = "src/bin.rs"
 
+[features]
+default = []
+bundle-plugin = []
+
 [dependencies]
-clap = "2.27.1"
-rouille = "2.1.0"
+clap = "2.27"
+csv = "1.0"
+env_logger = "0.5"
+failure = "0.1.3"
+log = "0.4"
+maplit = "1.0.1"
+notify = "4.0"
+rand = "0.4"
+regex = "1.0"
+reqwest = "0.9.5"
+rouille = "2.1"
 serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
-notify = "4.0.0"
-rand = "0.3"
-regex = "0.2"
-lazy_static = "1.0"
+uuid = { version = "0.7", features = ["v4", "serde"] }
+rbx_tree = "0.1.0"
+rbx_xml = "0.1.0"
+rbx_binary = "0.1.0"
+
+[dev-dependencies]
+tempfile = "3.0"
+walkdir = "2.1"
+lazy_static = "1.2"

server/README.md

@@ -0,0 +1,4 @@
+# Rojo Server
+This is the source to the Rojo server.
+
+Documentation is WIP.

server/src/bin.rs

@@ -1,30 +1,30 @@
-#[macro_use] extern crate serde_derive;
-#[macro_use] extern crate rouille;
-#[macro_use] extern crate clap;
-#[macro_use] extern crate lazy_static;
-extern crate notify;
-extern crate rand;
-extern crate serde;
-extern crate serde_json;
-extern crate regex;
+#[macro_use] extern crate log;
 
-pub mod web;
-pub mod core;
-pub mod project;
-pub mod pathext;
-pub mod vfs;
-pub mod rbx;
-pub mod plugin;
-pub mod plugins;
-pub mod commands;
+use std::{
+    path::{Path, PathBuf},
+    env,
+    process,
+};
 
-use std::path::{Path, PathBuf};
-use std::process;
+use clap::clap_app;
 
-use pathext::canonicalish;
+use librojo::commands;
+
+fn make_path_absolute(value: &Path) -> PathBuf {
+    if value.is_absolute() {
+        PathBuf::from(value)
+    } else {
+        let current_dir = env::current_dir().unwrap();
+        current_dir.join(value)
+    }
+}
 
 fn main() {
-    let matches = clap_app!(rojo =>
+    env_logger::Builder::from_default_env()
+        .default_format_timestamp(false)
+        .init();
+
+    let mut app = clap_app!(Rojo =>
         (version: env!("CARGO_PKG_VERSION"))
         (author: env!("CARGO_PKG_AUTHORS"))
         (about: env!("CARGO_PKG_DESCRIPTION"))
@@ -32,6 +32,7 @@ fn main() {
         (@subcommand init =>
             (about: "Creates a new Rojo project")
             (@arg PATH: "Path to the place to create the project. Defaults to the current directory.")
+            (@arg kind: --kind +takes_value "The kind of project to create, 'place' or 'model'. Defaults to place.")
         )
 
         (@subcommand serve =>
@@ -40,58 +41,132 @@ fn main() {
             (@arg port: --port +takes_value "The port to listen on. Defaults to 8000.")
         )
 
-        (@subcommand pack =>
-            (about: "Packs the project into a GUI installer bundle. NOT YET IMPLEMENTED!")
-            (@arg PROJECT: "Path to the project to pack. Defaults to the current directory.")
+        (@subcommand build =>
+            (about: "Generates an rbxmx model file from the project.")
+            (@arg PROJECT: "Path to the project to serve. Defaults to the current directory.")
+            (@arg output: --output -o +takes_value +required "Where to output the result.")
         )
 
-        (@arg verbose: --verbose "Enable extended logging.")
-    ).get_matches();
+        (@subcommand upload =>
+            (about: "Generates a place or model file out of the project and uploads it to Roblox.")
+            (@arg PROJECT: "Path to the project to upload. Defaults to the current directory.")
+            (@arg kind: --kind +takes_value "The kind of asset to generate, 'place', or 'model'. Defaults to place.")
+            (@arg cookie: --cookie +takes_value +required "Security cookie to authenticate with.")
+            (@arg asset_id: --asset_id +takes_value +required "Asset ID to upload to.")
+        )
+    );
 
-    let verbose = match matches.occurrences_of("verbose") {
-        0 => false,
-        _ => true,
-    };
+    // `get_matches` consumes self for some reason.
+    let matches = app.clone().get_matches();
 
     match matches.subcommand() {
-        ("init", sub_matches) => {
-            let sub_matches = sub_matches.unwrap();
-            let project_path = Path::new(sub_matches.value_of("PATH").unwrap_or("."));
-            let full_path = canonicalish(project_path);
+        ("init", Some(sub_matches)) => {
+            let fuzzy_project_path = make_path_absolute(Path::new(sub_matches.value_of("PATH").unwrap_or("")));
+            let kind = sub_matches.value_of("kind");
 
-            commands::init(&full_path);
+            let options = commands::InitOptions {
+                fuzzy_project_path,
+                kind,
+            };
+
+            match commands::init(&options) {
+                Ok(_) => {},
+                Err(e) => {
+                    error!("{}", e);
+                    process::exit(1);
+                },
+            }
         },
-        ("serve", sub_matches) => {
-            let sub_matches = sub_matches.unwrap();
-
-            let project_path = match sub_matches.value_of("PROJECT") {
-                Some(v) => canonicalish(PathBuf::from(v)),
+        ("serve", Some(sub_matches)) => {
+            let fuzzy_project_path = match sub_matches.value_of("PROJECT") {
+                Some(v) => make_path_absolute(Path::new(v)),
                 None => std::env::current_dir().unwrap(),
             };
 
-            let port = {
-                match sub_matches.value_of("port") {
-                    Some(source) => match source.parse::<u64>() {
-                        Ok(value) => Some(value),
-                        Err(_) => {
-                            eprintln!("Invalid port '{}'", source);
-                            process::exit(1);
-                        },
+            let port = match sub_matches.value_of("port") {
+                Some(v) => match v.parse::<u16>() {
+                    Ok(port) => Some(port),
+                    Err(_) => {
+                        error!("Invalid port {}", v);
+                        process::exit(1);
+                    },
+                },
+                None => None,
+            };
+
+            let options = commands::ServeOptions {
+                fuzzy_project_path,
+                port,
+            };
+
+            match commands::serve(&options) {
+                Ok(_) => {},
+                Err(e) => {
+                    error!("{}", e);
+                    process::exit(1);
+                },
+            }
+        },
+        ("build", Some(sub_matches)) => {
+            let fuzzy_project_path = match sub_matches.value_of("PROJECT") {
+                Some(v) => make_path_absolute(Path::new(v)),
+                None => std::env::current_dir().unwrap(),
+            };
+
+            let output_file = make_path_absolute(Path::new(sub_matches.value_of("output").unwrap()));
+
+            let options = commands::BuildOptions {
+                fuzzy_project_path,
+                output_file,
+                output_kind: None, // TODO: Accept from argument
+            };
+
+            match commands::build(&options) {
+                Ok(_) => {},
+                Err(e) => {
+                    error!("{}", e);
+                    process::exit(1);
+                },
+            }
+        },
+        ("upload", Some(sub_matches)) => {
+            let fuzzy_project_path = match sub_matches.value_of("PROJECT") {
+                Some(v) => make_path_absolute(Path::new(v)),
+                None => std::env::current_dir().unwrap(),
+            };
+
+            let kind = sub_matches.value_of("kind");
+            let security_cookie = sub_matches.value_of("cookie").unwrap();
+
+            let asset_id: u64 = {
+                let arg = sub_matches.value_of("asset_id").unwrap();
+
+                match arg.parse() {
+                    Ok(v) => v,
+                    Err(_) => {
+                        error!("Invalid place ID {}", arg);
+                        process::exit(1);
                     },
-                    None => None,
                 }
             };
 
-            commands::serve(&project_path, verbose, port);
-        },
-        ("pack", _) => {
-            eprintln!("'rojo pack' is not yet implemented!");
-            process::exit(1);
+            let options = commands::UploadOptions {
+                fuzzy_project_path,
+                security_cookie: security_cookie.to_string(),
+                asset_id,
+                kind,
+            };
+
+            match commands::upload(&options) {
+                Ok(_) => {},
+                Err(e) => {
+                    error!("{}", e);
+                    process::exit(1);
+                },
+            }
         },
         _ => {
-            eprintln!("Please specify a subcommand!");
-            eprintln!("Try 'rojo help' for information.");
-            process::exit(1);
+            app.print_help().expect("Could not print help text to stdout!");
         },
     }
-}
+}

server/src/commands/build.rs

@@ -0,0 +1,131 @@
+use std::{
+    path::PathBuf,
+    fs::File,
+    io,
+};
+
+use failure::Fail;
+
+use crate::{
+    rbx_session::construct_oneoff_tree,
+    project::{Project, ProjectLoadFuzzyError},
+    imfs::Imfs,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum OutputKind {
+    Rbxmx,
+    Rbxlx,
+    Rbxm,
+    Rbxl,
+}
+
+fn detect_output_kind(options: &BuildOptions) -> Option<OutputKind> {
+    let extension = options.output_file.extension()?.to_str()?;
+
+    match extension {
+        "rbxlx" => Some(OutputKind::Rbxlx),
+        "rbxmx" => Some(OutputKind::Rbxmx),
+        "rbxl" => Some(OutputKind::Rbxl),
+        "rbxm" => Some(OutputKind::Rbxm),
+        _ => None,
+    }
+}
+
+#[derive(Debug)]
+pub struct BuildOptions {
+    pub fuzzy_project_path: PathBuf,
+    pub output_file: PathBuf,
+    pub output_kind: Option<OutputKind>,
+}
+
+#[derive(Debug, Fail)]
+pub enum BuildError {
+    #[fail(display = "Could not detect what kind of file to create")]
+    UnknownOutputKind,
+
+    #[fail(display = "Project load error: {}", _0)]
+    ProjectLoadError(#[fail(cause)] ProjectLoadFuzzyError),
+
+    #[fail(display = "IO error: {}", _0)]
+    IoError(#[fail(cause)] io::Error),
+
+    #[fail(display = "XML model file error")]
+    XmlModelEncodeError(rbx_xml::EncodeError),
+
+    #[fail(display = "Binary model file error")]
+    BinaryModelEncodeError(rbx_binary::EncodeError)
+}
+
+impl From<ProjectLoadFuzzyError> for BuildError {
+    fn from(error: ProjectLoadFuzzyError) -> BuildError {
+        BuildError::ProjectLoadError(error)
+    }
+}
+
+impl From<io::Error> for BuildError {
+    fn from(error: io::Error) -> BuildError {
+        BuildError::IoError(error)
+    }
+}
+
+impl From<rbx_xml::EncodeError> for BuildError {
+    fn from(error: rbx_xml::EncodeError) -> BuildError {
+        BuildError::XmlModelEncodeError(error)
+    }
+}
+
+impl From<rbx_binary::EncodeError> for BuildError {
+    fn from(error: rbx_binary::EncodeError) -> BuildError {
+        BuildError::BinaryModelEncodeError(error)
+    }
+}
+
+pub fn build(options: &BuildOptions) -> Result<(), BuildError> {
+    let output_kind = options.output_kind
+        .or_else(|| detect_output_kind(options))
+        .ok_or(BuildError::UnknownOutputKind)?;
+
+    info!("Hoping to generate file of type {:?}", output_kind);
+
+    info!("Looking for project at {}", options.fuzzy_project_path.display());
+
+    let project = Project::load_fuzzy(&options.fuzzy_project_path)?;
+
+    info!("Found project at {}", project.file_location.display());
+    info!("Using project {:#?}", project);
+
+    let mut imfs = Imfs::new();
+    imfs.add_roots_from_project(&project)?;
+    let tree = construct_oneoff_tree(&project, &imfs);
+    let mut file = File::create(&options.output_file)?;
+
+    match output_kind {
+        OutputKind::Rbxmx => {
+            // Model files include the root instance of the tree and all its
+            // descendants.
+
+            let root_id = tree.get_root_id();
+            rbx_xml::encode(&tree, &[root_id], &mut file)?;
+        },
+        OutputKind::Rbxlx => {
+            // Place files don't contain an entry for the DataModel, but our
+            // RbxTree representation does.
+
+            let root_id = tree.get_root_id();
+            let top_level_ids = tree.get_instance(root_id).unwrap().get_children_ids();
+            rbx_xml::encode(&tree, top_level_ids, &mut file)?;
+        },
+        OutputKind::Rbxm => {
+            let root_id = tree.get_root_id();
+            rbx_binary::encode(&tree, &[root_id], &mut file)?;
+        },
+        OutputKind::Rbxl => {
+            let root_id = tree.get_root_id();
+            let top_level_ids = tree.get_instance(root_id).unwrap().get_children_ids();
+            rbx_binary::encode(&tree, top_level_ids, &mut file)?;
+        },
+    }
+
+    Ok(())
+}

server/src/commands/init.rs

@@ -1,16 +1,46 @@
-use std::path::PathBuf;
-use std::process;
+use std::{
+    path::PathBuf,
+};
 
-use project::Project;
+use failure::Fail;
 
-pub fn init(project_path: &PathBuf) {
-    match Project::init(project_path) {
-        Ok(_) => {
-            println!("Created new empty project at {}", project_path.display());
-        },
-        Err(e) => {
-            eprintln!("Failed to create new project.\n{}", e);
-            process::exit(1);
-        },
+use crate::project::{Project, ProjectInitError};
+
+#[derive(Debug, Fail)]
+pub enum InitError {
+    #[fail(display = "Invalid project kind '{}', valid kinds are 'place' and 'model'", _0)]
+    InvalidKind(String),
+
+    #[fail(display = "Project init error: {}", _0)]
+    ProjectInitError(#[fail(cause)] ProjectInitError)
+}
+
+impl From<ProjectInitError> for InitError {
+    fn from(error: ProjectInitError) -> InitError {
+        InitError::ProjectInitError(error)
     }
 }
+
+#[derive(Debug)]
+pub struct InitOptions<'a> {
+    pub fuzzy_project_path: PathBuf,
+    pub kind: Option<&'a str>,
+}
+
+pub fn init(options: &InitOptions) -> Result<(), InitError> {
+    let (project_path, project_kind) = match options.kind {
+        Some("place") | None => {
+            let path = Project::init_place(&options.fuzzy_project_path)?;
+            (path, "place")
+        },
+        Some("model") => {
+            let path = Project::init_model(&options.fuzzy_project_path)?;
+            (path, "model")
+        },
+        Some(invalid) => return Err(InitError::InvalidKind(invalid.to_string())),
+    };
+
+    println!("Created new {} project file at {}", project_kind, project_path.display());
+
+    Ok(())
+}

server/src/commands/mod.rs

@@ -1,5 +1,9 @@
 mod serve;
 mod init;
+mod build;
+mod upload;
 
 pub use self::serve::*;
 pub use self::init::*;
+pub use self::build::*;
+pub use self::upload::*;

server/src/commands/serve.rs

@@ -1,98 +1,54 @@
-use std::path::{Path, PathBuf};
-use std::process;
-use std::sync::{Arc, Mutex};
-use std::thread;
+use std::{
+    path::PathBuf,
+    sync::Arc,
+};
 
-use rand;
+use failure::Fail;
 
-use project::{Project, ProjectLoadError};
-use plugin::{PluginChain};
-use plugins::{DefaultPlugin, JsonModelPlugin, ScriptPlugin};
-use vfs::{VfsSession, VfsWatcher};
-use web;
+use crate::{
+    project::{Project, ProjectLoadFuzzyError},
+    web::Server,
+    session::Session,
+};
 
-pub fn serve(project_path: &PathBuf, verbose: bool, port: Option<u64>) {
-    let server_id = rand::random::<u64>();
+const DEFAULT_PORT: u16 = 34872;
 
-    let project = match Project::load(project_path) {
-        Ok(project) => {
-            println!("Using project \"{}\" from {}", project.name, project_path.display());
-            project
-        },
-        Err(err) => {
-            match err {
-                ProjectLoadError::InvalidJson(serde_err) => {
-                    eprintln!("Project contained invalid JSON!");
-                    eprintln!("{}", project_path.display());
-                    eprintln!("Error: {}", serde_err);
-
-                    process::exit(1);
-                },
-                ProjectLoadError::FailedToOpen | ProjectLoadError::FailedToRead => {
-                    eprintln!("Found project file, but failed to read it!");
-                    eprintln!("Check the permissions of the project file at {}", project_path.display());
-
-                    process::exit(1);
-                },
-                ProjectLoadError::DidNotExist => {
-                    eprintln!("Found no project file! Create one using 'rojo init'");
-                    eprintln!("Checked for a project at {}", project_path.display());
-
-                    process::exit(1);
-                },
-            }
-        },
-    };
-
-    if project.partitions.len() == 0 {
-        println!("");
-        println!("This project has no partitions and will not do anything when served!");
-        println!("This is usually a mistake -- edit rojo.json!");
-        println!("");
-    }
-
-    lazy_static! {
-        static ref PLUGIN_CHAIN: PluginChain = PluginChain::new(vec![
-            Box::new(ScriptPlugin::new()),
-            Box::new(JsonModelPlugin::new()),
-            Box::new(DefaultPlugin::new()),
-        ]);
-    }
-
-    let vfs = {
-        let mut vfs = VfsSession::new(&PLUGIN_CHAIN);
-
-        for (name, project_partition) in &project.partitions {
-            let path = {
-                let given_path = Path::new(&project_partition.path);
-
-                if given_path.is_absolute() {
-                    given_path.to_path_buf()
-                } else {
-                    project_path.join(given_path)
-                }
-            };
-
-            vfs.insert_partition(name, path);
-        }
-
-        Arc::new(Mutex::new(vfs))
-    };
-
-    {
-        let vfs = vfs.clone();
-        thread::spawn(move || {
-            VfsWatcher::new(vfs).start();
-        });
-    }
-
-    let web_config = web::WebConfig {
-        verbose,
-        port: port.unwrap_or(project.serve_port),
-        server_id,
-    };
-
-    println!("Server listening on port {}", web_config.port);
-
-    web::start(web_config, project.clone(), &PLUGIN_CHAIN, vfs.clone());
+#[derive(Debug)]
+pub struct ServeOptions {
+    pub fuzzy_project_path: PathBuf,
+    pub port: Option<u16>,
 }
+
+#[derive(Debug, Fail)]
+pub enum ServeError {
+   #[fail(display = "Project load error: {}", _0)]
+   ProjectLoadError(#[fail(cause)] ProjectLoadFuzzyError),
+}
+
+impl From<ProjectLoadFuzzyError> for ServeError {
+    fn from(error: ProjectLoadFuzzyError) -> ServeError {
+        ServeError::ProjectLoadError(error)
+    }
+}
+
+pub fn serve(options: &ServeOptions) -> Result<(), ServeError> {
+    info!("Looking for project at {}", options.fuzzy_project_path.display());
+
+    let project = Arc::new(Project::load_fuzzy(&options.fuzzy_project_path)?);
+
+    info!("Found project at {}", project.file_location.display());
+    info!("Using project {:#?}", project);
+
+    let session = Arc::new(Session::new(Arc::clone(&project)).unwrap());
+    let server = Server::new(Arc::clone(&session));
+
+    let port = options.port
+        .or(project.serve_port)
+        .unwrap_or(DEFAULT_PORT);
+
+    println!("Rojo server listening on port {}", port);
+
+    server.listen(port);
+
+    Ok(())
+}

server/src/commands/upload.rs

@@ -0,0 +1,114 @@
+use std::{
+    path::PathBuf,
+    io,
+};
+
+use failure::Fail;
+
+use reqwest::header::{ACCEPT, USER_AGENT, CONTENT_TYPE, COOKIE};
+
+use crate::{
+    rbx_session::construct_oneoff_tree,
+    project::{Project, ProjectLoadFuzzyError},
+    imfs::Imfs,
+};
+
+#[derive(Debug, Fail)]
+pub enum UploadError {
+    #[fail(display = "Roblox API Error: {}", _0)]
+    RobloxApiError(String),
+
+    #[fail(display = "Invalid asset kind: {}", _0)]
+    InvalidKind(String),
+
+    #[fail(display = "Project load error: {}", _0)]
+    ProjectLoadError(#[fail(cause)] ProjectLoadFuzzyError),
+
+    #[fail(display = "IO error: {}", _0)]
+    IoError(#[fail(cause)] io::Error),
+
+    #[fail(display = "HTTP error: {}", _0)]
+    HttpError(#[fail(cause)] reqwest::Error),
+
+    #[fail(display = "XML model file error")]
+    XmlModelEncodeError(rbx_xml::EncodeError),
+}
+
+impl From<ProjectLoadFuzzyError> for UploadError {
+    fn from(error: ProjectLoadFuzzyError) -> UploadError {
+        UploadError::ProjectLoadError(error)
+    }
+}
+
+impl From<io::Error> for UploadError {
+    fn from(error: io::Error) -> UploadError {
+        UploadError::IoError(error)
+    }
+}
+
+impl From<reqwest::Error> for UploadError {
+    fn from(error: reqwest::Error) -> UploadError {
+        UploadError::HttpError(error)
+    }
+}
+
+impl From<rbx_xml::EncodeError> for UploadError {
+    fn from(error: rbx_xml::EncodeError) -> UploadError {
+        UploadError::XmlModelEncodeError(error)
+    }
+}
+
+#[derive(Debug)]
+pub struct UploadOptions<'a> {
+    pub fuzzy_project_path: PathBuf,
+    pub security_cookie: String,
+    pub asset_id: u64,
+    pub kind: Option<&'a str>,
+}
+
+pub fn upload(options: &UploadOptions) -> Result<(), UploadError> {
+    // TODO: Switch to uploading binary format?
+
+    info!("Looking for project at {}", options.fuzzy_project_path.display());
+
+    let project = Project::load_fuzzy(&options.fuzzy_project_path)?;
+
+    info!("Found project at {}", project.file_location.display());
+    info!("Using project {:#?}", project);
+
+    let mut imfs = Imfs::new();
+    imfs.add_roots_from_project(&project)?;
+    let tree = construct_oneoff_tree(&project, &imfs);
+
+    let root_id = tree.get_root_id();
+    let mut contents = Vec::new();
+
+    match options.kind {
+        Some("place") | None => {
+            let top_level_ids = tree.get_instance(root_id).unwrap().get_children_ids();
+            rbx_xml::encode(&tree, top_level_ids, &mut contents)?;
+        },
+        Some("model") => {
+            rbx_xml::encode(&tree, &[root_id], &mut contents)?;
+        },
+        Some(invalid) => return Err(UploadError::InvalidKind(invalid.to_owned())),
+    }
+
+    let url = format!("https://data.roblox.com/Data/Upload.ashx?assetid={}", options.asset_id);
+
+    let client = reqwest::Client::new();
+    let mut response = client.post(&url)
+        .header(COOKIE, format!(".ROBLOSECURITY={}", &options.security_cookie))
+        .header(USER_AGENT, "Roblox/WinInet")
+        .header("Requester", "Client")
+        .header(CONTENT_TYPE, "application/xml")
+        .header(ACCEPT, "application/json")
+        .body(contents)
+        .send()?;
+
+    if !response.status().is_success() {
+        return Err(UploadError::RobloxApiError(response.text()?));
+    }
+
+    Ok(())
+}

server/src/core.rs

@@ -1 +0,0 @@
-pub type Route = Vec<String>;

server/src/fs_watcher.rs

@@ -0,0 +1,115 @@
+use std::{
+    sync::{mpsc, Arc, Mutex},
+    time::Duration,
+    thread,
+};
+
+use notify::{
+    self,
+    DebouncedEvent,
+    RecommendedWatcher,
+    RecursiveMode,
+    Watcher,
+};
+
+use crate::{
+    imfs::Imfs,
+    rbx_session::RbxSession,
+};
+
+const WATCH_TIMEOUT: Duration = Duration::from_millis(100);
+
+fn handle_event(imfs: &Mutex<Imfs>, rbx_session: &Mutex<RbxSession>, event: DebouncedEvent) {
+    match event {
+        DebouncedEvent::Create(path) => {
+            {
+                let mut imfs = imfs.lock().unwrap();
+                imfs.path_created(&path).unwrap();
+            }
+
+            {
+                let mut rbx_session = rbx_session.lock().unwrap();
+                rbx_session.path_created(&path);
+            }
+        },
+        DebouncedEvent::Write(path) => {
+            {
+                let mut imfs = imfs.lock().unwrap();
+                imfs.path_updated(&path).unwrap();
+            }
+
+            {
+                let mut rbx_session = rbx_session.lock().unwrap();
+                rbx_session.path_updated(&path);
+            }
+        },
+        DebouncedEvent::Remove(path) => {
+            {
+                let mut imfs = imfs.lock().unwrap();
+                imfs.path_removed(&path).unwrap();
+            }
+
+            {
+                let mut rbx_session = rbx_session.lock().unwrap();
+                rbx_session.path_removed(&path);
+            }
+        },
+        DebouncedEvent::Rename(from_path, to_path) => {
+            {
+                let mut imfs = imfs.lock().unwrap();
+                imfs.path_moved(&from_path, &to_path).unwrap();
+            }
+
+            {
+                let mut rbx_session = rbx_session.lock().unwrap();
+                rbx_session.path_renamed(&from_path, &to_path);
+            }
+        },
+        _ => {},
+    }
+}
+
+/// Watches for changes on the filesystem and links together the in-memory
+/// filesystem and in-memory Roblox tree.
+pub struct FsWatcher {
+    #[allow(unused)]
+    watchers: Vec<RecommendedWatcher>,
+}
+
+impl FsWatcher {
+    pub fn start(imfs: Arc<Mutex<Imfs>>, rbx_session: Arc<Mutex<RbxSession>>) -> FsWatcher {
+        let mut watchers = Vec::new();
+
+        {
+            let imfs_temp = imfs.lock().unwrap();
+
+            for root_path in imfs_temp.get_roots() {
+                let (watch_tx, watch_rx) = mpsc::channel();
+
+                let mut watcher = notify::watcher(watch_tx, WATCH_TIMEOUT)
+                    .expect("Could not create `notify` watcher");
+
+                watcher.watch(root_path, RecursiveMode::Recursive)
+                    .expect("Could not watch directory");
+
+                watchers.push(watcher);
+
+                let imfs = Arc::clone(&imfs);
+                let rbx_session = Arc::clone(&rbx_session);
+                let root_path = root_path.clone();
+
+                thread::spawn(move || {
+                    info!("Watcher thread ({}) started", root_path.display());
+                    while let Ok(event) = watch_rx.recv() {
+                        handle_event(&imfs, &rbx_session, event);
+                    }
+                    info!("Watcher thread ({}) stopped", root_path.display());
+                });
+            }
+        }
+
+        FsWatcher {
+            watchers,
+        }
+    }
+}

server/src/imfs.rs

@@ -0,0 +1,223 @@
+use std::{
+    collections::{HashMap, HashSet},
+    path::{Path, PathBuf},
+    fs,
+    io,
+};
+
+use crate::project::{Project, ProjectNode};
+
+fn add_sync_points(imfs: &mut Imfs, project_node: &ProjectNode) -> io::Result<()> {
+    match project_node {
+        ProjectNode::Instance(node) => {
+            for child in node.children.values() {
+                add_sync_points(imfs, child)?;
+            }
+        },
+        ProjectNode::SyncPoint(node) => {
+            imfs.add_root(&node.path)?;
+        },
+    }
+
+    Ok(())
+}
+
+/// The in-memory filesystem keeps a mirror of all files being watcher by Rojo
+/// in order to deduplicate file changes in the case of bidirectional syncing
+/// from Roblox Studio.
+#[derive(Debug, Clone)]
+pub struct Imfs {
+    items: HashMap<PathBuf, ImfsItem>,
+    roots: HashSet<PathBuf>,
+}
+
+impl Imfs {
+    pub fn new() -> Imfs {
+        Imfs {
+            items: HashMap::new(),
+            roots: HashSet::new(),
+        }
+    }
+
+    pub fn add_roots_from_project(&mut self, project: &Project) -> io::Result<()> {
+        add_sync_points(self, &project.tree)
+    }
+
+    pub fn get_roots(&self) -> &HashSet<PathBuf> {
+        &self.roots
+    }
+
+    pub fn get_items(&self) -> &HashMap<PathBuf, ImfsItem> {
+        &self.items
+    }
+
+    pub fn get(&self, path: &Path) -> Option<&ImfsItem> {
+        debug_assert!(path.is_absolute());
+        debug_assert!(self.is_within_roots(path));
+
+        self.items.get(path)
+    }
+
+    pub fn add_root(&mut self, path: &Path) -> io::Result<()> {
+        debug_assert!(path.is_absolute());
+        debug_assert!(!self.is_within_roots(path));
+
+        self.roots.insert(path.to_path_buf());
+
+        self.read_from_disk(path)
+    }
+
+    pub fn path_created(&mut self, path: &Path) -> io::Result<()> {
+        debug_assert!(path.is_absolute());
+        debug_assert!(self.is_within_roots(path));
+
+        self.read_from_disk(path)
+    }
+
+    pub fn path_updated(&mut self, path: &Path) -> io::Result<()> {
+        debug_assert!(path.is_absolute());
+        debug_assert!(self.is_within_roots(path));
+
+        self.read_from_disk(path)
+    }
+
+    pub fn path_removed(&mut self, path: &Path) -> io::Result<()> {
+        debug_assert!(path.is_absolute());
+        debug_assert!(self.is_within_roots(path));
+
+        self.remove_item(path);
+
+        if let Some(parent_path) = path.parent() {
+            self.unlink_child(parent_path, path);
+        }
+
+        Ok(())
+    }
+
+    pub fn path_moved(&mut self, from_path: &Path, to_path: &Path) -> io::Result<()> {
+        debug_assert!(from_path.is_absolute());
+        debug_assert!(self.is_within_roots(from_path));
+        debug_assert!(to_path.is_absolute());
+        debug_assert!(self.is_within_roots(to_path));
+
+        self.path_removed(from_path)?;
+        self.path_created(to_path)?;
+        Ok(())
+    }
+
+    pub fn get_root_for_path<'a>(&'a self, path: &Path) -> Option<&'a Path> {
+        for root_path in &self.roots {
+            if path.starts_with(root_path) {
+                return Some(root_path);
+            }
+        }
+
+        None
+    }
+
+    fn remove_item(&mut self, path: &Path) {
+        if let Some(ImfsItem::Directory(directory)) = self.items.remove(path) {
+            for child_path in &directory.children {
+                self.remove_item(child_path);
+            }
+        }
+    }
+
+    fn unlink_child(&mut self, parent: &Path, child: &Path) {
+        let parent_item = self.items.get_mut(parent);
+
+        match parent_item {
+            Some(ImfsItem::Directory(directory)) => {
+                directory.children.remove(child);
+            },
+            _ => {
+                panic!("Tried to unlink child of path that wasn't a directory!");
+            },
+        }
+    }
+
+    fn link_child(&mut self, parent: &Path, child: &Path) {
+        if self.is_within_roots(parent) {
+            let parent_item = self.items.get_mut(parent);
+
+            match parent_item {
+                Some(ImfsItem::Directory(directory)) => {
+                    directory.children.insert(child.to_path_buf());
+                },
+                _ => {
+                    panic!("Tried to link child of path that wasn't a directory!");
+                },
+            }
+        }
+    }
+
+    fn read_from_disk(&mut self, path: &Path) -> io::Result<()> {
+        let metadata = fs::metadata(path)?;
+
+        if metadata.is_file() {
+            let contents = fs::read(path)?;
+            let item = ImfsItem::File(ImfsFile {
+                path: path.to_path_buf(),
+                contents,
+            });
+
+            self.items.insert(path.to_path_buf(), item);
+
+            if let Some(parent_path) = path.parent() {
+                self.link_child(parent_path, path);
+            }
+
+            Ok(())
+        } else if metadata.is_dir() {
+            let item = ImfsItem::Directory(ImfsDirectory {
+                path: path.to_path_buf(),
+                children: HashSet::new(),
+            });
+
+            self.items.insert(path.to_path_buf(), item);
+
+            for entry in fs::read_dir(path)? {
+                let entry = entry?;
+                let child_path = entry.path();
+
+                self.read_from_disk(&child_path)?;
+            }
+
+            if let Some(parent_path) = path.parent() {
+                self.link_child(parent_path, path);
+            }
+
+            Ok(())
+        } else {
+            panic!("Unexpected non-file, non-directory item");
+        }
+    }
+
+    fn is_within_roots(&self, path: &Path) -> bool {
+        for root_path in &self.roots {
+            if path.starts_with(root_path) {
+                return true;
+            }
+        }
+
+        false
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct ImfsFile {
+    pub path: PathBuf,
+    pub contents: Vec<u8>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct ImfsDirectory {
+    pub path: PathBuf,
+    pub children: HashSet<PathBuf>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum ImfsItem {
+    File(ImfsFile),
+    Directory(ImfsDirectory),
+}

server/src/lib.rs

@@ -0,0 +1,23 @@
+#[macro_use]
+extern crate log;
+
+#[macro_use]
+extern crate serde_derive;
+
+#[cfg(test)]
+extern crate tempfile;
+
+// pub mod roblox_studio;
+pub mod commands;
+pub mod fs_watcher;
+pub mod imfs;
+pub mod message_queue;
+pub mod path_map;
+pub mod project;
+pub mod rbx_session;
+pub mod rbx_snapshot;
+pub mod session;
+pub mod session_id;
+pub mod visualize;
+pub mod web;
+pub mod web_util;

server/src/message_queue.rs

@@ -0,0 +1,79 @@
+use std::{
+    collections::HashMap,
+    sync::{
+        mpsc,
+        atomic::{AtomicUsize, Ordering},
+        RwLock,
+        Mutex,
+    },
+};
+
+/// A unique identifier, not guaranteed to be generated in any order.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ListenerId(usize);
+
+/// Generate a new ID, which has no defined ordering.
+pub fn get_listener_id() -> ListenerId {
+    static LAST_ID: AtomicUsize = AtomicUsize::new(0);
+
+    ListenerId(LAST_ID.fetch_add(1, Ordering::SeqCst))
+}
+
+#[derive(Default)]
+pub struct MessageQueue<T> {
+   messages: RwLock<Vec<T>>,
+   message_listeners: Mutex<HashMap<ListenerId, mpsc::Sender<()>>>,
+}
+
+impl<T: Clone> MessageQueue<T> {
+    pub fn new() -> MessageQueue<T> {
+        MessageQueue {
+            messages: RwLock::new(Vec::new()),
+            message_listeners: Mutex::new(HashMap::new()),
+        }
+    }
+
+    pub fn push_messages(&self, new_messages: &[T]) {
+        let message_listeners = self.message_listeners.lock().unwrap();
+
+        {
+            let mut messages = self.messages.write().unwrap();
+            messages.extend_from_slice(new_messages);
+        }
+
+        for listener in message_listeners.values() {
+            listener.send(()).unwrap();
+        }
+    }
+
+    pub fn subscribe(&self, sender: mpsc::Sender<()>) -> ListenerId {
+        let id = get_listener_id();
+
+        let mut message_listeners = self.message_listeners.lock().unwrap();
+        message_listeners.insert(id, sender);
+
+        id
+    }
+
+    pub fn unsubscribe(&self, id: ListenerId) {
+        let mut message_listeners = self.message_listeners.lock().unwrap();
+        message_listeners.remove(&id);
+    }
+
+    pub fn get_message_cursor(&self) -> u32 {
+        self.messages.read().unwrap().len() as u32
+    }
+
+    pub fn get_messages_since(&self, cursor: u32) -> (u32, Vec<T>) {
+        let messages = self.messages.read().unwrap();
+
+        let current_cursor = messages.len() as u32;
+
+        // Cursor is out of bounds or there are no new messages
+        if cursor >= current_cursor {
+            return (current_cursor, Vec::new());
+        }
+
+        (current_cursor, messages[(cursor as usize)..].to_vec())
+    }
+}

server/src/path_map.rs

@@ -0,0 +1,96 @@
+use std::{
+    path::{self, Path, PathBuf},
+    collections::{HashMap, HashSet},
+};
+
+#[derive(Debug, Serialize)]
+struct PathMapNode<T> {
+    value: T,
+    children: HashSet<PathBuf>,
+}
+
+/// A map from paths to instance IDs, with a bit of additional data that enables
+/// removing a path and all of its child paths from the tree more quickly.
+#[derive(Debug, Serialize)]
+pub struct PathMap<T> {
+    nodes: HashMap<PathBuf, PathMapNode<T>>,
+}
+
+impl<T> PathMap<T> {
+    pub fn new() -> PathMap<T> {
+        PathMap {
+            nodes: HashMap::new(),
+        }
+    }
+
+    pub fn get(&self, path: &Path) -> Option<&T> {
+        self.nodes.get(path).map(|v| &v.value)
+    }
+
+    pub fn insert(&mut self, path: PathBuf, value: T) {
+        if let Some(parent_path) = path.parent() {
+            if let Some(parent) = self.nodes.get_mut(parent_path) {
+                parent.children.insert(path.to_path_buf());
+            }
+        }
+
+        self.nodes.insert(path, PathMapNode {
+            value,
+            children: HashSet::new(),
+        });
+    }
+
+    pub fn remove(&mut self, root_path: &Path) -> Option<T> {
+        if let Some(parent_path) = root_path.parent() {
+            if let Some(parent) = self.nodes.get_mut(parent_path) {
+                parent.children.remove(root_path);
+            }
+        }
+
+        let mut root_node = match self.nodes.remove(root_path) {
+            Some(node) => node,
+            None => return None,
+        };
+
+        let root_value = root_node.value;
+        let mut to_visit: Vec<PathBuf> = root_node.children.drain().collect();
+
+        while let Some(path) = to_visit.pop() {
+            match self.nodes.remove(&path) {
+                Some(mut node) => {
+                    for child in node.children.drain() {
+                        to_visit.push(child);
+                    }
+                },
+                None => {
+                    warn!("Consistency issue; tried to remove {} but it was already removed", path.display());
+                },
+            }
+        }
+
+        Some(root_value)
+    }
+
+    pub fn descend(&self, start_path: &Path, target_path: &Path) -> PathBuf {
+        let relative_path = target_path.strip_prefix(start_path)
+            .expect("target_path did not begin with start_path");
+        let mut current_path = start_path.to_path_buf();
+
+        for component in relative_path.components() {
+            match component {
+                path::Component::Normal(name) => {
+                    let next_path = current_path.join(name);
+
+                    if self.nodes.contains_key(&next_path) {
+                        current_path = next_path;
+                    } else {
+                        return current_path;
+                    }
+                },
+                _ => unreachable!(),
+            }
+        }
+
+        current_path
+    }
+}

server/src/pathext.rs

@@ -1,120 +0,0 @@
-use std::env::current_dir;
-use std::path::{Component, Path, PathBuf};
-
-/// Converts a path to a 'route', used as the paths in Rojo.
-pub fn path_to_route<A, B>(root: A, value: B) -> Option<Vec<String>>
-where
-    A: AsRef<Path>,
-    B: AsRef<Path>,
-{
-    let root = root.as_ref();
-    let value = value.as_ref();
-
-    let relative = match value.strip_prefix(root) {
-        Ok(v) => v,
-        Err(_) => return None,
-    };
-
-    let result = relative
-        .components()
-        .map(|component| {
-            component.as_os_str().to_string_lossy().into_owned()
-        })
-        .collect::<Vec<_>>();
-
-    Some(result)
-}
-
-#[test]
-fn test_path_to_route() {
-    fn t(root: &Path, value: &Path, result: Option<Vec<String>>) {
-        assert_eq!(path_to_route(root, value), result);
-    }
-
-    t(
-        Path::new("/a/b/c"),
-        Path::new("/a/b/c/d"),
-        Some(vec!["d".to_string()]),
-    );
-    t(Path::new("/a/b"), Path::new("a"), None);
-}
-
-#[test]
-#[cfg(target_os = "windows")]
-fn test_path_to_route_windows() {
-    fn t(root: &Path, value: &Path, result: Option<Vec<String>>) {
-        assert_eq!(path_to_route(root, value), result);
-    }
-
-    t(
-        Path::new("C:\\foo"),
-        Path::new("C:\\foo\\bar\\baz"),
-        Some(vec!["bar".to_string(), "baz".to_string()]),
-    );
-}
-
-/// Turns the path into an absolute one, using the current working directory if
-/// necessary.
-pub fn canonicalish<T: AsRef<Path>>(value: T) -> PathBuf {
-    let cwd = current_dir().unwrap();
-
-    absoluteify(&cwd, value)
-}
-
-/// Converts the given path to be absolute if it isn't already using a given
-/// root.
-pub fn absoluteify<A, B>(root: A, value: B) -> PathBuf
-where
-    A: AsRef<Path>,
-    B: AsRef<Path>,
-{
-    let root = root.as_ref();
-    let value = value.as_ref();
-
-    if value.is_absolute() {
-        PathBuf::from(value)
-    } else {
-        root.join(value)
-    }
-}
-
-/// Collapses any `.` values along with any `..` values not at the start of the
-/// path.
-pub fn collapse<T: AsRef<Path>>(value: T) -> PathBuf {
-    let value = value.as_ref();
-
-    let mut buffer = Vec::new();
-
-    for component in value.components() {
-        match component {
-            Component::ParentDir => match buffer.pop() {
-                Some(_) => {},
-                None => buffer.push(component.as_os_str()),
-            },
-            Component::CurDir => {},
-            _ => {
-                buffer.push(component.as_os_str());
-            },
-        }
-    }
-
-    buffer.iter().fold(PathBuf::new(), |mut acc, &x| {
-        acc.push(x);
-        acc
-    })
-}
-
-#[test]
-fn test_collapse() {
-    fn identity(buf: PathBuf) {
-        assert_eq!(buf, collapse(&buf));
-    }
-
-    identity(PathBuf::from("C:\\foo\\bar"));
-    identity(PathBuf::from("/a/b/c"));
-    identity(PathBuf::from("a/b"));
-
-    assert_eq!(collapse(PathBuf::from("a/b/..")), PathBuf::from("a"));
-    assert_eq!(collapse(PathBuf::from("./a/b/c/..")), PathBuf::from("a/b"));
-    assert_eq!(collapse(PathBuf::from("../a")), PathBuf::from("../a"));
-}

server/src/plugin.rs

@@ -1,82 +0,0 @@
-use rbx::RbxInstance;
-use vfs::VfsItem;
-use core::Route;
-
-pub enum TransformFileResult {
-    Value(Option<RbxInstance>),
-    Pass,
-
-    // TODO: Error case
-}
-
-pub enum RbxChangeResult {
-    Write(Option<VfsItem>),
-    Pass,
-
-    // TODO: Error case
-}
-
-pub enum FileChangeResult {
-    MarkChanged(Option<Vec<Route>>),
-    Pass,
-}
-
-pub trait Plugin {
-    /// Invoked when a file is read from the filesystem and needs to be turned
-    /// into a Roblox instance.
-    fn transform_file(&self, plugins: &PluginChain, vfs_item: &VfsItem) -> TransformFileResult;
-
-    /// Invoked when a Roblox Instance change is reported by the Roblox Studio
-    /// plugin and needs to be turned into a file to save.
-    fn handle_rbx_change(&self, route: &Route, rbx_item: &RbxInstance) -> RbxChangeResult;
-
-    /// Invoked when a file changes on the filesystem. The result defines what
-    /// routes are marked as needing to be refreshed.
-    fn handle_file_change(&self, route: &Route) -> FileChangeResult;
-}
-
-/// A set of plugins that are composed in order.
-pub struct PluginChain {
-    plugins: Vec<Box<Plugin + Send + Sync>>,
-}
-
-impl PluginChain {
-    pub fn new(plugins: Vec<Box<Plugin + Send + Sync>>) -> PluginChain {
-        PluginChain {
-            plugins,
-        }
-    }
-
-    pub fn transform_file(&self, vfs_item: &VfsItem) -> Option<RbxInstance> {
-        for plugin in &self.plugins {
-            match plugin.transform_file(self, vfs_item) {
-                TransformFileResult::Value(rbx_item) => return rbx_item,
-                TransformFileResult::Pass => {},
-            }
-        }
-
-        None
-    }
-
-    pub fn handle_rbx_change(&self, route: &Route, rbx_item: &RbxInstance) -> Option<VfsItem> {
-        for plugin in &self.plugins {
-            match plugin.handle_rbx_change(route, rbx_item) {
-                RbxChangeResult::Write(vfs_item) => return vfs_item,
-                RbxChangeResult::Pass => {},
-            }
-        }
-
-        None
-    }
-
-    pub fn handle_file_change(&self, route: &Route) -> Option<Vec<Route>> {
-        for plugin in &self.plugins {
-            match plugin.handle_file_change(route) {
-                FileChangeResult::MarkChanged(changes) => return changes,
-                FileChangeResult::Pass => {},
-            }
-        }
-
-        None
-    }
-}

server/src/plugins/default_plugin.rs

@@ -1,67 +0,0 @@
-use std::collections::HashMap;
-
-use core::Route;
-use plugin::{Plugin, PluginChain, TransformFileResult, RbxChangeResult, FileChangeResult};
-use rbx::{RbxInstance, RbxValue};
-use vfs::VfsItem;
-
-/// A plugin with simple transforms:
-/// * Directories become Folder instances
-/// * Files become StringValue objects with 'Value' as their contents
-pub struct DefaultPlugin;
-
-impl DefaultPlugin {
-    pub fn new() -> DefaultPlugin {
-        DefaultPlugin
-    }
-}
-
-impl Plugin for DefaultPlugin {
-    fn transform_file(&self, plugins: &PluginChain, vfs_item: &VfsItem) -> TransformFileResult {
-        match vfs_item {
-            &VfsItem::File { ref contents, .. } => {
-                let mut properties = HashMap::new();
-
-                properties.insert("Value".to_string(), RbxValue::String {
-                    value: contents.clone(),
-                });
-
-                TransformFileResult::Value(Some(RbxInstance {
-                    name: vfs_item.name().clone(),
-                    class_name: "StringValue".to_string(),
-                    children: Vec::new(),
-                    properties,
-                    route: Some(vfs_item.route().to_vec()),
-                }))
-            },
-            &VfsItem::Dir { ref children, .. } => {
-                let mut rbx_children = Vec::new();
-
-                for (_, child_item) in children {
-                    match plugins.transform_file(child_item) {
-                        Some(rbx_item) => {
-                            rbx_children.push(rbx_item);
-                        },
-                        _ => {},
-                    }
-                }
-
-                TransformFileResult::Value(Some(RbxInstance {
-                    name: vfs_item.name().clone(),
-                    class_name: "*".to_string(),
-                    children: rbx_children,
-                    properties: HashMap::new(),
-                    route: Some(vfs_item.route().to_vec()),
-                }))
-            },
-        }
-    }
-
-    fn handle_file_change(&self, route: &Route) -> FileChangeResult {
-        FileChangeResult::MarkChanged(Some(vec![route.clone()]))
-    }
-
-    fn handle_rbx_change(&self, _route: &Route, _rbx_item: &RbxInstance) -> RbxChangeResult {
-        RbxChangeResult::Pass
-    }
-}

server/src/plugins/json_model_plugin.rs

@@ -1,55 +0,0 @@
-use regex::Regex;
-use serde_json;
-
-use core::Route;
-use plugin::{Plugin, PluginChain, TransformFileResult, RbxChangeResult, FileChangeResult};
-use rbx::RbxInstance;
-use vfs::VfsItem;
-
-lazy_static! {
-    static ref JSON_MODEL_PATTERN: Regex = Regex::new(r"^(.*?)\.model\.json$").unwrap();
-}
-
-pub struct JsonModelPlugin;
-
-impl JsonModelPlugin {
-    pub fn new() -> JsonModelPlugin {
-        JsonModelPlugin
-    }
-}
-
-impl Plugin for JsonModelPlugin {
-    fn transform_file(&self, _plugins: &PluginChain, vfs_item: &VfsItem) -> TransformFileResult {
-        match vfs_item {
-            &VfsItem::File { ref contents, .. } => {
-                let rbx_name = match JSON_MODEL_PATTERN.captures(vfs_item.name()) {
-                    Some(captures) => captures.get(1).unwrap().as_str().to_string(),
-                    None => return TransformFileResult::Pass,
-                };
-
-                let mut rbx_item: RbxInstance = match serde_json::from_str(contents) {
-                    Ok(v) => v,
-                    Err(e) => {
-                        eprintln!("Unable to parse JSON Model File named {}: {}", vfs_item.name(), e);
-
-                        return TransformFileResult::Pass; // This should be an error in the future!
-                    },
-                };
-
-                rbx_item.route = Some(vfs_item.route().to_vec());
-                rbx_item.name = rbx_name;
-
-                TransformFileResult::Value(Some(rbx_item))
-            },
-            &VfsItem::Dir { .. } => TransformFileResult::Pass,
-        }
-    }
-
-    fn handle_file_change(&self, _route: &Route) -> FileChangeResult {
-        FileChangeResult::Pass
-    }
-
-    fn handle_rbx_change(&self, _route: &Route, _rbx_item: &RbxInstance) -> RbxChangeResult {
-        RbxChangeResult::Pass
-    }
-}

server/src/plugins/mod.rs

@@ -1,7 +0,0 @@
-mod default_plugin;
-mod script_plugin;
-mod json_model_plugin;
-
-pub use self::default_plugin::*;
-pub use self::script_plugin::*;
-pub use self::json_model_plugin::*;

server/src/plugins/script_plugin.rs

@@ -1,124 +0,0 @@
-use std::collections::HashMap;
-
-use regex::Regex;
-
-use core::Route;
-use plugin::{Plugin, PluginChain, TransformFileResult, RbxChangeResult, FileChangeResult};
-use rbx::{RbxInstance, RbxValue};
-use vfs::VfsItem;
-
-lazy_static! {
-    static ref SERVER_PATTERN: Regex = Regex::new(r"^(.*?)\.server\.lua$").unwrap();
-    static ref CLIENT_PATTERN: Regex = Regex::new(r"^(.*?)\.client\.lua$").unwrap();
-    static ref MODULE_PATTERN: Regex = Regex::new(r"^(.*?)\.lua$").unwrap();
-}
-
-static SERVER_INIT: &'static str = "init.server.lua";
-static CLIENT_INIT: &'static str = "init.client.lua";
-static MODULE_INIT: &'static str = "init.lua";
-
-pub struct ScriptPlugin;
-
-impl ScriptPlugin {
-    pub fn new() -> ScriptPlugin {
-        ScriptPlugin
-    }
-}
-
-impl Plugin for ScriptPlugin {
-    fn transform_file(&self, plugins: &PluginChain, vfs_item: &VfsItem) -> TransformFileResult {
-        match vfs_item {
-            &VfsItem::File { ref contents, .. } => {
-                let name = vfs_item.name();
-
-                let (class_name, rbx_name) = {
-                    if let Some(captures) = SERVER_PATTERN.captures(name) {
-                        ("Script".to_string(), captures.get(1).unwrap().as_str().to_string())
-                    } else if let Some(captures) = CLIENT_PATTERN.captures(name) {
-                        ("LocalScript".to_string(), captures.get(1).unwrap().as_str().to_string())
-                    } else if let Some(captures) = MODULE_PATTERN.captures(name) {
-                        ("ModuleScript".to_string(), captures.get(1).unwrap().as_str().to_string())
-                    } else {
-                        return TransformFileResult::Pass;
-                    }
-                };
-
-                let mut properties = HashMap::new();
-
-                properties.insert("Source".to_string(), RbxValue::String {
-                    value: contents.clone(),
-                });
-
-                TransformFileResult::Value(Some(RbxInstance {
-                    name: rbx_name,
-                    class_name: class_name,
-                    children: Vec::new(),
-                    properties,
-                    route: Some(vfs_item.route().to_vec()),
-                }))
-            },
-            &VfsItem::Dir { ref children, .. } => {
-                let init_item = {
-                    let maybe_item = children.get(SERVER_INIT)
-                        .or(children.get(CLIENT_INIT))
-                        .or(children.get(MODULE_INIT));
-
-                    match maybe_item {
-                        Some(v) => v,
-                        None => return TransformFileResult::Pass,
-                    }
-                };
-
-                let mut rbx_item = match self.transform_file(plugins, init_item) {
-                    TransformFileResult::Value(Some(item)) => item,
-                    _ => {
-                        eprintln!("Inconsistency detected in ScriptPlugin!");
-                        return TransformFileResult::Pass;
-                    },
-                };
-
-                rbx_item.name.clear();
-                rbx_item.name.push_str(vfs_item.name());
-
-                for (child_name, child_item) in children {
-                    if child_name == init_item.name() {
-                        continue;
-                    }
-
-                    match plugins.transform_file(child_item) {
-                        Some(child_rbx_item) => {
-                            rbx_item.children.push(child_rbx_item);
-                        },
-                        _ => {},
-                    }
-                }
-
-                TransformFileResult::Value(Some(rbx_item))
-            },
-        }
-    }
-
-    fn handle_file_change(&self, route: &Route) -> FileChangeResult {
-        let leaf = match route.last() {
-            Some(v) => v,
-            None => return FileChangeResult::Pass,
-        };
-
-        let is_init = leaf == SERVER_INIT
-            || leaf == CLIENT_INIT
-            || leaf == MODULE_INIT;
-
-        if is_init {
-            let mut changed = route.clone();
-            changed.pop();
-
-            FileChangeResult::MarkChanged(Some(vec![changed]))
-        } else {
-            FileChangeResult::Pass
-        }
-    }
-
-    fn handle_rbx_change(&self, _route: &Route, _rbx_item: &RbxInstance) -> RbxChangeResult {
-        RbxChangeResult::Pass
-    }
-}

server/src/project.rs

@@ -1,165 +1,400 @@
-use std::collections::HashMap;
-use std::fmt;
-use std::fs::{self, File};
-use std::io::{Read, Write};
-use std::path::Path;
+use std::{
+    collections::{HashMap, HashSet},
+    fmt,
+    fs::{self, File},
+    io,
+    path::{Path, PathBuf},
+};
 
-use serde_json;
+use maplit::hashmap;
+use failure::Fail;
+use rbx_tree::RbxValue;
 
-pub static PROJECT_FILENAME: &'static str = "rojo.json";
+pub static PROJECT_FILENAME: &'static str = "roblox-project.json";
 
-#[derive(Debug)]
-pub enum ProjectLoadError {
-    DidNotExist,
-    FailedToOpen,
-    FailedToRead,
-    InvalidJson(serde_json::Error),
+// Serde is silly.
+const fn yeah() -> bool {
+    true
 }
 
-#[derive(Debug)]
-pub enum ProjectSaveError {
-    FailedToCreate,
+const fn is_true(value: &bool) -> bool {
+    *value
 }
 
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(untagged)]
+enum SourceProjectNode {
+    Instance {
+        #[serde(rename = "$className")]
+        class_name: String,
+
+        #[serde(rename = "$properties", default = "HashMap::new", skip_serializing_if = "HashMap::is_empty")]
+        properties: HashMap<String, RbxValue>,
+
+        #[serde(rename = "$ignoreUnknownInstances", default = "yeah", skip_serializing_if = "is_true")]
+        ignore_unknown_instances: bool,
+
+        #[serde(flatten)]
+        children: HashMap<String, SourceProjectNode>,
+    },
+    SyncPoint {
+        #[serde(rename = "$path")]
+        path: String,
+    }
+}
+
+impl SourceProjectNode {
+    pub fn into_project_node(self, project_file_location: &Path) -> ProjectNode {
+        match self {
+            SourceProjectNode::Instance { class_name, mut children, properties, ignore_unknown_instances } => {
+                let mut new_children = HashMap::new();
+
+                for (node_name, node) in children.drain() {
+                    new_children.insert(node_name, node.into_project_node(project_file_location));
+                }
+
+                ProjectNode::Instance(InstanceProjectNode {
+                    class_name,
+                    children: new_children,
+                    properties,
+                    metadata: InstanceProjectNodeMetadata {
+                        ignore_unknown_instances,
+                    },
+                })
+            },
+            SourceProjectNode::SyncPoint { path: source_path } => {
+                let path = if Path::new(&source_path).is_absolute() {
+                    PathBuf::from(source_path)
+                } else {
+                    let project_folder_location = project_file_location.parent().unwrap();
+                    project_folder_location.join(source_path)
+                };
+
+                ProjectNode::SyncPoint(SyncPointProjectNode {
+                    path,
+                })
+            },
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct SourceProject {
+    name: String,
+    tree: SourceProjectNode,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    serve_port: Option<u16>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    serve_place_ids: Option<HashSet<u64>>,
+}
+
+impl SourceProject {
+    pub fn into_project(self, project_file_location: &Path) -> Project {
+        let tree = self.tree.into_project_node(project_file_location);
+
+        Project {
+            name: self.name,
+            tree,
+            serve_port: self.serve_port,
+            serve_place_ids: self.serve_place_ids,
+            file_location: PathBuf::from(project_file_location),
+        }
+    }
+}
+
+#[derive(Debug, Fail)]
+pub enum ProjectLoadExactError {
+    #[fail(display = "IO error: {}", _0)]
+    IoError(#[fail(cause)] io::Error),
+
+    #[fail(display = "JSON error: {}", _0)]
+    JsonError(#[fail(cause)] serde_json::Error),
+}
+
+#[derive(Debug, Fail)]
+pub enum ProjectLoadFuzzyError {
+    #[fail(display = "Project not found")]
+    NotFound,
+
+    #[fail(display = "IO error: {}", _0)]
+    IoError(#[fail(cause)] io::Error),
+
+    #[fail(display = "JSON error: {}", _0)]
+    JsonError(#[fail(cause)] serde_json::Error),
+}
+
+impl From<ProjectLoadExactError> for ProjectLoadFuzzyError {
+    fn from(error: ProjectLoadExactError) -> ProjectLoadFuzzyError {
+        match error {
+            ProjectLoadExactError::IoError(inner) => ProjectLoadFuzzyError::IoError(inner),
+            ProjectLoadExactError::JsonError(inner) => ProjectLoadFuzzyError::JsonError(inner),
+        }
+    }
+}
+
+#[derive(Debug, Fail)]
 pub enum ProjectInitError {
-    AlreadyExists,
-    FailedToCreate,
-    FailedToWrite,
+    AlreadyExists(PathBuf),
+    IoError(#[fail(cause)] io::Error),
+    SaveError(#[fail(cause)] ProjectSaveError),
 }
 
 impl fmt::Display for ProjectInitError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &ProjectInitError::AlreadyExists => {
-                write!(f, "A project already exists at that location.")
+            ProjectInitError::AlreadyExists(path) => write!(output, "Path {} already exists", path.display()),
+            ProjectInitError::IoError(inner) => write!(output, "IO error: {}", inner),
+            ProjectInitError::SaveError(inner) => write!(output, "{}", inner),
+        }
+    }
+}
+
+#[derive(Debug, Fail)]
+pub enum ProjectSaveError {
+    #[fail(display = "JSON error: {}", _0)]
+    JsonError(#[fail(cause)] serde_json::Error),
+
+    #[fail(display = "IO error: {}", _0)]
+    IoError(#[fail(cause)] io::Error),
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct InstanceProjectNodeMetadata {
+    pub ignore_unknown_instances: bool,
+}
+
+impl Default for InstanceProjectNodeMetadata {
+    fn default() -> InstanceProjectNodeMetadata {
+        InstanceProjectNodeMetadata {
+            ignore_unknown_instances: true,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type")]
+pub enum ProjectNode {
+    Instance(InstanceProjectNode),
+    SyncPoint(SyncPointProjectNode),
+}
+
+impl ProjectNode {
+    fn to_source_node(&self, project_file_location: &Path) -> SourceProjectNode {
+        match self {
+            ProjectNode::Instance(node) => {
+                let mut children = HashMap::new();
+
+                for (key, child) in &node.children {
+                    children.insert(key.clone(), child.to_source_node(project_file_location));
+                }
+
+                SourceProjectNode::Instance {
+                    class_name: node.class_name.clone(),
+                    children,
+                    properties: node.properties.clone(),
+                    ignore_unknown_instances: node.metadata.ignore_unknown_instances,
+                }
             },
-            &ProjectInitError::FailedToCreate | &ProjectInitError::FailedToWrite => {
-                write!(f, "Failed to write to the given location.")
+            ProjectNode::SyncPoint(sync_node) => {
+                let project_folder_location = project_file_location.parent().unwrap();
+
+                let friendly_path = match sync_node.path.strip_prefix(project_folder_location) {
+                    Ok(stripped) => stripped.to_str().unwrap().replace("\\", "/"),
+                    Err(_) => format!("{}", sync_node.path.display()),
+                };
+
+                SourceProjectNode::SyncPoint {
+                    path: friendly_path,
+                }
             },
         }
     }
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct ProjectPartition {
-    /// A slash-separated path to a file or folder, relative to the project's
-    /// directory.
-    pub path: String,
-
-    /// A dot-separated route to a Roblox instance, relative to game.
-    pub target: String,
+pub struct InstanceProjectNode {
+    pub class_name: String,
+    pub children: HashMap<String, ProjectNode>,
+    pub properties: HashMap<String, RbxValue>,
+    pub metadata: InstanceProjectNodeMetadata,
 }
 
-/// Represents a project configured by a user for use with Rojo. Holds anything
-/// that can be configured with `rojo.json`.
-///
-/// In the future, this object will hold dependency information and other handy
-/// configurables
-#[derive(Clone, Debug, Serialize, Deserialize)]
-#[serde(default, rename_all = "camelCase")]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SyncPointProjectNode {
+    pub path: PathBuf,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Project {
     pub name: String,
-    pub serve_port: u64,
-    pub partitions: HashMap<String, ProjectPartition>,
+    pub tree: ProjectNode,
+    pub serve_port: Option<u16>,
+    pub serve_place_ids: Option<HashSet<u64>>,
+    pub file_location: PathBuf,
 }
 
 impl Project {
-    /// Creates a new empty Project object with the given name.
-    pub fn new<T: Into<String>>(name: T) -> Project {
-        Project {
-            name: name.into(),
-            ..Default::default()
+    pub fn init_place(project_fuzzy_path: &Path) -> Result<PathBuf, ProjectInitError> {
+        let project_path = Project::init_pick_path(project_fuzzy_path)?;
+        let project_folder_path = project_path.parent().unwrap();
+        let project_name = if project_fuzzy_path == project_path {
+            project_fuzzy_path.parent().unwrap().file_name().unwrap().to_str().unwrap()
+        } else {
+            project_fuzzy_path.file_name().unwrap().to_str().unwrap()
+        };
+
+        let tree = ProjectNode::Instance(InstanceProjectNode {
+            class_name: "DataModel".to_string(),
+            children: hashmap! {
+                String::from("ReplicatedStorage") => ProjectNode::Instance(InstanceProjectNode {
+                    class_name: String::from("ReplicatedStorage"),
+                    children: hashmap! {
+                        String::from("Source") => ProjectNode::SyncPoint(SyncPointProjectNode {
+                            path: project_folder_path.join("src"),
+                        }),
+                    },
+                    properties: HashMap::new(),
+                    metadata: Default::default(),
+                }),
+                String::from("HttpService") => ProjectNode::Instance(InstanceProjectNode {
+                    class_name: String::from("HttpService"),
+                    children: HashMap::new(),
+                    properties: hashmap! {
+                        String::from("HttpEnabled") => RbxValue::Bool {
+                            value: true,
+                        },
+                    },
+                    metadata: Default::default(),
+                }),
+            },
+            properties: HashMap::new(),
+            metadata: Default::default(),
+        });
+
+        let project = Project {
+            name: project_name.to_string(),
+            tree,
+            serve_port: None,
+            serve_place_ids: None,
+            file_location: project_path.clone(),
+        };
+
+        project.save()
+            .map_err(ProjectInitError::SaveError)?;
+
+        Ok(project_path)
+    }
+
+    pub fn init_model(project_fuzzy_path: &Path) -> Result<PathBuf, ProjectInitError> {
+        let project_path = Project::init_pick_path(project_fuzzy_path)?;
+        let project_folder_path = project_path.parent().unwrap();
+        let project_name = if project_fuzzy_path == project_path {
+            project_fuzzy_path.parent().unwrap().file_name().unwrap().to_str().unwrap()
+        } else {
+            project_fuzzy_path.file_name().unwrap().to_str().unwrap()
+        };
+
+        let tree = ProjectNode::SyncPoint(SyncPointProjectNode {
+            path: project_folder_path.join("src"),
+        });
+
+        let project = Project {
+            name: project_name.to_string(),
+            tree,
+            serve_port: None,
+            serve_place_ids: None,
+            file_location: project_path.clone(),
+        };
+
+        project.save()
+            .map_err(ProjectInitError::SaveError)?;
+
+        Ok(project_path)
+    }
+
+    fn init_pick_path(project_fuzzy_path: &Path) -> Result<PathBuf, ProjectInitError> {
+        let is_exact = project_fuzzy_path.extension().is_some();
+
+        let project_path = if is_exact {
+            project_fuzzy_path.to_path_buf()
+        } else {
+            project_fuzzy_path.join(PROJECT_FILENAME)
+        };
+
+        match fs::metadata(&project_path) {
+            Err(error) => match error.kind() {
+                io::ErrorKind::NotFound => {},
+                _ => return Err(ProjectInitError::IoError(error)),
+            },
+            Ok(_) => return Err(ProjectInitError::AlreadyExists(project_path)),
+        }
+
+        Ok(project_path)
+    }
+
+    pub fn locate(start_location: &Path) -> Option<PathBuf> {
+        // TODO: Check for specific error kinds, convert 'not found' to Result.
+        let location_metadata = fs::metadata(start_location).ok()?;
+
+        // If this is a file, we should assume it's the config we want
+        if location_metadata.is_file() {
+            return Some(start_location.to_path_buf());
+        } else if location_metadata.is_dir() {
+            let with_file = start_location.join(PROJECT_FILENAME);
+
+            if let Ok(with_file_metadata) = fs::metadata(&with_file) {
+                if with_file_metadata.is_file() {
+                    return Some(with_file);
+                } else {
+                    return None;
+                }
+            }
+        }
+
+        match start_location.parent() {
+            Some(parent_location) => Self::locate(parent_location),
+            None => None,
         }
     }
 
-    /// Initializes a new project inside the given folder path.
-    pub fn init<T: AsRef<Path>>(location: T) -> Result<Project, ProjectInitError> {
-        let location = location.as_ref();
-        let package_path = location.join(PROJECT_FILENAME);
+    pub fn load_fuzzy(fuzzy_project_location: &Path) -> Result<Project, ProjectLoadFuzzyError> {
+        let project_path = Self::locate(fuzzy_project_location)
+            .ok_or(ProjectLoadFuzzyError::NotFound)?;
 
-        // We abort if the project file already exists.
-        match fs::metadata(&package_path) {
-            Ok(_) => return Err(ProjectInitError::AlreadyExists),
-            Err(_) => {},
-        }
-
-        let mut file = match File::create(&package_path) {
-            Ok(f) => f,
-            Err(_) => return Err(ProjectInitError::FailedToCreate),
-        };
-
-        // Try to give the project a meaningful name.
-        // If we can't, we'll just fall back to a default.
-        let name = match location.file_name() {
-            Some(v) => v.to_string_lossy().into_owned(),
-            None => "new-project".to_string(),
-        };
-
-        // Configure the project with all of the values we know so far.
-        let project = Project::new(name);
-        let serialized = serde_json::to_string_pretty(&project).unwrap();
-
-        match file.write(serialized.as_bytes()) {
-            Ok(_) => {},
-            Err(_) => return Err(ProjectInitError::FailedToWrite),
-        }
-
-        Ok(project)
+        Self::load_exact(&project_path).map_err(From::from)
     }
 
-    /// Attempts to load a project from the file named PROJECT_FILENAME from the
-    /// given folder.
-    pub fn load<T: AsRef<Path>>(location: T) -> Result<Project, ProjectLoadError> {
-        let package_path = location.as_ref().join(Path::new(PROJECT_FILENAME));
+    pub fn load_exact(project_file_location: &Path) -> Result<Project, ProjectLoadExactError> {
+        let contents = fs::read_to_string(project_file_location)
+            .map_err(ProjectLoadExactError::IoError)?;
 
-        match fs::metadata(&package_path) {
-            Ok(_) => {},
-            Err(_) => return Err(ProjectLoadError::DidNotExist),
-        }
+        let parsed: SourceProject = serde_json::from_str(&contents)
+            .map_err(ProjectLoadExactError::JsonError)?;
 
-        let mut file = match File::open(&package_path) {
-            Ok(f) => f,
-            Err(_) => return Err(ProjectLoadError::FailedToOpen),
-        };
-
-        let mut contents = String::new();
-
-        match file.read_to_string(&mut contents) {
-            Ok(_) => {},
-            Err(_) => return Err(ProjectLoadError::FailedToRead),
-        }
-
-        match serde_json::from_str(&contents) {
-            Ok(v) => Ok(v),
-            Err(e) => return Err(ProjectLoadError::InvalidJson(e)),
-        }
+        Ok(parsed.into_project(project_file_location))
     }
 
-    /// Saves the given project file to the given folder with the appropriate name.
-    pub fn save<T: AsRef<Path>>(&self, location: T) -> Result<(), ProjectSaveError> {
-        let package_path = location.as_ref().join(Path::new(PROJECT_FILENAME));
+    pub fn save(&self) -> Result<(), ProjectSaveError> {
+        let source_project = self.to_source_project();
+        let mut file = File::create(&self.file_location)
+            .map_err(ProjectSaveError::IoError)?;
 
-        let mut file = match File::create(&package_path) {
-            Ok(f) => f,
-            Err(_) => return Err(ProjectSaveError::FailedToCreate),
-        };
-
-        let serialized = serde_json::to_string_pretty(self).unwrap();
-
-        file.write(serialized.as_bytes()).unwrap();
+        serde_json::to_writer_pretty(&mut file, &source_project)
+            .map_err(ProjectSaveError::JsonError)?;
 
         Ok(())
     }
-}
 
-impl Default for Project {
-    fn default() -> Project {
-        Project {
-            name: "new-project".to_string(),
-            serve_port: 8000,
-            partitions: HashMap::new(),
+    fn to_source_project(&self) -> SourceProject {
+        SourceProject {
+            name: self.name.clone(),
+            tree: self.tree.to_source_node(&self.file_location),
+            serve_port: self.serve_port,
+            serve_place_ids: self.serve_place_ids.clone(),
         }
     }
-}
+}

server/src/rbx.rs

@@ -1,34 +0,0 @@
-use std::collections::HashMap;
-
-/// Represents data about a Roblox instance
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "PascalCase")]
-pub struct RbxInstance {
-    pub name: String,
-    pub class_name: String,
-    pub children: Vec<RbxInstance>,
-    pub properties: HashMap<String, RbxValue>,
-
-    /// The route that this instance was generated from, if there was one.
-    pub route: Option<Vec<String>>,
-}
-
-/// Any kind value that can be used by Roblox
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "PascalCase", tag = "Type")]
-pub enum RbxValue {
-    #[serde(rename_all = "PascalCase")]
-    String {
-        value: String,
-    },
-    #[serde(rename_all = "PascalCase")]
-    Bool {
-        value: bool,
-    },
-    #[serde(rename_all = "PascalCase")]
-    Number {
-        value: f64,
-    },
-
-    // TODO: Compound types like Vector3
-}

server/src/rbx_session.rs

@@ -0,0 +1,539 @@
+use std::{
+    borrow::Cow,
+    collections::HashMap,
+    fmt,
+    path::{Path, PathBuf},
+    str,
+    sync::{Arc, Mutex},
+};
+
+use failure::Fail;
+
+use rbx_tree::{RbxTree, RbxInstanceProperties, RbxValue, RbxId};
+
+use crate::{
+    project::{Project, ProjectNode, InstanceProjectNodeMetadata},
+    message_queue::MessageQueue,
+    imfs::{Imfs, ImfsItem, ImfsFile},
+    path_map::PathMap,
+    rbx_snapshot::{RbxSnapshotInstance, InstanceChanges, snapshot_from_tree, reify_root, reconcile_subtree},
+};
+
+const INIT_SCRIPT: &str = "init.lua";
+const INIT_SERVER_SCRIPT: &str = "init.server.lua";
+const INIT_CLIENT_SCRIPT: &str = "init.client.lua";
+
+pub struct RbxSession {
+    tree: RbxTree,
+    path_map: PathMap<RbxId>,
+    instance_metadata_map: HashMap<RbxId, InstanceProjectNodeMetadata>,
+    sync_point_names: HashMap<PathBuf, String>,
+    message_queue: Arc<MessageQueue<InstanceChanges>>,
+    imfs: Arc<Mutex<Imfs>>,
+}
+
+impl RbxSession {
+    pub fn new(
+        project: Arc<Project>,
+        imfs: Arc<Mutex<Imfs>>,
+        message_queue: Arc<MessageQueue<InstanceChanges>>,
+    ) -> RbxSession {
+        let mut sync_point_names = HashMap::new();
+        let mut path_map = PathMap::new();
+        let mut instance_metadata_map = HashMap::new();
+
+        let tree = {
+            let temp_imfs = imfs.lock().unwrap();
+            construct_initial_tree(&project, &temp_imfs, &mut path_map, &mut instance_metadata_map, &mut sync_point_names)
+        };
+
+        RbxSession {
+            tree,
+            path_map,
+            instance_metadata_map,
+            sync_point_names,
+            message_queue,
+            imfs,
+        }
+    }
+
+    fn path_created_or_updated(&mut self, path: &Path) {
+        // TODO: Track paths actually updated in each step so we can ignore
+        // redundant changes.
+        let mut changes = InstanceChanges::default();
+
+        {
+            let imfs = self.imfs.lock().unwrap();
+            let root_path = imfs.get_root_for_path(path)
+                .expect("Path was outside in-memory filesystem roots");
+
+            // Find the closest instance in the tree that currently exists
+            let mut path_to_snapshot = self.path_map.descend(root_path, path);
+            let &instance_id = self.path_map.get(&path_to_snapshot).unwrap();
+
+            // If this is a file that might affect its parent if modified, we
+            // should snapshot its parent instead.
+            match path_to_snapshot.file_name().unwrap().to_str() {
+                Some(INIT_SCRIPT) | Some(INIT_SERVER_SCRIPT) | Some(INIT_CLIENT_SCRIPT) => {
+                    path_to_snapshot.pop();
+                },
+                _ => {},
+            }
+
+            trace!("Snapshotting path {}", path_to_snapshot.display());
+
+            let maybe_snapshot = snapshot_instances_from_imfs(&imfs, &path_to_snapshot, &mut self.sync_point_names)
+                .unwrap_or_else(|_| panic!("Could not generate instance snapshot for path {}", path_to_snapshot.display()));
+
+            let snapshot = match maybe_snapshot {
+                Some(snapshot) => snapshot,
+                None => {
+                    trace!("Path resulted in no snapshot being generated.");
+                    return;
+                },
+            };
+
+            trace!("Snapshot: {:#?}", snapshot);
+
+            reconcile_subtree(
+                &mut self.tree,
+                instance_id,
+                &snapshot,
+                &mut self.path_map,
+                &mut self.instance_metadata_map,
+                &mut changes,
+            );
+        }
+
+        if changes.is_empty() {
+            trace!("No instance changes triggered from file update.");
+        } else {
+            trace!("Pushing changes: {}", changes);
+            self.message_queue.push_messages(&[changes]);
+        }
+    }
+
+    pub fn path_created(&mut self, path: &Path) {
+        info!("Path created: {}", path.display());
+        self.path_created_or_updated(path);
+    }
+
+    pub fn path_updated(&mut self, path: &Path) {
+        info!("Path updated: {}", path.display());
+
+        {
+            let imfs = self.imfs.lock().unwrap();
+
+            // If the path doesn't exist or is a directory, we don't care if it
+            // updated
+            match imfs.get(path) {
+                Some(ImfsItem::Directory(_)) | None => {
+                    trace!("Updated path was a directory, ignoring.");
+                    return;
+                },
+                Some(ImfsItem::File(_)) => {},
+            }
+        }
+
+        self.path_created_or_updated(path);
+    }
+
+    pub fn path_removed(&mut self, path: &Path) {
+        info!("Path removed: {}", path.display());
+        self.path_map.remove(path);
+        self.path_created_or_updated(path);
+    }
+
+    pub fn path_renamed(&mut self, from_path: &Path, to_path: &Path) {
+        info!("Path renamed from {} to {}", from_path.display(), to_path.display());
+        self.path_map.remove(from_path);
+        self.path_created_or_updated(from_path);
+        self.path_created_or_updated(to_path);
+    }
+
+    pub fn get_tree(&self) -> &RbxTree {
+        &self.tree
+    }
+
+    pub fn get_instance_metadata(&self, id: RbxId) -> Option<&InstanceProjectNodeMetadata> {
+        self.instance_metadata_map.get(&id)
+    }
+
+    pub fn debug_get_path_map(&self) -> &PathMap<RbxId> {
+        &self.path_map
+    }
+}
+
+pub fn construct_oneoff_tree(project: &Project, imfs: &Imfs) -> RbxTree {
+    let mut path_map = PathMap::new();
+    let mut instance_metadata_map = HashMap::new();
+    let mut sync_point_names = HashMap::new();
+    construct_initial_tree(project, imfs, &mut path_map, &mut instance_metadata_map, &mut sync_point_names)
+}
+
+fn construct_initial_tree(
+    project: &Project,
+    imfs: &Imfs,
+    path_map: &mut PathMap<RbxId>,
+    instance_metadata_map: &mut HashMap<RbxId, InstanceProjectNodeMetadata>,
+    sync_point_names: &mut HashMap<PathBuf, String>,
+) -> RbxTree {
+    let snapshot = construct_project_node(
+        imfs,
+        &project.name,
+        &project.tree,
+        sync_point_names,
+    );
+
+    let mut changes = InstanceChanges::default();
+    let tree = reify_root(&snapshot, path_map, instance_metadata_map, &mut changes);
+
+    tree
+}
+
+fn construct_project_node<'a>(
+    imfs: &'a Imfs,
+    instance_name: &'a str,
+    project_node: &'a ProjectNode,
+    sync_point_names: &mut HashMap<PathBuf, String>,
+) -> RbxSnapshotInstance<'a> {
+    match project_node {
+        ProjectNode::Instance(node) => {
+            let mut children = Vec::new();
+
+            for (child_name, child_project_node) in &node.children {
+                children.push(construct_project_node(imfs, child_name, child_project_node, sync_point_names));
+            }
+
+            RbxSnapshotInstance {
+                class_name: Cow::Borrowed(&node.class_name),
+                name: Cow::Borrowed(instance_name),
+                properties: node.properties.clone(),
+                children,
+                source_path: None,
+                metadata: Some(node.metadata.clone()),
+            }
+        },
+        ProjectNode::SyncPoint(node) => {
+            // TODO: Propagate errors upward instead of dying
+            let mut snapshot = snapshot_instances_from_imfs(imfs, &node.path, sync_point_names)
+                .expect("Could not reify nodes from Imfs")
+                .expect("Sync point node did not result in an instance");
+
+            snapshot.name = Cow::Borrowed(instance_name);
+            sync_point_names.insert(node.path.clone(), instance_name.to_string());
+
+            snapshot
+        },
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+enum FileType {
+    ModuleScript,
+    ServerScript,
+    ClientScript,
+    StringValue,
+    LocalizationTable,
+    XmlModel,
+    BinaryModel,
+}
+
+fn get_trailing<'a>(input: &'a str, trailer: &str) -> Option<&'a str> {
+    if input.ends_with(trailer) {
+        let end = input.len().saturating_sub(trailer.len());
+        Some(&input[..end])
+    } else {
+        None
+    }
+}
+
+fn classify_file(file: &ImfsFile) -> Option<(&str, FileType)> {
+    static EXTENSIONS_TO_TYPES: &[(&str, FileType)] = &[
+        (".server.lua", FileType::ServerScript),
+        (".client.lua", FileType::ClientScript),
+        (".lua", FileType::ModuleScript),
+        (".csv", FileType::LocalizationTable),
+        (".txt", FileType::StringValue),
+        (".rbxmx", FileType::XmlModel),
+        (".rbxm", FileType::BinaryModel),
+    ];
+
+    let file_name = file.path.file_name()?.to_str()?;
+
+    for (extension, file_type) in EXTENSIONS_TO_TYPES {
+        if let Some(instance_name) = get_trailing(file_name, extension) {
+            return Some((instance_name, *file_type))
+        }
+    }
+
+    None
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "PascalCase")]
+struct LocalizationEntryCsv {
+    key: String,
+    context: String,
+    example: String,
+    source: String,
+    #[serde(flatten)]
+    values: HashMap<String, String>,
+}
+
+impl LocalizationEntryCsv {
+    fn to_json(self) -> LocalizationEntryJson {
+        LocalizationEntryJson {
+            key: self.key,
+            context: self.context,
+            example: self.example,
+            source: self.source,
+            values: self.values,
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct LocalizationEntryJson {
+    key: String,
+    context: String,
+    example: String,
+    source: String,
+    values: HashMap<String, String>,
+}
+
+#[derive(Debug, Fail)]
+enum SnapshotError {
+    DidNotExist(PathBuf),
+
+    // TODO: Add file path to the error message?
+    Utf8Error {
+        #[fail(cause)]
+        inner: str::Utf8Error,
+        path: PathBuf,
+    },
+
+    XmlModelDecodeError {
+        inner: rbx_xml::DecodeError,
+        path: PathBuf,
+    },
+
+    BinaryModelDecodeError {
+        inner: rbx_binary::DecodeError,
+        path: PathBuf,
+    },
+}
+
+impl fmt::Display for SnapshotError {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            SnapshotError::DidNotExist(path) => write!(output, "Path did not exist: {}", path.display()),
+            SnapshotError::Utf8Error { inner, path } => {
+                write!(output, "Invalid UTF-8: {} in path {}", inner, path.display())
+            },
+            SnapshotError::XmlModelDecodeError { inner, path } => {
+                write!(output, "Malformed rbxmx model: {:?} in path {}", inner, path.display())
+            },
+            SnapshotError::BinaryModelDecodeError { inner, path } => {
+                write!(output, "Malformed rbxm model: {:?} in path {}", inner, path.display())
+            },
+        }
+    }
+}
+
+fn snapshot_xml_model<'a>(
+    instance_name: Cow<'a, str>,
+    file: &ImfsFile,
+) -> Result<Option<RbxSnapshotInstance<'a>>, SnapshotError> {
+    let mut temp_tree = RbxTree::new(RbxInstanceProperties {
+        name: "Temp".to_owned(),
+        class_name: "Folder".to_owned(),
+        properties: HashMap::new(),
+    });
+
+    let root_id = temp_tree.get_root_id();
+    rbx_xml::decode(&mut temp_tree, root_id, file.contents.as_slice())
+        .map_err(|inner| SnapshotError::XmlModelDecodeError {
+            inner,
+            path: file.path.clone(),
+        })?;
+
+    let root_instance = temp_tree.get_instance(root_id).unwrap();
+    let children = root_instance.get_children_ids();
+
+    match children.len() {
+        0 => Ok(None),
+        1 => {
+            let mut snapshot = snapshot_from_tree(&temp_tree, children[0]).unwrap();
+            snapshot.name = instance_name;
+            Ok(Some(snapshot))
+        },
+        _ => panic!("Rojo doesn't have support for model files with multiple roots yet"),
+    }
+}
+
+fn snapshot_binary_model<'a>(
+    instance_name: Cow<'a, str>,
+    file: &ImfsFile,
+) -> Result<Option<RbxSnapshotInstance<'a>>, SnapshotError> {
+    let mut temp_tree = RbxTree::new(RbxInstanceProperties {
+        name: "Temp".to_owned(),
+        class_name: "Folder".to_owned(),
+        properties: HashMap::new(),
+    });
+
+    let root_id = temp_tree.get_root_id();
+    rbx_binary::decode(&mut temp_tree, root_id, file.contents.as_slice())
+        .map_err(|inner| SnapshotError::BinaryModelDecodeError {
+            inner,
+            path: file.path.clone(),
+        })?;
+
+    let root_instance = temp_tree.get_instance(root_id).unwrap();
+    let children = root_instance.get_children_ids();
+
+    match children.len() {
+        0 => Ok(None),
+        1 => {
+            let mut snapshot = snapshot_from_tree(&temp_tree, children[0]).unwrap();
+            snapshot.name = instance_name;
+            Ok(Some(snapshot))
+        },
+        _ => panic!("Rojo doesn't have support for model files with multiple roots yet"),
+    }
+}
+
+fn snapshot_instances_from_imfs<'a>(
+    imfs: &'a Imfs,
+    imfs_path: &Path,
+    sync_point_names: &HashMap<PathBuf, String>,
+) -> Result<Option<RbxSnapshotInstance<'a>>, SnapshotError> {
+    match imfs.get(imfs_path) {
+        Some(ImfsItem::File(file)) => {
+            let (instance_name, file_type) = match classify_file(file) {
+                Some(info) => info,
+                None => return Ok(None),
+            };
+
+            let instance_name = if let Some(actual_name) = sync_point_names.get(imfs_path) {
+                Cow::Owned(actual_name.clone())
+            } else {
+                Cow::Borrowed(instance_name)
+            };
+
+            let class_name = match file_type {
+                FileType::ModuleScript => "ModuleScript",
+                FileType::ServerScript => "Script",
+                FileType::ClientScript => "LocalScript",
+                FileType::StringValue => "StringValue",
+                FileType::LocalizationTable => "LocalizationTable",
+                FileType::XmlModel => return snapshot_xml_model(instance_name, file),
+                FileType::BinaryModel => return snapshot_binary_model(instance_name, file),
+            };
+
+            let contents = str::from_utf8(&file.contents)
+                .map_err(|inner| SnapshotError::Utf8Error {
+                    inner,
+                    path: imfs_path.to_path_buf(),
+                })?;
+
+            let mut properties = HashMap::new();
+
+            match file_type {
+                FileType::ModuleScript | FileType::ServerScript | FileType::ClientScript => {
+                    properties.insert(String::from("Source"), RbxValue::String {
+                        value: contents.to_string(),
+                    });
+                },
+                FileType::StringValue => {
+                    properties.insert(String::from("Value"), RbxValue::String {
+                        value: contents.to_string(),
+                    });
+                },
+                FileType::LocalizationTable => {
+                    let entries: Vec<LocalizationEntryJson> = csv::Reader::from_reader(contents.as_bytes())
+                        .deserialize()
+                        .map(|result| result.expect("Malformed localization table found!"))
+                        .map(LocalizationEntryCsv::to_json)
+                        .collect();
+
+                    let table_contents = serde_json::to_string(&entries)
+                        .expect("Could not encode JSON for localization table");
+
+                    properties.insert(String::from("Contents"), RbxValue::String {
+                        value: table_contents,
+                    });
+                },
+                FileType::XmlModel | FileType::BinaryModel => unreachable!(),
+            }
+
+            Ok(Some(RbxSnapshotInstance {
+                name: instance_name,
+                class_name: Cow::Borrowed(class_name),
+                properties,
+                children: Vec::new(),
+                source_path: Some(file.path.clone()),
+                metadata: None,
+            }))
+        },
+        Some(ImfsItem::Directory(directory)) => {
+            // TODO: Expand init support to handle server and client scripts
+            let init_path = directory.path.join(INIT_SCRIPT);
+            let init_server_path = directory.path.join(INIT_SERVER_SCRIPT);
+            let init_client_path = directory.path.join(INIT_CLIENT_SCRIPT);
+
+            let mut instance = if directory.children.contains(&init_path) {
+                snapshot_instances_from_imfs(imfs, &init_path, sync_point_names)?
+                    .expect("Could not snapshot instance from file that existed!")
+            } else if directory.children.contains(&init_server_path) {
+                snapshot_instances_from_imfs(imfs, &init_server_path, sync_point_names)?
+                    .expect("Could not snapshot instance from file that existed!")
+            } else if directory.children.contains(&init_client_path) {
+                snapshot_instances_from_imfs(imfs, &init_client_path, sync_point_names)?
+                    .expect("Could not snapshot instance from file that existed!")
+            } else {
+                RbxSnapshotInstance {
+                    class_name: Cow::Borrowed("Folder"),
+                    name: Cow::Borrowed(""),
+                    properties: HashMap::new(),
+                    children: Vec::new(),
+                    source_path: Some(directory.path.clone()),
+                    metadata: None,
+                }
+            };
+
+            // We have to be careful not to lose instance names that are
+            // specified in the project manifest. We store them in
+            // sync_point_names when the original tree is constructed.
+            instance.name = if let Some(actual_name) = sync_point_names.get(&directory.path) {
+                Cow::Owned(actual_name.clone())
+            } else {
+                Cow::Borrowed(directory.path
+                    .file_name().expect("Could not extract file name")
+                    .to_str().expect("Could not convert path to UTF-8"))
+            };
+
+            for child_path in &directory.children {
+                match child_path.file_name().unwrap().to_str().unwrap() {
+                    INIT_SCRIPT | INIT_SERVER_SCRIPT | INIT_CLIENT_SCRIPT => {
+                        // The existence of files with these names modifies the
+                        // parent instance and is handled above, so we can skip
+                        // them here.
+                    },
+                    _ => {
+                        match snapshot_instances_from_imfs(imfs, child_path, sync_point_names)? {
+                            Some(child) => {
+                                instance.children.push(child);
+                            },
+                            None => {},
+                        }
+                    },
+                }
+            }
+
+            Ok(Some(instance))
+        },
+        None => Err(SnapshotError::DidNotExist(imfs_path.to_path_buf())),
+    }
+}

server/src/rbx_snapshot.rs

@@ -0,0 +1,307 @@
+use std::{
+    str,
+    borrow::Cow,
+    collections::{HashMap, HashSet},
+    fmt,
+    path::PathBuf,
+};
+
+use rbx_tree::{RbxTree, RbxId, RbxInstanceProperties, RbxValue};
+
+use crate::{
+    path_map::PathMap,
+    project::InstanceProjectNodeMetadata,
+};
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+pub struct InstanceChanges {
+    pub added: HashSet<RbxId>,
+    pub removed: HashSet<RbxId>,
+    pub updated: HashSet<RbxId>,
+}
+
+impl fmt::Display for InstanceChanges {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(output, "InstanceChanges {{")?;
+
+        if !self.added.is_empty() {
+            writeln!(output, "    Added:")?;
+            for id in &self.added {
+                writeln!(output, "        {}", id)?;
+            }
+        }
+
+        if !self.removed.is_empty() {
+            writeln!(output, "    Removed:")?;
+            for id in &self.removed {
+                writeln!(output, "        {}", id)?;
+            }
+        }
+
+        if !self.updated.is_empty() {
+            writeln!(output, "    Updated:")?;
+            for id in &self.updated {
+                writeln!(output, "        {}", id)?;
+            }
+        }
+
+        writeln!(output, "}}")
+    }
+}
+
+impl InstanceChanges {
+    pub fn is_empty(&self) -> bool {
+        self.added.is_empty() && self.removed.is_empty() && self.updated.is_empty()
+    }
+}
+
+#[derive(Debug)]
+pub struct RbxSnapshotInstance<'a> {
+    pub name: Cow<'a, str>,
+    pub class_name: Cow<'a, str>,
+    pub properties: HashMap<String, RbxValue>,
+    pub children: Vec<RbxSnapshotInstance<'a>>,
+    pub source_path: Option<PathBuf>,
+    pub metadata: Option<InstanceProjectNodeMetadata>,
+}
+
+pub fn snapshot_from_tree(tree: &RbxTree, id: RbxId) -> Option<RbxSnapshotInstance<'static>> {
+    let instance = tree.get_instance(id)?;
+
+    let mut children = Vec::new();
+    for &child_id in instance.get_children_ids() {
+        children.push(snapshot_from_tree(tree, child_id)?);
+    }
+
+    Some(RbxSnapshotInstance {
+        name: Cow::Owned(instance.name.to_owned()),
+        class_name: Cow::Owned(instance.class_name.to_owned()),
+        properties: instance.properties.clone(),
+        children,
+        source_path: None,
+        metadata: None,
+    })
+}
+
+pub fn reify_root(
+    snapshot: &RbxSnapshotInstance,
+    path_map: &mut PathMap<RbxId>,
+    instance_metadata_map: &mut HashMap<RbxId, InstanceProjectNodeMetadata>,
+    changes: &mut InstanceChanges,
+) -> RbxTree {
+    let instance = reify_core(snapshot);
+    let mut tree = RbxTree::new(instance);
+    let root_id = tree.get_root_id();
+
+    if let Some(source_path) = &snapshot.source_path {
+        path_map.insert(source_path.clone(), root_id);
+    }
+
+    if let Some(metadata) = &snapshot.metadata {
+        instance_metadata_map.insert(root_id, metadata.clone());
+    }
+
+    changes.added.insert(root_id);
+
+    for child in &snapshot.children {
+        reify_subtree(child, &mut tree, root_id, path_map, instance_metadata_map, changes);
+    }
+
+    tree
+}
+
+pub fn reify_subtree(
+    snapshot: &RbxSnapshotInstance,
+    tree: &mut RbxTree,
+    parent_id: RbxId,
+    path_map: &mut PathMap<RbxId>,
+    instance_metadata_map: &mut HashMap<RbxId, InstanceProjectNodeMetadata>,
+    changes: &mut InstanceChanges,
+) {
+    let instance = reify_core(snapshot);
+    let id = tree.insert_instance(instance, parent_id);
+
+    if let Some(source_path) = &snapshot.source_path {
+        path_map.insert(source_path.clone(), id);
+    }
+
+    if let Some(metadata) = &snapshot.metadata {
+        instance_metadata_map.insert(id, metadata.clone());
+    }
+
+    changes.added.insert(id);
+
+    for child in &snapshot.children {
+        reify_subtree(child, tree, id, path_map, instance_metadata_map, changes);
+    }
+}
+
+pub fn reconcile_subtree(
+    tree: &mut RbxTree,
+    id: RbxId,
+    snapshot: &RbxSnapshotInstance,
+    path_map: &mut PathMap<RbxId>,
+    instance_metadata_map: &mut HashMap<RbxId, InstanceProjectNodeMetadata>,
+    changes: &mut InstanceChanges,
+) {
+    if let Some(source_path) = &snapshot.source_path {
+        path_map.insert(source_path.clone(), id);
+    }
+
+    if let Some(metadata) = &snapshot.metadata {
+        instance_metadata_map.insert(id, metadata.clone());
+    }
+
+    if reconcile_instance_properties(tree.get_instance_mut(id).unwrap(), snapshot) {
+        changes.updated.insert(id);
+    }
+
+    reconcile_instance_children(tree, id, snapshot, path_map, instance_metadata_map, changes);
+}
+
+fn reify_core(snapshot: &RbxSnapshotInstance) -> RbxInstanceProperties {
+    let mut properties = HashMap::new();
+
+    for (key, value) in &snapshot.properties {
+        properties.insert(key.clone(), value.clone());
+    }
+
+    let instance = RbxInstanceProperties {
+        name: snapshot.name.to_string(),
+        class_name: snapshot.class_name.to_string(),
+        properties,
+    };
+
+    instance
+}
+
+fn reconcile_instance_properties(instance: &mut RbxInstanceProperties, snapshot: &RbxSnapshotInstance) -> bool {
+    let mut has_diffs = false;
+
+    if instance.name != snapshot.name {
+        instance.name = snapshot.name.to_string();
+        has_diffs = true;
+    }
+
+    if instance.class_name != snapshot.class_name {
+        instance.class_name = snapshot.class_name.to_string();
+        has_diffs = true;
+    }
+
+    let mut property_updates = HashMap::new();
+
+    for (key, instance_value) in &instance.properties {
+        match snapshot.properties.get(key) {
+            Some(snapshot_value) => {
+                if snapshot_value != instance_value {
+                    property_updates.insert(key.clone(), Some(snapshot_value.clone()));
+                }
+            },
+            None => {
+                property_updates.insert(key.clone(), None);
+            },
+        }
+    }
+
+    for (key, snapshot_value) in &snapshot.properties {
+        if property_updates.contains_key(key) {
+            continue;
+        }
+
+        match instance.properties.get(key) {
+            Some(instance_value) => {
+                if snapshot_value != instance_value {
+                    property_updates.insert(key.clone(), Some(snapshot_value.clone()));
+                }
+            },
+            None => {
+                property_updates.insert(key.clone(), Some(snapshot_value.clone()));
+            },
+        }
+    }
+
+    has_diffs = has_diffs || !property_updates.is_empty();
+
+    for (key, change) in property_updates.drain() {
+        match change {
+            Some(value) => instance.properties.insert(key, value),
+            None => instance.properties.remove(&key),
+        };
+    }
+
+    has_diffs
+}
+
+fn reconcile_instance_children(
+    tree: &mut RbxTree,
+    id: RbxId,
+    snapshot: &RbxSnapshotInstance,
+    path_map: &mut PathMap<RbxId>,
+    instance_metadata_map: &mut HashMap<RbxId, InstanceProjectNodeMetadata>,
+    changes: &mut InstanceChanges,
+) {
+    let mut visited_snapshot_indices = HashSet::new();
+
+    let mut children_to_update: Vec<(RbxId, &RbxSnapshotInstance)> = Vec::new();
+    let mut children_to_add: Vec<&RbxSnapshotInstance> = Vec::new();
+    let mut children_to_remove: Vec<RbxId> = Vec::new();
+
+    let children_ids = tree.get_instance(id).unwrap().get_children_ids();
+
+    // Find all instances that were removed or updated, which we derive by
+    // trying to pair up existing instances to snapshots.
+    for &child_id in children_ids {
+        let child_instance = tree.get_instance(child_id).unwrap();
+
+        // Locate a matching snapshot for this instance
+        let mut matching_snapshot = None;
+        for (snapshot_index, child_snapshot) in snapshot.children.iter().enumerate() {
+            if visited_snapshot_indices.contains(&snapshot_index) {
+                continue;
+            }
+
+            // We assume that instances with the same name are probably pretty
+            // similar. This heuristic is similar to React's reconciliation
+            // strategy.
+            if child_snapshot.name == child_instance.name {
+                visited_snapshot_indices.insert(snapshot_index);
+                matching_snapshot = Some(child_snapshot);
+                break;
+            }
+        }
+
+        match matching_snapshot {
+            Some(child_snapshot) => {
+                children_to_update.push((child_instance.get_id(), child_snapshot));
+            },
+            None => {
+                children_to_remove.push(child_instance.get_id());
+            },
+        }
+    }
+
+    // Find all instancs that were added, which is just the snapshots we didn't
+    // match up to existing instances above.
+    for (snapshot_index, child_snapshot) in snapshot.children.iter().enumerate() {
+        if !visited_snapshot_indices.contains(&snapshot_index) {
+            children_to_add.push(child_snapshot);
+        }
+    }
+
+    for child_snapshot in &children_to_add {
+        reify_subtree(child_snapshot, tree, id, path_map, instance_metadata_map, changes);
+    }
+
+    for child_id in &children_to_remove {
+        if let Some(subtree) = tree.remove_instance(*child_id) {
+            for id in subtree.iter_all_ids() {
+                instance_metadata_map.remove(&id);
+                changes.removed.insert(id);
+            }
+        }
+    }
+
+    for (child_id, child_snapshot) in &children_to_update {
+        reconcile_subtree(tree, *child_id, child_snapshot, path_map, instance_metadata_map, changes);
+    }
+}

server/src/roblox_studio.rs

@@ -0,0 +1,63 @@
+//! Interactions with Roblox Studio's installation, including its location and
+//! mechanisms like PluginSettings.
+
+#![allow(dead_code)]
+
+use std::path::PathBuf;
+
+#[cfg(all(not(debug_assertions), not(feature = "bundle-plugin")))]
+compile_error!("`bundle-plugin` feature must be set for release builds.");
+
+#[cfg(feature = "bundle-plugin")]
+static PLUGIN_RBXM: &'static [u8] = include_bytes!("../target/plugin.rbxmx");
+
+#[cfg(target_os = "windows")]
+pub fn get_install_location() -> Option<PathBuf> {
+    use std::env;
+
+    let local_app_data = env::var("LocalAppData").ok()?;
+    let mut location = PathBuf::from(local_app_data);
+
+    location.push("Roblox");
+
+    Some(location)
+}
+
+#[cfg(target_os = "macos")]
+pub fn get_install_location() -> Option<PathBuf> {
+    unimplemented!();
+}
+
+#[cfg(not(any(target_os = "windows", target_os = "macos")))]
+pub fn get_install_location() -> Option<PathBuf> {
+    // Roblox Studio doesn't install on any other platforms!
+    None
+}
+
+pub fn get_plugin_location() -> Option<PathBuf> {
+    let mut location = get_install_location()?;
+
+    location.push("Plugins/Rojo.rbxmx");
+
+    Some(location)
+}
+
+#[cfg(feature = "bundle-plugin")]
+pub fn install_bundled_plugin() -> Option<()> {
+    use std::fs::File;
+    use std::io::Write;
+
+    info!("Installing plugin...");
+
+    let mut file = File::create(get_plugin_location()?).ok()?;
+    file.write_all(PLUGIN_RBXM).ok()?;
+
+    Some(())
+}
+
+#[cfg(not(feature = "bundle-plugin"))]
+pub fn install_bundled_plugin() -> Option<()> {
+    info!("Skipping plugin installation, bundle-plugin not set.");
+
+    Some(())
+}

server/src/session.rs

@@ -0,0 +1,61 @@
+use std::{
+    sync::{Arc, Mutex},
+    io,
+};
+
+use crate::{
+    message_queue::MessageQueue,
+    project::Project,
+    imfs::Imfs,
+    session_id::SessionId,
+    rbx_session::RbxSession,
+    rbx_snapshot::InstanceChanges,
+    fs_watcher::FsWatcher,
+};
+
+pub struct Session {
+    pub project: Arc<Project>,
+    pub session_id: SessionId,
+    pub message_queue: Arc<MessageQueue<InstanceChanges>>,
+    pub rbx_session: Arc<Mutex<RbxSession>>,
+    pub imfs: Arc<Mutex<Imfs>>,
+    _fs_watcher: FsWatcher,
+}
+
+impl Session {
+    pub fn new(project: Arc<Project>) -> io::Result<Session> {
+        let imfs = {
+            let mut imfs = Imfs::new();
+            imfs.add_roots_from_project(&project)?;
+
+            Arc::new(Mutex::new(imfs))
+        };
+        let message_queue = Arc::new(MessageQueue::new());
+
+        let rbx_session = Arc::new(Mutex::new(RbxSession::new(
+            Arc::clone(&project),
+            Arc::clone(&imfs),
+            Arc::clone(&message_queue),
+        )));
+
+        let fs_watcher = FsWatcher::start(
+            Arc::clone(&imfs),
+            Arc::clone(&rbx_session),
+        );
+
+        let session_id = SessionId::new();
+
+        Ok(Session {
+            project,
+            session_id,
+            message_queue,
+            rbx_session,
+            imfs,
+            _fs_watcher: fs_watcher,
+        })
+    }
+
+    pub fn get_project(&self) -> &Project {
+        &self.project
+    }
+}

server/src/session_id.rs

@@ -0,0 +1,11 @@
+use serde_derive::{Serialize, Deserialize};
+use uuid::Uuid;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct SessionId(Uuid);
+
+impl SessionId {
+    pub fn new() -> SessionId {
+        SessionId(Uuid::new_v4())
+    }
+}

server/src/vfs/mod.rs

@@ -1,7 +0,0 @@
-mod vfs_session;
-mod vfs_item;
-mod vfs_watcher;
-
-pub use self::vfs_session::*;
-pub use self::vfs_item::*;
-pub use self::vfs_watcher::*;

server/src/vfs/vfs_item.rs

@@ -1,36 +0,0 @@
-use std::collections::HashMap;
-
-/// A VfsItem represents either a file or directory as it came from the filesystem.
-///
-/// The interface here is intentionally simplified to make it easier to traverse
-/// files that have been read into memory.
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase", tag = "type")]
-pub enum VfsItem {
-    File {
-        route: Vec<String>,
-        file_name: String,
-        contents: String,
-    },
-    Dir {
-        route: Vec<String>,
-        file_name: String,
-        children: HashMap<String, VfsItem>,
-    },
-}
-
-impl VfsItem {
-    pub fn name(&self) -> &String {
-        match self {
-            &VfsItem::File { ref file_name , .. } => file_name,
-            &VfsItem::Dir { ref file_name , .. } => file_name,
-        }
-    }
-
-    pub fn route(&self) -> &[String] {
-        match self {
-            &VfsItem::File { ref route, .. } => route,
-            &VfsItem::Dir { ref route, .. } => route,
-        }
-    }
-}

server/src/vfs/vfs_session.rs

@@ -1,220 +0,0 @@
-use std::collections::HashMap;
-use std::fs::{self, File};
-use std::io::Read;
-use std::path::{Path, PathBuf};
-use std::time::Instant;
-
-use plugin::PluginChain;
-use vfs::VfsItem;
-
-/// Represents a virtual layer over multiple parts of the filesystem.
-///
-/// Paths in this system are represented as slices of strings, and are always
-/// relative to a partition, which is an absolute path into the real filesystem.
-pub struct VfsSession {
-    /// Contains all of the partitions mounted by the Vfs.
-    ///
-    /// These must be absolute paths!
-    partitions: HashMap<String, PathBuf>,
-
-    /// A chronologically-sorted list of routes that changed since the Vfs was
-    /// created, along with a timestamp denoting when.
-    change_history: Vec<VfsChange>,
-
-    /// When the Vfs was initialized; used for change tracking.
-    start_time: Instant,
-
-    plugin_chain: &'static PluginChain,
-}
-
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct VfsChange {
-    timestamp: f64,
-    route: Vec<String>,
-}
-
-impl VfsSession {
-    pub fn new(plugin_chain: &'static PluginChain) -> VfsSession {
-        VfsSession {
-            partitions: HashMap::new(),
-            start_time: Instant::now(),
-            change_history: Vec::new(),
-            plugin_chain,
-        }
-    }
-
-    pub fn get_partitions(&self) -> &HashMap<String, PathBuf> {
-        &self.partitions
-    }
-
-    pub fn insert_partition<P: Into<PathBuf>>(&mut self, name: &str, path: P) {
-        let path = path.into();
-
-        assert!(path.is_absolute());
-
-        self.partitions.insert(name.to_string(), path.into());
-    }
-
-    fn route_to_path(&self, route: &[String]) -> Option<PathBuf> {
-        let (partition_name, rest) = match route.split_first() {
-            Some((first, rest)) => (first, rest),
-            None => return None,
-        };
-
-        let partition = match self.partitions.get(partition_name) {
-            Some(v) => v,
-            None => return None,
-        };
-
-        // It's possible that the partition points to a file if `rest` is empty.
-        // Joining "" onto a path will put a trailing slash on, which causes
-        // file reads to fail.
-        let full_path = if rest.is_empty() {
-            partition.clone()
-        } else {
-            let joined = rest.join("/");
-            let relative = Path::new(&joined);
-
-            partition.join(relative)
-        };
-
-        Some(full_path)
-    }
-
-    fn read_dir<P: AsRef<Path>>(&self, route: &[String], path: P) -> Result<VfsItem, ()> {
-        let path = path.as_ref();
-        let reader = match fs::read_dir(path) {
-            Ok(v) => v,
-            Err(_) => return Err(()),
-        };
-
-        let mut children = HashMap::new();
-
-        for entry in reader {
-            let entry = match entry {
-                Ok(v) => v,
-                Err(_) => return Err(()),
-            };
-
-            let path = entry.path();
-            let name = path.file_name().unwrap().to_string_lossy().into_owned();
-
-            let mut child_route = route.iter().cloned().collect::<Vec<_>>();
-            child_route.push(name.clone());
-
-            match self.read_path(&child_route, &path) {
-                Ok(child_item) => {
-                    children.insert(name, child_item);
-                },
-                Err(_) => {},
-            }
-        }
-
-        let file_name = path.file_name().unwrap().to_string_lossy().into_owned();
-
-        Ok(VfsItem::Dir {
-            route: route.iter().cloned().collect::<Vec<_>>(),
-            file_name,
-            children,
-        })
-    }
-
-    fn read_file<P: AsRef<Path>>(&self, route: &[String], path: P) -> Result<VfsItem, ()> {
-        let path = path.as_ref();
-        let mut file = match File::open(path) {
-            Ok(v) => v,
-            Err(_) => return Err(()),
-        };
-
-        let mut contents = String::new();
-
-        match file.read_to_string(&mut contents) {
-            Ok(_) => {},
-            Err(_) => return Err(()),
-        }
-
-        let file_name = path.file_name().unwrap().to_string_lossy().into_owned();
-
-        Ok(VfsItem::File {
-            route: route.iter().cloned().collect::<Vec<_>>(),
-            file_name,
-            contents,
-        })
-    }
-
-    fn read_path<P: AsRef<Path>>(&self, route: &[String], path: P) -> Result<VfsItem, ()> {
-        let path = path.as_ref();
-
-        let metadata = match fs::metadata(path) {
-            Ok(v) => v,
-            Err(_) => return Err(()),
-        };
-
-        if metadata.is_dir() {
-            self.read_dir(route, path)
-        } else if metadata.is_file() {
-            self.read_file(route, path)
-        } else {
-            Err(())
-        }
-    }
-
-    /// Get the current time, used for logging timestamps for file changes.
-    pub fn current_time(&self) -> f64 {
-        let elapsed = self.start_time.elapsed();
-
-        elapsed.as_secs() as f64 + elapsed.subsec_nanos() as f64 * 1e-9
-    }
-
-    /// Register a new change to the filesystem at the given timestamp and VFS
-    /// route.
-    pub fn add_change(&mut self, timestamp: f64, route: Vec<String>) {
-        match self.plugin_chain.handle_file_change(&route) {
-            Some(routes) => {
-                for route in routes {
-                    self.change_history.push(VfsChange {
-                        timestamp,
-                        route,
-                    });
-                }
-            },
-            None => {}
-        }
-    }
-
-    /// Collect a list of changes that occured since the given timestamp.
-    pub fn changes_since(&self, timestamp: f64) -> &[VfsChange] {
-        let mut marker: Option<usize> = None;
-
-        for (index, value) in self.change_history.iter().enumerate().rev() {
-            if value.timestamp >= timestamp {
-                marker = Some(index);
-            } else {
-                break;
-            }
-        }
-
-        if let Some(index) = marker {
-            &self.change_history[index..]
-        } else {
-            &self.change_history[..0]
-        }
-    }
-
-    /// Read an item from the filesystem using the given VFS route.
-    pub fn read(&self, route: &[String]) -> Result<VfsItem, ()> {
-        match self.route_to_path(route) {
-            Some(path) => self.read_path(route, &path),
-            None => Err(()),
-        }
-    }
-
-    pub fn write(&self, _route: &[String], _item: VfsItem) -> Result<(), ()> {
-        unimplemented!()
-    }
-
-    pub fn delete(&self, _route: &[String]) -> Result<(), ()> {
-        unimplemented!()
-    }
-}

server/src/vfs/vfs_watcher.rs

@@ -1,108 +0,0 @@
-use std::path::PathBuf;
-use std::sync::{mpsc, Arc, Mutex};
-use std::thread;
-use std::time::Duration;
-
-use notify::{DebouncedEvent, RecommendedWatcher, RecursiveMode, Watcher};
-
-use pathext::path_to_route;
-use vfs::VfsSession;
-
-/// An object that registers watchers on the real filesystem and relays those
-/// changes to the virtual filesystem layer.
-pub struct VfsWatcher {
-    vfs: Arc<Mutex<VfsSession>>,
-}
-
-impl VfsWatcher {
-    pub fn new(vfs: Arc<Mutex<VfsSession>>) -> VfsWatcher {
-        VfsWatcher {
-            vfs,
-        }
-    }
-
-    fn start_watcher(
-        vfs: Arc<Mutex<VfsSession>>,
-        rx: mpsc::Receiver<DebouncedEvent>,
-        partition_name: String,
-        root_path: PathBuf,
-    ) {
-        loop {
-            let event = rx.recv().unwrap();
-
-            let mut vfs = vfs.lock().unwrap();
-            let current_time = vfs.current_time();
-
-            match event {
-                DebouncedEvent::Write(ref change_path) |
-                DebouncedEvent::Create(ref change_path) |
-                DebouncedEvent::Remove(ref change_path) => {
-                    if let Some(mut route) = path_to_route(&root_path, change_path) {
-                        route.insert(0, partition_name.clone());
-
-                        vfs.add_change(current_time, route);
-                    } else {
-                        eprintln!("Failed to get route from {}", change_path.display());
-                    }
-                },
-                DebouncedEvent::Rename(ref from_change, ref to_change) => {
-                    if let Some(mut route) = path_to_route(&root_path, from_change) {
-                        route.insert(0, partition_name.clone());
-
-                        vfs.add_change(current_time, route);
-                    } else {
-                        eprintln!("Failed to get route from {}", from_change.display());
-                    }
-
-                    if let Some(mut route) = path_to_route(&root_path, to_change) {
-                        route.insert(0, partition_name.clone());
-
-                        vfs.add_change(current_time, route);
-                    } else {
-                        eprintln!("Failed to get route from {}", to_change.display());
-                    }
-                },
-                _ => {},
-            }
-        }
-    }
-
-    pub fn start(self) {
-        let mut watchers = Vec::new();
-
-        // Create an extra scope so that `vfs` gets dropped and unlocked
-        {
-            let vfs = self.vfs.lock().unwrap();
-
-            for (ref partition_name, ref root_path) in vfs.get_partitions() {
-                let (tx, rx) = mpsc::channel();
-
-                let mut watcher: RecommendedWatcher = Watcher::new(tx, Duration::from_millis(200))
-                    .expect("Unable to create watcher! This is a bug in Rojo.");
-
-                match watcher.watch(&root_path, RecursiveMode::Recursive) {
-                    Ok(_) => (),
-                    Err(_) => {
-                        panic!("Unable to watch partition {}, with path {}! Make sure that it's a file or directory.", partition_name, root_path.display());
-                    },
-                }
-
-                watchers.push(watcher);
-
-                {
-                    let partition_name = partition_name.to_string();
-                    let root_path = root_path.to_path_buf();
-                    let vfs = self.vfs.clone();
-
-                    thread::spawn(move || {
-                        Self::start_watcher(vfs, rx, partition_name, root_path);
-                    });
-                }
-            }
-        }
-
-        loop {
-            thread::park();
-        }
-    }
-}

server/src/visualize.rs

@@ -0,0 +1,141 @@
+use std::{
+    fmt,
+    io::Write,
+    path::Path,
+    process::{Command, Stdio},
+};
+
+use rbx_tree::RbxId;
+
+use crate::{
+    imfs::{Imfs, ImfsItem},
+    rbx_session::RbxSession,
+};
+
+static GRAPHVIZ_HEADER: &str = r#"
+digraph RojoTree {
+    rankdir = "LR";
+    graph [
+        ranksep = "0.7",
+        nodesep = "0.5",
+    ];
+    node [
+        fontname = "Hack",
+        shape = "record",
+    ];
+"#;
+
+pub fn graphviz_to_svg(source: &str) -> String {
+    let mut child = Command::new("dot")
+        .arg("-Tsvg")
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()
+        .expect("Failed to spawn GraphViz process -- make sure it's installed in order to use /api/visualize");
+
+    {
+        let stdin = child.stdin.as_mut().expect("Failed to open stdin");
+        stdin.write_all(source.as_bytes()).expect("Failed to write to stdin");
+    }
+
+    let output = child.wait_with_output().expect("Failed to read stdout");
+    String::from_utf8(output.stdout).expect("Failed to parse stdout as UTF-8")
+}
+
+pub struct VisualizeRbxSession<'a>(pub &'a RbxSession);
+
+impl<'a> fmt::Display for VisualizeRbxSession<'a> {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(output, "{}", GRAPHVIZ_HEADER)?;
+
+        visualize_rbx_node(self.0, self.0.get_tree().get_root_id(), output)?;
+
+        writeln!(output, "}}")?;
+
+        Ok(())
+    }
+}
+
+fn visualize_rbx_node(session: &RbxSession, id: RbxId, output: &mut fmt::Formatter) -> fmt::Result {
+    let node = session.get_tree().get_instance(id).unwrap();
+
+    let mut node_label = format!("{}|{}|{}", node.name, node.class_name, id);
+
+    if let Some(metadata) = session.get_instance_metadata(id) {
+        node_label.push('|');
+        node_label.push_str(&serde_json::to_string(metadata).unwrap());
+    }
+
+    node_label = node_label
+        .replace("\"", "&quot;")
+        .replace("{", "\\{")
+        .replace("}", "\\}");
+
+    writeln!(output, "    \"{}\" [label=\"{}\"]", id, node_label)?;
+
+    for &child_id in node.get_children_ids() {
+        writeln!(output, "    \"{}\" -> \"{}\"", id, child_id)?;
+        visualize_rbx_node(session, child_id, output)?;
+    }
+
+    Ok(())
+}
+
+pub struct VisualizeImfs<'a>(pub &'a Imfs);
+
+impl<'a> fmt::Display for VisualizeImfs<'a> {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(output, "{}", GRAPHVIZ_HEADER)?;
+
+        for root_path in self.0.get_roots() {
+            visualize_root_path(self.0, root_path, output)?;
+        }
+
+        writeln!(output, "}}")?;
+
+        Ok(())
+    }
+}
+
+fn normalize_name(path: &Path) -> String {
+    path.to_str().unwrap().replace("\\", "/")
+}
+
+fn visualize_root_path(imfs: &Imfs, path: &Path, output: &mut fmt::Formatter) -> fmt::Result {
+    let normalized_name = normalize_name(path);
+    let item = imfs.get(path).unwrap();
+
+    writeln!(output, "    \"{}\"", normalized_name)?;
+
+    match item {
+        ImfsItem::File(_) => {},
+        ImfsItem::Directory(directory) => {
+            for child_path in &directory.children {
+                writeln!(output, "    \"{}\" -> \"{}\"", normalized_name, normalize_name(child_path))?;
+                visualize_path(imfs, child_path, output)?;
+            }
+        },
+    }
+
+    Ok(())
+}
+
+fn visualize_path(imfs: &Imfs, path: &Path, output: &mut fmt::Formatter) -> fmt::Result {
+    let normalized_name = normalize_name(path);
+    let short_name = path.file_name().unwrap().to_string_lossy();
+    let item = imfs.get(path).unwrap();
+
+    writeln!(output, "    \"{}\" [label = \"{}\"]", normalized_name, short_name)?;
+
+    match item {
+        ImfsItem::File(_) => {},
+        ImfsItem::Directory(directory) => {
+            for child_path in &directory.children {
+                writeln!(output, "    \"{}\" -> \"{}\"", normalized_name, normalize_name(child_path))?;
+                visualize_path(imfs, child_path, output)?;
+            }
+        },
+    }
+
+    Ok(())
+}

server/src/web.rs

@@ -1,225 +1,221 @@
-use std::io::Read;
-use std::sync::{Arc, Mutex};
+use std::{
+    borrow::Cow,
+    collections::{HashMap, HashSet},
+    sync::{mpsc, Arc},
+};
 
-use rouille;
-use serde;
-use serde_json;
+use rouille::{
+    self,
+    router,
+    Request,
+    Response,
+};
+use rbx_tree::{RbxId, RbxInstance};
 
-use project::Project;
-use vfs::{VfsSession, VfsChange};
-use rbx::RbxInstance;
-use plugin::PluginChain;
+use crate::{
+    session::Session,
+    session_id::SessionId,
+    project::InstanceProjectNodeMetadata,
+    rbx_snapshot::InstanceChanges,
+    visualize::{VisualizeRbxSession, VisualizeImfs, graphviz_to_svg},
+};
 
-static MAX_BODY_SIZE: usize = 25 * 1024 * 1024; // 25 MiB
-
-/// The set of configuration the web server needs to start.
-pub struct WebConfig {
-    pub port: u64,
-    pub verbose: bool,
-    pub server_id: u64,
-}
-
-#[derive(Debug, Serialize)]
-#[serde(rename_all = "camelCase")]
-struct ServerInfo<'a> {
-    server_version: &'static str,
-    protocol_version: u64,
-    server_id: &'a str,
-    project: &'a Project,
-    current_time: f64,
-}
-
-#[derive(Debug, Serialize)]
-#[serde(rename_all = "camelCase")]
-struct ReadResult<'a> {
-    items: Vec<Option<RbxInstance>>,
-    server_id: &'a str,
-    current_time: f64,
-}
-
-#[derive(Debug, Serialize)]
-#[serde(rename_all = "camelCase")]
-struct ChangesResult<'a> {
-    changes: &'a [VfsChange],
-    server_id: &'a str,
-    current_time: f64,
-}
-
-#[derive(Debug, Deserialize)]
-#[serde(rename_all = "camelCase")]
-struct WriteSpecifier {
-    route: String,
-    item: RbxInstance,
-}
-
-fn json<T: serde::Serialize>(value: T) -> rouille::Response {
-    let data = serde_json::to_string(&value).unwrap();
-    rouille::Response::from_data("application/json", data)
-}
-
-/// Pulls text that may be JSON out of a Rouille Request object.
+/// Used to attach metadata specific to Rojo to instances, which come from the
+/// rbx_tree crate.
 ///
-/// Doesn't do any actual parsing -- all this method does is verify the content
-/// type of the request and read the request's body.
-fn read_json_text(request: &rouille::Request) -> Option<String> {
-    // Bail out if the request body isn't marked as JSON
-    match request.header("Content-Type") {
-        Some(header) => if !header.starts_with("application/json") {
-            return None;
-        },
-        None => return None,
-    }
+/// Both fields are wrapped in Cow in order to make owned-vs-borrowed simpler
+/// for tests.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct InstanceWithMetadata<'a> {
+    #[serde(flatten)]
+    pub instance: Cow<'a, RbxInstance>,
 
-    let body = match request.data() {
-        Some(v) => v,
-        None => return None,
-    };
-
-    // Allocate a buffer and read up to MAX_BODY_SIZE+1 bytes into it.
-    let mut out = Vec::new();
-    match body.take(MAX_BODY_SIZE.saturating_add(1) as u64).read_to_end(&mut out) {
-        Ok(_) => {},
-        Err(_) => return None,
-    }
-
-    // If the body was too big (MAX_BODY_SIZE+1), we abort instead of trying to
-    // process it.
-    if out.len() > MAX_BODY_SIZE {
-        return None;
-    }
-
-    let parsed = match String::from_utf8(out) {
-        Ok(v) => v,
-        Err(_) => return None,
-    };
-
-    Some(parsed)
+    #[serde(rename = "Metadata")]
+    pub metadata: Option<Cow<'a, InstanceProjectNodeMetadata>>,
 }
 
-/// Reads the body out of a Rouille Request and attempts to turn it into JSON.
-fn read_json<T>(request: &rouille::Request) -> Option<T>
-where
-    T: serde::de::DeserializeOwned,
-{
-    let body = match read_json_text(&request) {
-        Some(v) => v,
-        None => return None,
-    };
-
-    let parsed = match serde_json::from_str(&body) {
-        Ok(v) => v,
-        Err(_) => return None,
-    };
-
-    // TODO: Change return type to some sort of Result
-
-    Some(parsed)
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ServerInfoResponse<'a> {
+    pub session_id: SessionId,
+    pub server_version: &'a str,
+    pub protocol_version: u64,
+    pub expected_place_ids: Option<HashSet<u64>>,
+    pub root_instance_id: RbxId,
 }
 
-/// Start the Rojo web server and park our current thread.
-pub fn start(config: WebConfig, project: Project, plugin_chain: &'static PluginChain, vfs: Arc<Mutex<VfsSession>>) {
-    let address = format!("localhost:{}", config.port);
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ReadResponse<'a> {
+    pub session_id: SessionId,
+    pub message_cursor: u32,
+    pub instances: HashMap<RbxId, InstanceWithMetadata<'a>>,
+}
 
-    let server_id = config.server_id.to_string();
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SubscribeResponse<'a> {
+    pub session_id: SessionId,
+    pub message_cursor: u32,
+    pub messages: Cow<'a, [InstanceChanges]>,
+}
+
+pub struct Server {
+    session: Arc<Session>,
+    server_version: &'static str,
+}
+
+impl Server {
+    pub fn new(session: Arc<Session>) -> Server {
+        Server {
+            session,
+            server_version: env!("CARGO_PKG_VERSION"),
+        }
+    }
+
+    #[allow(unreachable_code)]
+    pub fn handle_request(&self, request: &Request) -> Response {
+        trace!("Request {} {}", request.method(), request.url());
 
-    rouille::start_server(address, move |request| {
         router!(request,
             (GET) (/) => {
+                Response::text("Rojo is up and running!")
+            },
+
+            (GET) (/api/rojo) => {
                 // Get a summary of information about the server.
 
-                let current_time = {
-                    let vfs = vfs.lock().unwrap();
+                let rbx_session = self.session.rbx_session.lock().unwrap();
+                let tree = rbx_session.get_tree();
 
-                    vfs.current_time()
-                };
-
-                json(ServerInfo {
-                    server_version: env!("CARGO_PKG_VERSION"),
-                    protocol_version: 1,
-                    server_id: &server_id,
-                    project: &project,
-                    current_time,
+                Response::json(&ServerInfoResponse {
+                    server_version: self.server_version,
+                    protocol_version: 2,
+                    session_id: self.session.session_id,
+                    expected_place_ids: self.session.project.serve_place_ids.clone(),
+                    root_instance_id: tree.get_root_id(),
                 })
             },
 
-            (GET) (/changes/{ last_time: f64 }) => {
-                // Get the list of changes since the given time.
+            (GET) (/api/subscribe/{ cursor: u32 }) => {
+                // Retrieve any messages past the given cursor index, and if
+                // there weren't any, subscribe to receive any new messages.
 
-                let vfs = vfs.lock().unwrap();
-                let current_time = vfs.current_time();
-                let changes = vfs.changes_since(last_time);
+                let message_queue = Arc::clone(&self.session.message_queue);
 
-                json(ChangesResult {
-                    changes,
-                    server_id: &server_id,
-                    current_time,
-                })
-            },
+                // Did the client miss any messages since the last subscribe?
+                {
+                    let (new_cursor, new_messages) = message_queue.get_messages_since(cursor);
 
-            (POST) (/read) => {
-                // Read some instances from the server according to a JSON
-                // format body.
-
-                let read_request: Vec<Vec<String>> = match read_json(&request) {
-                    Some(v) => v,
-                    None => return rouille::Response::empty_400(),
-                };
-
-                // Read the files off of the filesystem that the client
-                // requested.
-                let (items, current_time) = {
-                    let vfs = vfs.lock().unwrap();
-
-                    let current_time = vfs.current_time();
-
-                    let mut items = Vec::new();
-
-                    for route in &read_request {
-                        match vfs.read(&route) {
-                            Ok(v) => items.push(Some(v)),
-                            Err(_) => items.push(None),
-                        }
+                    if !new_messages.is_empty() {
+                        return Response::json(&SubscribeResponse {
+                            session_id: self.session.session_id,
+                            messages: Cow::Borrowed(&new_messages),
+                            message_cursor: new_cursor,
+                        })
                     }
-
-                    (items, current_time)
-                };
-
-                // Transform all of our VfsItem objects into Roblox instances
-                // the client can use.
-                let rbx_items = items
-                    .iter()
-                    .map(|item| {
-                        match *item {
-                            Some(ref item) => plugin_chain.transform_file(item),
-                            None => None,
-                        }
-                    })
-                    .collect::<Vec<_>>();
-
-                if config.verbose {
-                    println!("Got read request: {:?}", read_request);
-                    println!("Responding with:\n\t{:?}", rbx_items);
                 }
 
-                json(ReadResult {
-                    server_id: &server_id,
-                    items: rbx_items,
-                    current_time,
+                let (tx, rx) = mpsc::channel();
+
+                let sender_id = message_queue.subscribe(tx);
+
+                match rx.recv() {
+                    Ok(_) => (),
+                    Err(_) => return Response::text("error!").with_status_code(500),
+                }
+
+                message_queue.unsubscribe(sender_id);
+
+                {
+                    let (new_cursor, new_messages) = message_queue.get_messages_since(cursor);
+
+                    return Response::json(&SubscribeResponse {
+                        session_id: self.session.session_id,
+                        messages: Cow::Owned(new_messages),
+                        message_cursor: new_cursor,
+                    })
+                }
+            },
+
+            (GET) (/api/read/{ id_list: String }) => {
+                let message_queue = Arc::clone(&self.session.message_queue);
+
+                let requested_ids: Option<Vec<RbxId>> = id_list
+                    .split(',')
+                    .map(RbxId::parse_str)
+                    .collect();
+
+                let requested_ids = match requested_ids {
+                    Some(id) => id,
+                    None => return rouille::Response::text("Malformed ID list").with_status_code(400),
+                };
+
+                let rbx_session = self.session.rbx_session.lock().unwrap();
+                let tree = rbx_session.get_tree();
+
+                let message_cursor = message_queue.get_message_cursor();
+
+                let mut instances = HashMap::new();
+
+                for &requested_id in &requested_ids {
+                    if let Some(instance) = tree.get_instance(requested_id) {
+                        let metadata = rbx_session.get_instance_metadata(requested_id)
+                            .map(Cow::Borrowed);
+
+                        instances.insert(instance.get_id(), InstanceWithMetadata {
+                            instance: Cow::Borrowed(instance),
+                            metadata,
+                        });
+
+                        for descendant in tree.descendants(requested_id) {
+                            let descendant_meta = rbx_session.get_instance_metadata(descendant.get_id())
+                                .map(Cow::Borrowed);
+
+                            instances.insert(descendant.get_id(), InstanceWithMetadata {
+                                instance: Cow::Borrowed(descendant),
+                                metadata: descendant_meta,
+                            });
+                        }
+                    }
+                }
+
+                Response::json(&ReadResponse {
+                    session_id: self.session.session_id,
+                    message_cursor,
+                    instances,
                 })
             },
 
-            (POST) (/write) => {
-                // Not yet implemented.
+            (GET) (/visualize/rbx) => {
+                let rbx_session = self.session.rbx_session.lock().unwrap();
 
-                let _write_request: Vec<WriteSpecifier> = match read_json(&request) {
-                    Some(v) => v,
-                    None => return rouille::Response::empty_400(),
-                };
+                let dot_source = format!("{}", VisualizeRbxSession(&rbx_session));
 
-                rouille::Response::empty_404()
+                Response::svg(graphviz_to_svg(&dot_source))
             },
 
-            _ => rouille::Response::empty_404()
+            (GET) (/visualize/imfs) => {
+                let imfs = self.session.imfs.lock().unwrap();
+
+                let dot_source = format!("{}", VisualizeImfs(&imfs));
+
+                Response::svg(graphviz_to_svg(&dot_source))
+            },
+
+            (GET) (/visualize/path_map) => {
+                let rbx_session = self.session.rbx_session.lock().unwrap();
+
+                Response::json(&rbx_session.debug_get_path_map())
+            },
+
+            _ => Response::empty_404()
         )
-    });
-}
+    }
+
+    pub fn listen(self, port: u16) {
+        let address = format!("0.0.0.0:{}", port);
+
+        rouille::start_server(address, move |request| self.handle_request(request));
+    }
+}