Merge plugin back into main repository (#49)

.editorconfig

@@ -4,12 +4,6 @@ root = true
 end_of_line = lf
 charset = utf-8
 
-[*.rs]
-indent_style = space
-indent_size = 4
-trim_trailing_whitespace = true
-insert_final_newline = true
-
 [*.json]
 indent_style = space
 indent_size = 2

.gitmodules

@@ -0,0 +1,15 @@
+[submodule "plugin/modules/roact"]
+	path = plugin/modules/roact
+	url = https://github.com/Roblox/roact.git
+[submodule "plugin/modules/rodux"]
+	path = plugin/modules/rodux
+	url = https://github.com/Roblox/rodux.git
+[submodule "plugin/modules/roact-rodux"]
+	path = plugin/modules/roact-rodux
+	url = https://github.com/Roblox/roact-rodux.git
+[submodule "plugin/modules/testez"]
+	path = plugin/modules/testez
+	url = https://github.com/Roblox/testez.git
+[submodule "plugin/modules/lemur"]
+	path = plugin/modules/lemur
+	url = https://github.com/LPGhatguy/lemur.git

.travis.yml

@@ -1,5 +1,39 @@
-language: rust
+matrix:
+  include:
+    - language: python
+      env:
+        - LUA="lua=5.1"
 
-rust:
+      before_install:
-  - stable
+        - pip install hererocks
-  - beta
+        - hererocks lua_install -r^ --$LUA
+        - export PATH=$PATH:$PWD/lua_install/bin
+
+      install:
+        - luarocks install luafilesystem
+        - luarocks install busted
+        - luarocks install luacov
+        - luarocks install luacov-coveralls
+        - luarocks install luacheck
+
+      script:
+        - cd plugin
+        - luacheck src
+        - lua -lluacov spec.lua
+
+      after_success:
+        - cd plugin
+        - luacov-coveralls -e $TRAVIS_BUILD_DIR/lua_install
+
+    - language: rust
+      rust: stable
+
+      script:
+        - cd server
+        - cargo test --verbose
+    - language: rust
+      rust: beta
+
+      script:
+        - cd server
+        - cargo test --verbose

CHANGES.md

@@ -1,7 +1,8 @@
 # Rojo Change Log
 
 ## Current Master
-*No changes*
+* Merged plugin repository into main Rojo repository for easier tracking
+* Improved `RouteMap` object tracking; this should fix some cases of duplicated instances being synced into the tree.
 
 ## 0.4.0 (March 27, 2018)
 * Protocol version 1, which shifts more responsibility onto the server

README.md

@@ -1,5 +1,5 @@
 <div align="center">
-  <img src="assets/rojo-logo.png" alt="Rojo" height="150" />
+  <img src="assets/rojo-logo.png" alt="Rojo" height="217" />
 </div>
 
 <div>&nbsp;</div>
@@ -14,15 +14,12 @@
 
 <hr />
 
-**Rojo** is a flexible multi-tool designed for creating robust Roblox projects. It's in early development, but is still useful for many projects.
+**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.
 
-This is the main Rojo repository, containing the Rojo CLI. The Roblox Studio plugin is contained in [the rojo-plugin repository](https://github.com/LPGhatguy/rojo-plugin).
-
 ## Features
-
+Rojo lets you:
-Rojo has a number of desirable features *right now*:
 
 * Work on scripts from the filesystem, in your favorite editor
 * Version your place, library, or plugin using Git or another VCS
@@ -30,24 +27,34 @@ Rojo has a number of desirable features *right now*:
 
 Later this year, Rojo will be able to:
 
-* Sync rbxmx-format Roblox models bi-directionally between the filesystem and Roblox Studio
+* Sync `rbxmx` models between the filesystem and Roblox Studio
-* Package libraries and plugins into `rbxmx` files from the command line
+* Package projects into `rbxmx` files from the command line
 
 ## Installation
 Rojo has two components:
-* The command line interface (CLI), written in Rust
-* The [Roblox Studio plugin](https://www.roblox.com/library/1211549683/Rojo), written in Lua
 
-To install the command line tool, there are two options:
+* The server, a binary written in Rust
-* Cargo, if you have Rust installed
+* The plugin, a Roblox Studio plugin written in Lua
-	* Use `cargo install rojo` -- Rojo will be available with the `rojo` command
-* Download a pre-built Windows binary from [the GitHub releases page](https://github.com/LPGhatguy/rojo/releases)
 
-## Usage
+It's important that the plugin and server are compatible. The plugin will show errors in the Roblox Studio Output window if there is a version mismatch.
+
+To install the server, either:
+
+* If you have Rust installed, use `cargo install rojo`
+* Or, download a pre-built Windows binary from [the GitHub releases page](https://github.com/LPGhatguy/rojo/releases)
+
+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
+
+## Server Usage
 For more help, use `rojo help`.
 
 ### New Project
-Just create a new folder and tell Rojo to initialize it!
+Create a new folder, then use `rojo init` inside that folder to initialize an empty project:
 
 ```sh
 mkdir my-new-project
@@ -56,9 +63,9 @@ cd my-new-project
 rojo init
 ```
 
-Rojo will create an empty project in the directory.
+Rojo will create an empty project file named `rojo.json` in the directory.
 
-The default project looks like this:
+The default project file is:
 
 ```json
 {
@@ -69,7 +76,7 @@ The default project looks like this:
 ```
 
 ### Start Dev Server
-To create a server that allows the Rojo Studio plugin to access your project, use:
+To start the Rojo dev server, use:
 
 ```sh
 rojo serve
@@ -83,7 +90,7 @@ The tool will tell you whether it found an existing project. You should then be
 In the mean-time, manually migrating scripts is probably the best route forward.
 
 ### Syncing into Roblox
-In order to sync code into Roblox, you'll need toadd one or more *partitions* to your configuration. A partition tells Rojo how to map directories on your filesystem to Roblox objects.
+In order to sync code into Roblox, you'll need to add one or more *partitions* to your configuration. A partition tells Rojo how to map directories on your filesystem to Roblox objects.
 
 Each entry in the `partitions` map has a unique name, a filesystem path, and the full name of the Roblox object to sync into.
 
@@ -142,9 +149,11 @@ Will turn into these instances in Roblox:
 * `my-game` (`LocalScript` with source from `my-game/init.client.lua`)
 	* `foo` (`ModuleScript` with source from `my-game/foo.lua`)
 
-`*.model.json` files are intended as a simple way to represent non-script Roblox instances on the filesystem until `rbxmx` and `rbxlx` support is implemented in Rojo.
+`*.model.json` files are a way to represent simple Roblox instances on the filesystem until `rbxmx` and `rbxlx` support is implemented in Rojo.
 
-JSON Model files are fairly strict, with every property being required. They generally look like this:
+This feature is intended for small instances, like `RemoteEvent` or `*Value` objects.
+
+JSON Model files are strict, with every property being required. They look like this:
 
 ```json
 {
@@ -192,9 +201,7 @@ I also have a couple tools that Rojo intends to replace:
 ## Contributing
 Pull requests are welcome!
 
-The `master` branch of both repositories have tests running on Travis for every commit and pull request. The test suite on `master` should always pass!
+All pull requests are run against a test suite on Travis CI. That test suite should always pass!
-
-The Rojo and Rojo Plugin repositories should stay in sync with eachother, so that the current `master` of each repository can be used together.
 
 ## License
 Rojo is available under the terms of the MIT license. See [LICENSE.md](LICENSE.md) for details.

plugin/.editorconfig

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

plugin/.gitignore

@@ -0,0 +1 @@
+/luacov.*

plugin/.luacheckrc

@@ -0,0 +1,56 @@
+stds.roblox = {
+	read_globals = {
+		game = {
+			other_fields = true,
+		},
+
+		-- Roblox globals
+		"script",
+
+		-- Extra functions
+		"tick", "warn", "spawn",
+		"wait", "settings", "typeof",
+
+		-- Types
+		"Vector2", "Vector3",
+		"Color3",
+		"UDim", "UDim2",
+		"Rect",
+		"CFrame",
+		"Enum",
+		"Instance",
+	}
+}
+
+stds.plugin = {
+	read_globals = {
+		"plugin",
+	}
+}
+
+stds.testez = {
+	read_globals = {
+		"describe",
+		"it", "itFOCUS", "itSKIP",
+		"FOCUS", "SKIP", "HACK_NO_XPCALL",
+		"expect",
+	}
+}
+
+ignore = {
+	"212", -- unused arguments
+	"421", -- shadowing local variable
+	"422", -- shadowing argument
+	"431", -- shadowing upvalue
+	"432", -- shadowing upvalue argument
+}
+
+std = "lua51+roblox"
+
+files["**/*.server.lua"] = {
+	std = "+plugin",
+}
+
+files["**/*.spec.lua"] = {
+	std = "+testez",
+}

plugin/.luacov

@@ -0,0 +1,8 @@
+return {
+	include = {
+		"^src",
+	},
+	exclude = {
+		"%.spec$",
+	},
+}

plugin/rojo.json

@@ -0,0 +1,30 @@
+{
+  "name": "rojo",
+  "servePort": 8000,
+  "partitions": {
+    "plugin": {
+      "path": "src",
+      "target": "ReplicatedStorage.Rojo.plugin"
+    },
+    "modules/roact": {
+      "path": "modules/roact/lib",
+      "target": "ReplicatedStorage.Rojo.modules.Roact"
+    },
+    "modules/rodux": {
+      "path": "modules/rodux/lib",
+      "target": "ReplicatedStorage.Rojo.modules.Rodux"
+    },
+    "modules/roact-rodux": {
+      "path": "modules/roact-rodux/lib",
+      "target": "ReplicatedStorage.Rojo.modules.RoactRodux"
+    },
+    "modules/testez": {
+      "path": "modules/testez/lib",
+      "target": "ReplicatedStorage.TestEZ"
+    },
+    "tests": {
+      "path": "tests",
+      "target": "TestService"
+    }
+  }
+}

plugin/spec.lua

@@ -0,0 +1,69 @@
+--[[
+	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"},
+}
+
+-- 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)
+
+-- Load TestEZ and run our tests
+local TestEZ = habitat:require(Root.TestEZ)
+
+local results = TestEZ.TestBootstrap:run(Root.Plugin, TestEZ.Reporters.TextReporter)
+
+-- Did something go wrong?
+if results.failureCount > 0 then
+	os.exit(1)
+end

plugin/src/Config.lua

@@ -0,0 +1,7 @@
+return {
+	pollingRate = 0.2,
+	version = {0, 4, 1},
+	expectedServerVersionString = "0.4.x",
+	protocolVersion = 1,
+	dev = false,
+}

plugin/src/Config.spec.lua

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

plugin/src/Http.lua

@@ -0,0 +1,67 @@
+local HttpService = game:GetService("HttpService")
+
+local HTTP_DEBUG = false
+
+local Promise = require(script.Parent.Promise)
+local HttpError = require(script.Parent.HttpError)
+local HttpResponse = require(script.Parent.HttpResponse)
+
+local function dprint(...)
+	if HTTP_DEBUG then
+		print(...)
+	end
+end
+
+local Http = {}
+Http.__index = Http
+
+function Http.new(baseUrl)
+	assert(type(baseUrl) == "string", "Http.new needs a baseUrl!")
+
+	local http = {
+		baseUrl = baseUrl
+	}
+
+	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)
+			end)
+
+			if ok then
+				dprint("\t", result, "\n")
+				resolve(HttpResponse.new(result))
+			else
+				reject(HttpError.fromErrorString(result))
+			end
+		end)
+	end)
+end
+
+function Http:post(endpoint, body)
+	dprint("\nPOST", endpoint)
+	dprint(body)
+	return Promise.new(function(resolve, reject)
+		spawn(function()
+			local ok, result = pcall(function()
+				return HttpService:PostAsync(self.baseUrl .. endpoint, body)
+			end)
+
+			if ok then
+				dprint("\t", result, "\n")
+				resolve(HttpResponse.new(result))
+			else
+				reject(HttpError.fromErrorString(result))
+			end
+		end)
+	end)
+end
+
+return Http

plugin/src/HttpError.lua

@@ -0,0 +1,57 @@
+local HttpError = {}
+HttpError.__index = HttpError
+
+HttpError.Error = {
+	HttpNotEnabled = {
+		message = "Rojo requires HTTP access, which is not enabled.\n" ..
+			"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!",
+	},
+	Unknown = {
+		message = "Rojo encountered an unknown error: {{message}}",
+	},
+}
+
+function HttpError.new(type, extraMessage)
+	extraMessage = extraMessage or ""
+	local message = type.message:gsub("{{message}}", extraMessage)
+
+	local err = {
+		type = type,
+		message = message,
+	}
+
+	setmetatable(err, HttpError)
+
+	return err
+end
+
+function HttpError:__tostring()
+	return self.message
+end
+
+--[[
+	This method shouldn't have to exist. Ugh.
+]]
+function HttpError.fromErrorString(err)
+	err = err:lower()
+
+	if err:find("^http requests are not enabled") then
+		return HttpError.new(HttpError.Error.HttpNotEnabled)
+	end
+
+	if err:find("^curl error") then
+		return HttpError.new(HttpError.Error.ConnectFailed)
+	end
+
+	return HttpError.new(HttpError.Error.Unknown, err)
+end
+
+function HttpError:report()
+	warn(self.message)
+end
+
+return HttpError

plugin/src/HttpResponse.lua

@@ -0,0 +1,20 @@
+local HttpService = game:GetService("HttpService")
+
+local HttpResponse = {}
+HttpResponse.__index = HttpResponse
+
+function HttpResponse.new(body)
+	local response = {
+		body = body,
+	}
+
+	setmetatable(response, HttpResponse)
+
+	return response
+end
+
+function HttpResponse:json()
+	return HttpService:JSONDecode(self.body)
+end
+
+return HttpResponse

plugin/src/Main.server.lua

@@ -0,0 +1,79 @@
+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()
+	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
+
+	-- When developing Rojo, there's no use in storing that version number.
+	if not Config.dev then
+		plugin:SetSetting("LastRojoVersion", Config.version)
+	end
+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", "")
+		.Click:Connect(function()
+			checkUpgrade()
+
+			pluginInstance:connect()
+				:catch(function(err)
+					warn(err)
+				end)
+		end)
+
+	toolbar:CreateButton("Sync In", "Sync into Roblox Studio", "")
+		.Click:Connect(function()
+			checkUpgrade()
+
+			pluginInstance:syncIn()
+				:catch(function(err)
+					warn(err)
+				end)
+		end)
+
+	toolbar:CreateButton("Toggle Polling", "Poll server for changes", "")
+		.Click:Connect(function()
+			checkUpgrade()
+
+			spawn(function()
+				pluginInstance:togglePolling()
+					:catch(function(err)
+						warn(err)
+					end)
+			end)
+		end)
+end
+
+main()

plugin/src/Plugin.lua

@@ -0,0 +1,198 @@
+local Config = require(script.Parent.Config)
+local Http = require(script.Parent.Http)
+local Server = require(script.Parent.Server)
+local Promise = require(script.Parent.Promise)
+local Reconciler = require(script.Parent.Reconciler)
+
+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(),
+		_server = nil,
+		_polling = false,
+	}
+
+	setmetatable(self, Plugin)
+
+	do
+		local screenGui = Instance.new("ScreenGui")
+		screenGui.Name = "Rojo UI"
+		screenGui.Parent = game.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
+	end
+
+	return self
+end
+
+function Plugin:server()
+	if not self._server then
+		self._server = Server.connect(self._http)
+			:catch(function(err)
+				self._server = nil
+				return Promise.reject(err)
+			end)
+	end
+
+	return self._server
+end
+
+function Plugin:connect()
+	print("Testing connection...")
+
+	return self:server()
+		:andThen(function(server)
+			return server:getInfo()
+		end)
+		:andThen(function(result)
+			print("Server found!")
+			print("Protocol version:", result.protocolVersion)
+			print("Server version:", result.serverVersion)
+		end)
+end
+
+function Plugin:togglePolling()
+	if self._polling then
+		self:stopPolling()
+
+		return Promise.resolve(nil)
+	else
+		return self:startPolling()
+	end
+end
+
+function Plugin:stopPolling()
+	if not self._polling then
+		return
+	end
+
+	print("Stopped polling.")
+
+	self._polling = false
+	self._label.Enabled = false
+end
+
+function Plugin:_pull(server, project, routes)
+	local items = server:read(routes):await()
+
+	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
+
+function Plugin:startPolling()
+	if self._polling then
+		return
+	end
+
+	print("Starting to poll...")
+
+	self._polling = true
+	self._label.Enabled = true
+
+	return self:server()
+		:andThen(function(server)
+			self:syncIn():await()
+
+			local project = server:getInfo():await().project
+
+			while self._polling do
+				local changes = server:getChanges():await()
+
+				if #changes > 0 then
+					local routes = {}
+
+					for _, change in ipairs(changes) do
+						table.insert(routes, change.route)
+					end
+
+					self:_pull(server, project, routes)
+				end
+
+				wait(Config.pollingRate)
+			end
+		end)
+		:catch(function()
+			self:stopPolling()
+		end)
+end
+
+function Plugin:syncIn()
+	print("Syncing from server...")
+
+	return self:server()
+		:andThen(function(server)
+			local project = server:getInfo():await().project
+
+			local routes = {}
+
+			for name in pairs(project.partitions) do
+				table.insert(routes, {name})
+			end
+
+			self:_pull(server, project, routes)
+
+			print("Sync successful!")
+		end)
+end
+
+return Plugin

plugin/src/Promise.lua

@@ -0,0 +1,311 @@
+--[[
+	An implementation of Promises similar to Promise/A+.
+]]
+
+local PROMISE_DEBUG = false
+
+-- If promise debugging is on, use a version of pcall that warns on failure.
+-- This is useful for finding errors that happen within Promise itself.
+local wpcall
+if PROMISE_DEBUG then
+	wpcall = function(f, ...)
+		local result = { pcall(f, ...) }
+
+		if not result[1] then
+			warn(result[2])
+		end
+
+		return unpack(result)
+	end
+else
+	wpcall = pcall
+end
+
+--[[
+	Creates a function that invokes a callback with correct error handling and
+	resolution mechanisms.
+]]
+local function createAdvancer(callback, resolve, reject)
+	return function(...)
+		local result = { wpcall(callback, ...) }
+		local ok = table.remove(result, 1)
+
+		if ok then
+			resolve(unpack(result))
+		else
+			reject(unpack(result))
+		end
+	end
+end
+
+local function isEmpty(t)
+	return next(t) == nil
+end
+
+local Promise = {}
+Promise.__index = Promise
+
+Promise.Status = {
+	Started = "Started",
+	Resolved = "Resolved",
+	Rejected = "Rejected",
+}
+
+--[[
+	Constructs a new Promise with the given initializing callback.
+
+	This is generally only called when directly wrapping a non-promise API into
+	a promise-based version.
+
+	The callback will receive 'resolve' and 'reject' methods, used to start
+	invoking the promise chain.
+
+	For example:
+
+		local function get(url)
+			return Promise.new(function(resolve, reject)
+				spawn(function()
+					resolve(HttpService:GetAsync(url))
+				end)
+			end)
+		end
+
+		get("https://google.com")
+			:andThen(function(stuff)
+				print("Got some stuff!", stuff)
+			end)
+]]
+function Promise.new(callback)
+	local promise = {
+		-- Used to locate where a promise was created
+		_source = debug.traceback(),
+
+		-- A tag to identify us as a promise
+		_type = "Promise",
+
+		_status = Promise.Status.Started,
+
+		-- A table containing a list of all results, whether success or failure.
+		-- Only valid if _status is set to something besides Started
+		_value = nil,
+
+		-- If an error occurs with no observers, this will be set.
+		_unhandledRejection = false,
+
+		-- Queues representing functions we should invoke when we update!
+		_queuedResolve = {},
+		_queuedReject = {},
+	}
+
+	setmetatable(promise, Promise)
+
+	local function resolve(...)
+		promise:_resolve(...)
+	end
+
+	local function reject(...)
+		promise:_reject(...)
+	end
+
+	local ok, err = wpcall(callback, resolve, reject)
+
+	if not ok and promise._status == Promise.Status.Started then
+		reject(err)
+	end
+
+	return promise
+end
+
+--[[
+	Create a promise that represents the immediately resolved value.
+]]
+function Promise.resolve(value)
+	return Promise.new(function(resolve)
+		resolve(value)
+	end)
+end
+
+--[[
+	Create a promise that represents the immediately rejected value.
+]]
+function Promise.reject(value)
+	return Promise.new(function(_, reject)
+		reject(value)
+	end)
+end
+
+--[[
+	Returns a new promise that:
+		* is resolved when all input promises resolve
+		* is rejected if ANY input promises reject
+]]
+function Promise.all(...)
+	error("unimplemented", 2)
+end
+
+--[[
+	Is the given object a Promise instance?
+]]
+function Promise.is(object)
+	if type(object) ~= "table" then
+		return false
+	end
+
+	return object._type == "Promise"
+end
+
+--[[
+	Creates a new promise that receives the result of this promise.
+
+	The given callbacks are invoked depending on that result.
+]]
+function Promise:andThen(successHandler, failureHandler)
+	self._unhandledRejection = false
+
+	-- Create a new promise to follow this part of the chain
+	return Promise.new(function(resolve, reject)
+		-- Our default callbacks just pass values onto the next promise.
+		-- This lets success and failure cascade correctly!
+
+		local successCallback = resolve
+		if successHandler then
+			successCallback = createAdvancer(successHandler, resolve, reject)
+		end
+
+		local failureCallback = reject
+		if failureHandler then
+			failureCallback = createAdvancer(failureHandler, resolve, reject)
+		end
+
+		if self._status == Promise.Status.Started then
+			-- If we haven't resolved yet, put ourselves into the queue
+			table.insert(self._queuedResolve, successCallback)
+			table.insert(self._queuedReject, failureCallback)
+		elseif self._status == Promise.Status.Resolved then
+			-- This promise has already resolved! Trigger success immediately.
+			successCallback(unpack(self._value))
+		elseif self._status == Promise.Status.Rejected then
+			-- This promise died a terrible death! Trigger failure immediately.
+			failureCallback(unpack(self._value))
+		end
+	end)
+end
+
+--[[
+	Used to catch any errors that may have occurred in the promise.
+]]
+function Promise:catch(failureCallback)
+	return self:andThen(nil, failureCallback)
+end
+
+--[[
+	Yield until the promise is completed.
+
+	This matches the execution model of normal Roblox functions.
+]]
+function Promise:await()
+	self._unhandledRejection = false
+
+	if self._status == Promise.Status.Started then
+		local result
+		local bindable = Instance.new("BindableEvent")
+
+		self:andThen(function(...)
+			result = {...}
+			bindable:Fire(true)
+		end, function(...)
+			result = {...}
+			bindable:Fire(false)
+		end)
+
+		local ok = bindable.Event:Wait()
+		bindable:Destroy()
+
+		if not ok then
+			error(tostring(result[1]), 2)
+		end
+
+		return unpack(result)
+	elseif self._status == Promise.Status.Resolved then
+		return unpack(self._value)
+	elseif self._status == Promise.Status.Rejected then
+		error(tostring(self._value[1]), 2)
+	end
+end
+
+function Promise:_resolve(...)
+	if self._status ~= Promise.Status.Started then
+		return
+	end
+
+	-- If the resolved value was a Promise, we chain onto it!
+	if Promise.is((...)) then
+		-- Without this warning, arguments sometimes mysteriously disappear
+		if select("#", ...) > 1 then
+			local message = (
+				"When returning a Promise from andThen, extra arguments are " ..
+				"discarded! See:\n\n%s"
+			):format(
+				self._source
+			)
+			warn(message)
+		end
+
+		(...):andThen(function(...)
+			self:_resolve(...)
+		end, function(...)
+			self:_reject(...)
+		end)
+
+		return
+	end
+
+	self._status = Promise.Status.Resolved
+	self._value = {...}
+
+	-- We assume that these callbacks will not throw errors.
+	for _, callback in ipairs(self._queuedResolve) do
+		callback(...)
+	end
+end
+
+function Promise:_reject(...)
+	if self._status ~= Promise.Status.Started then
+		return
+	end
+
+	self._status = Promise.Status.Rejected
+	self._value = {...}
+
+	-- If there are any rejection handlers, call those!
+	if not isEmpty(self._queuedReject) then
+		-- We assume that these callbacks will not throw errors.
+		for _, callback in ipairs(self._queuedReject) do
+			callback(...)
+		end
+	else
+		-- At this point, no one was able to observe the error.
+		-- An error handler might still be attached if the error occurred
+		-- synchronously. We'll wait one tick, and if there are still no
+		-- observers, then we should put a message in the console.
+
+		self._unhandledRejection = true
+		local err = tostring((...))
+
+		spawn(function()
+			-- Someone observed the error, hooray!
+			if not self._unhandledRejection then
+				return
+			end
+
+			-- Build a reasonable message
+			local message = ("Unhandled promise rejection:\n\n%s\n\n%s"):format(
+				err,
+				self._source
+			)
+			warn(message)
+		end)
+	end
+end
+
+return Promise

plugin/src/Promise.spec.lua

@@ -0,0 +1,262 @@
+return function()
+	local Promise = require(script.Parent.Promise)
+
+	describe("Promise.new", function()
+		it("should instantiate with a callback", function()
+			local promise = Promise.new(function() end)
+
+			expect(promise).to.be.ok()
+		end)
+
+		it("should invoke the given callback with resolve and reject", function()
+			local callCount = 0
+			local resolveArg
+			local rejectArg
+
+			local promise = Promise.new(function(resolve, reject)
+				callCount = callCount + 1
+				resolveArg = resolve
+				rejectArg = reject
+			end)
+
+			expect(promise).to.be.ok()
+
+			expect(callCount).to.equal(1)
+			expect(resolveArg).to.be.a("function")
+			expect(rejectArg).to.be.a("function")
+			expect(promise._status).to.equal(Promise.Status.Started)
+		end)
+
+		it("should resolve promises on resolve()", function()
+			local callCount = 0
+
+			local promise = Promise.new(function(resolve)
+				callCount = callCount + 1
+				resolve()
+			end)
+
+			expect(promise).to.be.ok()
+			expect(callCount).to.equal(1)
+			expect(promise._status).to.equal(Promise.Status.Resolved)
+		end)
+
+		it("should reject promises on reject()", function()
+			local callCount = 0
+
+			local promise = Promise.new(function(resolve, reject)
+				callCount = callCount + 1
+				reject()
+			end)
+
+			expect(promise).to.be.ok()
+			expect(callCount).to.equal(1)
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+		end)
+
+		it("should reject on error in callback", function()
+			local callCount = 0
+
+			local promise = Promise.new(function()
+				callCount = callCount + 1
+				error("hahah")
+			end)
+
+			expect(promise).to.be.ok()
+			expect(callCount).to.equal(1)
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]:find("hahah")).to.be.ok()
+		end)
+	end)
+
+	describe("Promise.resolve", function()
+		it("should immediately resolve with a value", function()
+			local promise = Promise.resolve(5)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Resolved)
+			expect(promise._value[1]).to.equal(5)
+		end)
+
+		it("should chain onto passed promises", function()
+			local promise = Promise.resolve(Promise.new(function(_, reject)
+				reject(7)
+			end))
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]).to.equal(7)
+		end)
+	end)
+
+	describe("Promise.reject", function()
+		it("should immediately reject with a value", function()
+			local promise = Promise.reject(6)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]).to.equal(6)
+		end)
+
+		it("should pass a promise as-is as an error", function()
+			local innerPromise = Promise.new(function(resolve)
+				resolve(6)
+			end)
+
+			local promise = Promise.reject(innerPromise)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]).to.equal(innerPromise)
+		end)
+	end)
+
+	describe("Promise:andThen", function()
+		it("should chain onto resolved promises", function()
+			local args
+			local argsLength
+			local callCount = 0
+			local badCallCount = 0
+
+			local promise = Promise.resolve(5)
+
+			local chained = promise
+				:andThen(function(...)
+					args = {...}
+					argsLength = select("#", ...)
+					callCount = callCount + 1
+				end, function()
+					badCallCount = badCallCount + 1
+				end)
+
+			expect(badCallCount).to.equal(0)
+
+			expect(callCount).to.equal(1)
+			expect(argsLength).to.equal(1)
+			expect(args[1]).to.equal(5)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Resolved)
+			expect(promise._value[1]).to.equal(5)
+
+			expect(chained).to.be.ok()
+			expect(chained).never.to.equal(promise)
+			expect(chained._status).to.equal(Promise.Status.Resolved)
+			expect(#chained._value).to.equal(0)
+		end)
+
+		it("should chain onto rejected promises", function()
+			local args
+			local argsLength
+			local callCount = 0
+			local badCallCount = 0
+
+			local promise = Promise.reject(5)
+
+			local chained = promise
+				:andThen(function(...)
+					badCallCount = badCallCount + 1
+				end, function(...)
+					args = {...}
+					argsLength = select("#", ...)
+					callCount = callCount + 1
+				end)
+
+			expect(badCallCount).to.equal(0)
+
+			expect(callCount).to.equal(1)
+			expect(argsLength).to.equal(1)
+			expect(args[1]).to.equal(5)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]).to.equal(5)
+
+			expect(chained).to.be.ok()
+			expect(chained).never.to.equal(promise)
+			expect(chained._status).to.equal(Promise.Status.Resolved)
+			expect(#chained._value).to.equal(0)
+		end)
+
+		it("should chain onto asynchronously resolved promises", function()
+			local args
+			local argsLength
+			local callCount = 0
+			local badCallCount = 0
+
+			local startResolution
+			local promise = Promise.new(function(resolve)
+				startResolution = resolve
+			end)
+
+			local chained = promise
+				:andThen(function(...)
+					args = {...}
+					argsLength = select("#", ...)
+					callCount = callCount + 1
+				end, function()
+					badCallCount = badCallCount + 1
+				end)
+
+			expect(callCount).to.equal(0)
+			expect(badCallCount).to.equal(0)
+
+			startResolution(6)
+
+			expect(badCallCount).to.equal(0)
+
+			expect(callCount).to.equal(1)
+			expect(argsLength).to.equal(1)
+			expect(args[1]).to.equal(6)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Resolved)
+			expect(promise._value[1]).to.equal(6)
+
+			expect(chained).to.be.ok()
+			expect(chained).never.to.equal(promise)
+			expect(chained._status).to.equal(Promise.Status.Resolved)
+			expect(#chained._value).to.equal(0)
+		end)
+
+		it("should chain onto asynchronously rejected promises", function()
+			local args
+			local argsLength
+			local callCount = 0
+			local badCallCount = 0
+
+			local startResolution
+			local promise = Promise.new(function(_, reject)
+				startResolution = reject
+			end)
+
+			local chained = promise
+				:andThen(function()
+					badCallCount = badCallCount + 1
+				end, function(...)
+					args = {...}
+					argsLength = select("#", ...)
+					callCount = callCount + 1
+				end)
+
+			expect(callCount).to.equal(0)
+			expect(badCallCount).to.equal(0)
+
+			startResolution(6)
+
+			expect(badCallCount).to.equal(0)
+
+			expect(callCount).to.equal(1)
+			expect(argsLength).to.equal(1)
+			expect(args[1]).to.equal(6)
+
+			expect(promise).to.be.ok()
+			expect(promise._status).to.equal(Promise.Status.Rejected)
+			expect(promise._value[1]).to.equal(6)
+
+			expect(chained).to.be.ok()
+			expect(chained).never.to.equal(promise)
+			expect(chained._status).to.equal(Promise.Status.Resolved)
+			expect(#chained._value).to.equal(0)
+		end)
+	end)
+end

plugin/src/Reconciler.lua

@@ -0,0 +1,203 @@
+local RouteMap = require(script.Parent.RouteMap)
+
+local function classEqual(rbx, className)
+	if className == "*" then
+		return true
+	end
+
+	return rbx.ClassName == className
+end
+
+local function reparent(rbx, parent)
+	if rbx then
+		-- 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.
+
+	An object is considered a match if they have the same Name and ClassName.
+
+	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!
+
+	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
+
+			for _, secondaryChild in ipairs(secondaryChildren) do
+				if primaryChild.ClassName == secondaryChild.ClassName and primaryChild.Name == secondaryChild.Name then
+					visited[secondaryChild] = true
+
+					return primaryChild, secondaryChild
+				end
+			end
+
+			return primaryChild, nil
+		end
+	end
+
+	return nil, nil
+end
+
+local Reconciler = {}
+Reconciler.__index = Reconciler
+
+function Reconciler.new()
+	local reconciler = {
+		_routeMap = RouteMap.new(),
+	}
+
+	setmetatable(reconciler, Reconciler)
+
+	return 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()
+
+	-- 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)
+	end
+end
+
+--[[
+	Construct a new Roblox object from the given item.
+]]
+function Reconciler:_reify(item)
+	local className = item.ClassName
+
+	-- "*" represents a match of any class. It reifies as a folder!
+	if className == "*" then
+		className = "Folder"
+	end
+
+	local rbx = Instance.new(className)
+	rbx.Name = item.Name
+
+	for key, property in pairs(item.Properties) do
+		-- TODO: Check for compound types, like Vector3!
+		rbx[key] = property.Value
+	end
+
+	self:_reconcileChildren(rbx, item)
+
+	if item.Route then
+		self._routeMap:insert(item.Route, rbx)
+	end
+
+	return rbx
+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
+			rbx:Destroy()
+		end
+
+		return nil
+	end
+
+	-- Item was created!
+	if not rbx then
+		return self:_reify(item)
+	end
+
+	-- Item changed type!
+	if not classEqual(rbx, item.ClassName) then
+		rbx:Destroy()
+
+		rbx = self:_reify(item)
+	end
+
+	-- Apply all properties, Roblox will de-duplicate changes
+	for key, property in pairs(item.Properties) do
+		-- TODO: Transform property value based on property.Type
+		-- Right now, we assume that 'value' is primitive!
+
+		rbx[key] = property.Value
+	end
+
+	-- Use a dumb algorithm for reconciling children
+	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)
+		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
+		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)
+end
+
+return Reconciler

plugin/src/RouteMap.lua

@@ -0,0 +1,103 @@
+--[[
+	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)
+
+	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 then
+		self._map[hashedRoute] = nil
+		self._reverseMap[rbx] = nil
+		self._connectionsByRbx[rbx] = nil
+	end
+end
+
+function RouteMap:removeByRbx(rbx)
+	local hashedRoute = self._reverseMap[rbx]
+
+	if hashedRoute then
+		self._map[hashedRoute] = nil
+		self._reverseMap[rbx] = nil
+		self._connectionsByRbx[rbx] = nil
+	end
+end
+
+function RouteMap:removeRbxDescendants(parentRbx)
+	for rbx in pairs(self._reverseMap) do
+		if rbx:IsDescendantOf(parentRbx) then
+			self:removeByRbx(rbx)
+		end
+	end
+end
+
+function RouteMap:clear()
+	self._map = {}
+	self._reverseMap = {}
+
+	for object in pairs(self._connectionsByRbx) do
+		object: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/Server.lua

@@ -0,0 +1,89 @@
+local HttpService = game:GetService("HttpService")
+
+local Config = require(script.Parent.Config)
+local Promise = require(script.Parent.Promise)
+local Version = require(script.Parent.Version)
+
+local Server = {}
+Server.__index = Server
+
+--[[
+	Create a new Server using the given HTTP implementation and replacer.
+
+	If the context becomes invalid, `replacer` will be invoked with a new
+	context that should be suitable to replace this one.
+
+	Attempting to invoke methods on an invalid conext will throw errors!
+]]
+function Server.connect(http)
+	local context = {
+		http = http,
+		serverId = nil,
+		currentTime = 0,
+	}
+
+	setmetatable(context, Server)
+
+	return context:_start()
+end
+
+function Server:_start()
+	return self:getInfo()
+		:andThen(function(response)
+			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.expectedServerVersionString,
+					response.serverVersion, response.protocolVersion
+				)
+
+				return Promise.reject(message)
+			end
+
+			self.serverId = response.serverId
+			self.currentTime = response.currentTime
+
+			return self
+		end)
+end
+
+function Server:getInfo()
+	return self.http:get("/")
+		:andThen(function(response)
+			response = response:json()
+
+			return response
+		end)
+end
+
+function Server:read(paths)
+	local body = HttpService:JSONEncode(paths)
+
+	return self.http:post("/read", body)
+		:andThen(function(response)
+			response = response:json()
+
+			return response.items
+		end)
+end
+
+function Server:getChanges()
+	local url = ("/changes/%f"):format(self.currentTime)
+
+	return self.http:get(url)
+		:andThen(function(response)
+			response = response:json()
+
+			self.currentTime = response.currentTime
+
+			return response.changes
+		end)
+end
+
+return Server

plugin/src/Version.lua

@@ -0,0 +1,40 @@
+local function compare(a, b)
+	if a > b then
+		return 1
+	elseif a < b then
+		return -1
+	end
+
+	return 0
+end
+
+local Version = {}
+
+--[[
+	Compares two versions of the form {major, minor, revision}.
+
+	If a is newer than b, 1.
+	If a is older than b, -1.
+	If a and b are the same, 0.
+]]
+function Version.compare(a, b)
+	local major = compare(a[1], b[1])
+	local minor = compare(a[2] or 0, b[2] or 0)
+	local revision = compare(a[3] or 0, b[3] or 0)
+
+	if major ~= 0 then
+		return major
+	end
+
+	if minor ~= 0 then
+		return minor
+	end
+
+	return revision
+end
+
+function Version.display(version)
+	return table.concat(version, ".")
+end
+
+return Version

plugin/src/Version.spec.lua

@@ -0,0 +1,28 @@
+return function()
+	local Version = require(script.Parent.Version)
+
+	it("should compare equal versions", function()
+		expect(Version.compare({1, 2, 3}, {1, 2, 3})).to.equal(0)
+		expect(Version.compare({0, 4, 0}, {0, 4})).to.equal(0)
+		expect(Version.compare({0, 0, 123}, {0, 0, 123})).to.equal(0)
+		expect(Version.compare({26}, {26})).to.equal(0)
+		expect(Version.compare({26, 42}, {26, 42})).to.equal(0)
+		expect(Version.compare({1, 0, 0}, {1})).to.equal(0)
+	end)
+
+	it("should compare newer, older versions", function()
+		expect(Version.compare({1}, {0})).to.equal(1)
+		expect(Version.compare({1, 1}, {1, 0})).to.equal(1)
+	end)
+
+	it("should compare different major versions", function()
+		expect(Version.compare({1, 3, 2}, {2, 2, 1})).to.equal(-1)
+		expect(Version.compare({1, 2}, {2, 1})).to.equal(-1)
+		expect(Version.compare({1}, {2})).to.equal(-1)
+	end)
+
+	it("should compare different minor versions", function()
+		expect(Version.compare({1, 2, 3}, {1, 3, 2})).to.equal(-1)
+		expect(Version.compare({50, 1}, {50, 2})).to.equal(-1)
+	end)
+end

plugin/src/runTests.lua

@@ -0,0 +1,4 @@
+return function()
+	local TestEZ = require(script.Parent.Parent.TestEZ)
+	TestEZ.TestBootstrap:run(script.Parent)
+end

plugin/tests/runTests.server.lua

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

server/.editorconfig

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