Release v7.0.0-alpha.4

* Ignore empty/whitespace-only model.json files

* Ignore no return value from model.json files during snapshot

* Use str::from_utf8 instead of String::from_utf8

* Revert "Ignore no return value from model.json files during snapshot"

This reverts commit 0aef16e30a.

* Add test for empty .model.json files

* Change empty .model.json check method

Co-authored-by: Lucien Greathouse <me@lpghatguy.com>

* Format code with cargo fmt

* Use raw string instead

Co-authored-by: Lucien Greathouse <me@lpghatguy.com>

CHANGELOG.md

@@ -2,6 +2,30 @@
 
 ## Unreleased Changes
 
+## [7.0.0-alpha.4][7.0.0-alpha.4] (May 5, 2021)
+* Added the `gameId` and `placeId` optional properties to project files.
+    * When connecting from the Rojo Roblox Studio plugin, Rojo will set the game and place ID of the current place to these values, if set.
+    * This is equivalent to running `game:SetUniverseId(...)` and `game:SetPlaceId(...)` from the command bar in Studio. 
+* Added "EXPERIMENTAL!" label to two-way sync toggle in Rojo's Roblox Studio plugin.
+* Fixed `Name` and `Parent` properties being allowed in Rojo projects. ([#413][pr-413])
+* Fixed "Open Scripts Externally" feature crashing Studio. ([#369][issue-369])
+* Empty `.model.json` files will no longer cause errors. ([#420][pr-420])
+* When specifying `$path` on a service, Rojo now keeps the correct class name. ([#331][issue-331])
+* Improved error messages for misconfigured projects.
+
+[issue-331]: https://github.com/rojo-rbx/rojo/issues/331
+[issue-369]: https://github.com/rojo-rbx/rojo/issues/369
+[pr-420]: https://github.com/rojo-rbx/rojo/pull/420
+[pr-413]: https://github.com/rojo-rbx/rojo/pull/413
+[7.0.0-alpha.4]: https://github.com/rojo-rbx/rojo/releases/tag/v7.0.0-alpha.4
+
+## [7.0.0-alpha.3][7.0.0-alpha.3] (February 19, 2021)
+* Updated dependencies, fixing `OptionalCoordinateFrame`-related issues.
+* Added `--address` flag to `rojo serve` to allow for external connections. ([#403][pr-403])
+
+[pr-403]: https://github.com/rojo-rbx/rojo/pull/403
+[7.0.0-alpha.3]: https://github.com/rojo-rbx/rojo/releases/tag/v7.0.0-alpha.3
+
 ## [7.0.0-alpha.2][7.0.0-alpha.2] (February 19, 2021)
 * Fixed incorrect protocol version between the client and server.
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rojo"
-version = "7.0.0-alpha.2"
+version = "7.0.0-alpha.4"
 authors = ["Lucien Greathouse <me@lpghatguy.com>"]
 description = "Enables professional-grade development tools for Roblox developers"
 license = "MPL-2.0"

foreman.toml

@@ -1,3 +1,3 @@
 [tools]
-rojo = { source = "rojo-rbx/rojo", version = "6.0.0-rc.3" }
+rojo = { source = "rojo-rbx/rojo", version = "6.1.0" }
 run-in-roblox = { source = "rojo-rbx/run-in-roblox", version = "0.3.0" }

plugin/rbx_dom_lua/.luacheckrc

@@ -1,44 +0,0 @@
-stds.roblox = {
-	read_globals = {
-		game = {
-			other_fields = true,
-		},
-
-		-- Roblox globals
-		"script",
-
-		-- Extra functions
-		"tick", "warn",
-		"wait", "typeof",
-
-		-- Types
-		"CFrame",
-		"Color3",
-		"Enum",
-		"Instance",
-		"NumberRange",
-		"Rect",
-		"UDim", "UDim2",
-		"Vector2", "Vector3",
-		"Vector2int16", "Vector3int16",
-	}
-}
-
-stds.testez = {
-	read_globals = {
-		"describe",
-		"it", "itFOCUS", "itSKIP",
-		"FOCUS", "SKIP", "HACK_NO_XPCALL",
-		"expect",
-	}
-}
-
-ignore = {
-	"212", -- unused arguments
-}
-
-std = "lua51+roblox"
-
-files["**/*.spec.lua"] = {
-	std = "+testez",
-}

plugin/rbx_dom_lua/README.md

@@ -1,2 +0,0 @@
-# rbx_dom_lua
-Roblox Lua implementation of rbx-dom mechanisms, intended to work with rbx_dom_weak and friends.

plugin/rbx_dom_lua/run-tests.lua

@@ -1 +0,0 @@
-require(game.ReplicatedStorage.TestEZ).TestBootstrap:run({game.ReplicatedStorage.RbxDom})

plugin/rbx_dom_lua/test

@@ -1,4 +0,0 @@
-#!/bin/sh
-
-rojo build test-place.project.json -o TestPlace.rbxlx
-run-in-roblox --script run-tests.lua --place TestPlace.rbxlx

plugin/rbx_dom_lua/test-place.project.json

@@ -1,35 +0,0 @@
-{
-  "name": "rbx_dom_lua test place",
-  "tree": {
-    "$className": "DataModel",
-    "ReplicatedStorage": {
-      "$className": "ReplicatedStorage",
-
-      "RbxDom": {
-        "$path": "src"
-      },
-      "TestEZ": {
-        "$path": "modules/testez/lib"
-      }
-    },
-    "ServerScriptService": {
-      "$className": "ServerScriptService",
-
-      "Run Tests": {
-        "$path": "run-tests.lua"
-      }
-    },
-    "Players": {
-      "$className": "Players",
-      "$properties": {
-        "CharacterAutoLoads": false
-      }
-    },
-    "HttpService": {
-      "$className": "HttpService",
-      "$properties": {
-        "HttpEnabled": true
-      }
-    }
-  }
-}

plugin/src/App/StatusPages/Settings.lua

@@ -205,7 +205,7 @@ function SettingsPage:render()
 			TwoWaySync = e(Setting, {
 				id = "twoWaySync",
 				name = "Two-Way Sync",
-				description = "Editing files in Studio will sync them into the filesystem",
+				description = "EXPERIMENTAL! Editing files in Studio will sync them into the filesystem",
 				transparency = self.props.transparency,
 				layoutOrder = 2,
 			}),

plugin/src/Config.lua

@@ -5,7 +5,7 @@ local isDevBuild = script.Parent.Parent:FindFirstChild("ROJO_DEV_BUILD") ~= nil
 return strict("Config", {
 	isDevBuild = isDevBuild,
 	codename = "Epiphany",
-	version = {7, 0, 0, "-alpha.2"},
+	version = {7, 0, 0, "-alpha.4"},
 	expectedServerVersionString = "7.0 or newer",
 	protocolVersion = 4,
 	defaultHost = "localhost",

plugin/src/ServeSession.lua

@@ -1,4 +1,5 @@
 local StudioService = game:GetService("StudioService")
+local RunService = game:GetService("RunService")
 
 local Log = require(script.Parent.Parent.Log)
 local Fmt = require(script.Parent.Parent.Fmt)
@@ -111,6 +112,7 @@ function ServeSession:start()
 	self.__apiContext:connect()
 		:andThen(function(serverInfo)
 			self:__setStatus(Status.Connected, serverInfo.projectName)
+			self:__applyGameAndPlaceId(serverInfo)
 
 			local rootInstanceId = serverInfo.rootInstanceId
 
@@ -128,6 +130,16 @@ function ServeSession:stop()
 	self:__stopInternal()
 end
 
+function ServeSession:__applyGameAndPlaceId(serverInfo)
+	if serverInfo.gameId ~= nil then
+		game:SetUniverseId(serverInfo.gameId)
+	end
+
+	if serverInfo.placeId ~= nil then
+		game:SetPlaceId(serverInfo.placeId)
+	end
+end
+
 function ServeSession:__onActiveScriptChanged(activeScript)
 	if not self.__openScriptsExternally then
 		Log.trace("Not opening script {} because feature not enabled.", activeScript)
@@ -150,10 +162,18 @@ function ServeSession:__onActiveScriptChanged(activeScript)
 
 	Log.debug("Trying to open script {} externally...", activeScript)
 
-	-- Force-close the script inside Studio
-	local existingParent = activeScript.Parent
-	activeScript.Parent = nil
-	activeScript.Parent = existingParent
+	-- Force-close the script inside Studio... with a small delay in the middle
+	-- to prevent Studio from crashing.
+	spawn(function()
+		local existingParent = activeScript.Parent
+		activeScript.Parent = nil
+
+		for i = 1, 3 do
+			RunService.Heartbeat:Wait()
+		end
+
+		activeScript.Parent = existingParent
+	end)
 
 	-- Notify the Rojo server to open this script
 	self.__apiContext:open(scriptId)

rojo-test/serve-test-snapshots/end_to_end__tests__serve__add_folder_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: add_folder
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-test-snapshots/end_to_end__tests__serve__edit_init_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: edit_init
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-test-snapshots/end_to_end__tests__serve__empty_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: empty
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-test-snapshots/end_to_end__tests__serve__empty_json_model_all-2.snap

@@ -0,0 +1,28 @@
+---
+source: tests/tests/serve.rs
+expression: "read_response.intern_and_redact(&mut redactions, root_id)"
+
+---
+instances:
+  id-2:
+    Children:
+      - id-3
+    ClassName: Folder
+    Id: id-2
+    Metadata:
+      ignoreUnknownInstances: false
+    Name: empty_folder
+    Parent: "00000000000000000000000000000000"
+    Properties: {}
+  id-3:
+    Children: []
+    ClassName: Model
+    Id: id-3
+    Metadata:
+      ignoreUnknownInstances: false
+    Name: test
+    Parent: id-2
+    Properties: {}
+messageCursor: 1
+sessionId: id-1
+

rojo-test/serve-test-snapshots/end_to_end__tests__serve__empty_json_model_all.snap

@@ -0,0 +1,18 @@
+---
+source: tests/tests/serve.rs
+expression: "read_response.intern_and_redact(&mut redactions, root_id)"
+
+---
+instances:
+  id-2:
+    Children: []
+    ClassName: Folder
+    Id: id-2
+    Metadata:
+      ignoreUnknownInstances: false
+    Name: empty_folder
+    Parent: "00000000000000000000000000000000"
+    Properties: {}
+messageCursor: 0
+sessionId: id-1
+

rojo-test/serve-test-snapshots/end_to_end__tests__serve__empty_json_model_info.snap

@@ -0,0 +1,14 @@
+---
+source: tests/tests/serve.rs
+expression: redactions.redacted_yaml(info)
+
+---
+expectedPlaceIds: ~
+gameId: ~
+placeId: ~
+projectName: empty_folder
+protocolVersion: 4
+rootInstanceId: id-2
+serverVersion: "[server-version]"
+sessionId: id-1
+

rojo-test/serve-test-snapshots/end_to_end__tests__serve__empty_json_model_subscribe.snap

@@ -0,0 +1,21 @@
+---
+source: tests/tests/serve.rs
+expression: "subscribe_response.intern_and_redact(&mut redactions, ())"
+
+---
+messageCursor: 1
+messages:
+  - added:
+      id-3:
+        Children: []
+        ClassName: Model
+        Id: id-3
+        Metadata:
+          ignoreUnknownInstances: false
+        Name: test
+        Parent: id-2
+        Properties: {}
+    removed: []
+    updated: []
+sessionId: id-1
+

rojo-test/serve-test-snapshots/end_to_end__tests__serve__move_folder_of_stuff_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: move_folder_of_stuff
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-test-snapshots/end_to_end__tests__serve__remove_file_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: remove_file
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-test-snapshots/end_to_end__tests__serve__scripts_info.snap

@@ -4,6 +4,8 @@ expression: redactions.redacted_yaml(info)
 
 ---
 expectedPlaceIds: ~
+gameId: ~
+placeId: ~
 projectName: scripts
 protocolVersion: 4
 rootInstanceId: id-2

rojo-test/serve-tests/empty_json_model/default.project.json

@@ -1,5 +1,5 @@
 {
-  "name": "rbx_dom_lua",
+  "name": "empty_folder",
   "tree": {
     "$path": "src"
   }

src/cli/mod.rs

@@ -12,6 +12,7 @@ use std::{
     env,
     error::Error,
     fmt,
+    net::IpAddr,
     path::{Path, PathBuf},
     str::FromStr,
 };
@@ -186,7 +187,11 @@ pub struct ServeCommand {
     #[structopt(default_value = "")]
     pub project: PathBuf,
 
-    /// The port to listen on. Defaults to the project's preference, or 34872 if
+    /// The IP address to listen on. Defaults to `127.0.0.1`.
+    #[structopt(long)]
+    pub address: Option<IpAddr>,
+
+    /// The port to listen on. Defaults to the project's preference, or `34872` if
     /// it has none.
     #[structopt(long)]
     pub port: Option<u16>,

src/cli/serve.rs

@@ -1,5 +1,7 @@
 use std::{
     io::{self, Write},
+    net::IpAddr,
+    net::Ipv4Addr,
     sync::Arc,
 };
 
@@ -13,6 +15,7 @@ use crate::{
     web::LiveServer,
 };
 
+const DEFAULT_BIND_ADDRESS: Ipv4Addr = Ipv4Addr::new(127, 0, 0, 1);
 const DEFAULT_PORT: u16 = 34872;
 
 pub fn serve(global: GlobalOptions, options: ServeCommand) -> Result<()> {
@@ -20,6 +23,8 @@ pub fn serve(global: GlobalOptions, options: ServeCommand) -> Result<()> {
 
     let session = Arc::new(ServeSession::new(vfs, &options.absolute_project())?);
 
+    let ip = options.address.unwrap_or(DEFAULT_BIND_ADDRESS.into());
+
     let port = options
         .port
         .or_else(|| session.project_port())
@@ -27,13 +32,13 @@ pub fn serve(global: GlobalOptions, options: ServeCommand) -> Result<()> {
 
     let server = LiveServer::new(session);
 
-    let _ = show_start_message(port, global.color.into());
-    server.start(port);
+    let _ = show_start_message(ip, port, global.color.into());
+    server.start((ip, port).into());
 
     Ok(())
 }
 
-fn show_start_message(port: u16, color: ColorChoice) -> io::Result<()> {
+fn show_start_message(bind_address: IpAddr, port: u16, color: ColorChoice) -> io::Result<()> {
     let writer = BufferWriter::stdout(color);
     let mut buffer = writer.buffer();
 
@@ -41,7 +46,12 @@ fn show_start_message(port: u16, color: ColorChoice) -> io::Result<()> {
 
     write!(&mut buffer, "  Address: ")?;
     buffer.set_color(ColorSpec::new().set_fg(Some(Color::Green)).set_bold(true))?;
-    writeln!(&mut buffer, "localhost")?;
+
+    if bind_address.is_loopback() {
+        writeln!(&mut buffer, "localhost")?;
+    } else {
+        writeln!(&mut buffer, "{}", bind_address)?;
+    }
 
     buffer.set_color(&ColorSpec::new())?;
     write!(&mut buffer, "  Port:    ")?;

src/project.rs

@@ -57,6 +57,14 @@ pub struct Project {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub serve_place_ids: Option<HashSet<u64>>,
 
+    /// If specified, sets the current place's place ID when connecting to the
+    /// Rojo server from Roblox Studio.
+    pub place_id: Option<u64>,
+
+    /// If specified, sets the current place's game ID when connecting to the
+    /// Rojo server from Roblox Studio.
+    pub game_id: Option<u64>,
+
     /// A list of globs, relative to the folder the project file is in, that
     /// match files that should be excluded if Rojo encounters them.
     #[serde(default, skip_serializing_if = "Vec::is_empty")]

src/serve_session.rs

@@ -195,6 +195,14 @@ impl ServeSession {
         self.root_project.serve_port
     }
 
+    pub fn place_id(&self) -> Option<u64> {
+        self.root_project.place_id
+    }
+
+    pub fn game_id(&self) -> Option<u64> {
+        self.root_project.game_id
+    }
+
     pub fn start_time(&self) -> Instant {
         self.start_time
     }

src/snapshot_middleware/json_model.rs

@@ -1,4 +1,4 @@
-use std::{borrow::Cow, collections::HashMap, path::Path};
+use std::{borrow::Cow, collections::HashMap, path::Path, str};
 
 use anyhow::Context;
 use memofs::Vfs;
@@ -18,7 +18,14 @@ pub fn snapshot_json_model(
     instance_name: &str,
 ) -> SnapshotInstanceResult {
     let contents = vfs.read(path)?;
-    let instance: JsonModel = serde_json::from_slice(&contents)
+    let contents_str = str::from_utf8(&contents)
+        .with_context(|| format!("File was not valid UTF-8: {}", path.display()))?;
+
+    if contents_str.trim().is_empty() {
+        return Ok(None);
+    }
+
+    let instance: JsonModel = serde_json::from_str(contents_str)
         .with_context(|| format!("File is not a valid JSON model: {}", path.display()))?;
 
     let mut snapshot = instance

src/snapshot_middleware/project.rs

@@ -1,6 +1,6 @@
 use std::{borrow::Cow, collections::HashMap, path::Path};
 
-use anyhow::Context;
+use anyhow::{bail, Context};
 use memofs::Vfs;
 use rbx_reflection::ClassTag;
 
@@ -66,11 +66,13 @@ pub fn snapshot_project_node(
 ) -> SnapshotInstanceResult {
     let project_folder = project_path.parent().unwrap();
 
-    let name = Cow::Owned(instance_name.to_owned());
-    let mut class_name = node
+    let class_name_from_project = node
         .class_name
         .as_ref()
         .map(|name| Cow::Owned(name.clone()));
+    let mut class_name_from_path = None;
+
+    let name = Cow::Owned(instance_name.to_owned());
     let mut properties = HashMap::new();
     let mut children = Vec::new();
     let mut metadata = InstanceMetadata::default();
@@ -85,24 +87,7 @@ pub fn snapshot_project_node(
         };
 
         if let Some(snapshot) = snapshot_from_vfs(context, vfs, &path)? {
-            // If a class name was already specified, then it'll override the
-            // class name of this snapshot ONLY if it's a Folder.
-            //
-            // This restriction is in place to prevent applying properties to
-            // instances that don't make sense. The primary use-case for using
-            // $className and $path at the same time is to use a directory as a
-            // service in a place file.
-            class_name = match class_name {
-                Some(class_name) => {
-                    if snapshot.class_name == "Folder" {
-                        Some(class_name)
-                    } else {
-                        // TODO: Turn this into an error object.
-                        panic!("If $className and $path are specified, $path must yield an instance of class Folder");
-                    }
-                }
-                None => Some(snapshot.class_name),
-            };
+            class_name_from_path = Some(snapshot.class_name);
 
             // Properties from the snapshot are pulled in unchanged, and
             // overridden by properties set on the project node.
@@ -129,34 +114,66 @@ pub fn snapshot_project_node(
         }
     }
 
-    let class_name = class_name
-        .or_else(|| {
-            // If className wasn't defined from another source, we may be able
-            // to infer one.
+    let class_name_from_inference = infer_class_name(&name, parent_class);
 
-            let parent_class = parent_class?;
+    let class_name = match (
+        class_name_from_project,
+        class_name_from_path,
+        class_name_from_inference,
+    ) {
+        // These are the easy, happy paths!
+        (Some(project), None, None) => project,
+        (None, Some(path), None) => path,
+        (None, None, Some(inference)) => inference,
 
-            if parent_class == "DataModel" {
-                // Members of DataModel with names that match known services are
-                // probably supposed to be those services.
+        // If the user specifies a class name, but there's an inferred class
+        // name, we prefer the name listed explicitly by the user.
+        (Some(project), None, Some(_)) => project,
 
-                let descriptor = rbx_reflection_database::get().classes.get(&name)?;
-
-                if descriptor.tags.contains(&ClassTag::Service) {
-                    return Some(name.clone());
-                }
-            } else if parent_class == "StarterPlayer" {
-                // StarterPlayer has two special members with their own classes.
-
-                if name == "StarterPlayerScripts" || name == "StarterCharacterScripts" {
-                    return Some(name.clone());
-                }
+        // If the user has a $path pointing to a folder and we're able to infer
+        // a class name, let's use the inferred name. If the path we're pointing
+        // to isn't a folder, though, that's a user error.
+        (None, Some(path), Some(inference)) => {
+            if path == "Folder" {
+                inference
+            } else {
+                path
             }
+        }
 
-            None
-        })
-        // TODO: Turn this into an error object.
-        .expect("$className or $path must be specified");
+        (Some(project), Some(path), _) => {
+            if path == "Folder" {
+                project
+            } else {
+                bail!(
+                    "ClassName for Instance \"{}\" was specified in both the project file (as \"{}\") and from the filesystem (as \"{}\").\n\
+                     If $className and $path are both set, $path must refer to a Folder.
+                     \n\
+                     Project path: {}\n\
+                     Filesystem path: {}\n",
+                    instance_name,
+                    project,
+                    path,
+                    project_path.display(),
+                    node.path.as_ref().unwrap().display()
+                );
+            }
+        }
+
+        (None, None, None) => {
+            bail!(
+                "Instance \"{}\" is missing some required information.\n\
+                 One of the following must be true:\n\
+                 - $className must be set to the name of a Roblox class\n\
+                 - $path must be set to a path of an instance\n\
+                 - The instance must be a known service, like ReplicatedStorage\n\
+                 \n\
+                 Project path: {}",
+                instance_name,
+                project_path.display(),
+            );
+        }
+    };
 
     for (child_name, child_project_node) in &node.children {
         if let Some(child) = snapshot_project_node(
@@ -182,6 +199,20 @@ pub fn snapshot_project_node(
                 )
             })?;
 
+        match key.as_str() {
+            "Name" | "Parent" => {
+                log::warn!(
+                    "Property '{}' cannot be set manually, ignoring. Attempted to set in '{}' at {}",
+                    key,
+                    instance_name,
+                    project_path.display()
+                );
+                continue;
+            }
+
+            _ => {}
+        }
+
         properties.insert(key.clone(), value);
     }
 
@@ -216,6 +247,32 @@ pub fn snapshot_project_node(
     }))
 }
 
+fn infer_class_name(name: &str, parent_class: Option<&str>) -> Option<Cow<'static, str>> {
+    // If className wasn't defined from another source, we may be able
+    // to infer one.
+
+    let parent_class = parent_class?;
+
+    if parent_class == "DataModel" {
+        // Members of DataModel with names that match known services are
+        // probably supposed to be those services.
+
+        let descriptor = rbx_reflection_database::get().classes.get(name)?;
+
+        if descriptor.tags.contains(&ClassTag::Service) {
+            return Some(Cow::Owned(name.to_owned()));
+        }
+    } else if parent_class == "StarterPlayer" {
+        // StarterPlayer has two special members with their own classes.
+
+        if name == "StarterPlayerScripts" || name == "StarterCharacterScripts" {
+            return Some(Cow::Owned(name.to_owned()));
+        }
+    }
+
+    None
+}
+
 // #[cfg(feature = "broken-tests")]
 #[cfg(test)]
 mod test {

src/snapshot_middleware/rbxm.rs

@@ -32,7 +32,7 @@ pub fn snapshot_rbxm(
         Ok(Some(snapshot))
     } else {
         anyhow::bail!(
-            "Rojo doesn't have support for model files with zero or more than one top-level instances yet.\n\n \
+            "Rojo currently only supports model files with one top-level instance.\n\n \
              Check the model file at path {}",
             path.display()
         );

src/snapshot_middleware/rbxmx.rs

@@ -35,7 +35,7 @@ pub fn snapshot_rbxmx(
         Ok(Some(snapshot))
     } else {
         anyhow::bail!(
-            "Rojo doesn't have support for model files with zero or more than one top-level instances yet.\n\n \
+            "Rojo currently only supports model files with one top-level instance.\n\n \
              Check the model file at path {}",
             path.display()
         );

src/web/api.rs

@@ -69,6 +69,8 @@ impl ApiService {
             session_id: self.serve_session.session_id(),
             project_name: self.serve_session.project_name().to_owned(),
             expected_place_ids: self.serve_session.serve_place_ids().cloned(),
+            place_id: self.serve_session.place_id(),
+            game_id: self.serve_session.game_id(),
             root_instance_id,
         })
     }

src/web/interface.rs

@@ -104,6 +104,8 @@ pub struct ServerInfoResponse {
     pub protocol_version: u64,
     pub project_name: String,
     pub expected_place_ids: Option<HashSet<u64>>,
+    pub game_id: Option<u64>,
+    pub place_id: Option<u64>,
     pub root_instance_id: Ref,
 }
 

src/web/mod.rs

@@ -4,7 +4,7 @@ pub mod interface;
 mod ui;
 mod util;
 
-use std::sync::Arc;
+use std::{net::SocketAddr, sync::Arc};
 
 use futures::{
     future::{self, FutureResult},
@@ -57,9 +57,7 @@ impl LiveServer {
         LiveServer { serve_session }
     }
 
-    pub fn start(self, port: u16) {
-        let address = ([127, 0, 0, 1], port).into();
-
+    pub fn start(self, address: SocketAddr) {
         let server = Server::bind(&address)
             .serve(move || {
                 let service: FutureResult<_, hyper::Error> =

test-projects/bad_classname_path_conflict/default.project.json

@@ -0,0 +1,7 @@
+{
+  "name": "bad_classname_path_conflict",
+  "tree": {
+    "$className": "DataModel",
+    "$path": "foo.txt"
+  }
+}

test-projects/bad_no_classname/default.project.json

@@ -0,0 +1,4 @@
+{
+  "name": "bad_no_classname",
+  "tree": {}
+}

tests/tests/serve.rs

@@ -186,3 +186,37 @@ fn move_folder_of_stuff() {
         );
     });
 }
+
+#[test]
+fn empty_json_model() {
+    run_serve_test("empty_json_model", |session, mut redactions| {
+        let info = session.get_api_rojo().unwrap();
+        let root_id = info.root_instance_id;
+
+        assert_yaml_snapshot!("empty_json_model_info", redactions.redacted_yaml(info));
+
+        let read_response = session.get_api_read(root_id).unwrap();
+        assert_yaml_snapshot!(
+            "empty_json_model_all",
+            read_response.intern_and_redact(&mut redactions, root_id)
+        );
+
+        fs::write(
+            session.path().join("src/test.model.json"),
+            r#"{"ClassName": "Model"}"#,
+        )
+        .unwrap();
+
+        let subscribe_response = session.get_api_subscribe(0).unwrap();
+        assert_yaml_snapshot!(
+            "empty_json_model_subscribe",
+            subscribe_response.intern_and_redact(&mut redactions, ())
+        );
+
+        let read_response = session.get_api_read(root_id).unwrap();
+        assert_yaml_snapshot!(
+            "empty_json_model_all-2",
+            read_response.intern_and_redact(&mut redactions, root_id)
+        );
+    });
+}