Use msgpack for API [rojo-rbx#1176]

Switches the rojo API to use msgpack instead of JSON.

Fixes rojo-rbx#363.
Fixes rojo-rbx#881.

Author: Quenty

.gitmodules

@@ -16,3 +16,6 @@
 [submodule "plugin/Packages/Highlighter"]
 	path = plugin/Packages/Highlighter
 	url = https://github.com/boatbomber/highlighter.git
+[submodule "plugin/Packages/msgpack-luau"]
+	path = plugin/Packages/msgpack-luau
+	url = https://github.com/cipharius/msgpack-luau/

CHANGELOG.md

@@ -34,6 +34,10 @@ Making a new release? Simply add the new header with the version and date undern
 
 [#1179]: https://github.com/rojo-rbx/rojo/pull/1179
 
+* `inf` and `nan` values in properties are now synced ([#1176])
+
+[#1176]: https://github.com/rojo-rbx/rojo/pull/1176
+
 ## [7.7.0-rc.1] (November 27th, 2025)
 
 * Fixed a bug where passing `--skip-git` to `rojo init` would still create a file named `gitignore.txt` ([#1172])

Cargo.lock

@@ -105,6 +105,8 @@ blake3 = "1.5.0"
 float-cmp = "0.9.0"
 indexmap = { version = "2.10.0", features = ["serde"] }
 normpath = "1.2.0"
+rmp-serde = "1.3.0"
+serde_bytes = "0.11.19"
 
 [target.'cfg(windows)'.dependencies]
 winreg = "0.10.1"

Cargo.toml

@@ -30,6 +30,11 @@ fn snapshot_from_fs_path(path: &Path) -> io::Result<VfsSnapshot> {
                 continue;
             }
 
+            // Ignore images in msgpack-luau because they aren't UTF-8 encoded.
+            if file_name.ends_with(".png") {
+                continue;
+            }
+
             let child_snapshot = snapshot_from_fs_path(&entry.path())?;
             children.push((file_name, child_snapshot));
         }

build.rs

@@ -1,5 +1,7 @@
 local HttpService = game:GetService("HttpService")
 
+local msgpack = require(script.Parent.Parent.msgpack)
+
 local stringTemplate = [[
 Http.Response {
 	code: %d
@@ -31,4 +33,8 @@ function Response:json()
 	return HttpService:JSONDecode(self.body)
 end
 
+function Response:msgpack()
+	return msgpack.decode(self.body)
+end
+
 return Response

plugin/Packages/msgpack-luau

@@ -1,7 +1,8 @@
 local HttpService = game:GetService("HttpService")
 
-local Promise = require(script.Parent.Promise)
 local Log = require(script.Parent.Log)
+local msgpack = require(script.Parent.msgpack)
+local Promise = require(script.Parent.Promise)
 
 local HttpError = require(script.Error)
 local HttpResponse = require(script.Response)
@@ -68,4 +69,12 @@ function Http.jsonDecode(source)
 	return HttpService:JSONDecode(source)
 end
 
+function Http.msgpackEncode(object)
+	return msgpack.encode(object)
+end
+
+function Http.msgpackDecode(source)
+	return msgpack.decode(source)
+end
+
 return Http

plugin/http/Response.lua

@@ -145,7 +145,7 @@ function ApiContext:connect()
 
 	return Http.get(url)
 		:andThen(rejectFailedRequests)
-		:andThen(Http.Response.json)
+		:andThen(Http.Response.msgpack)
 		:andThen(rejectWrongProtocolVersion)
 		:andThen(function(body)
 			assert(validateApiInfo(body))
@@ -163,7 +163,7 @@ end
 function ApiContext:read(ids)
 	local url = ("%s/api/read/%s"):format(self.__baseUrl, table.concat(ids, ","))
 
-	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.json):andThen(function(body)
+	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.msgpack):andThen(function(body)
 		if body.sessionId ~= self.__sessionId then
 			return Promise.reject("Server changed ID")
 		end
@@ -191,9 +191,9 @@ function ApiContext:write(patch)
 		table.insert(updated, fixedUpdate)
 	end
 
-	-- Only add the 'added' field if the table is non-empty, or else Roblox's
-	-- JSON implementation will turn the table into an array instead of an
-	-- object, causing API validation to fail.
+	-- Only add the 'added' field if the table is non-empty, or else the msgpack
+	-- encode implementation will turn the table into an array instead of a map,
+	-- causing API validation to fail.
 	local added
 	if next(patch.added) ~= nil then
 		added = patch.added
@@ -206,13 +206,16 @@ function ApiContext:write(patch)
 		added = added,
 	}
 
-	body = Http.jsonEncode(body)
+	body = Http.msgpackEncode(body)
 
-	return Http.post(url, body):andThen(rejectFailedRequests):andThen(Http.Response.json):andThen(function(responseBody)
-		Log.info("Write response: {:?}", responseBody)
+	return Http.post(url, body)
+		:andThen(rejectFailedRequests)
+		:andThen(Http.Response.msgpack)
+		:andThen(function(responseBody)
+			Log.info("Write response: {:?}", responseBody)
 
-		return responseBody
-	end)
+			return responseBody
+		end)
 end
 
 function ApiContext:connectWebSocket(packetHandlers)
@@ -234,7 +237,7 @@ function ApiContext:connectWebSocket(packetHandlers)
 		local closed, errored, received
 
 		received = self.__wsClient.MessageReceived:Connect(function(msg)
-			local data = Http.jsonDecode(msg)
+			local data = Http.msgpackDecode(msg)
 			if data.sessionId ~= self.__sessionId then
 				Log.warn("Received message with wrong session ID; ignoring")
 				return
@@ -280,7 +283,7 @@ end
 function ApiContext:open(id)
 	local url = ("%s/api/open/%s"):format(self.__baseUrl, id)
 
-	return Http.post(url, ""):andThen(rejectFailedRequests):andThen(Http.Response.json):andThen(function(body)
+	return Http.post(url, ""):andThen(rejectFailedRequests):andThen(Http.Response.msgpack):andThen(function(body)
 		if body.sessionId ~= self.__sessionId then
 			return Promise.reject("Server changed ID")
 		end
@@ -292,7 +295,7 @@ end
 function ApiContext:serialize(ids: { string })
 	local url = ("%s/api/serialize/%s"):format(self.__baseUrl, table.concat(ids, ","))
 
-	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.json):andThen(function(body)
+	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.msgpack):andThen(function(body)
 		if body.sessionId ~= self.__sessionId then
 			return Promise.reject("Server changed ID")
 		end
@@ -306,7 +309,7 @@ end
 function ApiContext:refPatch(ids: { string })
 	local url = ("%s/api/ref-patch/%s"):format(self.__baseUrl, table.concat(ids, ","))
 
-	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.json):andThen(function(body)
+	return Http.get(url):andThen(rejectFailedRequests):andThen(Http.Response.msgpack):andThen(function(body)
 		if body.sessionId ~= self.__sessionId then
 			return Promise.reject("Server changed ID")
 		end

plugin/http/init.lua

@@ -54,6 +54,10 @@ local function trueEquals(a, b): boolean
 		end
 		return true
 
+	-- For NaN, check if both values are not equal to themselves
+	elseif a ~= a and b ~= b then
+		return true
+
 	-- For numbers, compare with epsilon of 0.0001 to avoid floating point inequality
 	elseif typeA == "number" and typeB == "number" then
 		return fuzzyEq(a, b, 0.0001)
@@ -274,4 +278,4 @@ local function diff(instanceMap, virtualInstances, rootId)
 	return true, patch
 end
 
-return diff
+return diff