[rush] (BREAKING CHANGE) Overhaul watch-mode to facilitate orchestration

apps/rush/package.json

@@ -48,6 +48,7 @@
     "@rushstack/rush-amazon-s3-build-cache-plugin": "workspace:*",
     "@rushstack/rush-azure-storage-build-cache-plugin": "workspace:*",
     "@rushstack/rush-http-build-cache-plugin": "workspace:*",
+    "@rushstack/rush-serve-plugin": "workspace:*",
     "@types/semver": "7.7.1"
   },
   "exports": {

apps/rush/src/start-dev.ts

@@ -29,6 +29,7 @@ function includePlugin(pluginName: string, pluginPackageName?: string): void {
 includePlugin('rush-amazon-s3-build-cache-plugin');
 includePlugin('rush-azure-storage-build-cache-plugin');
 includePlugin('rush-http-build-cache-plugin');
+includePlugin('rush-serve-plugin');
 // Including this here so that developers can reuse it without installing the plugin a second time
 includePlugin('rush-azure-interactive-auth-plugin', '@rushstack/rush-azure-storage-build-cache-plugin');
 

common/changes/@microsoft/rush/watch-rework_2025-09-26-23-50.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "(PLUGIN BREAKING CHANGE) Overhaul watch-mode commands such that the graph is only created once at the start of command invocation, along with a stateful manager object. Plugins may now access the manager object and use it to orchestrate and tap into the build process.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}

common/config/rush-plugins/rush-serve-plugin.json

@@ -0,0 +1,7 @@
+{
+  "$schema": "https://developer.microsoft.com/json-schemas/rush/v5/rush-serve-plugin-options.schema.json",
+  "phasedCommands": ["start"],
+  "portParameterLongName": "--port",
+  "buildStatusWebSocketPath": "/ws",
+  "logServePath": "/logs"
+}

common/config/rush/command-line.json

@@ -245,24 +245,25 @@
       // Used for very simple builds that don't support CLI arguments like `--production` or `--fix`
       "name": "_phase:lite-build",
       "dependencies": {
-        "upstream": ["_phase:lite-build", "_phase:build"]
+        "upstream": ["_phase:build"]
       },
       "missingScriptBehavior": "silent",
       "allowWarningsOnSuccess": false
     },
     {
       "name": "_phase:build",
       "dependencies": {
-        "self": ["_phase:lite-build"],
-        "upstream": ["_phase:build"]
+        // Don't need to declare the dependency on _phase:build because it is transitive via _phase:lite-build
+        "self": ["_phase:lite-build"]
       },
       "missingScriptBehavior": "log",
       "allowWarningsOnSuccess": false
     },
     {
       "name": "_phase:test",
       "dependencies": {
-        "self": ["_phase:lite-build", "_phase:build"]
+        // Dependency on _phase:lite-build is transitive via _phase:build
+        "self": ["_phase:build"]
       },
       "missingScriptBehavior": "silent",
       "allowWarningsOnSuccess": false
@@ -494,6 +495,14 @@
       "associatedPhases": ["_phase:build", "_phase:test"],
       "associatedCommands": ["build", "rebuild", "test", "retest"]
     },
+    {
+      "longName": "--port",
+      "parameterKind": "integer",
+      "argumentName": "PORT",
+      "description": "The port to use for the server",
+      "associatedPhases": [],
+      "associatedCommands": ["start"]
+    },
     {
       "longName": "--update-snapshots",
       "parameterKind": "flag",

common/config/rush/experiments.json

@@ -88,7 +88,7 @@
    * of `_phase:<name>` if they exist. The created child process will be provided with an IPC channel and expected to persist
    * across invocations.
    */
-  // "useIPCScriptsInWatchMode": true,
+  "useIPCScriptsInWatchMode": true,
 
   /**
    * (UNDER DEVELOPMENT) The Rush alerts feature provides a way to send announcements to engineers

common/config/rush/nonbrowser-approved-packages.json

@@ -382,6 +382,10 @@
       "name": "@rushstack/rush-sdk",
       "allowedCategories": [ "libraries", "tests", "vscode-extensions" ]
     },
+    {
+      "name": "@rushstack/rush-serve-plugin",
+      "allowedCategories": [ "libraries" ]
+    },
     {
       "name": "@rushstack/set-webpack-public-path-plugin",
       "allowedCategories": [ "libraries", "tests" ]