Migrate from Rush to pnpm workspaces + Chronus (#5190)

## Summary

Migrates the monorepo from Rush to native pnpm workspaces with Chronus
for changelog management.

### Changes

- **Package management**: Rush → pnpm workspaces (via
`pnpm-workspace.yaml`)
- **Changelog/versioning**: `rush change` → `chronus add` / `chronus
verify` / `chronus version`
- **Root package.json**: Added with workspace-level scripts (`build`,
`test:ci`, `lint`, `format`, `watch`, etc.)
- **CI pipelines**: Updated all ADO pipelines and GitHub Actions to use
`pnpm` and `chronus` commands
- **Removed**: `rush.json`, `common/` directory, rush-specific eng
scripts (`bump-for-prerelease.js`, `helpers.js`, `format.js`, etc.)
- **Moved**: `common/config/webpack.base.config.js` →
`eng/config/webpack.base.config.js`
- **Simplified**: `workspace:~X.Y.Z` → `workspace:~` in all package.json
files

### New developer workflow

```bash
corepack enable
pnpm install
pnpm build
pnpm test:ci
pnpm change       # add changelog entry (replaces rush change)
```

Author: timotheeguerin

.chronus/changes/upgrade-rush-pnpm-2026-6-9-17-22.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@azure-tools/extension"
+---
+
+Remove unused npm dependency; simplify to always use Yarn

.chronus/changes/upgrade-rush-pnpm-2026-6-9-18-6.md

@@ -0,0 +1,8 @@
+---
+changeKind: fix
+packages:
+  - "@autorest/core"
+  - "autorest"
+---
+
+Update ExtensionManager.Create call after removing packageManagerType param

.chronus/config.yaml

@@ -0,0 +1,36 @@
+baseBranch: main
+baseRemote: https://github.com/Azure/autorest
+changelog: ["@chronus/github/changelog", { repo: "Azure/autorest" }]
+
+ignore:
+  - "@autorest/test-public-packages"
+
+changeKinds:
+  breaking:
+    versionType: major
+    title: Breaking Changes
+    description: Changes that break existing features
+
+  feature:
+    versionType: minor
+    title: Features
+    description: New features added
+
+  fix:
+    versionType: patch
+    title: Bug Fixes
+    description: Fixes to existing features
+
+  deprecation:
+    versionType: minor
+    title: Deprecations
+    description: Deprecated features
+
+  internal:
+    versionType: none
+    title: Internal
+    description: Internal changes that are not user facing
+
+changedFiles:
+  - "!**/*.md"
+  - "!**/*.test.ts"

.default-eslintrc.yaml

@@ -56,7 +56,7 @@ rules:
   "require-atomic-updates": off
 
   # Prettier config https://github.com/prettier/eslint-plugin-prettier#recommended-configuration
-  prettier/prettier: off # Don't run prettier in eslint we have rush check-format for that.
+  prettier/prettier: off # Don't run prettier in eslint we have pnpm format:check for that.
   arrow-body-style: off
   prefer-arrow-callback: off
 

.github/workflows/consitency-checks.yml

@@ -16,6 +16,8 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: 22.x
+      - run: corepack enable
+      - run: pnpm install --frozen-lockfile
       - run: |
           LABEL_NAME=Publish
           LABEL_URL=https://api.github.com/repos/Azure/autorest/issues/$PR_NUMBER/labels
@@ -25,7 +27,7 @@ jobs:
           then
             echo "Publish label was included in the PR, won't be checking for changelog."
           else
-            npx @microsoft/rush change --verify || { echo 'If you run the rush publish command locally and meant to publish the changes, add the publish label to the pr.' ; exit 1; }
+            pnpm chronus verify || { echo 'If you meant to publish the changes, add the publish label to the pr.' ; exit 1; }
           fi
         env:
           PR_NUMBER: ${{ github.event.pull_request.number }}

.github/workflows/prepare-auto-release-branch.yml

@@ -24,11 +24,10 @@ jobs:
         with:
           node-version: 22.x
 
-      - run: node common/scripts/install-run-rush.js install
+      - run: corepack enable
+
+      - run: pnpm install --frozen-lockfile
         name: Install dependencies
 
       - name: Create release branch
         run: node ./eng/scripts/publish.mjs
-
-      - run: node common/scripts/install-run-rush.js update
-        name: Regen lock file

.gitignore

@@ -285,10 +285,8 @@ jspm_packages/
 # Common toolchain intermediate files
 temp
 
-# Rush files
-common/temp/**
-package-deps.json
-common/config/rush/shrinkwrap.yaml
+# pnpm
+.chronus/artifacts
 
 # Code generation output for regression tests
 core/test/regression

.npmrc

@@ -0,0 +1,5 @@
+enable-pre-post-scripts=true
+only-built-dependencies[]=tree-sitter
+only-built-dependencies[]=tree-sitter-javascript
+only-built-dependencies[]=tree-sitter-python
+only-built-dependencies[]=tree-sitter-typescript

CONTRIBUTING.md

@@ -10,6 +10,7 @@ Then go to https://github.com/Azure/autorest/pull/new/publish/auto-release and c
   - **On windows**: Make sure to choose to install the native build dependencies in the setup
   - Alternatively follow instruction here https://github.com/nodejs/node-gyp
 - `python` 3.x
+- `pnpm` (enabled via corepack: `corepack enable`)
 
 Optional recommendation:
 
@@ -21,25 +22,25 @@ Optional recommendation:
 
 ## First build
 
-1. Install [rush.js](https://rushjs.io/pages/intro/get_started/) using
+1. Enable corepack (if not already)
 
 ```bash
-npm install -g @microsoft/rush
+corepack enable
 ```
 
 2. Install dependencies
 
 ```bash
-rush update
+pnpm install
 ```
 
 3. Build
 
 ```bash
-rush build
+pnpm build
 
 # or to do a force rebuild.
-rush rebuild
+pnpm rebuild
 ```
 
 ## Run in watch mode
@@ -48,9 +49,9 @@ When working on autorest it is recommended to have the compiler run in watch mod
 
 ```bash
 # Run for all packages.
-rush watch
+pnpm watch
 # Run for a specific package.
-npm run watch
+pnpm run watch
 ```
 
 ## Test
@@ -62,7 +63,7 @@ To run the test on the built product you have 2 options:
 1. Run all the tests using
 
 ```bash
-rush test:ci
+pnpm test:ci
 ```
 
 2. Run individual project tests(Recommended when working on test)
@@ -74,7 +75,7 @@ cd packages/<type>/<package>/
 # Run test in interactive mode
 npm test
 
-# Alternatively you can run them once with coverage(Same as rush test:ci)
+# Alternatively you can run them once with coverage(Same as pnpm test:ci)
 npm run test:ci
 ```
 
@@ -84,7 +85,7 @@ npm run test:ci
 
 ```bash
 # Run for all packages.
-rush lint
+pnpm lint
 # Run for a specific package.
 npm run lint
 ```
@@ -93,7 +94,7 @@ npm run lint
 
 ```bash
 # Run for all packages.
-rush clean
+pnpm clean
 # Run for a specific package.
 npm run clean
 ```
@@ -124,10 +125,10 @@ node <path-to-repo>/packages/apps/autorest/entrypoints/app.js
 
 Steps to do before making a pull request:
 
-1. Run `rush change` and describe the change and if it should be a `major`, `minor` or `patch` version.
+1. Run `pnpm change` and describe the change and if it should be a `major`, `minor` or `patch` version.
 
    - `major`: If there is a breaking change.(Except `autorest`, `@autorest/core` and `@autorest/modelefour` packages which should use minor bump for that.)
    - `minor`: If there is a new feature but not breaking(Except `autorest`, `@autorest/core` and `@autorest/modelefour` packages)
    - `patch`: For any bug fix.
 
-2. Run `rush format` to ensure the code is formatted correctly.
+2. Run `pnpm format` to ensure the code is formatted correctly.