GLSP-1636: Adopt pnpm as the monorepo package manager

.claude/skills/fix/SKILL.md

@@ -1,25 +1,33 @@
 ---
 name: fix
-description: Auto-fix lint, formatting, and copyright-header issues across the workspace, then run the tests to validate. IMPORTANT - Proactively invoke this skill after completing any code changes (new features, bug fixes, refactors) before reporting completion. Re-run it after manually addressing anything it could not auto-fix.
+description: Run the fix-and-verify suite for the workspace (build, auto-fix lint/format/headers, test). IMPORTANT - Proactively invoke this skill after completing any code changes (new features, bug fixes, refactors) before reporting completion.
 ---
 
 Run the auto-fix and validation suite for the GLSP dev-packages monorepo from the repository root.
 
-1. Auto-fix lint, formatting, and copyright headers. Run all three even if an earlier one reports remaining problems (they are independent):
+1. Build first. This is a hard gate: if the build fails, stop immediately, report the build errors, and do not run any of the following steps. 
+The build must pass before anything else runs. 
 
 ```bash
-yarn lint:fix
-yarn format
-yarn headers:fix -t changes
+pnpm build
 ```
 
-2. Run the test suite to validate behavior (tests are not auto-fixable) — **only if the change touched the CLI package** (`dev-packages/cli`), the only package with tests. Skip this step otherwise:
+2. Auto-fix lint, formatting, and copyright headers. Run all three even if an earlier one reports remaining problems (they are independent):
 
 ```bash
-yarn test
+pnpm lint:fix
+pnpm format
+pnpm headers:fix -t changes
+```
+
+3. Run the test suite to validate behavior (tests are not auto-fixable) — **only if the change touched the CLI package** (`dev-packages/cli`), the only package with tests. Skip this step otherwise:
+
+```bash
+pnpm test
 ```
 
 Then:
 
--   If `yarn lint:fix` reported lint errors it could not fix, or `yarn test` failed, fix them manually and re-run this skill.
--   Otherwise everything is clean (formatting and headers are corrected in place, lint has no remaining errors, tests pass) — report completion.
+-   If `pnpm build` failed, fix the build errors and re-run this skill.
+-   If `pnpm lint:fix` reported lint errors it could not fix, or `pnpm test` failed, fix them manually and re-run this skill.
+-   Otherwise if everything is clean (build succeeds, formatting and headers are corrected in place, lint has no remaining errors, tests pass) — report completion.

.claude/skills/releng-next/SKILL.md

@@ -28,7 +28,7 @@ All inputs are taken from the user's prompt. Use the defaults below for anything
 
 ## Conventions
 
-- Always use the **local** CLI built from this tooling repo: `yarn glsp …` (never `npx @eclipse-glsp/cli`). The maintainer wants the behavior of the code as it currently stands.
+- Always use the **local** CLI built from this tooling repo: `pnpm glsp …` (never `npx @eclipse-glsp/cli`). The maintainer wants the behavior of the code as it currently stands.
 - `releng prepare next` and `releng version` accept `-r/--repoDir <dir>` and `cd` into it internally, so stay in the tooling repo and point `-r` at each temp clone — do not run from inside each repo.
 - **Continue-on-error.** Never abort the whole run because one repo failed. Collect outcomes and report them at the end in the four buckets.
 - The 8 GLSP repos are: `glsp`, `glsp-client`, `glsp-server-node`, `glsp-theia-integration`, `glsp-vscode-integration`, `glsp-eclipse-integration`, `glsp-server`, `glsp-playwright`.
@@ -49,9 +49,10 @@ Run from the tooling repo root (`glsp/glsp`).
 
 2. Build the local CLI so `dist/cli.js` is current:
    ```bash
-   yarn
+   pnpm install
+   pnpm build
    ```
-   Confirm `yarn glsp --help` works before continuing.
+   Confirm `pnpm glsp --help` works before continuing.
 
 ---
 
@@ -68,10 +69,10 @@ Run from the tooling repo root (`glsp/glsp`).
 4. Clone the target repos fresh into `WORKDIR`, from the real upstream (no fork, so `origin = eclipse-glsp` and pushes/PRs target upstream):
    ```bash
    # full run (default): all 8 repos
-   yarn glsp repo clone --preset all -d "$WORKDIR"
+   pnpm glsp repo clone --preset all -d "$WORKDIR"
 
    # partial run: only the repos the user named (repo clone takes positional names)
-   yarn glsp repo clone <repo> [<repo> …] -d "$WORKDIR"
+   pnpm glsp repo clone <repo> [<repo> …] -d "$WORKDIR"
    ```
    Each repo lands at `$WORKDIR/<repo>` on its default branch. If any clone fails, record it as a failure for that repo but continue.
 
@@ -100,7 +101,7 @@ If the version ends with `-next` or `.SNAPSHOT`, the repo is **already on next**
 Build the command from the resolved inputs:
 
 ```bash
-yarn glsp releng prepare next -r "$WORKDIR/<repo>" [--no-push] [--draft]
+pnpm glsp releng prepare next -r "$WORKDIR/<repo>" [--no-push] [--draft]
 ```
 
 Add `--no-push` if no-push was requested, and `--draft` if draft was requested (draft is ignored by `prepare` when `--no-push` is also set).
@@ -184,7 +185,7 @@ Steps (share the same overall timeout as Phase 4):
    The nightly deploy is not instant — it may take many minutes after merge. If the overall timeout elapses first, leave eclipse-integration **deferred** and report it.
 2. **Retry prepare next** for eclipse-integration (same flags as the original run, push enabled):
    ```bash
-   yarn glsp releng prepare next -r "$WORKDIR/glsp-eclipse-integration"
+   pnpm glsp releng prepare next -r "$WORKDIR/glsp-eclipse-integration"
    ```
    - Throws again with the same P2 error → P2 not actually ready; keep polling (step 1) until timeout.
    - Other throw → record **❌ failed**.

.github/workflows/ci.yml

@@ -17,32 +17,26 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: 22.x
+          cache: pnpm
       - name: Build
-        run: yarn install
-      - name: Check for uncommitted changes in yarn.lock
-        run: |
-          if git diff --name-only | grep -q "^yarn.lock"; then
-            echo "::error::The yarn.lock file has uncommitted changes!"
-            exit 1
-          fi
+        run: pnpm build
   lint:
     name: Lint
     timeout-minutes: 60
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: 22.x
-      - name: Install
-        run: |
-          yarn install
+          cache: pnpm
       - name: Create eslint json report
-        run: |
-          yarn lint:ci
+        run: pnpm lint:ci
       - name: Create summary
         if: always()
         run: |

.github/workflows/e2e.yml

@@ -16,9 +16,11 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: 22.x
+          cache: pnpm
       - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.11'
@@ -32,9 +34,9 @@ jobs:
           python --version
           java -version
           mvn --version
-      - name: Install
-        run: yarn --skip-integrity-check --network-timeout 100000
+      - name: Build
+        run: pnpm build
       - name: E2E Tests
-        run: yarn test:e2e
+        run: pnpm test:e2e
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # https://github.com/microsoft/vscode-ripgrep/issues/9 (needed when e2e tests build the Theia repo)

.github/workflows/prepare-release.yml

@@ -81,10 +81,15 @@ jobs:
           path: release-repo
           ref: ${{ inputs.branch || github.event.inputs.branch }}
 
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
+        with:
+          package_json_file: glsp-release-helper/package.json
       - name: Set up Node.js
         uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: 22
+          cache: pnpm
+          cache-dependency-path: glsp-release-helper/pnpm-lock.yaml
 
       - name: Set up Java 21
         if: >-
@@ -101,12 +106,9 @@ jobs:
         with:
           python-version: '3.11'
 
-      - name: Install Yarn
-        run: npm install -g yarn
-
-      - name: Install dependencies in glsp-release-helper
+      - name: Build glsp-release-helper
         working-directory: ./glsp-release-helper
-        run: yarn install
+        run: pnpm build
 
       - name: Configure Git
         run: |
@@ -125,7 +127,7 @@ jobs:
           fi
 
           if [[ "${{ inputs.release_type || github.event.inputs.release_type }}" == "custom" ]]; then
-            yarn glsp releng prepare custom "${{ inputs.custom_version || github.event.inputs.custom_version }}" -r ${{ github.workspace }}/release-repo $DRAFT_FLAG
+            pnpm glsp releng prepare custom "${{ inputs.custom_version || github.event.inputs.custom_version }}" -r ${{ github.workspace }}/release-repo $DRAFT_FLAG
           else
-            yarn glsp releng prepare "${{ inputs.release_type || github.event.inputs.release_type }}" -r ${{ github.workspace }}/release-repo $DRAFT_FLAG
+            pnpm glsp releng prepare "${{ inputs.release_type || github.event.inputs.release_type }}" -r ${{ github.workspace }}/release-repo $DRAFT_FLAG
           fi

.github/workflows/publish.yml

@@ -45,7 +45,7 @@ jobs:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           ref: ${{ inputs.ref || github.event.inputs.ref || github.event.workflow_run.head_commit.id || github.sha }}
-          # Fetch all history for lerna to determine versions
+          # Fetch all history to determine the canary version
           fetch-depth: 0
 
       - name: Check for changes in "dev-packages" directory
@@ -64,24 +64,27 @@ jobs:
             echo "should_publish=true" >> $GITHUB_OUTPUT
           fi
 
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
+        if: steps.check_changes.outputs.should_publish == 'true'
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         if: steps.check_changes.outputs.should_publish == 'true'
         with:
           node-version: 22.x
+          cache: pnpm
           registry-url: 'https://registry.npmjs.org'
 
       - name: Build
         if: steps.check_changes.outputs.should_publish == 'true'
-        run: yarn
+        run: pnpm build
 
       - name: Publish to NPM
         if: steps.check_changes.outputs.should_publish == 'true'
         run: |
           DIST_TAG="${{ inputs.dist-tag || github.event.inputs.dist-tag || 'next' }}"
           if [[ "$DIST_TAG" == "next" ]]; then
-             yarn publish:next
+             pnpm publish:next
           elif [[ "$DIST_TAG" == "latest" ]]; then
-             yarn publish:latest
+             pnpm publish:latest
           else
             echo "Unknown dist-tag: $DIST_TAG"
             exit 1

.github/workflows/test.yml

@@ -21,15 +21,13 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: pnpm/action-setup@0e279bb959325dab635dd2c09392533439d90093 # v6.0.8
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: 22.x
-      - name: Install
-        run: |
-          yarn install
+          cache: pnpm
       - name: Test
-        run: |
-          yarn test:ci
+        run: pnpm test:ci
       - name: Publish Test Report
         uses: ctrf-io/github-test-reporter@0f299074936c32ccaab5be5230511f6b2b9080aa # v1.0.28
         with:

.prettierignore

@@ -14,7 +14,7 @@ WORKFLOW_STATUS.md
 
 # Lock files
 package-lock.json
-yarn.lock
+pnpm-lock.yaml
 
 # Logs
 *.log

.vscode/tasks.json

@@ -9,7 +9,7 @@
         "kind": "build",
         "isDefault": true
       },
-      "command": "yarn",
+      "command": "pnpm install && pnpm build",
       "presentation": {
         "reveal": "always",
         "panel": "dedicated"

AGENTS.md

@@ -6,7 +6,7 @@ Eclipse GLSP shared development tooling monorepo. Contains reusable dev packages
 
 ## Build & Development
 
-- **Package manager**: Yarn 1.x (classic) — do not use Yarn 2+/Berry or npm
-- **Build**: Run `yarn` from the repository root to build the entire project
-- **CLI**: Run `yarn glsp` to start the CLI
+- **Package manager**: pnpm — do not use yarn or npm
+- **Build**: Run `pnpm install` then `pnpm build` from the repository root to build the entire project
+- **CLI**: Run `pnpm glsp` to start the CLI
 - Refer to the scripts in the root `package.json` for available build, lint, and format commands

CLAUDE.md

@@ -8,12 +8,12 @@ Eclipse GLSP shared development tooling monorepo. Contains reusable dev packages
 
 ## Build & Development
 
-- **Package manager**: Yarn 1.x (classic) — do not use Yarn 2+/Berry or npm
-- **Build**: Run `yarn` from the repository root to build the entire project
-- **CLI**: Run `yarn glsp` to start the CLI
+- **Package manager**: pnpm — do not use yarn or npm
+- **Build**: Run `pnpm install` then `pnpm build` from the repository root to build the entire project
+- **CLI**: Run `pnpm glsp` to start the CLI
 - Refer to the scripts in the root `package.json` for available build, lint, and format commands
 
 ## Validation
 
-- **Tests**: `yarn test` runs the CLI unit tests (`dev-packages/cli`, the only package with tests)
+- **Tests**: `pnpm test` runs the CLI unit tests (`dev-packages/cli`, the only package with tests)
 - After completing any code changes, always run the `/fix` skill before reporting completion. It auto-fixes lint/format/header issues and — when the CLI package changed — runs the tests; manually resolve anything it could not auto-fix (remaining lint errors, test failures) and re-run it.