Switch from yarn to pnpm

.claude/settings.json

@@ -2,7 +2,9 @@
   "permissions": {
     "allow": [
       "WebFetch(domain:prettier.io)",
-      "Bash(npm run prettier:*)",
+      "WebFetch(domain:code.visualstudio.com)",
+      "Bash(pnpm prettier:*)",
+      "Bash(pnpm lint:*)",
       "mcp__ide__getDiagnostics"
     ],
     "deny": [],

.devcontainer/devcontainer.json

@@ -20,7 +20,7 @@
   },
 
   // Use 'postCreateCommand' to run commands after the container is created.
-  "postCreateCommand": "yarn install",
+  "postCreateCommand": "pnpm install",
 
   // Run as the node user for better security.
   "remoteUser": "node"

.github/PULL_REQUEST_TEMPLATE.md

@@ -20,8 +20,8 @@
 ## Checklist
 
 - [ ] I have read the [CONTRIBUTING](https://github.com/prettier/prettier-vscode/blob/main/CONTRIBUTING.md) guidelines
-- [ ] My code follows the code style of this project (`yarn lint` passes)
-- [ ] I have run `yarn prettier` to format my code
+- [ ] My code follows the code style of this project (`pnpm lint` passes)
+- [ ] I have run `pnpm prettier` to format my code
 - [ ] I have added/updated tests that prove my fix or feature works
-- [ ] All new and existing tests pass (`yarn test`)
+- [ ] All new and existing tests pass (`pnpm test`)
 - [ ] I have updated the [CHANGELOG.md](https://github.com/prettier/prettier-vscode/blob/main/CHANGELOG.md) with a summary of my changes

.github/copilot-instructions.md

@@ -0,0 +1,80 @@
+# Copilot Instructions
+
+This is the official Prettier VS Code extension (`prettier.prettier-vscode`). It provides code formatting using Prettier for Visual Studio Code, supporting JavaScript, TypeScript, CSS, HTML, Vue, and many other languages.
+
+## Development
+
+- Use `pnpm` as the package manager
+- Run `pnpm install` to install dependencies
+- Run `pnpm webpack` to build for development
+- Run `pnpm test` to run tests (no VS Code instance can be running)
+- Run `pnpm lint` to check linting
+- Run `pnpm prettier` to format code
+
+## Architecture
+
+Entry points:
+
+- Desktop: `src/extension.ts` → bundled to `dist/extension.js`
+- Browser: Same entry, bundled to `dist/web-extension.js` (uses `BrowserModuleResolver` instead of `ModuleResolver`)
+
+Core components:
+
+- `src/extension.ts` - Extension activation, creates ModuleResolver, PrettierEditService, and StatusBar
+- `src/PrettierEditService.ts` - Registers VS Code document formatting providers, handles format requests
+- `src/ModuleResolver.ts` - Resolves local/global Prettier installations, falls back to bundled Prettier
+- `src/PrettierWorkerInstance.ts` - Runs Prettier v3+ in a worker thread for async formatting
+- `src/PrettierMainThreadInstance.ts` - Runs Prettier v2 synchronously on main thread
+
+Webpack produces two bundles:
+
+- Node bundle (`dist/extension.js`) for desktop VS Code
+- Web bundle (`dist/web-extension.js`) for vscode.dev/browser
+
+## Code Style
+
+- Use TypeScript for all source code
+- Follow existing code patterns in the codebase
+- Extension settings are prefixed with `prettier.` and defined in `package.json`
+- Use the VS Code extension API patterns already established in the codebase
+
+## Testing
+
+- Test fixtures live in `test-fixtures/` with their own `package.json` and Prettier configurations
+- The `.do-not-use-prettier-vscode-root` marker file stops module resolver from searching above test fixtures
+- Tests run inside a VS Code instance using the Extension Development Host
+
+## Code Review Guidelines
+
+When reviewing pull requests, focus on:
+
+### Security
+
+- No hardcoded secrets or credentials
+- Workspace Trust is respected when resolving modules from untrusted workspaces
+- User input is validated before use in file paths or module resolution
+
+### VS Code Extension Best Practices
+
+- Disposables are properly registered with `context.subscriptions` to prevent memory leaks
+- Async operations handle errors appropriately
+- User-facing messages go through `LoggingService` or VS Code's message APIs
+- Settings changes are handled correctly (some require reload)
+
+### Prettier Compatibility
+
+- Changes work with both Prettier v2 (sync) and v3+ (async/worker)
+- Module resolution fallback chain is maintained: local → global → bundled
+- Config file watching covers all Prettier config formats
+
+### Performance
+
+- Avoid blocking the extension host main thread
+- Prettier v3+ should use worker threads via `PrettierWorkerInstance`
+- Module and config resolution results are cached appropriately
+
+### Browser Compatibility
+
+- Code in the main bundle should work in both Node.js and browser contexts
+- Browser-specific code uses `BrowserModuleResolver`
+- No Node.js-only APIs in shared code paths

.github/instructions/tests.instructions.md

@@ -0,0 +1,37 @@
+---
+applyTo: "src/test/**/*.ts"
+---
+
+# Test File Guidelines
+
+Tests run inside a VS Code Extension Development Host using Mocha.
+
+## Test Structure
+
+- Use Mocha's `suite()` and `test()` functions
+- Import assertions from `assert` module
+- Tests interact with real VS Code APIs
+
+## Test Fixtures
+
+- Test fixtures are in `test-fixtures/` directory (not `src/test/`)
+- Each fixture has its own `package.json` and Prettier configuration
+- Use `getWorkspaceFolderUri(workspaceFolderName)` to get fixture paths
+- Fixtures are added to `test.code-workspace` for the test runner
+
+## Formatting Tests
+
+- Use the `format()` helper to open and format documents
+- Compare results with `getText()` helper for expected output
+- Execute formatting via `vscode.commands.executeCommand("editor.action.formatDocument")`
+
+## Async Patterns
+
+- Tests are async - use `async/await`
+- Use `wait()` helper when needing delays
+- Prettier v3 formatting is async, may need retries for timing
+
+## Test File Naming
+
+- Name test files as `*.test.ts`
+- Group related tests in the same file (e.g., `format.test.ts`, `plugins.test.ts`)

.github/instructions/typescript.instructions.md

@@ -0,0 +1,39 @@
+---
+applyTo: "src/**/*.ts"
+---
+
+# TypeScript Source Guidelines
+
+This is a VS Code extension. Follow these patterns:
+
+## Imports
+
+- Import VS Code API from `vscode` module: `import { commands, workspace, window } from "vscode"`
+- Use named imports, not namespace imports
+- Group imports: vscode first, then node modules, then local modules
+
+## VS Code Extension Patterns
+
+- Use `ExtensionContext.subscriptions` to register disposables for cleanup
+- Access settings via `workspace.getConfiguration("prettier")`
+- Use `LoggingService` for all logging (not console.log)
+- Commands are registered via `commands.registerCommand()`
+
+## Class Patterns
+
+- Services follow dependency injection pattern (pass dependencies via constructor)
+- Key services: `LoggingService`, `ModuleResolver`, `PrettierEditService`, `StatusBar`
+- Use `Disposable` interface for cleanup
+
+## Prettier Integration
+
+- Support both Prettier v2 (sync, main thread) and v3+ (async, worker thread)
+- `PrettierMainThreadInstance` for v2, `PrettierWorkerInstance` for v3+
+- Module resolution: local install → global install → bundled Prettier
+- Handle `.prettierrc`, `.prettierignore`, and `package.json` prettier config
+
+## Error Handling
+
+- Log errors through `LoggingService`
+- Show user-facing errors via `window.showErrorMessage()`
+- Handle Workspace Trust restrictions appropriately

.github/instructions/workflows.instructions.md

@@ -0,0 +1,39 @@
+---
+applyTo: ".github/workflows/*.yaml"
+---
+
+# GitHub Actions Workflow Guidelines
+
+## Package Manager
+
+- Use `pnpm` as the package manager
+- Include `pnpm/action-setup@v4` before running pnpm commands
+- Use `actions/setup-node@v6` with `node-version-file: ".nvmrc"`
+
+## Checkout and Setup Pattern
+
+```yaml
+- uses: actions/checkout@v6
+- uses: actions/setup-node@v6
+  with:
+    node-version-file: ".nvmrc"
+- uses: pnpm/action-setup@v4
+- run: pnpm install
+```
+
+## Testing
+
+- Linux tests require Xvfb for display: `/usr/bin/Xvfb :99 -screen 0 1024x768x24`
+- Set `DISPLAY: ":99.0"` environment variable for tests on Linux
+- Tests run via `pnpm test`
+
+## Permissions
+
+- Use minimal required permissions for each job
+- Common permissions: `issues: write`, `pull-requests: write`, `contents: read`
+
+## Scripts in Workflows
+
+- For `actions/github-script@v7`, only use built-in Node.js modules (fs, path, etc.)
+- Do not use external npm packages like `js-yaml` in github-script (they are not available)
+- Use JSON format for config files that need to be read in workflows

.github/labels.json

@@ -0,0 +1,104 @@
+{
+  "labels": [
+    {
+      "name": "bug",
+      "color": "#d73a4a",
+      "description": "Something isn't working"
+    },
+    {
+      "name": "enhancement",
+      "color": "#a2eeef",
+      "description": "New feature or request"
+    },
+    {
+      "name": "documentation",
+      "color": "#0075ca",
+      "description": "Improvements or additions to documentation"
+    },
+    {
+      "name": "performance",
+      "color": "#f9d0c4",
+      "description": "Performance related issues"
+    },
+    {
+      "name": "triage-pending",
+      "color": "#fbca04",
+      "description": "Awaiting initial triage"
+    },
+    {
+      "name": "need-more-info",
+      "color": "#d876e3",
+      "description": "Further information is requested"
+    },
+    {
+      "name": "stale",
+      "color": "#ffffff",
+      "description": "No recent activity"
+    },
+    {
+      "name": "locked",
+      "color": "#ededed",
+      "description": "Locked due to inactivity"
+    },
+    {
+      "name": "duplicate",
+      "color": "#cfd3d7",
+      "description": "This issue or PR already exists"
+    },
+    {
+      "name": "invalid",
+      "color": "#e4e669",
+      "description": "This doesn't seem right"
+    },
+    {
+      "name": "wontfix",
+      "color": "#ffffff",
+      "description": "This will not be worked on"
+    },
+    {
+      "name": "help-wanted",
+      "color": "#008672",
+      "description": "Extra attention is needed"
+    },
+    {
+      "name": "good-first-issue",
+      "color": "#7057ff",
+      "description": "Good for newcomers"
+    },
+    {
+      "name": "pinned",
+      "color": "#006b75",
+      "description": "Pinned issue - will not be marked stale"
+    },
+    {
+      "name": "prettier-core",
+      "color": "#bfdadc",
+      "description": "Issue is with Prettier core, not the extension"
+    },
+    {
+      "name": "config",
+      "color": "#c2e0c6",
+      "description": "Related to configuration"
+    },
+    {
+      "name": "plugin",
+      "color": "#d4c5f9",
+      "description": "Related to Prettier plugins"
+    },
+    {
+      "name": "breaking-change",
+      "color": "#b60205",
+      "description": "Breaking change"
+    },
+    {
+      "name": "dependencies",
+      "color": "#0366d6",
+      "description": "Pull requests that update a dependency"
+    },
+    {
+      "name": "github_actions",
+      "color": "#000000",
+      "description": "Pull requests that update GitHub Actions"
+    }
+  ]
+}