test: add unit and VS Code test layers

.github/dependabot.yml

@@ -0,0 +1,11 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: /
+    schedule:
+      interval: weekly
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly

.github/workflows/ci.yaml

@@ -12,16 +12,17 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       - name: Install dependencies
         run: npm ci
 
@@ -37,6 +38,9 @@ jobs:
       - name: Build extension
         run: npm run compile
 
+      - name: Run tests
+        run: xvfb-run -a npm test
+
       - name: Package extension
         run: npx vsce package
 
@@ -46,16 +50,17 @@ jobs:
     needs: test
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       - run: npm ci
 
       - name: Set pre-release version
@@ -72,16 +77,17 @@ jobs:
     needs: test
     if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       - run: npm ci
 
       - name: Set pre-release version

.github/workflows/release.yaml

@@ -10,16 +10,17 @@ jobs:
     name: 'Check version'
     runs-on: ubuntu-latest
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: ${{ env.FETCH_DEPTH }}
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       - name: Validate package version matches git tag
         run: |
           TAG_VERSION=${GITHUB_REF#refs/tags/v}
@@ -34,16 +35,17 @@ jobs:
     runs-on: ubuntu-latest
     needs: check-version
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       # Install Node dependencies.
       - run: npm ci
 
@@ -56,16 +58,17 @@ jobs:
     runs-on: ubuntu-latest
     needs: check-version
     steps:
-      - name: Install Nodejs
-        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
-        with:
-          node-version: 24
-
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
+      - name: Install Nodejs
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
       # Install Node dependencies.
       - run: npm ci
 

.github/workflows/security-audit.yaml

@@ -0,0 +1,24 @@
+name: Dependency security audit
+
+on:
+  schedule:
+    - cron: '23 4 * * 1'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Install Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
+      - run: npm ci
+      - run: npm audit --audit-level=high

.husky/pre-commit

@@ -0,0 +1 @@
+npx lint-staged --concurrent false

.nvmrc

@@ -0,0 +1 @@
+24.21.0

.prettierrc

@@ -5,6 +5,7 @@
     "printWidth": 120,
     "tabWidth": 4,
     "useTabs": false,
+    "endOfLine": "auto",
     "overrides": [
         {
             "files": ["*.yml", "*.yaml"],

.vscode-test.mjs

@@ -0,0 +1,10 @@
+import { defineConfig } from '@vscode/test-cli';
+
+export default defineConfig({
+    files: 'out/test/**/*.vscode.test.js',
+    version: 'stable',
+    mocha: {
+        ui: 'tdd',
+        timeout: 20_000,
+    },
+});

CONTRIBUTING.md

@@ -20,8 +20,12 @@ Code extension that integrates Pixi environments with the Python Environments ex
 
 3. **Development workflow**
     ```bash
-    npm run compile    # Build the extension
-    npm run watch      # Watch for changes during development
+    npm run compile       # Build the extension
+    npm run watch         # Watch for changes during development
+    npm run typecheck     # Check TypeScript types without creating output files
+    npm run test:unit     # Run fast Node.js unit tests
+    npm run test:vscode   # Run tests in an isolated VS Code extension host
+    npm test              # Run all checks and tests
     ```
 
 ## Code style and quality
@@ -42,6 +46,19 @@ npm run format          # Auto-fix formatting issues
 npm run lint -- --fix   # Auto-fix linting issues where possible
 ```
 
+### Tests
+
+Use unit tests for pure TypeScript logic, such as Pixi command construction and parsing. They run directly in Node.js and
+must not import the `vscode` runtime module.
+
+Use VS Code extension-host tests for interactions with the `vscode` API, extension activation, and extension
+contributions. The first run downloads an isolated VS Code instance into `.vscode-test/`; later runs reuse it.
+
+The CI `test` job runs `npm test` before either pre-release publishing job is allowed to start.
+
+After `npm install`, Husky installs a pre-commit hook that applies ESLint fixes and Prettier to staged files. The full
+lint, formatting, and compile checks run in CI.
+
 ## Making a contribution
 
 ### 1. Fork and branch

README.md

@@ -74,6 +74,10 @@ Check the "Pixi Environment Manager" output channel:
 - Verify `pixi.toml` or `pyproject.toml` exists in project root
 - Run `pixi install` to ensure environments are set up
 
+## Contributing
+
+See [CONTRIBUTING.md](CONTRIBUTING.md) for development setup and workflow details.
+
 ## License
 
 MIT