create a ci pipeline to build & test

Author: Markus Howard

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Use Node.js 22
+      uses: actions/setup-node@v4
+      with:
+        node-version: '22'
+        cache: 'npm'
+    - name: Install dependencies
+      run: npm ci
+    - run: npm run build
+    - name: Run ESLint
+      run: npm run lint
+    - name: Ensure no changes
+      run: git diff --exit-code
+
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: Use Node.js 22
+      uses: actions/setup-node@v4
+      with:
+        # https://github.com/microsoft/playwright-mcp/issues/344
+        node-version: '22'
+        cache: 'npm'
+    - name: Install dependencies
+      run: npm ci
+    - name: Build
+      run: npm run build
+    - name: Run tests
+      run: npm test