workflows: add workflow to avoid checking in ungenerated code (#41)

.github/workflows/verify-build.yml

@@ -0,0 +1,40 @@
+name: Verify Build Output
+
+on:
+  pull_request:
+    branches:
+      - main
+      - master
+
+jobs:
+  verify-build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: '16'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: |
+          npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Check for changes
+        run: |
+          # Ignore yarn.lock changes since we're using npm
+          git update-index --assume-unchanged yarn.lock || true
+          if [[ -n "$(git status --porcelain)" ]]; then
+            echo "::error::Build generated new changes. Please commit the generated files."
+            git status
+            git diff
+            exit 1
+          fi