build: use API extractor to track public API surface (zwave-js#4860)

.gitattributes

@@ -3,3 +3,7 @@ specs/** linguist-vendored
 
 # Use JSONC for syntax highlighting in config files
 packages/config/config/**/*.json linguist-language=jsonc
+
+# And API extractor configuration
+api-extractor-*.json  linguist-language=jsonc
+api-extractor.json  linguist-language=jsonc

.github/workflows/api-surface.yml

@@ -0,0 +1,52 @@
+name: Check public API surface
+
+# Run this workflow on all pull requests
+on:
+  pull_request: {}
+
+jobs:
+  # This job checks if a PR changes the public API surface
+  check-api-surface:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [16.x] # This should be LTS
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v3
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'yarn'
+
+    - name: Install dependencies
+      run: yarn install --immutable
+
+    - name: Compile TypeScript code
+      run: yarn run build
+
+    - name: Generate API report
+      run: yarn run extract-api
+
+    - name: Show changes
+      if: failure()
+      run: |
+        cat packages/*/.tmp/api.md
+
+    - name: Comment on PR
+      if: failure()
+      run: |
+        echo "The public API surface has changed!" >> $GITHUB_STEP_SUMMARY
+        echo "Please run" >> $GITHUB_STEP_SUMMARY
+        echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+        echo "yarn clean" >> $GITHUB_STEP_SUMMARY
+        echo "yarn build" >> $GITHUB_STEP_SUMMARY
+        echo "yarn extract-api --local" >> $GITHUB_STEP_SUMMARY
+        echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+        echo "and review the changes, then commit them if desired." >> $GITHUB_STEP_SUMMARY
+        echo "" >> $GITHUB_STEP_SUMMARY

.vscode/settings.json

@@ -48,7 +48,9 @@
 		"(!test)/cache": true
 	},
 	"files.associations": {
-		"**/config/**/*.json": "jsonc"
+		"**/config/**/*.json": "jsonc",
+		"api-extractor-*.json": "jsonc",
+		"api-extractor.json": "jsonc"
 	},
 	"editor.rulers": [72, 80, 120],
 	"files.participants.timeout": 10000,