chore: add e2e tests (microsoft#655)

Author: mxschmitt

.github/workflows/build.yml

@@ -0,0 +1,31 @@
+name: Test
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    name: Playwright
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v2
+      with:
+        node-version: '14'
+    - run: npm i -g npm@8
+    - name: Install dependencies
+      run: npm ci
+    - name: Build site
+      run: npm run build
+    - name: Install Playwright Browsers
+      run: npx playwright install --with-deps
+    - name: Run Playwright tests
+      run: npx playwright test
+    - uses: actions/upload-artifact@v2
+      if: always()
+      with:
+        name: playwright-report
+        path: playwright-report/
+        retention-days: 30

.github/workflows/test.yml

@@ -23,4 +23,7 @@ node_modules
 /versioned_sidebars
 /versions.json
 /docusaurus.config.js
-/playwright/
+/playwright/
+/test-results/
+/playwright-report/
+/playwright/.cache/

.gitignore

@@ -65,6 +65,26 @@ To roll the docs in PowerShell, make sure you set the env variable correctly, i.
 $env:SRC_DIR="C:\Users\user\src\playwright"; npm run roll
 ```
 
+### Run end-to-end tests
+
+#### Run on local machine
+
+Run this on one terminal:
+
+```sh
+npm run start-nodejs
+```
+
+and this on another, it will automatically use the local docusaurus server:
+
+```sh
+npx playwright test nodejs
+```
+
+#### Run on different environment
+
+You can set the `BASE_URL=https://playwright.dev` env var, otherwise `http://localhost:3000` gets used by default.
+
 ### Publishing Doc Changes After a Release
 
 In [microsoft/playwright](https://github.com/microsoft/playwright):