Add a script to test the bundle that will be uploaded to CDN

Add a `test:cdn_bundle` NPM script and run it in CI. This script tests
the bundle that the `.github/workflows/cdn.yml` workflow will upload to
the CDN, by checking that, when this bundle is imported by a web page,
it gives access to a working Spaces client.

The approach (using Playwright and a local web server powered by
Express) is based heavily on that used by the `test:playwright` NPM
script in ably-js at commit 83b4516. I then incorporated Dom’s
suggestion of using Playwright’s built-in test-running functionality,
taking code from his draft PR #218.

.eslintrc.js

@@ -42,7 +42,7 @@ module.exports = {
       extends: ['plugin:jsdoc/recommended'],
     },
   ],
-  ignorePatterns: ['dist', 'build', 'examples'],
+  ignorePatterns: ['dist', 'build', 'examples', 'test/ably-common'],
   settings: {
     jsdoc: {
       tagNamePreference: {

.github/workflows/cdn.yml

@@ -45,5 +45,6 @@ jobs:
         run: |
           npm ci
           npm run build
+        # Note: If you modify what we upload to the CDN, you must make sure you keep the `test:cdn-bundle` NPM script in sync with your changes.
       - run: |
           aws s3 cp ./dist/iife/index.bundle.js s3://${{ github.event.inputs.bucket }}/spaces/${{ github.event.inputs.version }}/iife/index.bundle.js

.github/workflows/dev-ci.yml

@@ -80,3 +80,16 @@ jobs:
           sourcePath: docs/typedoc/generated
           githubToken: ${{ secrets.GITHUB_TOKEN }}
           artifactName: typedoc
+  test-cdn-bundle:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 18
+      - run: npm ci
+      - run: npx playwright install chromium
+      - run: npm run build
+      - run: npm run test:cdn-bundle

.gitignore

@@ -6,6 +6,7 @@ node_modules/
 coverage
 .env
 docs/typedoc/generated/
+test-results/
 
 # Local Netlify folder
 .netlify

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "test/ably-common"]
+	path = test/ably-common
+	url = https://github.com/ably/ably-common.git

.prettierignore

@@ -0,0 +1 @@
+test/ably-common/

CONTRIBUTING.md

@@ -34,3 +34,12 @@ To run the Jest tests, simply run the following command:
 ```bash
 npm test
 ```
+
+### CDN bundle test
+
+To test the bundle that we upload to the CDN:
+
+1. Initialize submodules: `git submodule update --init`
+2. Install browser for Playwright to use: `npx run playwright install chromium`
+3. Build the bundle: `npm run build`
+4. Run the test: `npm run test:cdn-bundle`