Replace Karma with Vitest for JavaScript testing (#2197)

* Replace Karma with Vitest to run JS tests
* Update JS packages
* Allow developers to track JS code coverage

Author: milmazz

.github/workflows/ci.yml

@@ -54,12 +54,7 @@ jobs:
 
       # Test JS
       - run: npm run lint --prefix assets
-      - name: npm run test --prefix assets
-        run: |
-          sudo apt-get install xvfb
-          xvfb-run --auto-servernum npm run test --prefix assets
-        env:
-          CI: true
+      - run: npm run test --prefix assets
 
       # Push updated assets if all good
       - name: Push updated assets

.gitignore

@@ -34,3 +34,6 @@ formatters/html/dist/html.js
 
 # Ignore escript when built
 /ex_doc
+
+# Ignore coverage directory created by Vitest
+assets/coverage/

assets/README.md

@@ -7,7 +7,7 @@ To work on these assets you need to have [Node.js] and [npm] installed. (npm is
 Assets are built with [esbuild], which, along with the JavaScript linter and test-runner, is set as a dependency in the assets `package.json` and installed via [npm]:
 
 ```bash
-$ npm install --prefix assets
+npm install --prefix assets
 ```
 
 ## `npm run` scripts
@@ -17,7 +17,7 @@ The following scripts are available from the root folder of the project.
 ### `build`
 
 ```bash
-$ npm run --prefix assets build
+npm run --prefix assets build
 ```
 
 Build a complete production bundle, including JavaScript and CSS.
@@ -27,7 +27,7 @@ Build a complete production bundle, including JavaScript and CSS.
 ### `build:watch`
 
 ```bash
-$ npm run --prefix assets build:watch
+npm run --prefix assets build:watch
 ```
 
 Run the `build` command with watch mode set, providing for automatic assets rebuilds on every asset file change.
@@ -37,30 +37,37 @@ Additionally, in watch mode, the docs are built after every asset rebuild, meani
 ### `lint`
 
 ```bash
-$ npm run --prefix assets lint
+npm run --prefix assets lint
 ```
 
 Lint all JavaScript files using [ESLint].
 
 ### `lint:fix`
 
 ```bash
-$ npm run --prefix assets lint:fix
+npm run --prefix assets lint:fix
 ```
 
 Lint and automatically fix all JavaScript files using [ESLint].
 
 ### `test`
 
 ```bash
-$ npm run --prefix assets test
+npm run --prefix assets test
 ```
 
-Run all the available JavaScript tests using [Karma].
+Run all the available JavaScript tests using [Vitest].
 
+### `test:coverage`
+
+```bash
+npm run --prefix assets test:coverage
+```
+
+Run all the available JavaScript tests with code coverage using [Vitest].
 
 [esbuild]: https://esbuild.github.io
 [Node.js]: https://nodejs.org/
 [npm]: https://www.npmjs.com/
 [ESLint]: https://eslint.org/
-[Karma]: https://karma-runner.github.io/
+[Vitest]: https://vitest.dev/