test: Set up Vitest (#131)

* build: Add vitest

* build: Add @testing-library/react

* build: Add @testing-library/user-event

* build: Add jsdom

* build: Add @testing-library/dom

* build: Add @testing-library/jest-dom

* test: Configure Vitest

* test: Assert editor load notice

* build: Add test-js make command

* ci: Run JavaScript tests in CI

* docs: Document test commands

* test: Clean up stubbed test globals

Avoid cryptic errors from lingering global stubs.

Author: dcalhoun

.buildkite/pipeline.yml

@@ -15,6 +15,10 @@ steps:
       command: make lint-js
       plugins: *plugins
 
+    - label: ':javascript: Test JavaScript'
+      command: make test-js
+      plugins: *plugins
+
     - label: ':android: Publish Android Library'
       command: |
           make build

Makefile

@@ -44,6 +44,9 @@ fmt-js: npm-dependencies
 lint-js: npm-dependencies
 	npm run lint
 
+test-js: npm-dependencies
+	npm run test -- run
+
 local-android-library: build
 	echo "--- :android: Building Library"
 	./android/gradlew -p ./android :gutenberg:publishToMavenLocal -exclude-task prepareToPublishToS3

README.md

@@ -60,6 +60,26 @@ GUTENBERG_EDITOR_URL=http://<YOUR_LOCAL_IP>:5173/
 
 </details>
 
+## Testing
+
+To run the JavaScript tests, run the following command in your terminal:
+
+```bash
+make test-js
+```
+
+To run the Swift tests, run the following command in your terminal:
+
+```bash
+make test-swift
+```
+
+To run the Android tests, run the following command in your terminal:
+
+```bash
+make test-android
+```
+
 ## Production
 
 To build GutenbergKit for production run the following command in your terminal:

__mocks__/@wordpress/components/index.jsx

@@ -0,0 +1,14 @@
+export const Notice = ( { children, actions } ) => (
+	<div data-testid="mock-notice">
+		<span>{ children }</span>
+		{ actions?.map( ( action, index ) => (
+			<button
+				key={ index }
+				onClick={ action.onClick }
+				data-variant={ action.variant }
+			>
+				{ action.label }
+			</button>
+		) ) }
+	</div>
+);

__mocks__/@wordpress/i18n/index.js

@@ -0,0 +1,3 @@
+import { vi } from 'vitest';
+
+export const __ = vi.fn( ( text ) => text );