Chore: homepage tests (#6278)

docs/widgets/authoring/getting-started.md

@@ -33,6 +33,32 @@ Once dependencies have been installed you can lint your code with
 pnpm lint
 ```
 
+## Testing
+
+Homepage uses [Vitest](https://vitest.dev/) for unit and component tests.
+
+Run the test suite:
+
+```bash
+pnpm test
+```
+
+Run the test suite with coverage:
+
+```bash
+pnpm test:coverage
+```
+
+### What tests to include
+
+- New or updated widgets should generally include a component test near the widget component (for example `src/widgets/<widget>/component.test.jsx`) that covers realistic behavior: loading/placeholder state, error state, and a representative "happy path" render.
+- If you add or change a widget definition file (`src/widgets/<widget>/widget.js`), add/update its corresponding unit test (`src/widgets/<widget>/widget.test.js`) to cover the config/mapping behavior.
+- If your widget requires a custom proxy (`src/widgets/<widget>/proxy.js`), add a proxy unit test (`src/widgets/<widget>/proxy.test.js`) that validates:
+  - request construction (URL, query params, headers/auth)
+  - response mapping (what the widget consumes)
+  - error pathways (upstream error, unexpected payloads)
+- Avoid placing test files under `src/pages/**` (Next.js treats files there as routes). Page tests should live under `src/__tests__/pages/**`.
+
 ## Code formatting with pre-commit hooks
 
 To ensure a consistent style and formatting across the project source, the project utilizes Git [`pre-commit`](https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks) hooks to perform some formatting and linting before a commit is allowed.