snapshot of https://github.com/TanStack/query.git (main, 2026-09-16; blobs > 131072B omitted)

docs/framework/preact/guides/testing.md

@@ -0,0 +1,48 @@
+---
+id: testing
+title: Testing
+ref: docs/framework/react/guides/testing.md
+replace: { 'react-query': 'preact-query', 'React': 'Preact' }
+---
+
+[//]: # 'Install'
+
+Writing unit tests for these custom hooks can be done by means of the [Preact Testing Library](https://github.com/testing-library/preact-testing-library), which provides `renderHook` and re-exports the `@testing-library/dom` helpers such as `waitFor`.
+
+Install this by running:
+
+```sh
+npm install @testing-library/preact --save-dev
+```
+
+[//]: # 'Install'
+[//]: # 'ExampleFirstTest'
+
+```tsx
+import { renderHook, waitFor } from '@testing-library/preact'
+
+const queryClient = new QueryClient()
+const wrapper = ({ children }) => (
+  <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+)
+
+const { result } = renderHook(() => useCustomHook(), { wrapper })
+
+await waitFor(() => expect(result.current.isSuccess).toBe(true))
+
+expect(result.current.data).toEqual('Hello')
+```
+
+[//]: # 'ExampleFirstTest'
+[//]: # 'NoteWaitFor1'
+
+Here we are making use of `waitFor` and waiting until the query status indicates that the request has succeeded. This way we know that our hook has finished and should have the correct data.
+
+[//]: # 'NoteWaitFor1'
+[//]: # 'NoteWaitFor2'
+[//]: # 'NoteWaitFor2'
+[//]: # 'FurtherReading'
+
+For additional tips and an alternative setup using `mock-service-worker`, have a look at [TkDodo's article on testing](https://tkdodo.eu/blog/testing-react%2Dquery). It's written for a different framework adapter, but the same approach applies here.
+
+[//]: # 'FurtherReading'