Simple and complete React hooks testing utilities that encourage good testing practices.
npm install @testing-library/preact-hooks
preact port of the the @testing-library/react-hooks library.
@testing-library/react-hooks?Currently, due to the use of react-test-renderer, the react hooks testing library most likely will never be compatible with preact.
At the time of writing, a library did not exist to test preact hooks.
1. You're writing a library with one or more custom hooks that are not directly tied to a component
2. You have a complex hook that is difficult to test through component interactions
1. Your hook is defined alongside a component and is only used there
2. Your hook is easy to test by just testing the components using it
Install with your favorite package manager
```
yarn add -D @testing-library/preact-hooks
OR
npm install --save-dev @testing-library/preact-hooks
`typescript
import { useState, useCallback } from 'preact/hooks';
const useCounter = () => {
const [count, setCount] = useState(0);
const increment = useCallback(() => setCount(c => c + 1));
return {
count,
increment
}
}
export default useCounter;
`
`typescript
import { renderHook, act } from '@testing-library/preact-hooks';
import useCounter from './useCounter';
test('should increment counter', () => {
const { result } = renderHook(() => useCounter());
act(() => {
result.current.increment();
});
expect(result.current.count).toBe(1);
});
`
Sometimes, hooks may need access to values or functionality outside of itself that are provided by a context provider or some other HOC.
`typescript jsx
import { createContext } from 'preact'
import { useState, useCallback, useContext } from 'preact/hooks'
const CounterStepContext = createContext(1)
export const CounterStepProvider = ({ step, children }) => (
)
export function useCounter(initialValue = 0) {
const [count, setCount] = useState(initialValue)
const step = useContext(CounterStepContext)
const increment = useCallback(() => setCount((x) => x + step), [step])
const reset = useCallback(() => setCount(initialValue), [initialValue])
return { count, increment, reset }
}
`
In our test, we simply use CoounterStepProvider as the wrapper when rendering the hook:
`typescript
import { renderHook, act } from '@testing-library/preact-hooks'
import { CounterStepProvider, useCounter } from './counter'
test('should use custom step when incrementing', () => {
const wrapper = ({ children }) =>
const { result } = renderHook(() => useCounter(), { wrapper })
act(() => {
result.current.increment()
})
expect(result.current.count).toBe(2)
})
`
- [ ] remove @ts-nocheck` flag from tests
- [ ] fix disabled auto clean up tests