一个简单的 react hooks 功能，请教 jest 单元测试怎么写

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› React

这是一个创建于 1165 天前的主题，其中的信息可能已经有所发展或是发生改变。

就是实现一个异步操作（比如接口）的 loading 功能

export const useLoading = <T extends (...arg: any) => any>(
  callback: T,
  deps: any[] = [],
): [boolean, (...args: any[]) => Promise<ReturnType<T>>] => {
  const [loading, setLoading] = useState(false);
  const executor = useCallback(async (...args) => {
    try {
      setLoading(true);
      return await callback(...args);
    } finally {
      setLoading(false);
    }
  }, deps);
  return [loading, executor];
};

下面是我写的，第一个 expect 运行对，第二个 expect 想验证函数执行完后 loading 变回 false，但是运行 result.current[0]实际为 true，请教各位大佬

import {renderHook, act} from '@testing-library/react-hooks'
describe('useLoading', () => {
	it('useLoading', async () => {	
     	jest.useFakeTimers();
          const fn = async () => {
            return new Promise((resolve, reject) => {
              setTimeout(() => resolve(true), 1000);
            });
          };
          const { result } = renderHook(() => useLoading(fn));
          act(() => {
            const [, executor] = result.current;
            executor();
            jest.advanceTimersByTime(500);
          });
          expect(result.current[0]).toBe(true);
          act(() => {
            jest.runAllTicks();
            jest.runAllTimers();
          });
          expect(result.current[0]).toBe(false);
     });
 })

const

Executor

expect

2 条回复 • 2021-10-20 23:11:59 +08:00

CodingNaux

2021-10-19 12:50:43 +08:00

```typescript
describe("useLoading", () => {
it("useLoading", async () => {
jest.useFakeTimers();
const fn = async () => {
return new Promise((resolve, reject) => {
setTimeout(() => resolve(true), 1000);
});
};
const { result, waitForNextUpdate } = renderHook(() => useLoading(fn));
act(() => {
const [, executor] = result.current;
executor();
jest.advanceTimersByTime(500);
});
expect(result.current[0]).toBe(true);
act(() => {
jest.runAllTicks();
jest.runAllTimers();
});
await waitForNextUpdate();
expect(result.current[0]).toBe(false);
});
});
```

waitForNextUpdate,https://react-hooks-testing-library.com/usage/advanced-hooks#async

chenliangngng

2021-10-20 23:11:59 +08:00

@CodingNaux 感谢大佬