# Jest

## Links

* [Mocking Node modules](https://jestjs.io/docs/en/manual-mocks#mocking-node-modules)
* [mockFn.mockClear](https://jestjs.io/docs/en/mock-function-api.html#mockfnmockclear)
* [mockFn.mockReset](https://jestjs.io/docs/en/mock-function-api.html#mockfnmockreset)
* [expect.anything()](https://jestjs.io/docs/en/expect#expectanything)

### Asynchronous or time-based events (timers)

```js
describe('do some crazy stuff with timers.', () => {
  beforeEach(() => {
    // declare the intent of using timers
    jest.useFakeTimers()
  })

 it('should .', () => {
    // mock if needed
    const callback = jest.fn()

    // mount component

    // follow by expect before timers

    // execute timers
    jest.runAllTimers()

    // expect something after timers have been executed
    expect(callback).toHaveBeenCalledTimes(1)
  })
```

### Verify that function was called with multiple arguments

[`.toHaveBeenCalledWith(arg1, arg2, ...)`](https://jestjs.io/docs/en/expect#tohavebeencalledwitharg1-arg2-)

Also available under the alias: `.toBeCalledWith()`

### Verify that the same function was called multiple times with different arguments

```javascript
it('should be able to change access rights.', () => {
  expect(onUpdateAccess).not.toBeCalled()

  const newAccess = {
    ...report.access,
    view: {
      type: 'user',
      id: '3',
    },
  }

  component.find(Rights).prop('onChange')(newAccess)

  expect(onUpdateAccess).toBeCalledTimes(2)
  expect(onUpdateAccess).toBeCalledWith('edit', newAccess.edit)
  expect(onUpdateAccess).toBeCalledWith('view', newAccess.view)
})
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://alexgrischuk.gitbook.io/wiki/coding/jest.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.