我怎样才能获得在jest模拟函数中调用的参数？

Question

我怎样才能获得在jest模拟函数中调用的参数？

我想检查对象传递作为参数.

Answer 1

只需使用mockObject.calls.在我的情况下我用过:

const call = mockUpload.mock.calls[0][0]

这是关于该属性的文档mock

Answer 2

您可以与或toHaveBeenCalledWith()一起使用expect.stringContainingexpect.arrayContaining()expect.objectContaining()

...
const { host } = new URL(url);
expect(mockedFunction).toHaveBeenCalledWith("param1", expect.stringContaining(`http://${host}...`);

Answer 3

这是断言所传递参数的简单方法。

expect(mockedFunction).toHaveBeenCalledWith("param1","param2");

Answer 4

使用参数捕获器，如下所示：

let barArgCaptor;
const appendChildMock = jest
    .spyOn(foo, "bar")
    .mockImplementation(
    (arg) => (barArgCaptor = arg)
    );

然后你就可以expect随心所欲地对俘虏的属性进行评价了：

expect(barArgCaptor.property1).toEqual("Fool of a Took!");
expect(barArgCaptor.property2).toEqual(true);

Answer 5

我发现我经常想要验证对模拟函数的精确调用的确切参数；我的方法是：

let mockFn = jest.fn((/* ... */) => { /* ... */ });

// ... do some testing which triggers `mockFn` ...

expect(mockFn.mock.calls).toEqual([

  // Ensure `mockFn` was called exactly 3 times:
  
  // The 1st time with arguments "a" and 1,
  [ 'a', 1 ],

  // 2nd time with arguments "b" and 2,
  [ 'b', 2 ],
  
  // 3rd time with arguments "c" and 3
  [ 'c', 3 ]

]);