Jest function toHaveBeenCalledWith to ignore object order

Question

Im testing with what arguments a function was called but its not passing because the order of properties inside an object, like:

const obj = {
  name: 'Bla',
  infos: {
    info1: '1',
    info2: '2'
  }
}

expect(function).toHaveBeenCalledWith(obj)

The error says that was called like this: { name: 'bla', infos: {info2: '2', info1: '1'} }

I changed orders but didn't work.

Answer 1

You could follow a similar approach to this SO answer .

Example:

// Assuming some mock setup like this...
const mockFuncton = jest.fn();

const expectedObj = {
  name: 'Bla',
  infos: {
    info1: '1',
    info2: '2'
  }
}

// Perform operation(s) being tested...

// Expect the function to have been called at least once
expect(mockFuncton).toHaveBeenCalled();

// Get the 1st argument from the mock function call
const functionArg = mockFuncton.mock.calls[0][0];

// Expect that argument matches the expected object
expect(functionArg).toMatchObject(expectedObj);

// Comparison using toEqual() instead which might be a better approach for your usecase
expect(functionArg).toEqual(expectedObj);

Expect.toMatchObject() Docs

Expect.toEqual() Docs

Answer 2

  it('does not care on properties ordering', () => {
    const a = jest.fn();
    a({ a: 1, b: 2, c: {d1: 1, d2: 2} });
    expect(a).toHaveBeenCalledWith({c: {d2: 2, d1: 1}, b: 2, a: 1});
  });

passes for me with Jest 24.9.0

Under the hood , Jest applies "isEqual" check, not referential check

But we cannot check for functions equality this way. Also partial matching will need custom matcher.