How can I get the arguments called in jest mock function?

Question

How can I get the arguments called in jest mock function?

I want to inspect the object that is passed as argument.

Answer 1

Here is a simple way to assert the parameter passed.

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

Answer 2

I prefer lastCalledWith() over toHaveBeenCalledWith(). They are both the same but the former is shorter and help me reduce the cognitive load when reading code.

expect(mockedFn).lastCalledWith('arg1', 'arg2')

Answer 3

Just use mockObject.calls. In my case I used:

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

Here's the documentation about the mock property