jest: Understandable error messages when using spread operator with expect.any(Object)

🚀 Feature Proposal

Understandable error messages when using object destructuring with expect.any(Object).

Motivation

Let’s consider following functions

const createEvent = (event, payload) => ({
  eventType: event,
  ...payload,
})

const getEvents = () => ([
	createEvent('evt1', { some: 'payload' }),
	createEvent('evt2', { some: 'payload' }),
])

Let’s say you want to test that getEvents gives you appropriate actions and you already tested createEvent so you use it in your next test suites and write something like this

test('this test fails :(', () => {
	const expectedEvents = [
		createEvent('evt1', expect.any(Object)),
		createEvent('evt2', expect.any(Object)),
	]

	expect(getEvents()).toEqual(expectedEvents);
});

You will get a close to cryptic error TypeError: val.toAsymmetricMatcher is not a function with no clue what you need to fix.

Maybe there’s a way to detect this kind of mistakes and provide a more user-friendly error message?