Using expect.any(String) in object comparison in jest

Question

I have a code like below

    expect(insertedData).toEqual({
                id: expect.any(String),
                clientId: 'client1',
                ...

I expect id should match any string, but what I get as result is

Not sure what I missed.

Also I used like below still same error

expect(insertedData).toEqual(expect.objectContaining({

Tetracaine

It is probably because the constructor of the id and lastModifiedDate fields' values are not String. Can you check it? – Torn

They're going to be an ObjectId and a Date, no? – Kamasutra

Answer 1

It happens to me. Turns out the problem is not with the fields with expect.any() but the other field. Seems it just bad diff there.

Nupercaine

Answer 2

The problem on your expression relies on the first expectation which is

toEqual()

the expectation should use toMatchObject like:

expect(insertedData).toMatchObject({...

Glasshouse

expect(insertedData).objectContaining({... Gives the error Property 'objectContaining' does not exist on type 'JestMatchers<any>'.ts(2339) – Persistence

The documentation reads: Matches anything but null or undefined. You can use it inside toEqual or toBeCalledWith instead of a literal value. For example, if you want to check that a mock function is called with a non-null argument: – Nightwear