Jest expect to array contains element

Let’s suppose that I have the following code:

const id = '1'

const arrayOfIds = ['1', '2', '3']

And I want to check if id is in arrayOfIds

Something like this

expect(id).toBeIn(arrayOfIds)

How can I do this with Jest?

Answer

Use .toContain when you want to check that an item is in an array. For testing the items in the array, this uses ===, a strict equality check.

test('is id in arrayOfIds', () => {
        const id = '1';
        const arrayOfIds = ['1', '2', '3'];
        expect(arrayOfIds).toContain(id);
});