How do you change the behaviour of a mocked import in Jest?

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After you’ve mocked the module and replaced the methodToMock with a spy, you need to import it. Then, at each test, you can change the behaviour of methodToMock by calling the mockImplementation spy method.

jest.mock('the-package-to-mock', () => ({
    methodToMock: jest.fn()
}))

import { methodToMock } from 'the-package-to-mock'

it('Test A', () => {
    methodToMock.mockImplementation(() => 'Value A')
    // Test your function that uses the mocked package's function here.
})

it('Test B', () => {
    methodToMock.mockImplementation(() => 'Value B')
    // Test the code again, but now your function will get a different value when it calls the mocked package's function.
})

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