I have

abc.js

const a = (a)=>{
    return (b(a) + 1)
}

const b = (num)=>{
    return(num + 1)
}

module.exports = {
    a,
    b
}

When I do my test for function a, I wanted a mock implementation of function b. but function a, after mocking, still has been using the original implementation instead of my mock.

my test looks something like

abs.test.js

const { a } = require('./abc')

describe('/abc functions',()=>{

    beforeEach(()=>{
        jest.mock('./abc',()=>(
       b = jest.fn.mockReturnValue(5)
     ))
    })

    afterEach(()=>{
        jest.clearAllMocks()
    })

    it('uses the b() mock',()=>{



        const aResult = a(1)
        expect(aResult).toBe(6)
    })

})

but I get a result of 2 or whatever the original implementation is. I just wanted my function a to use my mock and it never does. it always goes back to the original implementation.

I tried jest.isolate() to isolate the function im testing. I tried differernt ways of mocking like jest.fn(), jest.spyOn, and the method about jest.requireActual(moduleName)

I tried b = jest.fn().mockImplementation(()=>{})

I am confused as to why function a, even after Isolation, still relies on original implementation of function b...

thank you in advance!