How to mock function imported directly into the tested file with Jest

file-to-test.js

import { exampleFunction } from "./file";

export class ExampleClass {
  someFunction(){
    return exampleFunction()
  }
}

file.js

export const exampleFunction = () => 'SOMETHING-A'

jest-mock-things-example.spec.js

import * as fileExports from "./file";
import * as ExampleClass from "./file-to-test";

const exampleClass = new ExampleClass()

describe('Some describe', () => {
    it('must mock value', (done) => {
        const newReturnValue = 'ANOTHER-THING';
        jest.spyOn(fileExports, 'exampleFunction').mockImplementation(() => newReturnValue);
        
        expect(exampleClass.someFunction()).toBe(newReturnValue); // This works correctly.
        done();
    });
});