For tutorial: Mastering the Art of Mocking ES Modules in Jest

functionToTest_wrong.spec.js

import { jest } from "@jest/globals"
import * as Dependency from "./dependency.js"
import { functionToTest } from "./functionToTest.js"

describe("functionToTest", () => {
  afterEach(() => {
    jest.restoreAllMocks()
  })

  it("should return the correct value 1", () => {
    const mockedDependencyValue = "the mocked dependency 1"
    jest.spyOn(Dependency, "dependency").mockReturnValue(mockedDependencyValue)
    expect(functionToTest()).toBe(mockedDependencyValue)
  })
  
  it("should return the correct value 2", () => {
    const mockedDependencyValue = "the mocked dependency 2"
    jest.spyOn(Dependency, "dependency").mockReturnValue(mockedDependencyValue)
    expect(functionToTest()).toBe(mockedDependencyValue)
  })
})