Thursday, 1 November, 2018 UTC


When mocking a JavaScript function during a unit test, it can be helpful to force a mock function to return a value of your choosing. This allows you to verify that functions you're testing will behave correctly for every possible use case. Much like [`sinon.spy()`](, [`sinon.stub()`]( creates a mock function that prevents a real function from running. But, unlike `spy`, it also allows you to declare what value you'd like the mock function to return.