Is there a method in Jest similar to the "when" method in the Mockito framework for testing?

Is there a way to mock a class from a route using Jest in TypeScript? I came across the "when" method in the mockito framework, but I'm wondering if Jest has something similar for this purpose.

Answer №1

Unfortunately, there is no default feature within jest that achieves this specific functionality. However, you can achieve a similar outcome using alternative methods:

  1. Integrate the logic directly into your mock function:
const spy = jest
   .spyOn(myObject, 'do')
   .mockImplementation((someNumber) => someNumber > 1 ? true : false)
  1. Create a sequence of return values to test different scenarios consecutively:
const = jest
  .spyOn(myObject, 'do')
  .mockReturnValue(true)
  .mockReturnValueOnce(false)
  .mockReturnValueOnce(true);

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