Introduction

The primary objective of unit testing is to test a method, object, or component in isolation and see how it behaves in different circumstances. However, there are situations where a method/object has dependencies on other methods or objects. In this scenario, we need to design tests/specs across the units/methods or components to validate behavior or simulate a real-time scenario. However, due to non-availability of dependent methods/objects or a staging/production environment, it is quite challenging to write Jasmine tests for methods that have dependencies on other methods/objects. This is where mocks come into the picture. A mock is a fake object that replaces the original object/method and imitates the behavior of the real object, without going into the nitty-gritty of creating the real object/method.

Mocks work by implementing the proxy model. Whenever we create a mock object, it creates a proxy object, which replaces the real object/method. In our test method, we can...