Mockito

Mockito is a unit test frame work helps in creating mocks and spies in simple way.

For more details on Mocks and Spies, Please refer below introduction

Introduction To Unit Testing

• Dummy - an empty object passed in an invocation (usually only to satisfy a compiler when a method ar- gument is required)
• Fake - an object having a functional implementation, but usually in a simplified form, just to satisfy the test (e.g., an in-memory database)
• Stub - an object with hardcoded behavior suitable for a given test (or a group of tests)
• Mock - an object with the ability to

             a) have a programmed expected behavior, and

 b) verify the interactions occurring in its lifetime (this object is usually created with the help  of mocking framework)

• Spy - a mock created as a proxy to an existing real object; some methods can be stubbed, while the un- stubbed ones are forwarded to the covered object