0Pricing
Testing Mastery: JUnit, Mockito & Integration Tests · Lesson

Stubbing Return Values

Configure mock objects to return specific values or throw exceptions when their methods are invoked.

Intro to Stubbing Mocks

When you create a mock object, it doesn't have any real behavior. Its methods do nothing by default, often returning null, 0, or empty collections.

Stubbing is the process of teaching a mock object how to respond to specific method calls. It's like giving your mock a script to follow!

This allows you to control the exact conditions for your tests, isolating the code you're actually testing.

Making Mocks Return Values

The most common way to stub a mock is using when().thenReturn(). This tells Mockito: "When this specific method is called on the mock, return this predefined value."

  • when(mock.someMethod()).thenReturn(value);

The value can be any object or primitive type that matches the method's return type.

All lessons in this course

  1. Stubbing Return Values
  2. Mockito Argument Matchers
  3. Spying on Real Objects
  4. Throwing Exceptions and Consecutive Calls
← Back to Testing Mastery: JUnit, Mockito & Integration Tests