Programming Groovy 2

18.10 Mocking Using the Groovy Mock Library

Groovy’s mock library implemented in the ​groovy.mock.interceptor​ package is useful for mocking deeper dependencies—that is, instances of collaborators/dependent objects created within the methods we’re testing. ​StubFor​ and ​MockFor​ are the two classes that take care of this. Let’s look at them one at a time.

​StubFor​ and ​MockFor​ are intended to intercept calls to methods like categories do (see Section 18.6, ​Mocking Using Categories​). However, unlike with categories, we don’t have to create separate classes for mocking. We introduce the mock methods on instances of ​StubFor​ or ​MockFor​, and these classes take care of replacing the ​MetaClass​ for the object we’re mocking.

In ​Stubs ...