Programming Groovy 2

18.6 Mocking Using Categories

In Section 13.1, ​Injecting Methods Using Categories​, we discussed how categories provide controlled aspect-oriented programming (AOP) in Groovy. In this section we’ll see how we can use it to create mocks.

import com.agiledeveloper.CodeWithHeavierDependencies

class TestUsingCategories extends GroovyTestCase {
  void testMyMethod() {
    def testObj = new CodeWithHeavierDependencies()

    use(MockHelper) {
      testObj.myMethod()

      assertEquals 35, MockHelper.result
    }
  }
}

class MockHelper {
  def static result

  def static println(self, text) { result = text }

  def static someAction(CodeWithHeavierDependencies self) { 25 } ...