Test Mixins

Originally reported on Google Code with ID 218

There are situations where a bunch of tests should be applied to a code base. We are
currently using derived classes which is a pain, especially when your code under tests
should support either only a subset or  multiple category of tests (which results in
many abstract base specs and many concrete specs for the code under test ...)

This could be solved with test mixins in an elegant way. Here is an example 

class SpecMixin (extends SpecificationMixin?) {

  def "test something"() {
    when:
    objectUnderTest.doSomething()
    then:
    objectUnderTest.somethingDone()
  }

}

@Mixin(SpecMixin)
class RealSpec extends Specification {
  def objectUnderTest = new ObjectUnderTest()
}

The mixin, as well as the test should be able to access properties (as done with objectUnderTest
in this example) and the test lifecycle methods should be mixed in as well.

Reported by peter.rietzler@gmx.net on 2011-12-02 18:16:03

The issue names no implementation files, tests, or entry points. Start by locating Spock's specification and mixin handling, then assess how the requested example should support shared properties, test methods, and lifecycle methods; done means the mixin can be applied to a specification with those behaviors working together.