gistfile1.txt

package advanced;

import com.sandwich.koan.Koan;
import static com.sandwich.util.Assert.fail;

public class AboutMocks {
	
	static interface Collaborator {
		public void doBusinessStuff();
	}
	
	static class ExplosiveCollaborator implements Collaborator {
		public void doBusinessStuff() {
			fail("Default collaborator's behavior is complicating testing.");
		}
	}
	
	static class ClassUnderTest {
		Collaborator c;
		public ClassUnderTest(){
			// default is to pass a broken Collaborator, test should pass one
			// that doesn't throw exception
			this(new ExplosiveCollaborator());
		}
		public ClassUnderTest(Collaborator c){
			this.c = c;
		}
		public boolean doSomething(){
			c.doBusinessStuff();
			return true;
		}
	}
	
	@Koan
	public void simpleAnonymousMock(){


		new ClassUnderTest().doSomething();
	}
	
}

earlier I had tried

    public void simpleAnonymousMock(){
           new ClassUnderTest(
                    new Collaborator(){

            @Override
            public void doBusinessStuff() {
                //These are not the droids you're looking for
            }
        });
    new ClassUnderTest().doSomething();
}

but it still failed