core/runtime/src/test/java/org/apache/zest/runtime/mixin/MixinPrecedenceTest.java

/*
 * Copyright (c) 2008, Rickard Öberg. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.zest.runtime.mixin;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import org.junit.Test;
import org.apache.zest.api.composite.TransientComposite;
import org.apache.zest.api.mixin.Mixins;
import org.apache.zest.bootstrap.AssemblyException;
import org.apache.zest.bootstrap.ModuleAssembly;
import org.apache.zest.test.AbstractQi4jTest;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;

/**
 * Test mixin declaration precedence satisfiedBy
 */
public class MixinPrecedenceTest
    extends AbstractQi4jTest
{

    public void assemble( ModuleAssembly module )
        throws AssemblyException
    {
        module.transients( TestComposite1.class,
                           TestComposite2.class,
                           TestComposite3.class );
    }

    @Test
    public void whenMultipleTypedMixinsPrecedence()
    {
        TestComposite1 instance = module.newTransient( TestComposite1.class );
        assertThat( "Mixin precedence", instance.AMethod(), equalTo( "A1" ) );
    }

    @Test
    public void whenGenericAndTypedMixinPrecedence()
    {
        TestComposite2 instance = module.newTransient( TestComposite2.class );
        assertThat( "Typed mixin is chosen over generic mixin", instance.AMethod(), equalTo( "A1" ) );
    }

    @Test
    public void whenMultipleGenericMixinsPrecedence()
    {
        TestComposite3 instance = module.newTransient( TestComposite3.class );
        assertEquals( "GM1", instance.AMethod() );
    }

    @Mixins( { AMixin1.class, AMixin2.class } )
    public static interface TestComposite1
        extends A, TransientComposite
    {
    }

    @Mixins( { GenericMixin1.class, AMixin1.class } )
    public static interface TestComposite2
        extends A, TransientComposite
    {
    }

    @Mixins( { GenericMixin1.class, GenericMixin2.class } )
    public static interface TestComposite3
        extends A, TransientComposite
    {
    }

    public interface A
    {
        String AMethod();
    }

    public static class AMixin1
        implements A
    {

        public String AMethod()
        {
            return "A1";
        }
    }

    public static class AMixin2
        implements A
    {

        public String AMethod()
        {
            return "A2";
        }
    }

    public static class GenericMixin1
        implements InvocationHandler
    {
        public Object invoke( Object object, Method method, Object[] objects )
            throws Throwable
        {
            return "GM1";
        }
    }

    public static class GenericMixin2
        implements InvocationHandler
    {
        public Object invoke( Object object, Method method, Object[] objects )
            throws Throwable
        {
            return "GM2";
        }
    }
}