/*
* Copyright 2010 The Rabbit Eclipse Plug-in Project
*
* 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 rabbit.ui.internal.viewers;
import com.google.common.base.Joiner;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import org.junit.Before;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.Nullable;
/**
* Base test class for forwarding test classes.
*/
public abstract class ForwardingTestCase {
/**
* A list containing each method call as a string using
* {@link #callToString(String, Object...)}.
*/
private List<String> calls = new ArrayList<String>();
@Before
public void clearMethodCalls() {
calls.clear();
}
/**
* Asserts that only the given method with the given arguments is called on
* the current proxy.
* @param methodName The name of the method.
* @param args The arguments passed to the method.
*/
protected void assertCall(String methodName, @Nullable Object... args) {
assertThat(methodsCalled(), is(callToString(methodName, args)));
}
/**
* Converts a method call to string.
* @param methodName the name of the method.
* @param args the arguments passed to the invocation, nullable.
* @return a string representation of this method invocation.
*/
protected String callToString(String methodName, @Nullable Object... args) {
if (args == null) {
args = new Object[0];
}
return new StringBuilder(methodName)
.append("(")
.append(Joiner.on(", ").useForNull("null").join(args))
.append(")")
.toString();
}
/**
* Gets a string representation of all the method calls. Each call is built
* using {@link #callToString(String, Object...)} and then joined together
* using a ', '
*/
protected String methodsCalled() {
return Joiner.on(", ").join(calls);
}
/**
* Creates a new instance of the given interface. When any method of the proxy
* is called, the call will be recorded, then {@link #methodsCalled()} will
* return the method call.
* @param c the instance type.
* @return an instance.
*/
protected <T> T newProxy(Class<T> c) {
ClassLoader loader = c.getClassLoader();
Class<?>[] types = {c};
InvocationHandler handler = new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
calls.add(callToString(method.getName(), args));
if (method.getReturnType() == boolean.class) {
return Boolean.FALSE;
}
return null;
}
};
@SuppressWarnings("unchecked")
T instance = (T) Proxy.newProxyInstance(loader, types, handler);
return instance;
}
}