com.google.gwt.junit.GWTMockUtilities Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* 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 com.google.gwt.junit;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.GWTBridge;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Defangs {@link GWT#create(Class)} to allow unit tests to mock out Widgets and
* other UIObjects.
*/
public class GWTMockUtilities {
/**
* Replace the normal GWT.create() behavior with a method that returns null
* instead of throwing a runtime exception. This is to allow JUnit tests to
* mock classes that make GWT.create() calls in their static initializers.
* This is not for use with GWTTestCase, and is not for use testing widgets
* themselves. Rather, it is to allow pure java unit tests of classes that
* need to manipulate widgets.
*
*
* NOTE: Be sure to call {@link #restore} in your tearDown
* method, to avoid confusing downstream tests.
*
*
* Sample use:
*
*
@Override
* public void setUp() throws Exception {
* super.setUp();
* GWTMockUtilities.disarm();
* }
*
* @Override
* public void tearDown() {
* GWTMockUtilities.restore();
* }
*
* public void testSomething() {
* MyStatusWidget mock = EasyMock.createMock(MyStatusWidget.class);
* EasyMock.expect(mock.setText("expected text"));
* EasyMock.replay(mock);
*
* StatusController controller = new StatusController(mock);
* controller.setStatus("expected text");
*
* EasyMock.verify(mock);
* }
*
*/
public static void disarm() {
GWTBridge bridge = new GWTDummyBridge();
setGwtBridge(bridge);
}
public static void restore() {
setGwtBridge(null);
}
/**
* Install the given instance of {@link GWTBridge}, allowing it to override
* the behavior of calls to {@link GWT#create(Class)}.
*/
private static void setGwtBridge(GWTBridge bridge) {
Class gwtClass = GWT.class;
Class[] paramTypes = new Class[] {GWTBridge.class};
Method setBridgeMethod = null;
try {
setBridgeMethod = gwtClass.getDeclaredMethod("setBridge", paramTypes);
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
}
setBridgeMethod.setAccessible(true);
try {
setBridgeMethod.invoke(gwtClass, new Object[] {bridge});
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
} catch (InvocationTargetException e) {
throw new RuntimeException(e);
}
}
}