/*
* Copyright (c) 2007 Mockito contributors
* This program is made available under the terms of the MIT License.
*/
package org.mockito.internal.stubbing.defaultanswers;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import org.mockito.internal.creation.ClassNameFinder;
import org.mockito.internal.util.MockUtil;
import org.mockito.internal.util.ObjectMethodsGuru;
import org.mockito.internal.util.Primitives;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.mock.MockName;
import org.mockito.stubbing.Answer;
/**
* Default answer of every Mockito mock.
* <ul>
* <li>
* Returns appropriate primitive for primitive-returning methods
* </li>
* <li>
* Returns consistent values for primitive wrapper classes (e.g. int-returning method retuns 0 <b>and</b> Integer-returning method returns 0, too)
* </li>
* <li>
* Returns empty collection for collection-returning methods (works for most commonly used collection types)
* </li>
* <li>
* Returns description of mock for toString() method
* </li>
* <li>
* Returns non-zero for Comparable#compareTo(T other) method (see issue 184)
* </li>
* <li>
* Returns null for everything else
* </li>
* </ul>
*/
public class ReturnsEmptyValues implements Answer<Object>, Serializable {
private static final long serialVersionUID = 1998191268711234347L;
ObjectMethodsGuru methodsGuru = new ObjectMethodsGuru();
/* (non-Javadoc)
* @see org.mockito.stubbing.Answer#answer(org.mockito.invocation.InvocationOnMock)
*/
public Object answer(InvocationOnMock invocation) {
if (methodsGuru.isToString(invocation.getMethod())) {
Object mock = invocation.getMock();
MockName name = new MockUtil().getMockName(mock);
if (name.isDefault()) {
return "Mock for " + ClassNameFinder.classNameForMock(mock) + ", hashCode: " + mock.hashCode();
} else {
return name.toString();
}
} else if (methodsGuru.isCompareToMethod(invocation.getMethod())) {
//see issue 184.
//mocks by default should not return 0 for compareTo because they are not the same. Hence we return 1 (anything but 0 is good).
//Only for compareTo() method by the Comparable interface
return 1;
}
Class<?> returnType = invocation.getMethod().getReturnType();
return returnValueFor(returnType);
}
Object returnValueFor(Class<?> type) {
if (Primitives.isPrimitiveOrWrapper(type)) {
return Primitives.defaultValueForPrimitiveOrWrapper(type);
//new instances are used instead of Collections.emptyList(), etc.
//to avoid UnsupportedOperationException if code under test modifies returned collection
} else if (type == Collection.class) {
return new LinkedList<Object>();
} else if (type == Set.class) {
return new HashSet<Object>();
} else if (type == HashSet.class) {
return new HashSet<Object>();
} else if (type == SortedSet.class) {
return new TreeSet<Object>();
} else if (type == TreeSet.class) {
return new TreeSet<Object>();
} else if (type == LinkedHashSet.class) {
return new LinkedHashSet<Object>();
} else if (type == List.class) {
return new LinkedList<Object>();
} else if (type == LinkedList.class) {
return new LinkedList<Object>();
} else if (type == ArrayList.class) {
return new ArrayList<Object>();
} else if (type == Map.class) {
return new HashMap<Object, Object>();
} else if (type == HashMap.class) {
return new HashMap<Object, Object>();
} else if (type == SortedMap.class) {
return new TreeMap<Object, Object>();
} else if (type == TreeMap.class) {
return new TreeMap<Object, Object>();
} else if (type == LinkedHashMap.class) {
return new LinkedHashMap<Object, Object>();
}
// TODO return empty Iterable ; see issue 175
//Let's not care about the rest of collections.
return null;
}
}