/* * Copyright 2011 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.testing.littlemock; import java.io.File; import java.io.ObjectInputStream; import java.io.ObjectStreamClass; import java.lang.reflect.Field; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.concurrent.Callable; import java.util.concurrent.CopyOnWriteArrayList; import java.util.concurrent.atomic.AtomicLong; import java.util.concurrent.atomic.AtomicReference; /** * Very lightweight and simple mocking framework, inspired by Mockito, http://mockito.org. * *

It supports only a small subset of the APIs provided by Mockito and other mocking * frameworks. * *

This project was originally designed to be lightweight and suitable for platforms that don't * support dynamic class generation, for example Android. Since the release of the open * source dexmaker project http://code.google.com/p/dexmaker/ we can now mock concrete classes * too. * *

Here is an example of how to use the framework. * *

Suppose that we have this interface: *

 *     public interface Foo {
 *       public String aString(int input);
 *       public void doSomething();
 *     }
 * 
* *

Then stubbing out mocks works as follows: *

 *     Foo mockFoo = mock(Foo.class);  // Create the mock.
 *     doReturn("hello").when(mockFoo).aString(anyInt());  // Stub the mock to return "hello".
 *     doThrow(new IOException("oh noes")).when(mockFoo).doSomething();
 *     assertEquals("hello", mockFoo.aString(5));  // Use the mock - performs as expected.
 *     mockFoo.doSomething();  // This will throw an IOException.
 * 
* *

You can verify in the 'natural place', after the method call has happened, like this: *

 *     Foo mockFoo = mock(Foo.class);
 *     assertEquals(null, mockFoo.aString(6));  // Unstubbed method calls return a sensible default.
 *     verify(mockFoo).aString(6);  // This will pass, aString() was called once.
 *     verify(mockFoo, never()).doSomething();  // This will pass, doSomething was never called.
 *     verify(mockFoo, times(3)).aString(anyInt());  // This will fail, was called once only.
 * 
* *

The documentation is still incomplete. You can look at the {@link LittleMockTest} class and * its unit tests - since they tell you exactly what operations are supported and how to use them. * *

The reasons I much prefer Mockito's approach to the one of EasyMock are as follows: *

* *

There were enough reasons that I wanted to give Mockito a try. It didn't work on Android * because of issues with class generation. So I looked at the documentation and examples page and * added tests for all the examples, and then implemented the this framework. I should stress that * this is a clean-room implementation, and as such it's possible that there are a couple of methods * that don't work in the same way as Mockito's implementation. Where that is the case I think we * should fix once we discover them. There is also some functionality missing, but it will be added * in due course. * *

Over time, the API has diverged slightly from the one of Mockito, as I have added APIs that I * found convenient but that did not have an equivalent in Mockite itself. For anything that has an * equivalent in Mockito I tried to keep the same name and syntax, to make it easier to transition * between using one framework to using the other, e.g., when developing both an Android application * using this framework and a desktop application using Mockito. * * @author hugohudson@gmail.com (Hugo Hudson) */ /*@NotThreadSafe*/ public class LittleMock { /** Generates a {@link Behaviour} suitable for void methods. */ public static Behaviour doNothing() { return doReturn(null); } /** Generates a {@link Behaviour} that returns the given result. */ public static Behaviour doReturn(final T result) { return new BehaviourImpl(new Action() { @Override public T doAction(Method method, Object[] args) { return result; } @Override public Class getReturnType() { return (result == null) ? null : result.getClass(); } }); } /** * Gets a {@link Behaviour} that will execute the given {@link Callable} and return its result. */ public static Behaviour doAnswer(final Callable callable) { return new BehaviourImpl(new Action() { @Override public T doAction(Method method, Object[] args) throws Throwable { return callable.call(); } @Override public Class getReturnType() { return null; } }); } /** Returns a {@link Behaviour} that throws the given {@link Throwable}. */ public static Behaviour doThrow(final T exception) { return new BehaviourImpl(new Action() { @Override public Object doAction(Method method, Object[] args) throws Throwable { throw exception; } @Override public Class getReturnType() { return null; } }); } /** Begins a verification step on a mock: the next method invocation on that mock will verify. */ public static T verify(T mock, CallCount howManyTimes) { return verify(mock, howManyTimes, null); } private static final class OrderChecker { private MethodCall mLastCall; public void checkOrder(List calls, String fieldName) { MethodCall lastTrial = null; for (MethodCall trial : calls) { if (mLastCall == null || mLastCall.mInvocationOrder < trial.mInvocationOrder) { mLastCall = trial; return; } lastTrial = trial; } fail(formatFailedVerifyOrderMessage(mLastCall, lastTrial, fieldName)); } private String formatFailedVerifyOrderMessage(MethodCall lastCall, MethodCall thisCall, String fieldName) { StringBuffer sb = new StringBuffer(); sb.append("\nCall to:"); appendDebugStringForMethodCall(sb, thisCall.mMethod, thisCall.mElement, fieldName, false); sb.append("\nShould have happened after:"); appendDebugStringForMethodCall(sb, lastCall.mMethod, lastCall.mElement, fieldName, false); sb.append("\nBut the calls happened in the wrong order"); sb.append("\n"); return sb.toString(); } } private static T verify(T mock, CallCount howManyTimes, OrderChecker orderCounter) { if (howManyTimes == null) { throw new IllegalArgumentException("Can't pass null for howManyTimes parameter"); } DefaultInvocationHandler handler = getHandlerFrom(mock); checkState(handler.mHowManyTimes == null, "Unfinished verify() statements"); checkState(handler.mOrderCounter == null, "Unfinished verify() statements"); checkState(handler.mStubbingAction == null, "Unfinished stubbing statements"); checkNoMatchers(); handler.mHowManyTimes = howManyTimes; handler.mOrderCounter = orderCounter; sUnfinishedCallCounts.add(howManyTimes); return handler.getVerifyingMock(); } /** The list of outstanding calls to verify() that haven't finished, used to check for errors. */ private static List sUnfinishedCallCounts = new ArrayList(); /** The list of outstanding calls to when() that haven't finished, used to check for errors. */ private static List sUnfinishedStubbingActions = new ArrayList(); /** Begins a verification step for exactly one method call. */ public static T verify(T mock) { return verify(mock, times(1)); } /** Assert that no method calls at all happened on these mocks. */ public static void verifyZeroInteractions(Object... mocks) { checkNoMatchers(); for (Object mock : mocks) { List mMethodCalls = getHandlerFrom(mock).mRecordedCalls; expect(mMethodCalls.isEmpty(), "Mock expected zero interactions, had " + mMethodCalls); } } /** Assert that there are no unverified method calls on these mocks. */ public static void verifyNoMoreInteractions(Object... mocks) { StackTraceElement callSite = new Exception().getStackTrace()[1]; for (Object mock : mocks) { verifyNoMoreInteractions(mock, callSite); } } /** Check that there are no unverified actions on the given mock. */ private static void verifyNoMoreInteractions(Object mock, StackTraceElement callSite) { checkNoMatchers(); DefaultInvocationHandler handlerFrom = getHandlerFrom(mock); List unverifiedCalls = new ArrayList(); for (MethodCall method : handlerFrom.mRecordedCalls) { if (!method.mWasVerified) { unverifiedCalls.add(method); } } if (unverifiedCalls.size() > 0) { StringBuffer sb = new StringBuffer(); sb.append("\nWe found these unverified calls:"); for (MethodCall method : unverifiedCalls) { appendDebugStringForMethodCall(sb, method.mMethod, method.mElement, handlerFrom.mFieldName, false); } sb.append("\n\nAfter final interaction was verified:\n"); sb.append(" at ").append(callSite).append("\n"); throw new AssertionError(sb.toString()); } } /** Creates a {@link CallCount} that matches exactly the given number of calls. */ public static CallCount times(long n) { return new CallCount(n, n); } /** Claims that the verified call must happen before the given timeout. */ public static Timeout timeout(long timeoutMillis) { return new Timeout(1, 1, timeoutMillis); } /** Creates a {@link CallCount} that only matches if the method was never called. */ public static CallCount never() { return new CallCount(0, 0); } /** Creates a {@link CallCount} that matches at least one method call. */ public static CallCount atLeastOnce() { return new CallCount(1, Long.MAX_VALUE); } /** Creates a {@link CallCount} that matches any number of method calls, including none at all. */ public static CallCount anyTimes() { return new CallCount(0, Long.MAX_VALUE); } /** Creates a {@link CallCount} that matches at least the given number of calls. */ public static CallCount atLeast(long n) { return new CallCount(n, Long.MAX_VALUE); } /** Creates a {@link CallCount} that matches up to the given number of calls but no more. */ public static CallCount atMost(long n) { return new CallCount(0, n); } /** Creates a {@link CallCount} that matches any number of calls between the two given bounds. */ public static CallCount between(long lower, long upper) { return new CallCount(lower, upper); } /** * Creates an argument matcher that matches any object, don't use for primitives. *

* Note: This does not enforce that the object is of type {@code T}; use * {@link #isA(Class)} to do that. */ public static T anyObject() { return LittleMock.addMatcher(new MatchAnything(), null); } /** Generates an argument matcher that matches any string. */ public static String anyString() { return isA(String.class); } /** Generates an argument matcher that matches any int. */ public static int anyInt() { return addMatcher(new MatchAnything(), 0); } /** Generates an argument matcher that matches any float. */ public static float anyFloat() { return addMatcher(new MatchAnything(), 0f); } /** Generates an argument matcher that matches any double. */ public static double anyDouble() { return addMatcher(new MatchAnything(), 0.0); } /** Generates an argument matcher that matches any boolean. */ public static boolean anyBoolean() { return addMatcher(new MatchAnything(), false); } /** Generates an argument matcher that matches any short. */ public static short anyShort() { return addMatcher(new MatchAnything(), (short) 0); } /** Generates an argument matcher that matches any char. */ public static char anyChar() { return addMatcher(new MatchAnything(), '\u0000'); } /** Generates an argument matcher that matches any long. */ public static long anyLong() { return addMatcher(new MatchAnything(), 0L); } /** Generates an argument matcher that matches any byte. */ public static byte anyByte() { return addMatcher(new MatchAnything(), (byte) 0); } /** Generates an argument matcher that matches exactly this value. */ public static T eq(final T expected) { return addMatcher(new ArgumentMatcher() { @Override public boolean matches(Object value) { return areEqual(expected, value); } }, expected); } /** An argument matcher that matches any value of the given type or a subtype thereof. */ public static T isA(final Class clazz) { return LittleMock.addMatcher(new ArgumentMatcher() { @Override public boolean matches(Object value) { return value == null || clazz.isAssignableFrom(value.getClass()); } }, null); } /** * Injects fields annotated with {@link Mock} with a newly created mock, and those * annotated with {@link Captor} with a suitable capture object. * *

This operation is recursive, and travels up the class hierarchy, in order to set all * suitably annotated fields. */ public static void initMocks(Object instance) throws Exception { injectMocksForClass(instance, instance.getClass()); } /** Recurse up the class hierarchy injecting mocks as we go, stopping when we reach Object. */ private static void injectMocksForClass(Object instance, Class clazz) throws Exception { if (clazz.equals(Object.class)) { return; } for (Field field : clazz.getDeclaredFields()) { if (field.getAnnotation(Mock.class) != null) { setField(field, instance, mock(field.getType(), field.getName())); } else if (field.getAnnotation(Captor.class) != null) { setField(field, instance, createCaptor()); } } injectMocksForClass(instance, clazz.getSuperclass()); } /** * Creates a correctly typed {@link ArgumentCaptor} , it's easier to use * {@link #initMocks(Object)}. */ public static ArgumentCaptor createCaptor() { return new ArgumentCaptorImpl(); } /** * Create a correctly typed ArgumentCaptor that also works for primitive types. * For example, to capture an int, use * ArgumentCaptor c = createCaptor(Integer.class); */ public static ArgumentCaptor createCaptor(Class clazz) { return new ArgumentCaptorImpl(clazz); } /** Implementation of the {@link ArgumentCaptor} interface. */ private static class ArgumentCaptorImpl implements ArgumentCaptor { private final ArrayList mAllValues = new ArrayList(); private T mValue; private Class mClass; private ArgumentCaptorImpl() { mClass = null; } private ArgumentCaptorImpl(Class clazz) { mClass = clazz; } public void setValue(T value) { mValue = value; mAllValues.add(mValue); } @Override public T getValue() { return mValue; } @Override public List getAllValues() { return mAllValues; } @Override public T capture() { if (mClass != null) { if (Integer.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, 0); } if (Float.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, 0f); } if (Double.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, 0.0); } if (Boolean.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, false); } if (Short.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, (short) 0); } if (Character.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, '\u0000'); } if (Long.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, 0L); } if (Byte.class.isAssignableFrom(mClass)) { return (T) LittleMock.addMatcher(this, (byte) 0); } } return LittleMock.addMatcher(this, null); } @Override public boolean matches(Object value) { // A capture always matches any argument. // This is so that verify(mMock).someMethod(capture(mCapture)) will match any and all calls // to someMethod() and we will capture the values into mCapture. return true; } } /** * Creates a mock, more easily done via the {@link #initMocks(Object)} method. * *

Also if you use this method to create your mock, the field in the error messages will * be named the same as your class passed in, you only get the actual field name if you * use the annotation. * * @throws IllegalArgumentException if the class you pass in is null */ public static T mock(Class clazz) { if (clazz == null) { throw new IllegalArgumentException("Class to mock was null"); } return mock(clazz, getDefaultFieldNameFor(clazz)); } /** Creates a mock, more easily done via the {@link #initMocks(Object)} method. */ @SuppressWarnings("unchecked") private static T mock(Class clazz, String fieldName) { return (T) createProxy(clazz, new DefaultInvocationHandler(clazz, fieldName)); } /** Pick a suitable name for a field of the given clazz. */ private static String getDefaultFieldNameFor(Class clazz) { return clazz.getSimpleName().substring(0, 1).toLowerCase() + clazz.getSimpleName().substring(1); } /** Clears out the expectations on these mocks. */ public static void reset(Object... mocks) { for (Object mock : mocks) { getHandlerFrom(mock).reset(); } } /** Use this in tear down to check for programming errors. */ public static void checkForProgrammingErrorsDuringTearDown() { checkNoMatchers(); checkNoUnfinishedCalls(sUnfinishedCallCounts, "verify()"); checkNoUnfinishedCalls(sUnfinishedStubbingActions, "stubbing"); } /** Helper function to check that there are no verify or stubbing commands outstanding. */ private static void checkNoUnfinishedCalls(List list, String type) { if (!list.isEmpty()) { list.clear(); throw new IllegalStateException("Unfinished " + type + " statements"); } } /** Implementation of {@link Behaviour}. */ private static class BehaviourImpl implements Behaviour { private final Action mAction; private BehaviourImpl(Action action) { mAction = action; } @Override public T when(T mock) { DefaultInvocationHandler handler = getHandlerFrom(mock); checkState(handler.mHowManyTimes == null, "Unfinished verify() statements"); checkState(handler.mOrderCounter == null, "Unfinished verify() statements"); checkState(handler.mStubbingAction == null, "Unfinished stubbing statements"); handler.mStubbingAction = mAction; sUnfinishedStubbingActions.add(mAction); return handler.getStubbingMock(); } } /** * The static list of argument matchers, used in the next method call to the mock. * *

In order to support the syntax like this: verify(mFoo).someMethod(anyInt()), it is * required that the anyInt() method store the value somewhere for use when the someMethod * is invoked. That somewhere has to be static. I don't like it any more than you do. * *

The same goes for anything that is passed into the someMethod as an argument - be it * a capture(mCaptureString) or eq(5) or whatever. * *

Avoiding the use of statics requires that we change the syntax of the verify statement, * and I can't think of an elegant way of doing it, and in any case I really like the current * syntax, so for now a static variable it is. * *

This match arguments list should contain either zero elements (the next method call will * not use any argument matchers) or it should contain exactly one argument matcher for * every argument being passed to the next method call. You can't mix argument matchers and * raw values. */ private static final List sMatchArguments = new ArrayList(); /** Global invocation order of every mock method call. */ private static final AtomicLong sGlobalInvocationOrder = new AtomicLong(); /** Encapsulates a single call of a method with associated arguments. */ private static class MethodCall { /** The method call. */ private final Method mMethod; /** The arguments provided at the time the call happened. */ private final Object[] mArgs; /** The order in which this method call was invoked. */ private final long mInvocationOrder; /** The line from the test that invoked the handler to create this method call. */ private final StackTraceElement mElement; /** Keeps track of method calls that have been verified, for verifyNoMoreInteractions(). */ public boolean mWasVerified = false; public MethodCall(Method method, StackTraceElement element, Object[] args) { mMethod = method; mElement = element; mArgs = args; mInvocationOrder = sGlobalInvocationOrder.getAndIncrement(); } public boolean argsMatch(Object[] args) { return Arrays.equals(mArgs, args); } @Override public String toString() { return "MethodCall [method=" + mMethod + ", args=" + Arrays.toString(mArgs) + "]"; } } private static boolean areMethodsSame(Method first, Method second) { return areEqual(first.getDeclaringClass(), second.getDeclaringClass()) && areEqual(first.getName(), second.getName()) && areEqual(first.getReturnType(), second.getReturnType()) && Arrays.equals(first.getParameterTypes(), second.getParameterTypes()); } private static boolean areEqual(Object a, Object b) { if (a == null) { return b == null; } return a.equals(b); } /** * Magically handles the invoking of method calls. * *

This object is in one of three states, default (where invoking methods returns default * values and records the call), verifying (where invoking method calls makes sure that those * method calls happen with the supplied arguments or matchers) or stubbing (where the next method * call tells us which arguments to match in order to perform the desired behaviour). */ private static class DefaultInvocationHandler implements InvocationHandler { private static Method sEqualsMethod; private static Method sHashCodeMethod; private static Method sToStringMethod; static { try { sEqualsMethod = Object.class.getMethod("equals", Object.class); sHashCodeMethod = Object.class.getMethod("hashCode"); sToStringMethod = Object.class.getMethod("toString"); } catch (SecurityException e) { // Should never happen. throw new RuntimeException("Your JVM/classloader is broken", e); } catch (NoSuchMethodException e) { // Should never happen. throw new RuntimeException("Your JVM/classloader is broken", e); } } /** The class of the mocked objects. */ private final Class mClazz; /** The field name in which the mock is assigned. */ private final String mFieldName; /** The list of method calls executed on the mock. */ private List mRecordedCalls = new CopyOnWriteArrayList(); /** The list of method calls that were stubbed out and their corresponding actions. */ private List mStubbedCalls = new CopyOnWriteArrayList(); /** * The number of times a given call should be verified. * *

It is not null when in the verification state, and it is actually used to determine if we * are in the verification state. * *

It is reset to null once the verification has occurred. */ private CallCount mHowManyTimes = null; private OrderChecker mOrderCounter = null; /** * The action to be associated with the stubbed method. * *

It is not null when in the stubbing state, and it is actually used to determine if we are * in the stubbing state. */ private Action mStubbingAction = null; /** Dynamic proxy used to verify calls against this mock. */ private final Object mVerifyingMock; /** Dynamic proxy used to stub calls against this mock. */ private final Object mStubbingMock; /** * Creates a new invocation handler for an object. * * @param clazz the class the object belongs to * @param fieldName The name to be used to refer to the object. This may either be the name of * the field this mock will be stored into (in case it uses @Mock) or a suitable name to * use to refer to the object in error messages, based on the name of the class itself. */ public DefaultInvocationHandler(Class clazz, String fieldName) { mClazz = clazz; mFieldName = fieldName; mVerifyingMock = createVerifyingMock(clazz); mStubbingMock = createStubbingMock(clazz); } // Safe if you call getHandlerFrom(mock).getVerifyingMock(), since this is guaranteed to be // of the same type as mock itself. @SuppressWarnings("unchecked") public T getVerifyingMock() { return (T) mVerifyingMock; } // Safe if you call getHandlerFrom(mock).getStubbingMock(), since this is guaranteed to be // of the same type as mock itself. @SuppressWarnings("unchecked") public T getStubbingMock() { return (T) mStubbingMock; } /** Used to check that we always stub and verify from the same thread. */ private AtomicReference mCurrentThread = new AtomicReference(); /** Check that we are stubbing and verifying always from the same thread. */ private void checkThread() { Thread currentThread = Thread.currentThread(); mCurrentThread.compareAndSet(null, currentThread); if (mCurrentThread.get() != currentThread) { throw new IllegalStateException("Must always mock and stub from one thread only. " + "This thread: " + currentThread + ", the other thread: " + mCurrentThread.get()); } } /** Generate the dynamic proxy that will handle verify invocations. */ private Object createVerifyingMock(Class clazz) { return createProxy(clazz, new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { checkThread(); expect(mHowManyTimes != null, "verifying mock doesn't know how many times"); try { ArgumentMatcher[] matchers = checkClearAndGetMatchers(method); StackTraceElement callSite = new Exception().getStackTrace()[2]; MethodCall methodCall = new MethodCall(method, callSite, args); innerVerify(method, matchers, methodCall, proxy, callSite, mHowManyTimes, mOrderCounter); return defaultReturnValue(method.getReturnType()); } finally { sUnfinishedCallCounts.remove(mHowManyTimes); mHowManyTimes = null; mOrderCounter = null; } } }); } /** Generate the dynamic proxy that will handle stubbing invocations. */ private Object createStubbingMock(Class clazz) { return createProxy(clazz, new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { checkThread(); expect(mStubbingAction != null, "stubbing mock doesn't know what action to perform"); try { ArgumentMatcher[] matchers = checkClearAndGetMatchers(method); StackTraceElement callSite = new Exception().getStackTrace()[2]; MethodCall methodCall = new MethodCall(method, callSite, args); innerStub(method, matchers, methodCall, callSite, mStubbingAction); return defaultReturnValue(method.getReturnType()); } finally { sUnfinishedStubbingActions.remove(mStubbingAction); mStubbingAction = null; } } }); } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { StackTraceElement callSite = new Exception().getStackTrace()[2]; MethodCall methodCall = new MethodCall(method, callSite, args); return innerRecord(method, args, methodCall, proxy, callSite); } /** * Checks whether the given method is one of the special object methods that should not * verified or stubbed. *

* If this is one of such methods, it throws an AssertionException. * * @param method the method to be checked * @param operation the name of the operation, used for generating a helpful message */ private void checkSpecialObjectMethods(Method method, String operation) { if (areMethodsSame(method, sEqualsMethod) || areMethodsSame(method, sHashCodeMethod) || areMethodsSame(method, sToStringMethod)) { fail("cannot " + operation + " call to " + method); } } private void reset() { mRecordedCalls.clear(); mStubbedCalls.clear(); mHowManyTimes = null; mOrderCounter = null; mStubbingAction = null; } private Object innerRecord(Method method, final Object[] args, MethodCall methodCall, Object proxy, StackTraceElement callSite) throws Throwable { if (areMethodsSame(method, sEqualsMethod)) { // Use identify for equality, the default behavior on object. return proxy == args[0]; } else if (areMethodsSame(method, sHashCodeMethod)) { // This depends on the fact that each mock has its own DefaultInvocationHandler. return hashCode(); } else if (areMethodsSame(method, sToStringMethod)) { // This is used to identify this is a mock, e.g., in error messages. return "Mock<" + mClazz.getName() + ">"; } mRecordedCalls.add(methodCall); for (StubbedCall stubbedCall : mStubbedCalls) { if (areMethodsSame(stubbedCall.mMethodCall.mMethod, methodCall.mMethod)) { if (stubbedCall.mMethodCall.argsMatch(methodCall.mArgs)) { methodCall.mWasVerified = true; return stubbedCall.mAction.doAction(method, args); } } } // If no stub is defined, return the default value. return defaultReturnValue(method.getReturnType()); } private void innerStub(Method method, final ArgumentMatcher[] matchers, MethodCall methodCall, StackTraceElement callSite, final Action stubbingAction) { checkSpecialObjectMethods(method, "stub"); checkThisActionCanBeUsedForThisMethod(method, stubbingAction, callSite); if (matchers.length == 0) { // If there are no matchers, then this is a simple stubbed method call with an action. mStubbedCalls.add(0, new StubbedCall(methodCall, stubbingAction)); return; } // If there are matchers, then we need to make a new method call which matches only // when all the matchers match. Further, the action that method call needs to take // is to first record the values into any captures that may be present, and only then // proceed to execute the original action. MethodCall matchMatchersMethodCall = new MethodCall(method, callSite, matchers) { @Override public boolean argsMatch(Object[] args) { return doMatchersMatch(matchers, args); } }; Action setCapturesThenAction = new Action() { @Override public Object doAction(Method innerMethod, Object[] innerArgs) throws Throwable { setCaptures(matchers, innerArgs); return stubbingAction.doAction(innerMethod, innerArgs); } @Override public Class getReturnType() { return stubbingAction.getReturnType(); } }; mStubbedCalls.add(0, new StubbedCall(matchMatchersMethodCall, setCapturesThenAction)); } private void checkThisActionCanBeUsedForThisMethod(Method method, final Action stubbingAction, StackTraceElement callSite) { Class methodType = method.getReturnType(); Class actionType = stubbingAction.getReturnType(); if (actionType == null) { // We could not determine the type returned by this action at the time we // created it. At this time we cannot check that the returned value is // appropriate to the return type of the method. // However, if the type is not correct, any actual invocation of the method // will fail later on. return; } if (!methodType.isAssignableFrom(actionType)) { if (methodType.isPrimitive() && actionType.equals(PRIMITIVE_TO_BOXED_LOOKUP.get(methodType))) { return; } StringBuffer sb = new StringBuffer(); sb.append("\nCan't return ").append(actionType.getSimpleName()).append(" from stub for:"); appendDebugStringForMethodCall(sb, method, callSite, mFieldName, true); sb.append("\n"); throw new IllegalArgumentException(sb.toString()); } } private boolean doMatchersMatch(ArgumentMatcher[] matchers, Object[] args) { for (int i = 0; i < matchers.length; ++i) { if (!matchers[i].matches(args[i])) { return false; } } return true; } private void innerVerify(Method method, ArgumentMatcher[] matchers, MethodCall methodCall, Object proxy, StackTraceElement callSite, CallCount callCount, OrderChecker orderCounter) { checkSpecialObjectMethods(method, "verify"); List calls = countMatchingInvocations(method, matchers, methodCall); long callTimeout = callCount.getTimeout(); checkState(orderCounter == null || callTimeout == 0, "can't inorder verify with a timeout"); if (callTimeout > 0) { long endTime = System.currentTimeMillis() + callTimeout; while (!callCount.matches(calls.size())) { try { Thread.sleep(1); } catch (InterruptedException e) { fail("interrupted whilst waiting to verify"); } if (System.currentTimeMillis() > endTime) { fail(formatFailedVerifyMessage(methodCall, calls.size(), callTimeout, callCount)); } calls = countMatchingInvocations(method, matchers, methodCall); } } else { if (orderCounter != null) { orderCounter.checkOrder(calls, mFieldName); } else if (!callCount.matches(calls.size())) { fail(formatFailedVerifyMessage(methodCall, calls.size(), 0, callCount)); } } } private List countMatchingInvocations(Method method, ArgumentMatcher[] matchers, MethodCall methodCall) { List methodCalls = new ArrayList(); for (MethodCall call : mRecordedCalls) { if (areMethodsSame(call.mMethod, method)) { if ((matchers.length > 0 && doMatchersMatch(matchers, call.mArgs)) || call.argsMatch(methodCall.mArgs)) { setCaptures(matchers, call.mArgs); methodCalls.add(call); call.mWasVerified = true; } } } return methodCalls; } private String formatFailedVerifyMessage(MethodCall methodCall, int total, long timeoutMillis, CallCount callCount) { StringBuffer sb = new StringBuffer(); sb.append("\nExpected ").append(callCount); if (timeoutMillis > 0) { sb.append(" within " + timeoutMillis + "ms"); } sb.append(" to:"); appendDebugStringForMethodCall(sb, methodCall.mMethod, methodCall.mElement, mFieldName, false); sb.append("\n\n"); if (mRecordedCalls.size() == 0) { sb.append("No method calls happened on this mock"); } else { sb.append("Method calls that did happen:"); for (MethodCall recordedCall : mRecordedCalls) { appendDebugStringForMethodCall(sb, recordedCall.mMethod, recordedCall.mElement, mFieldName, false); } } sb.append("\n"); return sb.toString(); } /** All matchers that are captures will store the corresponding arg value. */ // This suppress warning means that I'm calling setValue with something that I can't promise // is of the right type. But I think it is unavoidable. Certainly I could give a better // error message than the class cast exception you'll get when you try to retrieve the value. @SuppressWarnings("unchecked") private void setCaptures(ArgumentMatcher[] matchers, Object[] args) { for (int i = 0; i < matchers.length; ++i) { if (matchers[i] instanceof ArgumentCaptorImpl) { ArgumentCaptorImpl.class.cast(matchers[i]).setValue(args[i]); } } } /** An empty array of matchers, to optimise the toArray() call below. */ private static final ArgumentMatcher[] EMPTY_MATCHERS_ARRAY = new ArgumentMatcher[0]; /** Makes sure that we have the right number of MATCH_ARGUMENTS for the given method. */ private ArgumentMatcher[] checkClearAndGetMatchers(Method method) { ArgumentMatcher[] matchers = sMatchArguments.toArray(EMPTY_MATCHERS_ARRAY); sMatchArguments.clear(); if (matchers.length > 0 && method.getParameterTypes().length != matchers.length) { throw new IllegalArgumentException("You can't mix matchers and regular objects."); } return matchers; } } private static void appendDebugStringForMethodCall(StringBuffer sb, Method method, StackTraceElement callSite, String fieldName, boolean showReturnType) { sb.append("\n "); if (showReturnType) { sb.append("(").append(method.getReturnType().getSimpleName()).append(") "); } sb.append(fieldName).append(".").append(method.getName()).append("("); int i = 0; for (Class type : method.getParameterTypes()) { if (++i > 1) { sb.append(", "); } sb.append(type.getSimpleName()); } sb.append(")\n at ").append(callSite); } /** Call this function when you don't expect there to be any outstanding matcher objects. */ private static void checkNoMatchers() { if (sMatchArguments.size() > 0) { sMatchArguments.clear(); throw new IllegalStateException("You have outstanding matchers, must be programming error"); } } /** A pairing of a method call and an action to be performed when that call happens. */ private static class StubbedCall { private final MethodCall mMethodCall; private final Action mAction; public StubbedCall(MethodCall methodCall, Action action) { mMethodCall = methodCall; mAction = action; } @Override public String toString() { return "StubbedCall [methodCall=" + mMethodCall + ", action=" + mAction + "]"; } } /** Represents an action to be performed as a result of a method call. */ private interface Action { public Object doAction(Method method, Object[] arguments) throws Throwable; /** The type of the action, or null if we can't determine the type at stub time. */ public Class getReturnType(); } /** Represents something capable of testing if it matches an argument or not. */ public interface ArgumentMatcher { public boolean matches(Object value); } /** A matcher that matches any argument. */ private static class MatchAnything implements ArgumentMatcher { @Override public boolean matches(Object value) { return true; } } /** Encapsulates the number of times a method is called, between upper and lower bounds. */ private static class CallCount { private long mLowerBound; private long mUpperBound; public CallCount(long lowerBound, long upperBound) { mLowerBound = lowerBound; mUpperBound = upperBound; } /** Tells us if this call count matches a desired count. */ public boolean matches(long total) { return total >= mLowerBound && total <= mUpperBound; } /** Tells us how long we should block waiting for the verify to happen. */ public long getTimeout() { return 0; } public CallCount setLowerBound(long lowerBound) { mLowerBound = lowerBound; return this; } public CallCount setUpperBound(long upperBound) { mUpperBound = upperBound; return this; } @Override public String toString() { if (mLowerBound == mUpperBound) { return "exactly " + mLowerBound + plural(" call", mLowerBound); } else { return "between " + mLowerBound + plural(" call", mLowerBound) + " and " + mUpperBound + plural(" call", mUpperBound); } } } /** Encapsulates adding number of times behaviour to a call count with timeout. */ public static final class Timeout extends CallCount { private long mTimeoutMillis; public Timeout(long lowerBound, long upperBound, long timeoutMillis) { super(lowerBound, upperBound); mTimeoutMillis = timeoutMillis; } @Override public long getTimeout() { return mTimeoutMillis; } public CallCount times(int times) { return setLowerBound(times).setUpperBound(times); } public CallCount atLeast(long n) { return setLowerBound(n).setUpperBound(Long.MAX_VALUE); } public CallCount atLeastOnce() { return setLowerBound(1).setUpperBound(Long.MAX_VALUE); } public CallCount between(long n, long m) { return setLowerBound(n).setUpperBound(m); } } /** Helper method to add an 's' to a string iff the count is not 1. */ private static String plural(String prefix, long count) { return (count == 1) ? prefix : (prefix + "s"); } /** Helps us implement the eq(), any() and capture() and other methods on one line. */ private static T addMatcher(ArgumentMatcher argument, T value) { sMatchArguments.add(argument); return value; } /** A custom argument matcher, should be used only for object arguments not primitives. */ public static T matches(ArgumentMatcher argument) { sMatchArguments.add(argument); return null; } /** Utility method to throw an AssertionError if an assertion fails. */ private static void expect(boolean result, String message) { if (!result) { fail(message); } } /** Throws an AssertionError exception with a message. */ private static void fail(String message) { throw new AssertionError(message); } /** Static mapping from class type to default value for that type. */ private static final Map, Object> DEFAULT_RETURN_VALUE_LOOKUP; static { DEFAULT_RETURN_VALUE_LOOKUP = new HashMap, Object>(); DEFAULT_RETURN_VALUE_LOOKUP.put(int.class, 0); DEFAULT_RETURN_VALUE_LOOKUP.put(boolean.class, false); DEFAULT_RETURN_VALUE_LOOKUP.put(byte.class, (byte) 0); DEFAULT_RETURN_VALUE_LOOKUP.put(long.class, (long) 0); DEFAULT_RETURN_VALUE_LOOKUP.put(short.class, (short) 0); DEFAULT_RETURN_VALUE_LOOKUP.put(float.class, (float) 0); DEFAULT_RETURN_VALUE_LOOKUP.put(double.class, (double) 0); DEFAULT_RETURN_VALUE_LOOKUP.put(char.class, '\u0000'); DEFAULT_RETURN_VALUE_LOOKUP.put(String.class, null); } /** Static lookup from primitive types to their boxed versions. */ private static final Map, Class> PRIMITIVE_TO_BOXED_LOOKUP; static { PRIMITIVE_TO_BOXED_LOOKUP = new HashMap, Class>(); PRIMITIVE_TO_BOXED_LOOKUP.put(int.class, Integer.class); PRIMITIVE_TO_BOXED_LOOKUP.put(boolean.class, Boolean.class); PRIMITIVE_TO_BOXED_LOOKUP.put(byte.class, Byte.class); PRIMITIVE_TO_BOXED_LOOKUP.put(long.class, Long.class); PRIMITIVE_TO_BOXED_LOOKUP.put(short.class, Short.class); PRIMITIVE_TO_BOXED_LOOKUP.put(float.class, Float.class); PRIMITIVE_TO_BOXED_LOOKUP.put(double.class, Double.class); PRIMITIVE_TO_BOXED_LOOKUP.put(char.class, Character.class); } /** For a given class type, returns the default value for that type. */ private static Object defaultReturnValue(Class returnType) { return DEFAULT_RETURN_VALUE_LOOKUP.get(returnType); } /** Gets a suitable class loader for use with the proxy. */ private static ClassLoader getClassLoader() { return LittleMock.class.getClassLoader(); } /** Sets a member field on an object via reflection (can set private members too). */ private static void setField(Field field, Object object, Object value) throws Exception { field.setAccessible(true); field.set(object, value); field.setAccessible(false); } /** Helper method to throw an IllegalStateException if given condition is not met. */ private static void checkState(boolean condition, String message) { if (!condition) { throw new IllegalStateException(message); } } /** Helper method to throw an IllegalStateException if given condition is not met. */ private static void checkState(boolean condition) { if (!condition) { throw new IllegalStateException(); } } /** * If the input object is one of our mocks, returns the {@link DefaultInvocationHandler} * we constructed it with. Otherwise fails with {@link IllegalArgumentException}. */ private static DefaultInvocationHandler getHandlerFrom(Object mock) { try { InvocationHandler invocationHandler = Proxy.getInvocationHandler(mock); if (invocationHandler instanceof DefaultInvocationHandler) { return (DefaultInvocationHandler) invocationHandler; } } catch (IllegalArgumentException expectedIfNotAProxy) {} try { Class proxyBuilder = Class.forName("com.google.dexmaker.stock.ProxyBuilder"); Method getHandlerMethod = proxyBuilder.getMethod("getInvocationHandler", Object.class); Object invocationHandler = getHandlerMethod.invoke(proxyBuilder, mock); if (invocationHandler instanceof DefaultInvocationHandler) { return (DefaultInvocationHandler) invocationHandler; } } catch (Exception expectedIfNotAProxyBuilderMock) {} try { // Try with javassist. Class proxyObjectClass = Class.forName("javassist.util.proxy.ProxyObject"); Method getHandlerMethod = proxyObjectClass.getMethod("getHandler"); Object methodHandler = getHandlerMethod.invoke(mock); InvocationHandler invocationHandler = Proxy.getInvocationHandler(methodHandler); Method getOriginalMethod = invocationHandler.getClass().getMethod("$$getOriginal"); Object original = getOriginalMethod.invoke(invocationHandler); if (original instanceof DefaultInvocationHandler) { return (DefaultInvocationHandler) original; } } catch (Exception expectedIfNotJavassistProxy) {} throw new IllegalArgumentException("not a valid mock: " + mock); } private static boolean canUseJavassist() { try { Class.forName("javassist.util.proxy.ProxyFactory"); return true; } catch (Exception expectedIfNotJavassistProxy) { return false; } } /** Create a dynamic proxy for the given class, delegating to the given invocation handler. */ private static Object createProxy(Class clazz, final InvocationHandler handler) { // Interfaces are simple. Just proxy them using java.lang.reflect.Proxy. if (clazz.isInterface()) { return Proxy.newProxyInstance(getClassLoader(), new Class[] { clazz }, handler); } // Try with javassist. if (canUseJavassist()) { try { Class proxyFactoryClass = Class.forName("javassist.util.proxy.ProxyFactory"); Object proxyFactory = proxyFactoryClass.newInstance(); Method setSuperclassMethod = proxyFactoryClass.getMethod("setSuperclass", Class.class); setSuperclassMethod.invoke(proxyFactory, clazz); Class methodFilterClass = Class.forName("javassist.util.proxy.MethodFilter"); InvocationHandler methodFilterHandler = new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { checkState(method.getName().equals("isHandled")); checkState(args.length == 1); checkState(args[0] instanceof Method); Method invokedMethod = (Method) args[0]; String methodName = invokedMethod.getName(); Class[] params = invokedMethod.getParameterTypes(); if ("equals".equals(methodName) && params.length == 1 && Object.class.equals(params[0])) { return false; } if ("hashCode".equals(methodName) && params.length == 0) { return false; } if ("toString".equals(methodName) && params.length == 0) { return false; } if ("finalize".equals(methodName) && params.length == 0) { return false; } return true; } }; Object methodFilter = Proxy.newProxyInstance(getClassLoader(), new Class[] { methodFilterClass }, methodFilterHandler); Method setFilterMethod = proxyFactoryClass.getMethod("setFilter", methodFilterClass); setFilterMethod.invoke(proxyFactory, methodFilter); Method createClassMethod = proxyFactoryClass.getMethod("createClass"); Class createdClass = (Class) createClassMethod.invoke(proxyFactory); InvocationHandler methodHandlerHandler = new InvocationHandler() { @SuppressWarnings("unused") public InvocationHandler $$getOriginal() { return handler; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { checkState(method.getName().equals("invoke")); checkState(args.length == 4); checkState(args[1] instanceof Method); Method invokedMethod = (Method) args[1]; checkState(args[3] instanceof Object[]); return handler.invoke(args[0], invokedMethod, (Object[]) args[3]); } }; Class methodHandlerClass = Class.forName("javassist.util.proxy.MethodHandler"); Object methodHandler = Proxy.newProxyInstance(getClassLoader(), new Class[] { methodHandlerClass }, methodHandlerHandler); Object proxy = unsafeCreateInstance(createdClass); Class proxyObjectClass = Class.forName("javassist.util.proxy.ProxyObject"); Method setHandlerMethod = proxyObjectClass.getMethod("setHandler", methodHandlerClass); setHandlerMethod.invoke(proxy, methodHandler); return proxy; } catch (Exception e) { // Not supported, something went wrong. Fall through, try android dexmaker. e.printStackTrace(System.err); } } // So, this is a class. First try using Android's ProxyBuilder from dexmaker. try { Class proxyBuilder = Class.forName("com.google.dexmaker.stock.ProxyBuilder"); Method forClassMethod = proxyBuilder.getMethod("forClass", Class.class); Object builder = forClassMethod.invoke(null, clazz); Method dexCacheMethod = builder.getClass().getMethod("dexCache", File.class); File directory = AppDataDirGuesser.getsInstance().guessSuitableDirectoryForGeneratedClasses(); builder = dexCacheMethod.invoke(builder, directory); Method buildClassMethod = builder.getClass().getMethod("buildProxyClass"); Class resultClass = (Class) buildClassMethod.invoke(builder); Object proxy = unsafeCreateInstance(resultClass); Field handlerField = resultClass.getDeclaredField("$__handler"); handlerField.setAccessible(true); handlerField.set(proxy, handler); return proxy; } catch (Exception e) { throw new IllegalStateException("Could not mock this concrete class", e); } } /** Attempt to construct an instance of the class using hacky methods to avoid calling super. */ @SuppressWarnings("unchecked") private static T unsafeCreateInstance(Class clazz) { // try jvm try { Class unsafeClass = Class.forName("sun.misc.Unsafe"); Field f = unsafeClass.getDeclaredField("theUnsafe"); f.setAccessible(true); final Object unsafe = f.get(null); final Method allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class); return (T) allocateInstance.invoke(unsafe, clazz); } catch (Exception ignored) {} // try dalvikvm, pre-gingerbread try { final Method newInstance = ObjectInputStream.class.getDeclaredMethod( "newInstance", Class.class, Class.class); newInstance.setAccessible(true); return (T) newInstance.invoke(null, clazz, Object.class); } catch (Exception ignored) {} // try dalvikvm, post-gingerbread try { Method getConstructorId = ObjectStreamClass.class.getDeclaredMethod( "getConstructorId", Class.class); getConstructorId.setAccessible(true); final int constructorId = (Integer) getConstructorId.invoke(null, Object.class); final Method newInstance = ObjectStreamClass.class.getDeclaredMethod( "newInstance", Class.class, int.class); newInstance.setAccessible(true); return (T) newInstance.invoke(null, clazz, constructorId); } catch (Exception ignored) {} // try dalvikvm, with change https://android-review.googlesource.com/#/c/52331/ try { Method getConstructorId = ObjectStreamClass.class .getDeclaredMethod("getConstructorId", Class.class); getConstructorId.setAccessible(true); final long constructorId = (Long) getConstructorId.invoke(null, Object.class); final Method newInstance = ObjectStreamClass.class .getDeclaredMethod("newInstance", Class.class, long.class); newInstance.setAccessible(true); return (T) newInstance.invoke(null, clazz, constructorId); } catch (Exception ignored) {} throw new IllegalStateException("unsafe create instance failed"); } /** See {@link LittleMock#inOrder(Object[])}. */ public interface InOrder { T verify(T mock); } /** * Used to verify that invocations happen in a given order. *

* Still slight experimental at the moment: you can only verify one method call at a time, * and we ignore the mocks array you pass in as an argument, you may use the returned inorder * to verify all mocks. *

* This implementation is simple: the InOrder you get from this call can be used to verify that * a sequence of method calls happened in the order you specify. Every verify you make with * this InOrder will be compared with every other verify you made, to make sure that all the * original invocations happened in exactly that same order. */ public static InOrder inOrder(Object... mocks) { return new InOrder() { private final OrderChecker mChecker = new OrderChecker(); @Override public T verify(T mock) { return LittleMock.verify(mock, times(1), mChecker); } }; } }