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Diffstat (limited to 'src/com/google/testing/littlemock/LittleMock.java')
| -rw-r--r-- | src/com/google/testing/littlemock/LittleMock.java | 881 |
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diff --git a/src/com/google/testing/littlemock/LittleMock.java b/src/com/google/testing/littlemock/LittleMock.java new file mode 100644 index 0000000..03e2c7a --- /dev/null +++ b/src/com/google/testing/littlemock/LittleMock.java @@ -0,0 +1,881 @@ +/* + * 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.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.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.concurrent.Callable; + +/** + * Very lightweight and simple mocking framework, inspired by Mockito, http://mockito.org. + * + * <p>It has a number of limitations, including: + * <ul> + * <li>Doesn't support mocking concrete classes, <b>interfaces only</b>.</li> + * + * <li><b>Is not thread-safe.</b> You'll need to provide your own synchronization if you want to + * run multi-threaded unit tests.</li> + * + * <li>It supports only a <b>small subset</b> of the APIs provided by Mockito and other mocking + * frameworks.</li> + * </ul> + * + * <p>This project was designed to be lightweight and suitable for platforms that don't support + * dynamic class generation, for example Android. + * + * <p>Here is an example of how to use the framework. + * + * <p>Suppose that we have this interface: + * <pre> + * public interface Foo { + * public String aString(int input); + * public void doSomething(); + * } + * </pre> + * + * <p>Then stubbing out mocks works as follows: + * <pre> + * 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. + * </pre> + * + * <p>You can verify in the 'natural place', after the method call has happened, like this: + * <pre> + * 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. + * </pre> + * + * <p>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. + * + * <p>The reasons I much prefer Mockito's approach to the one of EasyMock are as follows: + * <ul> + * <li>No need to remember to put your mocks in replay mode.</li> + * <li>No need to remember to call verify, a dangerous source of false-positive tests or + * alternatively over-specified tests.</li> + * <li>Much less over-specification: only verify what you actually care about.</li> + * <li>Which in turn leads to better separated tests, each test verifying only a part of the + * desired behaviour.</li> + * <li>Which also leads to less fragile tests, where adding another method call on your + * dependencies doesn't break unrelated tests.</li> + * <li>More natural order for tests: set up stubs, execute tests, verify that it worked.</li> + * <li>More unified syntax that doesn't require special case for differences between void method + * calls and method calls that return a value.</li> + * </ul> + * + * <p>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. + * + * <p>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 <T> 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 <T> Behaviour doAnswer(final Callable<T> 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 <T extends Throwable> 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> T verify(T mock, CallCount howManyTimes) { + if (howManyTimes == null) { + throw new IllegalArgumentException("Can't pass null for howManyTimes parameter"); + } + checkNoMatchers(); + getHandlerFrom(mock).mHowManyTimes = howManyTimes; + return mock; + } + + /** Begins a verification step for exactly one method call. */ + public static <T> 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) { + LinkedList<MethodCall> 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<MethodCall> unverifiedCalls = new ArrayList<MethodCall>(); + 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); } + + /** 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. + * <p> + * <b>Note</b>: This does not enforce that the object is of type {@code T}; use + * {@link #isA(Class)} to do that. + */ + public static <T> T anyObject() { return LittleMock.<T>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> T eq(final T expected) { + return addMatcher(new ArgumentMatcher() { + @Override + public boolean matches(Object value) { + return (expected == null) ? (value == null) : expected.equals(value); + } + }, expected); + } + + /** An argument matcher that matches any value of the given type or a subtype thereof. */ + public static <T> T isA(final Class<T> clazz) { + return LittleMock.<T>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. + * + * <p>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 <T> ArgumentCaptor<T> createCaptor() { + return new ArgumentCaptorImpl<T>(); + } + + /** Implementation of the {@link ArgumentCaptor} interface. */ + private static class ArgumentCaptorImpl<T extends Object> implements ArgumentCaptor<T> { + private final ArrayList<T> mAllValues = new ArrayList<T>(); + private T mValue; + + private ArgumentCaptorImpl() { + } + + public void setValue(T value) { + mValue = value; + mAllValues.add(mValue); + } + + @Override + public T getValue() { + return mValue; + } + + @Override + public List<T> getAllValues() { + return mAllValues; + } + + @Override + public T capture() { + return LittleMock.<T>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. + * + * <p>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> T mock(Class<T> 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. */ + private static <T> T mock(Class<T> clazz, String fieldName) { + return LittleMock.<T>newProxy(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(); } + + /** Implementation of {@link Behaviour}. */ + private static class BehaviourImpl implements Behaviour { + private final Action mAction; + + private BehaviourImpl(Action action) { + mAction = action; + } + + @Override + public <T> T when(T mock) { + getHandlerFrom(mock).mStubbingAction = mAction; + return mock; + } + } + + /** + * The static list of argument matchers, used in the next method call to the mock. + * + * <p>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. + * + * <p>The same goes for anything that is passed into the someMethod as an argument - be it + * a capture(mCaptureString) or eq(5) or whatever. + * + * <p>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. + * + * <p>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<ArgumentMatcher> sMatchArguments = new ArrayList<ArgumentMatcher>(); + + /** 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 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; + } + + public boolean argsMatch(Object[] args) { + return Arrays.equals(mArgs, args); + } + + @Override + public String toString() { + return "MethodCall [method=" + mMethod + ", args=" + Arrays.toString(mArgs) + "]"; + } + } + + /** + * Magically handles the invoking of method calls. + * + * <p>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 LinkedList<MethodCall> mRecordedCalls = new LinkedList<MethodCall>(); + /** The list of method calls that were stubbed out and their corresponding actions. */ + private LinkedList<StubbedCall> mStubbedCalls = new LinkedList<StubbedCall>(); + /** + * The number of times a given call should be verified. + * + * <p>It is not null when in the verification state, and it is actually used to determine if we + * are in the verification state. + * + * <p>It is reset to null once the verification has occurred. + */ + private CallCount mHowManyTimes = null; + /** + * The action to be associated with the stubbed method. + * + * <p>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; + + /** + * 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; + } + + @Override + public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { + ArgumentMatcher[] matchers = checkClearAndGetMatchers(method); + StackTraceElement callSite = new Exception().getStackTrace()[2]; + MethodCall methodCall = new MethodCall(method, callSite, args); + if (mHowManyTimes != null) { + innerVerify(method, matchers, methodCall, proxy, callSite); + mHowManyTimes = null; + return defaultReturnValue(method.getReturnType()); + } else if (mStubbingAction != null) { + innerStub(method, matchers, methodCall, callSite); + mStubbingAction = null; + return defaultReturnValue(method.getReturnType()); + } else { + 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. + * <p> + * 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 (method.equals(sEqualsMethod) + || method.equals(sHashCodeMethod) + || method.equals(sToStringMethod)) { + fail("cannot " + operation + " call to " + method); + } + } + + private void reset() { + mRecordedCalls.clear(); + mStubbedCalls.clear(); + mHowManyTimes = null; + mStubbingAction = null; + } + + private Object innerRecord(Method method, final Object[] args, + MethodCall methodCall, Object proxy, StackTraceElement callSite) throws Throwable { + if (method.equals(sEqualsMethod)) { + // Use identify for equality, the default behavior on object. + return proxy == args[0]; + } else if (method.equals(sHashCodeMethod)) { + // This depends on the fact that each mock has its own DefaultInvocationHandler. + return hashCode(); + } else if (method.equals(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 (stubbedCall.mMethodCall.mMethod.equals(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 = mStubbingAction; + 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.addFirst(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.addFirst(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) { + checkSpecialObjectMethods(method, "verify"); + int total = 0; + for (MethodCall call : mRecordedCalls) { + if (call.mMethod.equals(method)) { + if ((matchers.length > 0 && doMatchersMatch(matchers, call.mArgs)) || + call.argsMatch(methodCall.mArgs)) { + setCaptures(matchers, call.mArgs); + ++total; + call.mWasVerified = true; + } + } + } + expect(mHowManyTimes.matches(total), formatFailedVerifyMessage(methodCall, total)); + } + + private String formatFailedVerifyMessage(MethodCall methodCall, int total) { + StringBuffer sb = new StringBuffer(); + sb.append("\nExpected ").append(mHowManyTimes).append(" to:"); + appendDebugStringForMethodCall(sb, methodCall.mMethod, + methodCall.mElement, mFieldName, false); + sb.append("\n\n"); + if (mRecordedCalls.size() == 0) { + sb.append("No method calls happened to 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. */ + /*package*/ 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 { + long mLowerBound; + long mUpperBound; + + private 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; + } + + @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); + } + } + } + + /** 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> T addMatcher(ArgumentMatcher argument, T value) { + sMatchArguments.add(argument); + return value; + } + + /** 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<Class<?>, Object> DEFAULT_RETURN_VALUE_LOOKUP; + static { + DEFAULT_RETURN_VALUE_LOOKUP = new HashMap<Class<?>, 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<?>, Class<?>> PRIMITIVE_TO_BOXED_LOOKUP; + static { + PRIMITIVE_TO_BOXED_LOOKUP = new HashMap<Class<?>, 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); + } + + /** + * 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) { + InvocationHandler invocationHandler = Proxy.getInvocationHandler(mock); + if (!(invocationHandler instanceof DefaultInvocationHandler)) { + throw new IllegalArgumentException("not a valid mock: " + mock); + } + return (DefaultInvocationHandler) invocationHandler; + } + + /** Builds a dynamic proxy that implements the given interface, delegating to given handler. */ + @SuppressWarnings("unchecked") + private static <T> T newProxy(Class<?> theInterface, InvocationHandler theHandler) { + return (T) Proxy.newProxyInstance(getClassLoader(), new Class<?>[]{ theInterface }, theHandler); + } + + /** 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); + } +} |