LittleMock.java revision 00e20ef3c702f7388c98bdeee300d218c7871f4d
1/* 2 * Copyright 2011 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.google.testing.littlemock; 18 19import java.io.File; 20import java.io.ObjectInputStream; 21import java.io.ObjectStreamClass; 22import java.lang.reflect.Field; 23import java.lang.reflect.InvocationHandler; 24import java.lang.reflect.Method; 25import java.lang.reflect.Proxy; 26import java.util.ArrayList; 27import java.util.Arrays; 28import java.util.HashMap; 29import java.util.List; 30import java.util.Map; 31import java.util.concurrent.Callable; 32import java.util.concurrent.CopyOnWriteArrayList; 33import java.util.concurrent.atomic.AtomicReference; 34 35/** 36 * Very lightweight and simple mocking framework, inspired by Mockito, http://mockito.org. 37 * 38 * <p>It supports only a <b>small subset</b> of the APIs provided by Mockito and other mocking 39 * frameworks. 40 * 41 * <p>This project was originally designed to be lightweight and suitable for platforms that don't 42 * support dynamic class generation, for example Android. Since the release of the open 43 * source dexmaker project http://code.google.com/p/dexmaker/ we can now mock concrete classes 44 * too. 45 * 46 * <p>Here is an example of how to use the framework. 47 * 48 * <p>Suppose that we have this interface: 49 * <pre> 50 * public interface Foo { 51 * public String aString(int input); 52 * public void doSomething(); 53 * } 54 * </pre> 55 * 56 * <p>Then stubbing out mocks works as follows: 57 * <pre> 58 * Foo mockFoo = mock(Foo.class); // Create the mock. 59 * doReturn("hello").when(mockFoo).aString(anyInt()); // Stub the mock to return "hello". 60 * doThrow(new IOException("oh noes")).when(mockFoo).doSomething(); 61 * assertEquals("hello", mockFoo.aString(5)); // Use the mock - performs as expected. 62 * mockFoo.doSomething(); // This will throw an IOException. 63 * </pre> 64 * 65 * <p>You can verify in the 'natural place', after the method call has happened, like this: 66 * <pre> 67 * Foo mockFoo = mock(Foo.class); 68 * assertEquals(null, mockFoo.aString(6)); // Unstubbed method calls return a sensible default. 69 * verify(mockFoo).aString(6); // This will pass, aString() was called once. 70 * verify(mockFoo, never()).doSomething(); // This will pass, doSomething was never called. 71 * verify(mockFoo, times(3)).aString(anyInt()); // This will fail, was called once only. 72 * </pre> 73 * 74 * <p>The documentation is still incomplete. You can look at the {@link LittleMockTest} class and 75 * its unit tests - since they tell you exactly what operations are supported and how to use them. 76 * 77 * <p>The reasons I much prefer Mockito's approach to the one of EasyMock are as follows: 78 * <ul> 79 * <li>No need to remember to put your mocks in replay mode.</li> 80 * <li>No need to remember to call verify, a dangerous source of false-positive tests or 81 * alternatively over-specified tests.</li> 82 * <li>Much less over-specification: only verify what you actually care about.</li> 83 * <li>Which in turn leads to better separated tests, each test verifying only a part of the 84 * desired behaviour.</li> 85 * <li>Which also leads to less fragile tests, where adding another method call on your 86 * dependencies doesn't break unrelated tests.</li> 87 * <li>Simpler sharing of common setup method with specific tests overridding individual 88 * behavious however they want to, only the most recent stubbed call is the one that counts.</li> 89 * <li>More natural order for tests: set up stubs, execute tests, verify that it worked.</li> 90 * <li>More unified syntax that doesn't require special case for differences between void method 91 * calls and method calls that return a value.</li> 92 * </ul> 93 * 94 * <p>There were enough reasons that I wanted to give Mockito a try. It didn't work on Android 95 * because of issues with class generation. So I looked at the documentation and examples page and 96 * added tests for all the examples, and then implemented the this framework. I should stress that 97 * this is a clean-room implementation, and as such it's possible that there are a couple of methods 98 * that don't work in the same way as Mockito's implementation. Where that is the case I think we 99 * should fix once we discover them. There is also some functionality missing, but it will be added 100 * in due course. 101 * 102 * <p>Over time, the API has diverged slightly from the one of Mockito, as I have added APIs that I 103 * found convenient but that did not have an equivalent in Mockite itself. For anything that has an 104 * equivalent in Mockito I tried to keep the same name and syntax, to make it easier to transition 105 * between using one framework to using the other, e.g., when developing both an Android application 106 * using this framework and a desktop application using Mockito. 107 * 108 * @author hugohudson@gmail.com (Hugo Hudson) 109 */ 110/*@NotThreadSafe*/ 111public class LittleMock { 112 /** Generates a {@link Behaviour} suitable for void methods. */ 113 public static Behaviour doNothing() { return doReturn(null); } 114 115 /** Generates a {@link Behaviour} that returns the given result. */ 116 public static <T> Behaviour doReturn(final T result) { 117 return new BehaviourImpl(new Action() { 118 @Override public T doAction(Method method, Object[] args) { return result; } 119 @Override public Class<?> getReturnType() { 120 return (result == null) ? null : result.getClass(); 121 } 122 }); 123 } 124 125 /** 126 * Gets a {@link Behaviour} that will execute the given {@link Callable} and return its result. 127 */ 128 public static <T> Behaviour doAnswer(final Callable<T> callable) { 129 return new BehaviourImpl(new Action() { 130 @Override 131 public T doAction(Method method, Object[] args) throws Throwable { return callable.call(); } 132 @Override 133 public Class<?> getReturnType() { return null; } 134 }); 135 } 136 137 /** Returns a {@link Behaviour} that throws the given {@link Throwable}. */ 138 public static <T extends Throwable> Behaviour doThrow(final T exception) { 139 return new BehaviourImpl(new Action() { 140 @Override 141 public Object doAction(Method method, Object[] args) throws Throwable { throw exception; } 142 @Override 143 public Class<?> getReturnType() { return null; } 144 }); 145 } 146 147 /** Begins a verification step on a mock: the next method invocation on that mock will verify. */ 148 public static <T> T verify(T mock, CallCount howManyTimes) { 149 if (howManyTimes == null) { 150 throw new IllegalArgumentException("Can't pass null for howManyTimes parameter"); 151 } 152 DefaultInvocationHandler handler = getHandlerFrom(mock); 153 checkState(handler.mHowManyTimes == null, "Unfinished verify() statements"); 154 checkState(handler.mStubbingAction == null, "Unfinished stubbing statements"); 155 checkNoMatchers(); 156 handler.mHowManyTimes = howManyTimes; 157 sUnfinishedCallCounts.add(howManyTimes); 158 return handler.<T>getVerifyingMock(); 159 } 160 161 /** The list of outstanding calls to verify() that haven't finished, used to check for errors. */ 162 private static List<CallCount> sUnfinishedCallCounts = new ArrayList<CallCount>(); 163 164 /** The list of outstanding calls to when() that haven't finished, used to check for errors. */ 165 private static List<Action> sUnfinishedStubbingActions = new ArrayList<Action>(); 166 167 /** Begins a verification step for exactly one method call. */ 168 public static <T> T verify(T mock) { return verify(mock, times(1)); } 169 170 /** Assert that no method calls at all happened on these mocks. */ 171 public static void verifyZeroInteractions(Object... mocks) { 172 checkNoMatchers(); 173 for (Object mock : mocks) { 174 List<MethodCall> mMethodCalls = getHandlerFrom(mock).mRecordedCalls; 175 expect(mMethodCalls.isEmpty(), "Mock expected zero interactions, had " + mMethodCalls); 176 } 177 } 178 179 /** Assert that there are no unverified method calls on these mocks. */ 180 public static void verifyNoMoreInteractions(Object... mocks) { 181 StackTraceElement callSite = new Exception().getStackTrace()[1]; 182 for (Object mock : mocks) { 183 verifyNoMoreInteractions(mock, callSite); 184 } 185 } 186 187 /** Check that there are no unverified actions on the given mock. */ 188 private static void verifyNoMoreInteractions(Object mock, StackTraceElement callSite) { 189 checkNoMatchers(); 190 DefaultInvocationHandler handlerFrom = getHandlerFrom(mock); 191 List<MethodCall> unverifiedCalls = new ArrayList<MethodCall>(); 192 for (MethodCall method : handlerFrom.mRecordedCalls) { 193 if (!method.mWasVerified) { 194 unverifiedCalls.add(method); 195 } 196 } 197 if (unverifiedCalls.size() > 0) { 198 StringBuffer sb = new StringBuffer(); 199 sb.append("\nWe found these unverified calls:"); 200 for (MethodCall method : unverifiedCalls) { 201 appendDebugStringForMethodCall(sb, method.mMethod, 202 method.mElement, handlerFrom.mFieldName, false); 203 } 204 sb.append("\n\nAfter final interaction was verified:\n"); 205 sb.append(" at ").append(callSite).append("\n"); 206 throw new AssertionError(sb.toString()); 207 } 208 } 209 210 /** Creates a {@link CallCount} that matches exactly the given number of calls. */ 211 public static CallCount times(long n) { return new CallCount(n, n); } 212 213 /** Claims that the verified call must happen before the given timeout. */ 214 public static Timeout timeout(long timeoutMillis) { 215 return new Timeout(1, 1, timeoutMillis); 216 } 217 218/** Creates a {@link CallCount} that only matches if the method was never called. */ 219 public static CallCount never() { return new CallCount(0, 0); } 220 221 /** Creates a {@link CallCount} that matches at least one method call. */ 222 public static CallCount atLeastOnce() { return new CallCount(1, Long.MAX_VALUE); } 223 224 /** Creates a {@link CallCount} that matches any number of method calls, including none at all. */ 225 public static CallCount anyTimes() { return new CallCount(0, Long.MAX_VALUE); } 226 227 /** Creates a {@link CallCount} that matches at least the given number of calls. */ 228 public static CallCount atLeast(long n) { return new CallCount(n, Long.MAX_VALUE); } 229 230 /** Creates a {@link CallCount} that matches up to the given number of calls but no more. */ 231 public static CallCount atMost(long n) { return new CallCount(0, n); } 232 233 /** Creates a {@link CallCount} that matches any number of calls between the two given bounds. */ 234 public static CallCount between(long lower, long upper) { return new CallCount(lower, upper); } 235 236 /** 237 * Creates an argument matcher that matches any object, don't use for primitives. 238 * <p> 239 * <b>Note</b>: This does not enforce that the object is of type {@code T}; use 240 * {@link #isA(Class)} to do that. 241 */ 242 public static <T> T anyObject() { return LittleMock.<T>addMatcher(new MatchAnything(), null); } 243 244 /** Generates an argument matcher that matches any string. */ 245 public static String anyString() { return isA(String.class); } 246 247 /** Generates an argument matcher that matches any int. */ 248 public static int anyInt() { return addMatcher(new MatchAnything(), 0); } 249 250 /** Generates an argument matcher that matches any float. */ 251 public static float anyFloat() { return addMatcher(new MatchAnything(), 0f); } 252 253 /** Generates an argument matcher that matches any double. */ 254 public static double anyDouble() { return addMatcher(new MatchAnything(), 0.0); } 255 256 /** Generates an argument matcher that matches any boolean. */ 257 public static boolean anyBoolean() { return addMatcher(new MatchAnything(), false); } 258 259 /** Generates an argument matcher that matches any short. */ 260 public static short anyShort() { return addMatcher(new MatchAnything(), (short) 0); } 261 262 /** Generates an argument matcher that matches any char. */ 263 public static char anyChar() { return addMatcher(new MatchAnything(), '\u0000'); } 264 265 /** Generates an argument matcher that matches any long. */ 266 public static long anyLong() { return addMatcher(new MatchAnything(), 0L); } 267 268 /** Generates an argument matcher that matches any byte. */ 269 public static byte anyByte() { return addMatcher(new MatchAnything(), (byte) 0); } 270 271 /** Generates an argument matcher that matches exactly this value. */ 272 public static <T> T eq(final T expected) { 273 return addMatcher(new ArgumentMatcher() { 274 @Override 275 public boolean matches(Object value) { 276 return (expected == null) ? (value == null) : expected.equals(value); 277 } 278 }, expected); 279 } 280 281 /** An argument matcher that matches any value of the given type or a subtype thereof. */ 282 public static <T> T isA(final Class<T> clazz) { 283 return LittleMock.<T>addMatcher(new ArgumentMatcher() { 284 @Override 285 public boolean matches(Object value) { 286 return value == null || clazz.isAssignableFrom(value.getClass()); 287 } 288 }, null); 289 } 290 291 /** 292 * Injects fields annotated with {@link Mock} with a newly created mock, and those 293 * annotated with {@link Captor} with a suitable capture object. 294 * 295 * <p>This operation is recursive, and travels up the class hierarchy, in order to set all 296 * suitably annotated fields. 297 */ 298 public static void initMocks(Object instance) throws Exception { 299 injectMocksForClass(instance, instance.getClass()); 300 } 301 302 /** Recurse up the class hierarchy injecting mocks as we go, stopping when we reach Object. */ 303 private static void injectMocksForClass(Object instance, Class<?> clazz) 304 throws Exception { 305 if (clazz.equals(Object.class)) { 306 return; 307 } 308 for (Field field : clazz.getDeclaredFields()) { 309 if (field.getAnnotation(Mock.class) != null) { 310 setField(field, instance, mock(field.getType(), field.getName())); 311 } else if (field.getAnnotation(Captor.class) != null) { 312 setField(field, instance, createCaptor()); 313 } 314 } 315 injectMocksForClass(instance, clazz.getSuperclass()); 316 } 317 318 /** 319 * Creates a correctly typed {@link ArgumentCaptor} , it's easier to use 320 * {@link #initMocks(Object)}. 321 */ 322 public static <T> ArgumentCaptor<T> createCaptor() { 323 return new ArgumentCaptorImpl<T>(); 324 } 325 326 /** 327 * Create a correctly typed ArgumentCaptor that also works for primitive types. 328 * For example, to capture an int, use 329 * <code>ArgumentCaptor<Integer> c = createCaptor(Integer.class);</code> 330 */ 331 public static <T> ArgumentCaptor<T> createCaptor(Class<T> clazz) { 332 return new ArgumentCaptorImpl<T>(clazz); 333 } 334 335 /** Implementation of the {@link ArgumentCaptor} interface. */ 336 private static class ArgumentCaptorImpl<T extends Object> implements ArgumentCaptor<T> { 337 private final ArrayList<T> mAllValues = new ArrayList<T>(); 338 private T mValue; 339 private Class<T> mClass; 340 341 private ArgumentCaptorImpl() { 342 mClass = null; 343 } 344 345 private ArgumentCaptorImpl(Class<T> clazz) { 346 mClass = clazz; 347 } 348 349 public void setValue(T value) { 350 mValue = value; 351 mAllValues.add(mValue); 352 } 353 354 @Override 355 public T getValue() { 356 return mValue; 357 } 358 359 @Override 360 public List<T> getAllValues() { 361 return mAllValues; 362 } 363 364 @Override 365 public T capture() { 366 if (mClass != null) { 367 if (Integer.class.isAssignableFrom(mClass)) { 368 return (T) LittleMock.<Integer>addMatcher(this, 0); 369 } 370 if (Float.class.isAssignableFrom(mClass)) { 371 return (T) LittleMock.<Float>addMatcher(this, 0f); 372 } 373 if (Double.class.isAssignableFrom(mClass)) { 374 return (T) LittleMock.<Double>addMatcher(this, 0.0); 375 } 376 if (Boolean.class.isAssignableFrom(mClass)) { 377 return (T) LittleMock.<Boolean>addMatcher(this, false); 378 } 379 if (Short.class.isAssignableFrom(mClass)) { 380 return (T) LittleMock.<Short>addMatcher(this, (short) 0); 381 } 382 if (Character.class.isAssignableFrom(mClass)) { 383 return (T) LittleMock.<Character>addMatcher(this, '\u0000'); 384 } 385 if (Long.class.isAssignableFrom(mClass)) { 386 return (T) LittleMock.<Long>addMatcher(this, 0L); 387 } 388 if (Byte.class.isAssignableFrom(mClass)) { 389 return (T) LittleMock.<Byte>addMatcher(this, (byte) 0); 390 } 391 } 392 return LittleMock.<T>addMatcher(this, null); 393 } 394 395 396 @Override 397 public boolean matches(Object value) { 398 // A capture always matches any argument. 399 // This is so that verify(mMock).someMethod(capture(mCapture)) will match any and all calls 400 // to someMethod() and we will capture the values into mCapture. 401 return true; 402 } 403 } 404 405 /** 406 * Creates a mock, more easily done via the {@link #initMocks(Object)} method. 407 * 408 * <p>Also if you use this method to create your mock, the field in the error messages will 409 * be named the same as your class passed in, you only get the actual field name if you 410 * use the annotation. 411 * 412 * @throws IllegalArgumentException if the class you pass in is null 413 */ 414 public static <T> T mock(Class<T> clazz) { 415 if (clazz == null) { 416 throw new IllegalArgumentException("Class to mock was null"); 417 } 418 return mock(clazz, getDefaultFieldNameFor(clazz)); 419 } 420 421 /** Creates a mock, more easily done via the {@link #initMocks(Object)} method. */ 422 @SuppressWarnings("unchecked") 423 private static <T> T mock(Class<T> clazz, String fieldName) { 424 return (T) createProxy(clazz, new DefaultInvocationHandler(clazz, fieldName)); 425 } 426 427 /** Pick a suitable name for a field of the given clazz. */ 428 private static String getDefaultFieldNameFor(Class<?> clazz) { 429 return clazz.getSimpleName().substring(0, 1).toLowerCase() 430 + clazz.getSimpleName().substring(1); 431 } 432 433 /** Clears out the expectations on these mocks. */ 434 public static void reset(Object... mocks) { 435 for (Object mock : mocks) { 436 getHandlerFrom(mock).reset(); 437 } 438 } 439 440 /** Use this in tear down to check for programming errors. */ 441 public static void checkForProgrammingErrorsDuringTearDown() { 442 checkNoMatchers(); 443 checkNoUnfinishedCalls(sUnfinishedCallCounts, "verify()"); 444 checkNoUnfinishedCalls(sUnfinishedStubbingActions, "stubbing"); 445 } 446 447 /** Helper function to check that there are no verify or stubbing commands outstanding. */ 448 private static void checkNoUnfinishedCalls(List<?> list, String type) { 449 if (!list.isEmpty()) { 450 list.clear(); 451 throw new IllegalStateException("Unfinished " + type + " statements"); 452 } 453 } 454 455 /** Implementation of {@link Behaviour}. */ 456 private static class BehaviourImpl implements Behaviour { 457 private final Action mAction; 458 459 private BehaviourImpl(Action action) { 460 mAction = action; 461 } 462 463 @Override 464 public <T> T when(T mock) { 465 DefaultInvocationHandler handler = getHandlerFrom(mock); 466 checkState(handler.mHowManyTimes == null, "Unfinished verify() statements"); 467 checkState(handler.mStubbingAction == null, "Unfinished stubbing statements"); 468 handler.mStubbingAction = mAction; 469 sUnfinishedStubbingActions.add(mAction); 470 return handler.<T>getStubbingMock(); 471 } 472 } 473 474 /** 475 * The static list of argument matchers, used in the next method call to the mock. 476 * 477 * <p>In order to support the syntax like this: verify(mFoo).someMethod(anyInt()), it is 478 * required that the anyInt() method store the value somewhere for use when the someMethod 479 * is invoked. That somewhere has to be static. I don't like it any more than you do. 480 * 481 * <p>The same goes for anything that is passed into the someMethod as an argument - be it 482 * a capture(mCaptureString) or eq(5) or whatever. 483 * 484 * <p>Avoiding the use of statics requires that we change the syntax of the verify statement, 485 * and I can't think of an elegant way of doing it, and in any case I really like the current 486 * syntax, so for now a static variable it is. 487 * 488 * <p>This match arguments list should contain either zero elements (the next method call will 489 * not use any argument matchers) or it should contain exactly one argument matcher for 490 * every argument being passed to the next method call. You can't mix argument matchers and 491 * raw values. 492 */ 493 private static final List<ArgumentMatcher> sMatchArguments = new ArrayList<ArgumentMatcher>(); 494 495 /** Encapsulates a single call of a method with associated arguments. */ 496 private static class MethodCall { 497 /** The method call. */ 498 private final Method mMethod; 499 /** The arguments provided at the time the call happened. */ 500 private final Object[] mArgs; 501 /** The line from the test that invoked the handler to create this method call. */ 502 private final StackTraceElement mElement; 503 /** Keeps track of method calls that have been verified, for verifyNoMoreInteractions(). */ 504 public boolean mWasVerified = false; 505 506 public MethodCall(Method method, StackTraceElement element, Object[] args) { 507 mMethod = method; 508 mElement = element; 509 mArgs = args; 510 } 511 512 public boolean argsMatch(Object[] args) { 513 return Arrays.equals(mArgs, args); 514 } 515 516 @Override 517 public String toString() { 518 return "MethodCall [method=" + mMethod + ", args=" + Arrays.toString(mArgs) + "]"; 519 } 520 } 521 522 /** 523 * Magically handles the invoking of method calls. 524 * 525 * <p>This object is in one of three states, default (where invoking methods returns default 526 * values and records the call), verifying (where invoking method calls makes sure that those 527 * method calls happen with the supplied arguments or matchers) or stubbing (where the next method 528 * call tells us which arguments to match in order to perform the desired behaviour). 529 */ 530 private static class DefaultInvocationHandler implements InvocationHandler { 531 private static Method sEqualsMethod; 532 private static Method sHashCodeMethod; 533 private static Method sToStringMethod; 534 535 static { 536 try { 537 sEqualsMethod = Object.class.getMethod("equals", Object.class); 538 sHashCodeMethod = Object.class.getMethod("hashCode"); 539 sToStringMethod = Object.class.getMethod("toString"); 540 } catch (SecurityException e) { 541 // Should never happen. 542 throw new RuntimeException("Your JVM/classloader is broken", e); 543 } catch (NoSuchMethodException e) { 544 // Should never happen. 545 throw new RuntimeException("Your JVM/classloader is broken", e); 546 } 547 } 548 549 /** The class of the mocked objects. */ 550 private final Class<?> mClazz; 551 /** The field name in which the mock is assigned. */ 552 private final String mFieldName; 553 554 /** The list of method calls executed on the mock. */ 555 private List<MethodCall> mRecordedCalls = new CopyOnWriteArrayList<MethodCall>(); 556 /** The list of method calls that were stubbed out and their corresponding actions. */ 557 private List<StubbedCall> mStubbedCalls = new CopyOnWriteArrayList<StubbedCall>(); 558 559 /** 560 * The number of times a given call should be verified. 561 * 562 * <p>It is not null when in the verification state, and it is actually used to determine if we 563 * are in the verification state. 564 * 565 * <p>It is reset to null once the verification has occurred. 566 */ 567 private CallCount mHowManyTimes = null; 568 569 /** 570 * The action to be associated with the stubbed method. 571 * 572 * <p>It is not null when in the stubbing state, and it is actually used to determine if we are 573 * in the stubbing state. 574 */ 575 private Action mStubbingAction = null; 576 577 /** Dynamic proxy used to verify calls against this mock. */ 578 private final Object mVerifyingMock; 579 580 /** Dynamic proxy used to stub calls against this mock. */ 581 private final Object mStubbingMock; 582 583 /** 584 * Creates a new invocation handler for an object. 585 * 586 * @param clazz the class the object belongs to 587 * @param fieldName The name to be used to refer to the object. This may either be the name of 588 * the field this mock will be stored into (in case it uses @Mock) or a suitable name to 589 * use to refer to the object in error messages, based on the name of the class itself. 590 */ 591 public DefaultInvocationHandler(Class<?> clazz, String fieldName) { 592 mClazz = clazz; 593 mFieldName = fieldName; 594 mVerifyingMock = createVerifyingMock(clazz); 595 mStubbingMock = createStubbingMock(clazz); 596 } 597 598 // Safe if you call getHandlerFrom(mock).getVerifyingMock(), since this is guaranteed to be 599 // of the same type as mock itself. 600 @SuppressWarnings("unchecked") 601 public <T> T getVerifyingMock() { 602 return (T) mVerifyingMock; 603 } 604 605 // Safe if you call getHandlerFrom(mock).getStubbingMock(), since this is guaranteed to be 606 // of the same type as mock itself. 607 @SuppressWarnings("unchecked") 608 public <T> T getStubbingMock() { 609 return (T) mStubbingMock; 610 } 611 612 /** Used to check that we always stub and verify from the same thread. */ 613 private AtomicReference<Thread> mCurrentThread = new AtomicReference<Thread>(); 614 615 /** Check that we are stubbing and verifying always from the same thread. */ 616 private void checkThread() { 617 Thread currentThread = Thread.currentThread(); 618 mCurrentThread.compareAndSet(null, currentThread); 619 if (mCurrentThread.get() != currentThread) { 620 throw new IllegalStateException("Must always mock and stub from one thread only. " 621 + "This thread: " + currentThread + ", the other thread: " + mCurrentThread.get()); 622 } 623 } 624 625 /** Generate the dynamic proxy that will handle verify invocations. */ 626 private Object createVerifyingMock(Class<?> clazz) { 627 return createProxy(clazz, new InvocationHandler() { 628 @Override 629 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { 630 checkThread(); 631 expect(mHowManyTimes != null, "verifying mock doesn't know how many times"); 632 try { 633 ArgumentMatcher[] matchers = checkClearAndGetMatchers(method); 634 StackTraceElement callSite = new Exception().getStackTrace()[2]; 635 MethodCall methodCall = new MethodCall(method, callSite, args); 636 innerVerify(method, matchers, methodCall, proxy, callSite, mHowManyTimes); 637 return defaultReturnValue(method.getReturnType()); 638 } finally { 639 sUnfinishedCallCounts.remove(mHowManyTimes); 640 mHowManyTimes = null; 641 } 642 } 643 }); 644 } 645 646 /** Generate the dynamic proxy that will handle stubbing invocations. */ 647 private Object createStubbingMock(Class<?> clazz) { 648 return createProxy(clazz, new InvocationHandler() { 649 @Override 650 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { 651 checkThread(); 652 expect(mStubbingAction != null, "stubbing mock doesn't know what action to perform"); 653 try { 654 ArgumentMatcher[] matchers = checkClearAndGetMatchers(method); 655 StackTraceElement callSite = new Exception().getStackTrace()[2]; 656 MethodCall methodCall = new MethodCall(method, callSite, args); 657 innerStub(method, matchers, methodCall, callSite, mStubbingAction); 658 return defaultReturnValue(method.getReturnType()); 659 } finally { 660 sUnfinishedStubbingActions.remove(mStubbingAction); 661 mStubbingAction = null; 662 } 663 } 664 }); 665 } 666 667 @Override 668 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { 669 StackTraceElement callSite = new Exception().getStackTrace()[2]; 670 MethodCall methodCall = new MethodCall(method, callSite, args); 671 return innerRecord(method, args, methodCall, proxy, callSite); 672 } 673 674 /** 675 * Checks whether the given method is one of the special object methods that should not 676 * verified or stubbed. 677 * <p> 678 * If this is one of such methods, it throws an AssertionException. 679 * 680 * @param method the method to be checked 681 * @param operation the name of the operation, used for generating a helpful message 682 */ 683 private void checkSpecialObjectMethods(Method method, String operation) { 684 if (method.equals(sEqualsMethod) 685 || method.equals(sHashCodeMethod) 686 || method.equals(sToStringMethod)) { 687 fail("cannot " + operation + " call to " + method); 688 } 689 } 690 691 private void reset() { 692 mRecordedCalls.clear(); 693 mStubbedCalls.clear(); 694 mHowManyTimes = null; 695 mStubbingAction = null; 696 } 697 698 private Object innerRecord(Method method, final Object[] args, 699 MethodCall methodCall, Object proxy, StackTraceElement callSite) throws Throwable { 700 if (method.equals(sEqualsMethod)) { 701 // Use identify for equality, the default behavior on object. 702 return proxy == args[0]; 703 } else if (method.equals(sHashCodeMethod)) { 704 // This depends on the fact that each mock has its own DefaultInvocationHandler. 705 return hashCode(); 706 } else if (method.equals(sToStringMethod)) { 707 // This is used to identify this is a mock, e.g., in error messages. 708 return "Mock<" + mClazz.getName() + ">"; 709 } 710 mRecordedCalls.add(methodCall); 711 for (StubbedCall stubbedCall : mStubbedCalls) { 712 if (stubbedCall.mMethodCall.mMethod.equals(methodCall.mMethod)) { 713 if (stubbedCall.mMethodCall.argsMatch(methodCall.mArgs)) { 714 methodCall.mWasVerified = true; 715 return stubbedCall.mAction.doAction(method, args); 716 } 717 } 718 } 719 // If no stub is defined, return the default value. 720 return defaultReturnValue(method.getReturnType()); 721 } 722 723 private void innerStub(Method method, final ArgumentMatcher[] matchers, MethodCall methodCall, 724 StackTraceElement callSite, final Action stubbingAction) { 725 checkSpecialObjectMethods(method, "stub"); 726 checkThisActionCanBeUsedForThisMethod(method, stubbingAction, callSite); 727 if (matchers.length == 0) { 728 // If there are no matchers, then this is a simple stubbed method call with an action. 729 mStubbedCalls.add(0, new StubbedCall(methodCall, stubbingAction)); 730 return; 731 } 732 // If there are matchers, then we need to make a new method call which matches only 733 // when all the matchers match. Further, the action that method call needs to take 734 // is to first record the values into any captures that may be present, and only then 735 // proceed to execute the original action. 736 MethodCall matchMatchersMethodCall = new MethodCall(method, callSite, matchers) { 737 @Override 738 public boolean argsMatch(Object[] args) { return doMatchersMatch(matchers, args); } 739 }; 740 Action setCapturesThenAction = new Action() { 741 @Override 742 public Object doAction(Method innerMethod, Object[] innerArgs) throws Throwable { 743 setCaptures(matchers, innerArgs); 744 return stubbingAction.doAction(innerMethod, innerArgs); 745 } 746 @Override 747 public Class<?> getReturnType() { 748 return stubbingAction.getReturnType(); 749 } 750 }; 751 mStubbedCalls.add(0, new StubbedCall(matchMatchersMethodCall, setCapturesThenAction)); 752 } 753 754 private void checkThisActionCanBeUsedForThisMethod(Method method, final Action stubbingAction, 755 StackTraceElement callSite) { 756 Class<?> methodType = method.getReturnType(); 757 Class<?> actionType = stubbingAction.getReturnType(); 758 if (actionType == null) { 759 // We could not determine the type returned by this action at the time we 760 // created it. At this time we cannot check that the returned value is 761 // appropriate to the return type of the method. 762 // However, if the type is not correct, any actual invocation of the method 763 // will fail later on. 764 return; 765 } 766 if (!methodType.isAssignableFrom(actionType)) { 767 if (methodType.isPrimitive() && 768 actionType.equals(PRIMITIVE_TO_BOXED_LOOKUP.get(methodType))) { 769 return; 770 } 771 StringBuffer sb = new StringBuffer(); 772 sb.append("\nCan't return ").append(actionType.getSimpleName()).append(" from stub for:"); 773 appendDebugStringForMethodCall(sb, method, callSite, mFieldName, true); 774 sb.append("\n"); 775 throw new IllegalArgumentException(sb.toString()); 776 } 777 } 778 779 private boolean doMatchersMatch(ArgumentMatcher[] matchers, Object[] args) { 780 for (int i = 0; i < matchers.length; ++i) { 781 if (!matchers[i].matches(args[i])) { 782 return false; 783 } 784 } 785 return true; 786 } 787 788 private void innerVerify(Method method, ArgumentMatcher[] matchers, MethodCall methodCall, 789 Object proxy, StackTraceElement callSite, CallCount callCount) { 790 checkSpecialObjectMethods(method, "verify"); 791 int total = countMatchingInvocations(method, matchers, methodCall); 792 long callTimeout = callCount.getTimeout(); 793 if (callTimeout > 0) { 794 long endTime = System.currentTimeMillis() + callTimeout; 795 while (!callCount.matches(total)) { 796 try { 797 Thread.sleep(1); 798 } catch (InterruptedException e) { 799 fail("interrupted whilst waiting to verify"); 800 } 801 if (System.currentTimeMillis() > endTime) { 802 fail(formatFailedVerifyMessage(methodCall, total, callTimeout, callCount)); 803 } 804 total = countMatchingInvocations(method, matchers, methodCall); 805 } 806 } else { 807 if (!callCount.matches(total)) { 808 fail(formatFailedVerifyMessage(methodCall, total, 0, callCount)); 809 } 810 } 811 } 812 813 private int countMatchingInvocations(Method method, ArgumentMatcher[] matchers, 814 MethodCall methodCall) { 815 int total = 0; 816 for (MethodCall call : mRecordedCalls) { 817 if (call.mMethod.equals(method)) { 818 if ((matchers.length > 0 && doMatchersMatch(matchers, call.mArgs)) || 819 call.argsMatch(methodCall.mArgs)) { 820 setCaptures(matchers, call.mArgs); 821 ++total; 822 call.mWasVerified = true; 823 } 824 } 825 } 826 return total; 827 } 828 829 private String formatFailedVerifyMessage(MethodCall methodCall, int total, long timeoutMillis, 830 CallCount callCount) { 831 StringBuffer sb = new StringBuffer(); 832 sb.append("\nExpected ").append(callCount); 833 if (timeoutMillis > 0) { 834 sb.append(" within " + timeoutMillis + "ms"); 835 } 836 sb.append(" to:"); 837 appendDebugStringForMethodCall(sb, methodCall.mMethod, 838 methodCall.mElement, mFieldName, false); 839 sb.append("\n\n"); 840 if (mRecordedCalls.size() == 0) { 841 sb.append("No method calls happened on this mock"); 842 } else { 843 sb.append("Method calls that did happen:"); 844 for (MethodCall recordedCall : mRecordedCalls) { 845 appendDebugStringForMethodCall(sb, recordedCall.mMethod, 846 recordedCall.mElement, mFieldName, false); 847 } 848 } 849 sb.append("\n"); 850 return sb.toString(); 851 } 852 853 /** All matchers that are captures will store the corresponding arg value. */ 854 // This suppress warning means that I'm calling setValue with something that I can't promise 855 // is of the right type. But I think it is unavoidable. Certainly I could give a better 856 // error message than the class cast exception you'll get when you try to retrieve the value. 857 @SuppressWarnings("unchecked") 858 private void setCaptures(ArgumentMatcher[] matchers, Object[] args) { 859 for (int i = 0; i < matchers.length; ++i) { 860 if (matchers[i] instanceof ArgumentCaptorImpl) { 861 ArgumentCaptorImpl.class.cast(matchers[i]).setValue(args[i]); 862 } 863 } 864 } 865 866 /** An empty array of matchers, to optimise the toArray() call below. */ 867 private static final ArgumentMatcher[] EMPTY_MATCHERS_ARRAY = new ArgumentMatcher[0]; 868 869 /** Makes sure that we have the right number of MATCH_ARGUMENTS for the given method. */ 870 private ArgumentMatcher[] checkClearAndGetMatchers(Method method) { 871 ArgumentMatcher[] matchers = sMatchArguments.toArray(EMPTY_MATCHERS_ARRAY); 872 sMatchArguments.clear(); 873 if (matchers.length > 0 && method.getParameterTypes().length != matchers.length) { 874 throw new IllegalArgumentException("You can't mix matchers and regular objects."); 875 } 876 return matchers; 877 } 878 } 879 880 private static void appendDebugStringForMethodCall(StringBuffer sb, Method method, 881 StackTraceElement callSite, String fieldName, boolean showReturnType) { 882 sb.append("\n "); 883 if (showReturnType) { 884 sb.append("(").append(method.getReturnType().getSimpleName()).append(") "); 885 } 886 sb.append(fieldName).append(".").append(method.getName()).append("("); 887 int i = 0; 888 for (Class<?> type : method.getParameterTypes()) { 889 if (++i > 1) { 890 sb.append(", "); 891 } 892 sb.append(type.getSimpleName()); 893 } 894 sb.append(")\n at ").append(callSite); 895 } 896 897 /** Call this function when you don't expect there to be any outstanding matcher objects. */ 898 private static void checkNoMatchers() { 899 if (sMatchArguments.size() > 0) { 900 sMatchArguments.clear(); 901 throw new IllegalStateException("You have outstanding matchers, must be programming error"); 902 } 903 } 904 905 /** A pairing of a method call and an action to be performed when that call happens. */ 906 private static class StubbedCall { 907 private final MethodCall mMethodCall; 908 private final Action mAction; 909 910 public StubbedCall(MethodCall methodCall, Action action) { 911 mMethodCall = methodCall; 912 mAction = action; 913 } 914 915 @Override 916 public String toString() { 917 return "StubbedCall [methodCall=" + mMethodCall + ", action=" + mAction + "]"; 918 } 919 } 920 921 /** Represents an action to be performed as a result of a method call. */ 922 private interface Action { 923 public Object doAction(Method method, Object[] arguments) throws Throwable; 924 /** The type of the action, or null if we can't determine the type at stub time. */ 925 public Class<?> getReturnType(); 926 } 927 928 /** Represents something capable of testing if it matches an argument or not. */ 929 /*package*/ interface ArgumentMatcher { 930 public boolean matches(Object value); 931 } 932 933 /** A matcher that matches any argument. */ 934 private static class MatchAnything implements ArgumentMatcher { 935 @Override 936 public boolean matches(Object value) { return true; } 937 } 938 939 /** Encapsulates the number of times a method is called, between upper and lower bounds. */ 940 private static class CallCount { 941 private long mLowerBound; 942 private long mUpperBound; 943 944 public CallCount(long lowerBound, long upperBound) { 945 mLowerBound = lowerBound; 946 mUpperBound = upperBound; 947 } 948 949 /** Tells us if this call count matches a desired count. */ 950 public boolean matches(long total) { 951 return total >= mLowerBound && total <= mUpperBound; 952 } 953 954 /** Tells us how long we should block waiting for the verify to happen. */ 955 public long getTimeout() { 956 return 0; 957 } 958 959 public CallCount setLowerBound(long lowerBound) { 960 mLowerBound = lowerBound; 961 return this; 962 } 963 964 public CallCount setUpperBound(long upperBound) { 965 mUpperBound = upperBound; 966 return this; 967 } 968 969 @Override 970 public String toString() { 971 if (mLowerBound == mUpperBound) { 972 return "exactly " + mLowerBound + plural(" call", mLowerBound); 973 } else { 974 return "between " + mLowerBound + plural(" call", mLowerBound) + " and " + 975 mUpperBound + plural(" call", mUpperBound); 976 } 977 } 978 } 979 980 /** Encapsulates adding number of times behaviour to a call count with timeout. */ 981 public static final class Timeout extends CallCount { 982 private long mTimeoutMillis; 983 984 public Timeout(long lowerBound, long upperBound, long timeoutMillis) { 985 super(lowerBound, upperBound); 986 mTimeoutMillis = timeoutMillis; 987 } 988 989 @Override 990 public long getTimeout() { 991 return mTimeoutMillis; 992 } 993 994 public CallCount times(int times) { return setLowerBound(times).setUpperBound(times); } 995 public CallCount atLeast(long n) { return setLowerBound(n).setUpperBound(Long.MAX_VALUE); } 996 public CallCount atLeastOnce() { return setLowerBound(1).setUpperBound(Long.MAX_VALUE); } 997 public CallCount between(long n, long m) { return setLowerBound(n).setUpperBound(m); } 998 } 999 1000 /** Helper method to add an 's' to a string iff the count is not 1. */ 1001 private static String plural(String prefix, long count) { 1002 return (count == 1) ? prefix : (prefix + "s"); 1003 } 1004 1005 /** Helps us implement the eq(), any() and capture() and other methods on one line. */ 1006 private static <T> T addMatcher(ArgumentMatcher argument, T value) { 1007 sMatchArguments.add(argument); 1008 return value; 1009 } 1010 1011 /** Utility method to throw an AssertionError if an assertion fails. */ 1012 private static void expect(boolean result, String message) { 1013 if (!result) { 1014 fail(message); 1015 } 1016 } 1017 1018 /** Throws an AssertionError exception with a message. */ 1019 private static void fail(String message) { 1020 throw new AssertionError(message); 1021 } 1022 1023 /** Static mapping from class type to default value for that type. */ 1024 private static final Map<Class<?>, Object> DEFAULT_RETURN_VALUE_LOOKUP; 1025 static { 1026 DEFAULT_RETURN_VALUE_LOOKUP = new HashMap<Class<?>, Object>(); 1027 DEFAULT_RETURN_VALUE_LOOKUP.put(int.class, 0); 1028 DEFAULT_RETURN_VALUE_LOOKUP.put(boolean.class, false); 1029 DEFAULT_RETURN_VALUE_LOOKUP.put(byte.class, (byte) 0); 1030 DEFAULT_RETURN_VALUE_LOOKUP.put(long.class, (long) 0); 1031 DEFAULT_RETURN_VALUE_LOOKUP.put(short.class, (short) 0); 1032 DEFAULT_RETURN_VALUE_LOOKUP.put(float.class, (float) 0); 1033 DEFAULT_RETURN_VALUE_LOOKUP.put(double.class, (double) 0); 1034 DEFAULT_RETURN_VALUE_LOOKUP.put(char.class, '\u0000'); 1035 DEFAULT_RETURN_VALUE_LOOKUP.put(String.class, null); 1036 } 1037 1038 /** Static lookup from primitive types to their boxed versions. */ 1039 private static final Map<Class<?>, Class<?>> PRIMITIVE_TO_BOXED_LOOKUP; 1040 static { 1041 PRIMITIVE_TO_BOXED_LOOKUP = new HashMap<Class<?>, Class<?>>(); 1042 PRIMITIVE_TO_BOXED_LOOKUP.put(int.class, Integer.class); 1043 PRIMITIVE_TO_BOXED_LOOKUP.put(boolean.class, Boolean.class); 1044 PRIMITIVE_TO_BOXED_LOOKUP.put(byte.class, Byte.class); 1045 PRIMITIVE_TO_BOXED_LOOKUP.put(long.class, Long.class); 1046 PRIMITIVE_TO_BOXED_LOOKUP.put(short.class, Short.class); 1047 PRIMITIVE_TO_BOXED_LOOKUP.put(float.class, Float.class); 1048 PRIMITIVE_TO_BOXED_LOOKUP.put(double.class, Double.class); 1049 PRIMITIVE_TO_BOXED_LOOKUP.put(char.class, Character.class); 1050 } 1051 1052 /** For a given class type, returns the default value for that type. */ 1053 private static Object defaultReturnValue(Class<?> returnType) { 1054 return DEFAULT_RETURN_VALUE_LOOKUP.get(returnType); 1055 } 1056 1057 /** Gets a suitable class loader for use with the proxy. */ 1058 private static ClassLoader getClassLoader() { 1059 return LittleMock.class.getClassLoader(); 1060 } 1061 1062 /** Sets a member field on an object via reflection (can set private members too). */ 1063 private static void setField(Field field, Object object, Object value) throws Exception { 1064 field.setAccessible(true); 1065 field.set(object, value); 1066 field.setAccessible(false); 1067 } 1068 1069 /** Helper method to throw an IllegalStateException if given condition is not met. */ 1070 private static void checkState(boolean condition, String message) { 1071 if (!condition) { 1072 throw new IllegalStateException(message); 1073 } 1074 } 1075 1076 /** 1077 * If the input object is one of our mocks, returns the {@link DefaultInvocationHandler} 1078 * we constructed it with. Otherwise fails with {@link IllegalArgumentException}. 1079 */ 1080 private static DefaultInvocationHandler getHandlerFrom(Object mock) { 1081 try { 1082 InvocationHandler invocationHandler = Proxy.getInvocationHandler(mock); 1083 if (invocationHandler instanceof DefaultInvocationHandler) { 1084 return (DefaultInvocationHandler) invocationHandler; 1085 } 1086 } catch (IllegalArgumentException expectedIfNotAProxy) {} 1087 try { 1088 Class<?> proxyBuilder = Class.forName("com.google.dexmaker.stock.ProxyBuilder"); 1089 Method getHandlerMethod = proxyBuilder.getMethod("getInvocationHandler", Object.class); 1090 Object invocationHandler = getHandlerMethod.invoke(proxyBuilder, mock); 1091 if (invocationHandler instanceof DefaultInvocationHandler) { 1092 return (DefaultInvocationHandler) invocationHandler; 1093 } 1094 } catch (Exception expectedIfNotAProxyBuilderMock) {} 1095 throw new IllegalArgumentException("not a valid mock: " + mock); 1096 } 1097 1098 /** Create a dynamic proxy for the given class, delegating to the given invocation handler. */ 1099 private static Object createProxy(Class<?> clazz, InvocationHandler handler) { 1100 if (clazz.isInterface()) { 1101 return Proxy.newProxyInstance(getClassLoader(), new Class<?>[] { clazz }, handler); 1102 } 1103 try { 1104 Class<?> proxyBuilder = Class.forName("com.google.dexmaker.stock.ProxyBuilder"); 1105 Method forClassMethod = proxyBuilder.getMethod("forClass", Class.class); 1106 Object builder = forClassMethod.invoke(null, clazz); 1107 Method dexCacheMethod = builder.getClass().getMethod("dexCache", File.class); 1108 File directory = AppDataDirGuesser.getsInstance().guessSuitableDirectoryForGeneratedClasses(); 1109 builder = dexCacheMethod.invoke(builder, directory); 1110 Method buildClassMethod = builder.getClass().getMethod("buildProxyClass"); 1111 Class<?> resultClass = (Class<?>) buildClassMethod.invoke(builder); 1112 Object proxy = unsafeCreateInstance(resultClass); 1113 Field handlerField = resultClass.getDeclaredField("$__handler"); 1114 handlerField.setAccessible(true); 1115 handlerField.set(proxy, handler); 1116 return proxy; 1117 } catch (Exception e) { 1118 throw new IllegalStateException("Could not mock this concrete class", e); 1119 } 1120 } 1121 1122 /** Attempt to construct an instance of the class using hacky methods to avoid calling super. */ 1123 @SuppressWarnings("unchecked") 1124 private static <T> T unsafeCreateInstance(Class<T> clazz) { 1125 // try dalvikvm, pre-gingerbread 1126 try { 1127 final Method newInstance = ObjectInputStream.class.getDeclaredMethod( 1128 "newInstance", Class.class, Class.class); 1129 newInstance.setAccessible(true); 1130 return (T) newInstance.invoke(null, clazz, Object.class); 1131 } catch (Exception ignored) {} 1132 // try dalvikvm, post-gingerbread 1133 try { 1134 Method getConstructorId = ObjectStreamClass.class.getDeclaredMethod( 1135 "getConstructorId", Class.class); 1136 getConstructorId.setAccessible(true); 1137 final int constructorId = (Integer) getConstructorId.invoke(null, Object.class); 1138 final Method newInstance = ObjectStreamClass.class.getDeclaredMethod( 1139 "newInstance", Class.class, int.class); 1140 newInstance.setAccessible(true); 1141 return (T) newInstance.invoke(null, clazz, constructorId); 1142 } catch (Exception ignored) {} 1143 throw new IllegalStateException("unsafe create instance failed"); 1144 } 1145} 1146