001/* 002 * Copyright (C) 2012 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.testing; 018 019import static com.google.common.base.Predicates.and; 020import static com.google.common.base.Predicates.not; 021import static com.google.common.testing.AbstractPackageSanityTests.Chopper.suffix; 022 023import com.google.common.annotations.GwtIncompatible; 024import com.google.common.annotations.J2ktIncompatible; 025import com.google.common.annotations.VisibleForTesting; 026import com.google.common.base.Optional; 027import com.google.common.base.Predicate; 028import com.google.common.collect.HashMultimap; 029import com.google.common.collect.ImmutableList; 030import com.google.common.collect.Iterables; 031import com.google.common.collect.Lists; 032import com.google.common.collect.Maps; 033import com.google.common.collect.Multimap; 034import com.google.common.collect.Sets; 035import com.google.common.reflect.ClassPath; 036import com.google.common.testing.NullPointerTester.Visibility; 037import com.google.j2objc.annotations.J2ObjCIncompatible; 038import java.io.IOException; 039import java.io.Serializable; 040import java.util.LinkedHashSet; 041import java.util.List; 042import java.util.Locale; 043import java.util.TreeMap; 044import java.util.logging.Level; 045import java.util.logging.Logger; 046import junit.framework.AssertionFailedError; 047import junit.framework.TestCase; 048import org.junit.Test; 049 050/** 051 * Automatically runs sanity checks against top level classes in the same package of the test that 052 * extends {@code AbstractPackageSanityTests}. Currently sanity checks include {@link 053 * NullPointerTester}, {@link EqualsTester} and {@link SerializableTester}. For example: 054 * 055 * <pre> 056 * public class PackageSanityTests extends AbstractPackageSanityTests {} 057 * </pre> 058 * 059 * <p>Note that only top-level classes with either a non-private constructor or a non-private static 060 * factory method to construct instances can have their instance methods checked. For example: 061 * 062 * <pre> 063 * public class Address { 064 * private final String city; 065 * private final String state; 066 * private final String zipcode; 067 * 068 * public Address(String city, String state, String zipcode) {...} 069 * 070 * {@literal @Override} public boolean equals(Object obj) {...} 071 * {@literal @Override} public int hashCode() {...} 072 * ... 073 * } 074 * </pre> 075 * 076 * <p>No cascading checks are performed against the return values of methods unless the method is a 077 * static factory method. Neither are semantics of mutation methods such as {@code 078 * someList.add(obj)} checked. For more detailed discussion of supported and unsupported cases, see 079 * {@link #testEquals}, {@link #testNulls} and {@link #testSerializable}. 080 * 081 * <p>For testing against the returned instances from a static factory class, such as 082 * 083 * <pre> 084 * interface Book {...} 085 * public class Books { 086 * public static Book hardcover(String title) {...} 087 * public static Book paperback(String title) {...} 088 * } 089 * </pre> 090 * 091 * <p>please use {@link ClassSanityTester#forAllPublicStaticMethods}. 092 * 093 * <p>If not all classes on the classpath should be covered, {@link #ignoreClasses} can be used to 094 * exclude certain classes. As a special case, classes with an underscore in the name (like {@code 095 * AutoValue_Foo}) can be excluded using <code>ignoreClasses({@link #UNDERSCORE_IN_NAME})</code>. 096 * 097 * <p>{@link #setDefault} allows subclasses to specify default values for types. 098 * 099 * <p>This class incurs IO because it scans the classpath and reads classpath resources. 100 * 101 * @author Ben Yu 102 * @since 14.0 103 */ 104// TODO: Switch to JUnit 4 and use @Parameterized and @BeforeClass 105// Note: @Test annotations are deliberate, as some subclasses specify @RunWith(JUnit4). 106@GwtIncompatible 107@J2ktIncompatible 108@J2ObjCIncompatible // com.google.common.reflect.ClassPath 109@ElementTypesAreNonnullByDefault 110public abstract class AbstractPackageSanityTests extends TestCase { 111 112 /** 113 * A predicate that matches classes with an underscore in the class name. This can be used with 114 * {@link #ignoreClasses} to exclude generated classes, such as the {@code AutoValue_Foo} classes 115 * generated by <a href="https://github.com/google/auto/tree/master/value">AutoValue</a>. 116 * 117 * @since 19.0 118 */ 119 public static final Predicate<Class<?>> UNDERSCORE_IN_NAME = 120 (Class<?> c) -> c.getSimpleName().contains("_"); 121 122 /* The names of the expected method that tests null checks. */ 123 private static final ImmutableList<String> NULL_TEST_METHOD_NAMES = 124 ImmutableList.of( 125 "testNulls", "testNull", 126 "testNullPointers", "testNullPointer", 127 "testNullPointerExceptions", "testNullPointerException"); 128 129 /* The names of the expected method that tests serializable. */ 130 private static final ImmutableList<String> SERIALIZABLE_TEST_METHOD_NAMES = 131 ImmutableList.of( 132 "testSerializable", "testSerialization", 133 "testEqualsAndSerializable", "testEqualsAndSerialization"); 134 135 /* The names of the expected method that tests equals. */ 136 private static final ImmutableList<String> EQUALS_TEST_METHOD_NAMES = 137 ImmutableList.of( 138 "testEquals", 139 "testEqualsAndHashCode", 140 "testEqualsAndSerializable", 141 "testEqualsAndSerialization", 142 "testEquality"); 143 144 private static final Chopper TEST_SUFFIX = 145 suffix("Test").or(suffix("Tests")).or(suffix("TestCase")).or(suffix("TestSuite")); 146 147 private final Logger logger = Logger.getLogger(getClass().getName()); 148 private final ClassSanityTester tester = new ClassSanityTester(); 149 private Visibility visibility = Visibility.PACKAGE; 150 private Predicate<Class<?>> classFilter = 151 (Class<?> cls) -> visibility.isVisible(cls.getModifiers()); 152 153 /** 154 * Restricts the sanity tests for public API only. By default, package-private API are also 155 * covered. 156 */ 157 protected final void publicApiOnly() { 158 visibility = Visibility.PUBLIC; 159 } 160 161 /** 162 * Tests all top-level {@link Serializable} classes in the package. For a serializable Class 163 * {@code C}: 164 * 165 * <ul> 166 * <li>If {@code C} explicitly implements {@link Object#equals}, the deserialized instance will 167 * be checked to be equal to the instance before serialization. 168 * <li>If {@code C} doesn't explicitly implement {@code equals} but instead inherits it from a 169 * superclass, no equality check is done on the deserialized instance because it's not clear 170 * whether the author intended for the class to be a value type. 171 * <li>If a constructor or factory method takes a parameter whose type is interface, a dynamic 172 * proxy will be passed to the method. It's possible that the method body expects an 173 * instance method of the passed-in proxy to be of a certain value yet the proxy isn't aware 174 * of the assumption, in which case the equality check before and after serialization will 175 * fail. 176 * <li>If the constructor or factory method takes a parameter that {@link 177 * AbstractPackageSanityTests} doesn't know how to construct, the test will fail. 178 * <li>If there is no visible constructor or visible static factory method declared by {@code 179 * C}, {@code C} is skipped for serialization test, even if it implements {@link 180 * Serializable}. 181 * <li>Serialization test is not performed on method return values unless the method is a 182 * visible static factory method whose return type is {@code C} or {@code C}'s subtype. 183 * </ul> 184 * 185 * <p>In all cases, if {@code C} needs custom logic for testing serialization, you can add an 186 * explicit {@code testSerializable()} test in the corresponding {@code CTest} class, and {@code 187 * C} will be excluded from automated serialization test performed by this method. 188 */ 189 @Test 190 public void testSerializable() throws Exception { 191 // TODO: when we use @BeforeClass, we can pay the cost of class path scanning only once. 192 for (Class<?> classToTest : 193 findClassesToTest(loadClassesInPackage(), SERIALIZABLE_TEST_METHOD_NAMES)) { 194 if (Serializable.class.isAssignableFrom(classToTest)) { 195 try { 196 Object instance = tester.instantiate(classToTest); 197 if (instance != null) { 198 if (isEqualsDefined(classToTest)) { 199 SerializableTester.reserializeAndAssert(instance); 200 } else { 201 SerializableTester.reserialize(instance); 202 } 203 } 204 } catch (Throwable e) { 205 throw sanityError(classToTest, SERIALIZABLE_TEST_METHOD_NAMES, "serializable test", e); 206 } 207 } 208 } 209 } 210 211 /** 212 * Performs {@link NullPointerTester} checks for all top-level classes in the package. For a class 213 * {@code C} 214 * 215 * <ul> 216 * <li>All visible static methods are checked such that passing null for any parameter that's 217 * not annotated nullable (according to the rules of {@link NullPointerTester}) should throw 218 * {@link NullPointerException}. 219 * <li>If there is any visible constructor or visible static factory method declared by the 220 * class, all visible instance methods will be checked too using the instance created by 221 * invoking the constructor or static factory method. 222 * <li>If the constructor or factory method used to construct instance takes a parameter that 223 * {@link AbstractPackageSanityTests} doesn't know how to construct, the test will fail. 224 * <li>If there is no visible constructor or visible static factory method declared by {@code 225 * C}, instance methods are skipped for nulls test. 226 * <li>Nulls test is not performed on method return values unless the method is a visible static 227 * factory method whose return type is {@code C} or {@code C}'s subtype. 228 * </ul> 229 * 230 * <p>In all cases, if {@code C} needs custom logic for testing nulls, you can add an explicit 231 * {@code testNulls()} test in the corresponding {@code CTest} class, and {@code C} will be 232 * excluded from the automated null tests performed by this method. 233 */ 234 @Test 235 public void testNulls() throws Exception { 236 for (Class<?> classToTest : findClassesToTest(loadClassesInPackage(), NULL_TEST_METHOD_NAMES)) { 237 try { 238 tester.doTestNulls(classToTest, visibility); 239 } catch (Throwable e) { 240 throw sanityError(classToTest, NULL_TEST_METHOD_NAMES, "nulls test", e); 241 } 242 } 243 } 244 245 /** 246 * Tests {@code equals()} and {@code hashCode()} implementations for every top-level class in the 247 * package, that explicitly implements {@link Object#equals}. For a class {@code C}: 248 * 249 * <ul> 250 * <li>The visible constructor or visible static factory method with the most parameters is used 251 * to construct the sample instances. In case of tie, the candidate constructors or 252 * factories are tried one after another until one can be used to construct sample 253 * instances. 254 * <li>For the constructor or static factory method used to construct instances, it's checked 255 * that when equal parameters are passed, the result instance should also be equal; and vice 256 * versa. 257 * <li>Inequality check is not performed against state mutation methods such as {@link 258 * List#add}, or functional update methods such as {@link 259 * com.google.common.base.Joiner#skipNulls}. 260 * <li>If the constructor or factory method used to construct instance takes a parameter that 261 * {@link AbstractPackageSanityTests} doesn't know how to construct, the test will fail. 262 * <li>If there is no visible constructor or visible static factory method declared by {@code 263 * C}, {@code C} is skipped for equality test. 264 * <li>Equality test is not performed on method return values unless the method is a visible 265 * static factory method whose return type is {@code C} or {@code C}'s subtype. 266 * </ul> 267 * 268 * <p>In all cases, if {@code C} needs custom logic for testing {@code equals()}, you can add an 269 * explicit {@code testEquals()} test in the corresponding {@code CTest} class, and {@code C} will 270 * be excluded from the automated {@code equals} test performed by this method. 271 */ 272 @Test 273 public void testEquals() throws Exception { 274 for (Class<?> classToTest : 275 findClassesToTest(loadClassesInPackage(), EQUALS_TEST_METHOD_NAMES)) { 276 if (!classToTest.isEnum() && isEqualsDefined(classToTest)) { 277 try { 278 tester.doTestEquals(classToTest); 279 } catch (Throwable e) { 280 throw sanityError(classToTest, EQUALS_TEST_METHOD_NAMES, "equals test", e); 281 } 282 } 283 } 284 } 285 286 /** 287 * Sets the default value for {@code type}, when dummy value for a parameter of the same type 288 * needs to be created in order to invoke a method or constructor. The default value isn't used in 289 * testing {@link Object#equals} because more than one sample instances are needed for testing 290 * inequality. 291 */ 292 protected final <T> void setDefault(Class<T> type, T value) { 293 tester.setDefault(type, value); 294 } 295 296 /** 297 * Sets two distinct values for {@code type}. These values can be used for both null pointer 298 * testing and equals testing. 299 * 300 * @since 17.0 301 */ 302 protected final <T> void setDistinctValues(Class<T> type, T value1, T value2) { 303 tester.setDistinctValues(type, value1, value2); 304 } 305 306 /** Specifies that classes that satisfy the given predicate aren't tested for sanity. */ 307 protected final void ignoreClasses(Predicate<? super Class<?>> condition) { 308 this.classFilter = and(this.classFilter, not(condition)); 309 } 310 311 private static AssertionFailedError sanityError( 312 Class<?> cls, List<String> explicitTestNames, String description, Throwable e) { 313 String message = 314 String.format( 315 Locale.ROOT, 316 "Error in automated %s of %s\n" 317 + "If the class is better tested explicitly, you can add %s() to %sTest", 318 description, 319 cls, 320 explicitTestNames.get(0), 321 cls.getName()); 322 AssertionFailedError error = new AssertionFailedError(message); 323 error.initCause(e); 324 return error; 325 } 326 327 /** 328 * Finds the classes not ending with a test suffix and not covered by an explicit test whose name 329 * is {@code explicitTestNames}. 330 */ 331 @VisibleForTesting 332 List<Class<?>> findClassesToTest( 333 Iterable<? extends Class<?>> classes, Iterable<String> explicitTestNames) { 334 // "a.b.Foo" -> a.b.Foo.class 335 TreeMap<String, Class<?>> classMap = Maps.newTreeMap(); 336 for (Class<?> cls : classes) { 337 classMap.put(cls.getName(), cls); 338 } 339 // Foo.class -> [FooTest.class, FooTests.class, FooTestSuite.class, ...] 340 Multimap<Class<?>, Class<?>> testClasses = HashMultimap.create(); 341 LinkedHashSet<Class<?>> candidateClasses = Sets.newLinkedHashSet(); 342 for (Class<?> cls : classes) { 343 Optional<String> testedClassName = TEST_SUFFIX.chop(cls.getName()); 344 if (testedClassName.isPresent()) { 345 Class<?> testedClass = classMap.get(testedClassName.get()); 346 if (testedClass != null) { 347 testClasses.put(testedClass, cls); 348 } 349 } else { 350 candidateClasses.add(cls); 351 } 352 } 353 List<Class<?>> result = Lists.newArrayList(); 354 NEXT_CANDIDATE: 355 for (Class<?> candidate : Iterables.filter(candidateClasses, classFilter)) { 356 for (Class<?> testClass : testClasses.get(candidate)) { 357 if (hasTest(testClass, explicitTestNames)) { 358 // covered by explicit test 359 continue NEXT_CANDIDATE; 360 } 361 } 362 result.add(candidate); 363 } 364 return result; 365 } 366 367 private List<Class<?>> loadClassesInPackage() throws IOException { 368 List<Class<?>> classes = Lists.newArrayList(); 369 String packageName = getClass().getPackage().getName(); 370 for (ClassPath.ClassInfo classInfo : 371 ClassPath.from(getClass().getClassLoader()).getTopLevelClasses(packageName)) { 372 Class<?> cls; 373 try { 374 cls = classInfo.load(); 375 } catch (NoClassDefFoundError e) { 376 // In case there were linking problems, this is probably not a class we care to test anyway. 377 logger.log(Level.SEVERE, "Cannot load class " + classInfo + ", skipping...", e); 378 continue; 379 } 380 if (!cls.isInterface()) { 381 classes.add(cls); 382 } 383 } 384 return classes; 385 } 386 387 private static boolean hasTest(Class<?> testClass, Iterable<String> testNames) { 388 for (String testName : testNames) { 389 try { 390 testClass.getMethod(testName); 391 return true; 392 } catch (NoSuchMethodException e) { 393 continue; 394 } 395 } 396 return false; 397 } 398 399 private static boolean isEqualsDefined(Class<?> cls) { 400 try { 401 return !cls.getDeclaredMethod("equals", Object.class).isSynthetic(); 402 } catch (NoSuchMethodException e) { 403 return false; 404 } 405 } 406 407 abstract static class Chopper { 408 409 final Chopper or(Chopper you) { 410 Chopper i = this; 411 return new Chopper() { 412 @Override 413 Optional<String> chop(String str) { 414 return i.chop(str).or(you.chop(str)); 415 } 416 }; 417 } 418 419 abstract Optional<String> chop(String str); 420 421 static Chopper suffix(String suffix) { 422 return new Chopper() { 423 @Override 424 Optional<String> chop(String str) { 425 if (str.endsWith(suffix)) { 426 return Optional.of(str.substring(0, str.length() - suffix.length())); 427 } else { 428 return Optional.absent(); 429 } 430 } 431 }; 432 } 433 } 434}