1 /* 2 * Copyright (C) 2008 The Guava Authors 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 17 package com.google.common.collect.testing.features; 18 19 import com.google.common.annotations.GwtCompatible; 20 import com.google.common.collect.testing.Helpers; 21 22 import java.lang.annotation.Inherited; 23 import java.lang.annotation.Retention; 24 import java.lang.annotation.RetentionPolicy; 25 import java.util.Collection; 26 import java.util.Collections; 27 import java.util.Set; 28 29 /** 30 * When describing the features of the collection produced by a given generator 31 * (i.e. in a call to {@link 32 * com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder#withFeatures(Feature...)}), 33 * this annotation specifies each of the different sizes for which a test suite 34 * should be built. (In a typical case, the features should include {@link 35 * CollectionSize#ANY}.) These semantics are thus a little different 36 * from those of other Collection-related features such as {@link 37 * CollectionFeature} or {@link SetFeature}. 38 * <p> 39 * However, when {@link CollectionSize.Require} is used to annotate a test it 40 * behaves normally (i.e. it requires the collection instance under test to be 41 * a certain size for the test to run). Note that this means a test should not 42 * require more than one CollectionSize, since a particular collection instance 43 * can only be one size at once. 44 * 45 * @author George van den Driessche 46 */ 47 // Enum values use constructors with generic varargs. 48 @SuppressWarnings("unchecked") 49 @GwtCompatible 50 public enum CollectionSize implements Feature<Collection>, 51 Comparable<CollectionSize> { 52 /** Test an empty collection. */ 53 ZERO(0), 54 /** Test a one-element collection. */ 55 ONE(1), 56 /** Test a three-element collection. */ 57 SEVERAL(3), 58 /* 59 * TODO: add VERY_LARGE, noting that we currently assume that the fourth 60 * sample element is not in any collection 61 */ 62 63 ANY( 64 ZERO, 65 ONE, 66 SEVERAL 67 ); 68 69 private final Set<Feature<? super Collection>> implied; 70 private final Integer numElements; 71 72 CollectionSize(int numElements) { 73 this.implied = Collections.emptySet(); 74 this.numElements = numElements; 75 } 76 77 CollectionSize(Feature<? super Collection> ... implied) { 78 // Keep the order here, so that PerCollectionSizeTestSuiteBuilder 79 // gives a predictable order of test suites. 80 this.implied = Helpers.copyToSet(implied); 81 this.numElements = null; 82 } 83 84 @Override 85 public Set<Feature<? super Collection>> getImpliedFeatures() { 86 return implied; 87 } 88 89 public int getNumElements() { 90 if (numElements == null) { 91 throw new IllegalStateException( 92 "A compound CollectionSize doesn't specify a number of elements."); 93 } 94 return numElements; 95 } 96 97 @Retention(RetentionPolicy.RUNTIME) 98 @Inherited 99 @TesterAnnotation 100 public @interface Require { 101 CollectionSize[] value() default {}; 102 CollectionSize[] absent() default {}; 103 } 104 } 105
