1 /* 2 * Copyright (C) 2007 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; 18 19 import com.google.common.annotations.GwtCompatible; 20 21 import java.util.Collection; 22 23 /** 24 * Base class for collection testers. 25 * 26 * @param <E> the element type of the collection to be tested. 27 * 28 * @author Kevin Bourrillion 29 */ 30 @GwtCompatible 31 public abstract class AbstractCollectionTester<E> 32 extends AbstractContainerTester<Collection<E>, E> { 33 34 // TODO: replace this with an accessor. 35 protected Collection<E> collection; 36 actualContents()37 @Override protected Collection<E> actualContents() { 38 return collection; 39 } 40 41 // TODO: dispose of this once collection is encapsulated. resetContainer(Collection<E> newContents)42 @Override protected Collection<E> resetContainer(Collection<E> newContents) { 43 collection = super.resetContainer(newContents); 44 return collection; 45 } 46 47 /** @see AbstractContainerTester#resetContainer() */ resetCollection()48 protected void resetCollection() { 49 resetContainer(); 50 } 51 52 /** 53 * @return an array of the proper size with {@code null} inserted into the 54 * middle element. 55 */ createArrayWithNullElement()56 protected E[] createArrayWithNullElement() { 57 E[] array = createSamplesArray(); 58 array[getNullLocation()] = null; 59 return array; 60 } 61 initCollectionWithNullElement()62 protected void initCollectionWithNullElement() { 63 E[] array = createArrayWithNullElement(); 64 resetContainer(getSubjectGenerator().create(array)); 65 } 66 67 /** 68 * Equivalent to {@link #expectMissing(Object[]) expectMissing}{@code (null)} 69 * except that the call to {@code contains(null)} is permitted to throw a 70 * {@code NullPointerException}. 71 * 72 * @param message message to use upon assertion failure 73 */ expectNullMissingWhenNullUnsupported(String message)74 protected void expectNullMissingWhenNullUnsupported(String message) { 75 try { 76 assertFalse(message, actualContents().contains(null)); 77 } catch (NullPointerException tolerated) { 78 // Tolerated 79 } 80 } 81 } 82