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; 18 19 import java.util.Collection; 20 import java.util.List; 21 import java.util.Map; 22 23 /** 24 * To be implemented by test generators of things that can contain 25 * elements. Such things include both {@link Collection} and {@link Map}; since 26 * there isn't an established collective noun that encompasses both of these, 27 * 'container' is used. 28 * 29 * <p>This class is GWT compatible. 30 * 31 * @author George van den Driessche 32 */ 33 public interface TestContainerGenerator<T, E> { 34 /** 35 * Returns the sample elements that this generate populates its container 36 * with. 37 */ 38 SampleElements<E> samples(); 39 40 /** 41 * Creates a new container containing the given elements. TODO: would be nice 42 * to figure out how to use E... or E[] as a parameter type, but this doesn't 43 * seem to work because Java creates an array of the erased type. 44 */ 45 T create(Object ... elements); 46 47 /** 48 * Helper method to create an array of the appropriate type used by this 49 * generator. The returned array will contain only nulls. 50 */ 51 E[] createArray(int length); 52 53 /** 54 * Returns the iteration ordering of elements, given the order in 55 * which they were added to the container. This method may return the 56 * original list unchanged, the original list modified in place, or a 57 * different list. 58 * 59 * <p>This method runs only when {@link 60 * com.google.common.collect.testing.features.CollectionFeature#KNOWN_ORDER} 61 * is specified when creating the test suite. It should never run when testing 62 * containers such as {@link java.util.HashSet}, which have a 63 * non-deterministic iteration order. 64 */ 65 Iterable<E> order(List<E> insertionOrder); 66 } 67
