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 com.google.common.annotations.GwtCompatible; 20 import java.util.Collection; 21 import java.util.List; 22 import java.util.Map; 23 24 /** 25 * To be implemented by test generators of things that can contain elements. Such things include 26 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that 27 * encompasses both of these, 'container' is used. 28 * 29 * @author George van den Driessche 30 */ 31 @GwtCompatible 32 public interface TestContainerGenerator<T, E> { 33 /** Returns the sample elements that this generate populates its container with. */ samples()34 SampleElements<E> samples(); 35 36 /** 37 * Creates a new container containing the given elements. TODO: would be nice to figure out how to 38 * use E... or E[] as a parameter type, but this doesn't seem to work because Java creates an 39 * array of the erased type. 40 */ create(Object... elements)41 T create(Object... elements); 42 43 /** 44 * Helper method to create an array of the appropriate type used by this generator. The returned 45 * array will contain only nulls. 46 */ createArray(int length)47 E[] createArray(int length); 48 49 /** 50 * Returns the iteration ordering of elements, given the order in which they were added to the 51 * container. This method may return the original list unchanged, the original list modified in 52 * place, or a different list. 53 * 54 * <p>If the order is non-deterministic, as with {@link java.util.HashSet}, this method can return 55 * its input unmodified. Provided that the test suite is built without {@link 56 * com.google.common.collect.testing.features.CollectionFeature#KNOWN_ORDER}, the tests will look 57 * only at the returned contents without regard for order. 58 */ order(List<E> insertionOrder)59 Iterable<E> order(List<E> insertionOrder); 60 } 61