guava

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/*
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 * Copyright (C) 2008 The Guava Authors
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 * http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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package com.google.common.collect.testing.testers;
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import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_QUERIES;
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import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
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import static com.google.common.collect.testing.features.CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;
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import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
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import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
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import static com.google.common.collect.testing.features.CollectionSize.ZERO;
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import com.google.common.annotations.GwtCompatible;
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import com.google.common.collect.testing.AbstractCollectionTester;
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import com.google.common.collect.testing.WrongType;
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import com.google.common.collect.testing.features.CollectionFeature;
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import com.google.common.collect.testing.features.CollectionSize;
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import java.util.ConcurrentModificationException;
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import java.util.Iterator;
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import org.junit.Ignore;
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/**
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 * A generic JUnit test which tests {@code remove} operations on a collection. Can't be invoked
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 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
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 *
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 * @author George van den Driessche
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 */
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@GwtCompatible
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@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
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public class CollectionRemoveTester<E> extends AbstractCollectionTester<E> {
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  @CollectionFeature.Require(SUPPORTS_REMOVE)
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  @CollectionSize.Require(absent = ZERO)
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  public void testRemove_present() {
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    int initialSize = collection.size();
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    assertTrue("remove(present) should return true", collection.remove(e0()));
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    assertEquals(
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        "remove(present) should decrease a collection's size by one.",
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        initialSize - 1,
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        collection.size());
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    expectMissing(e0());
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  }
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  @CollectionFeature.Require({SUPPORTS_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
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  @CollectionSize.Require(SEVERAL)
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  public void testRemovePresentConcurrentWithIteration() {
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    try {
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      Iterator<E> iterator = collection.iterator();
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      assertTrue(collection.remove(e0()));
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      iterator.next();
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      fail("Expected ConcurrentModificationException");
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    } catch (ConcurrentModificationException expected) {
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      // success
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    }
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  }
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  @CollectionFeature.Require(SUPPORTS_REMOVE)
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  public void testRemove_notPresent() {
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    assertFalse("remove(notPresent) should return false", collection.remove(e3()));
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    expectUnchanged();
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  }
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  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
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  @CollectionSize.Require(absent = ZERO)
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  public void testRemove_nullPresent() {
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    collection = getSubjectGenerator().create(createArrayWithNullElement());
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    int initialSize = collection.size();
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    assertTrue("remove(null) should return true", collection.remove(null));
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    assertEquals(
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        "remove(present) should decrease a collection's size by one.",
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        initialSize - 1,
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        collection.size());
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    expectMissing((E) null);
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  }
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  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
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  @CollectionSize.Require(absent = ZERO)
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  public void testRemove_unsupported() {
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    try {
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      collection.remove(e0());
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      fail("remove(present) should throw UnsupportedOperationException");
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    } catch (UnsupportedOperationException expected) {
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    }
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    expectUnchanged();
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    assertTrue("remove(present) should not remove the element", collection.contains(e0()));
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  }
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  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
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  public void testRemove_unsupportedNotPresent() {
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    try {
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      assertFalse(
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          "remove(notPresent) should return false or throw UnsupportedOperationException",
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          collection.remove(e3()));
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    } catch (UnsupportedOperationException tolerated) {
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    }
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    expectUnchanged();
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    expectMissing(e3());
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  }
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  @CollectionFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_QUERIES)
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  public void testRemove_nullNotSupported() {
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    try {
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      assertFalse(
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          "remove(null) should return false or throw NullPointerException",
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          collection.remove(null));
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    } catch (NullPointerException tolerated) {
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    }
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    expectUnchanged();
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  }
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  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
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  public void testRemove_nullAllowed() {
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    assertFalse("remove(null) should return false", collection.remove(null));
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    expectUnchanged();
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  }
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  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
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  @CollectionSize.Require(absent = ZERO)
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  public void testIteratorRemove_unsupported() {
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    Iterator<E> iterator = collection.iterator();
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    iterator.next();
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    try {
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      iterator.remove();
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      fail("iterator.remove() should throw UnsupportedOperationException");
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    } catch (UnsupportedOperationException expected) {
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    }
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    expectUnchanged();
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    assertTrue(collection.contains(e0()));
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  }
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  @CollectionFeature.Require(SUPPORTS_REMOVE)
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  public void testRemove_wrongType() {
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    try {
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      assertFalse(collection.remove(WrongType.VALUE));
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    } catch (ClassCastException tolerated) {
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    }
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    expectUnchanged();
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  }
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}
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