testing/testers/MapCreationTester.java

/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.MapFeature.REJECTS_DUPLICATES_AT_CREATION;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.AbstractMapTester;
import com.google.common.collect.testing.Helpers;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;

import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import java.util.Map.Entry;

/**
 * A generic JUnit test which tests creation (typically through a constructor or
 * static factory method) of a map. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * <p>This class is GWT compatible.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
public class MapCreationTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeySupported() {
    initMapWithNullKey();
    expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {
    try {
      initMapWithNullKey();
      fail("Creating a map containing a null key should fail");
    } catch (NullPointerException expected) {
    }
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullValueSupported() {
    initMapWithNullValue();
    expectContents(createArrayWithNullValue());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullValueUnsupported() {
    try {
      initMapWithNullValue();
      fail("Creating a map containing a null value should fail");
    } catch (NullPointerException expected) {
    }
  }

  @MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyAndValueSupported() {
    Entry<K, V>[] entries = createSamplesArray();
    entries[getNullLocation()] = entry(null, null);
    resetMap(entries);
    expectContents(entries);
  }

  @MapFeature.Require(value = ALLOWS_NULL_KEYS,
      absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nullDuplicatesNotRejected() {
    expectFirstRemoved(getEntriesMultipleNullKeys());
  }

  @MapFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nonNullDuplicatesNotRejected() {
    expectFirstRemoved(getEntriesMultipleNonNullKeys());
  }

  @MapFeature.Require({ALLOWS_NULL_KEYS, REJECTS_DUPLICATES_AT_CREATION})
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nullDuplicatesRejected() {
    Entry<K, V>[] entries = getEntriesMultipleNullKeys();
    try {
      resetMap(entries);
      fail("Should reject duplicate null elements at creation");
    } catch (IllegalArgumentException expected) {
    }
  }

  @MapFeature.Require(REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nonNullDuplicatesRejected() {
    Entry<K, V>[] entries = getEntriesMultipleNonNullKeys();
    try {
      resetMap(entries);
      fail("Should reject duplicate non-null elements at creation");
    } catch (IllegalArgumentException expected) {
    }
  }

  private Entry<K, V>[] getEntriesMultipleNullKeys() {
    Entry<K, V>[] entries = createArrayWithNullKey();
    entries[0] = entry(null, entries[0].getValue());
    return entries;
  }

  private Entry<K, V>[] getEntriesMultipleNonNullKeys() {
    Entry<K, V>[] entries = createSamplesArray();
    entries[0] = entry(samples.e1.getKey(), samples.e0.getValue());
    return entries;
  }

  private void expectFirstRemoved(Entry<K, V>[] entries) {
    resetMap(entries);

    List<Entry<K, V>> expectedWithDuplicateRemoved =
        Arrays.asList(entries).subList(1, getNumElements());
    expectContents(expectedWithDuplicateRemoved);
  }

  /**
   * Returns the {@link Method} instance for {@link
   * #testCreateWithNullKeyUnsupported()} so that tests can suppress it
   * with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5045147">Sun
   * bug 5045147</a> is fixed.
   */
  @GwtIncompatible("reflection")
  public static Method getCreateWithNullKeyUnsupportedMethod() {
    return Helpers.getMethod(MapCreationTester.class, "testCreateWithNullKeyUnsupported");
  }
}