test/com/google/common/collect/EnumBiMapTest.java

/*
 * Copyright (C) 2007 Google Inc.
 *
 * 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;

import static com.google.common.testing.junit3.JUnitAsserts.assertContentsInOrder;
import com.google.common.testutils.SerializableTester;

import junit.framework.TestCase;

import java.util.Collections;
import java.util.Map;

/**
 * Tests for {@code EnumBiMap}.
 *
 * @author Mike Bostock
 * @author Jared Levy
 */
public class EnumBiMapTest extends TestCase {
  private enum Currency { DOLLAR, FRANC, PESO }
  private enum Country { CANADA, CHILE, SWITZERLAND }

  public void testCreate() {
    EnumBiMap<Currency, Country> bimap =
        EnumBiMap.create(Currency.class, Country.class);
    assertTrue(bimap.isEmpty());
    assertEquals("{}", bimap.toString());
    assertEquals(HashBiMap.create(), bimap);
    bimap.put(Currency.DOLLAR, Country.CANADA);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, Country> map = ImmutableMap.of(
        Currency.DOLLAR, Country.CANADA,
        Currency.PESO, Country.CHILE,
        Currency.FRANC, Country.SWITZERLAND);
    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));

    /* Map must have at least one entry if not an EnumBiMap. */
    try {
      EnumBiMap.create(Collections.<Currency, Country>emptyMap());
      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {}
    try {
      EnumBiMap.create(
          EnumHashBiMap.<Currency, Country>create(Currency.class));
      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {}

    /* Map can be empty if it's an EnumBiMap. */
    Map<Currency, Country> emptyBimap =
        EnumBiMap.create(Currency.class, Country.class);
    bimap = EnumBiMap.create(emptyBimap);
    assertTrue(bimap.isEmpty());
  }

  public void testEnumBiMapConstructor() {
    /* Test that it copies existing entries. */
    EnumBiMap<Currency, Country> bimap1 =
        EnumBiMap.create(Currency.class, Country.class);
    bimap1.put(Currency.DOLLAR, Country.CANADA);
    EnumBiMap<Currency, Country> bimap2 =
        EnumBiMap.create(bimap1);
    assertEquals(Country.CANADA, bimap2.get(Currency.DOLLAR));
    assertEquals(bimap1, bimap2);
    bimap2.inverse().put(Country.SWITZERLAND, Currency.FRANC);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.FRANC));
    assertNull(bimap1.get(Currency.FRANC));
    assertFalse(bimap2.equals(bimap1));

    /* Test that it can be empty. */
    EnumBiMap<Currency, Country> emptyBimap =
        EnumBiMap.create(Currency.class, Country.class);
    EnumBiMap<Currency, Country> bimap3 =
        EnumBiMap.create(emptyBimap);
    assertEquals(bimap3, emptyBimap);
  }

  public void testKeyType() {
    EnumBiMap<Currency, Country> bimap =
        EnumBiMap.create(Currency.class, Country.class);
    assertEquals(Currency.class, bimap.keyType());
  }

  public void testValueType() {
    EnumBiMap<Currency, Country> bimap =
        EnumBiMap.create(Currency.class, Country.class);
    assertEquals(Country.class, bimap.valueType());
  }

  public void testSerialization() {
    Map<Currency, Country> map = ImmutableMap.of(
        Currency.DOLLAR, Country.CANADA,
        Currency.PESO, Country.CHILE,
        Currency.FRANC, Country.SWITZERLAND);
    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);

    BiMap<Currency, Country> copy =
        SerializableTester.reserializeAndAssert(bimap);
    assertEquals(bimap.inverse(), copy.inverse());
  }

  public void testIterationOrder() {
    // The enum orderings are alphabetical, leading to the bimap and its inverse
    // having inconsistent iteration orderings.
    Map<Currency, Country> map = ImmutableMap.of(
        Currency.DOLLAR, Country.CANADA,
        Currency.PESO, Country.CHILE,
        Currency.FRANC, Country.SWITZERLAND);
    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);

    // forward map ordered by currency
    assertContentsInOrder(bimap.keySet(),
        Currency.DOLLAR, Currency.FRANC, Currency.PESO);
    // forward map ordered by currency (even for country values)
    assertContentsInOrder(bimap.values(),
        Country.CANADA, Country.SWITZERLAND, Country.CHILE);
    // backward map ordered by country
    assertContentsInOrder(bimap.inverse().keySet(),
        Country.CANADA, Country.CHILE, Country.SWITZERLAND);
    // backward map ordered by country (even for currency values)
    assertContentsInOrder(bimap.inverse().values(),
        Currency.DOLLAR, Currency.PESO, Currency.FRANC);
  }

  /* Remaining behavior tested by AbstractBiMapTest. */
}