guava-tests/test/com/google/common/collect/MutableClassToInstanceMapTest.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;

import com.google.common.collect.ImmutableClassToInstanceMapTest.TestClassToInstanceMapGenerator;
import com.google.common.collect.testing.MapTestSuiteBuilder;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import com.google.common.collect.testing.testers.MapPutTester;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

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

/**
 * Unit test of {@link MutableClassToInstanceMap}.
 *
 * @author Kevin Bourrillion
 */
public class MutableClassToInstanceMapTest extends TestCase {
  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTestSuite(MutableClassToInstanceMapTest.class);

    // Suppress this one because the tester framework doesn't understand that
    // *some* remappings will be allowed and others not.
    Method remapTest = null;
    try {
      remapTest = MapPutTester.class.getMethod(
          "testPut_replaceNullValueWithNonNullSupported");
    } catch (NoSuchMethodException e) {
      throw new AssertionError();
    }

    suite.addTest(MapTestSuiteBuilder
        .using(new TestClassToInstanceMapGenerator() {
          // Other tests will verify what real, warning-free usage looks like
          // but here we have to do some serious fudging
          @Override
          @SuppressWarnings("unchecked")
          public Map<Class, Number> create(Object... elements) {
            MutableClassToInstanceMap<Number> map
                = MutableClassToInstanceMap.create();
            for (Object object : elements) {
              Entry<Class, Number> entry = (Entry<Class, Number>) object;
              map.putInstance(entry.getKey(), entry.getValue());
            }
            return (Map) map;
          }
        })
        .named("MutableClassToInstanceMap")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.RESTRICTS_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            CollectionSize.ANY,
            CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
            MapFeature.ALLOWS_ANY_NULL_QUERIES)
        .suppressing(remapTest)
        .createTestSuite());

    return suite;
  }

  private ClassToInstanceMap<Number> map;

  @Override protected void setUp() throws Exception {
    map = MutableClassToInstanceMap.create();
  }

  public void testConstraint() {

    /**
     * We'll give ourselves a pass on testing all the possible ways of
     * breaking the constraint, because we know that newClassMap() is
     * implemented using ConstrainedMap which is itself well-tested.
     * A purist would object to this, but what can I say, we're dirty
     * cheaters.
     */

    map.put(Integer.class, new Integer(5));
    try {
      map.put(Double.class, new Long(42));
      fail();
    } catch (ClassCastException expected) {
    }
    // Won't compile: map.put(String.class, "x");
  }

  public void testPutAndGetInstance() {
    assertNull(map.putInstance(Integer.class, new Integer(5)));

    Integer oldValue = map.putInstance(Integer.class, new Integer(7));
    assertEquals(5, (int) oldValue);

    Integer newValue = map.getInstance(Integer.class);
    assertEquals(7, (int) newValue);

    // Won't compile: map.putInstance(Double.class, new Long(42));
  }

  public void testNull() {
    try {
      map.put(null, new Integer(1));
      fail();
    } catch (NullPointerException expected) {
    }
    map.putInstance(Integer.class, null);
    assertNull(map.get(Integer.class));
    assertNull(map.getInstance(Integer.class));

    map.put(Long.class, null);
    assertNull(map.get(Long.class));
    assertNull(map.getInstance(Long.class));
  }

  public void testPrimitiveAndWrapper() {
    assertNull(map.getInstance(int.class));
    assertNull(map.getInstance(Integer.class));

    assertNull(map.putInstance(int.class, 0));
    assertNull(map.putInstance(Integer.class, 1));
    assertEquals(2, map.size());

    assertEquals(0, (int) map.getInstance(int.class));
    assertEquals(1, (int) map.getInstance(Integer.class));

    assertEquals(0, (int) map.putInstance(int.class, null));
    assertEquals(1, (int) map.putInstance(Integer.class, null));

    assertNull(map.getInstance(int.class));
    assertNull(map.getInstance(Integer.class));
    assertEquals(2, map.size());
  }
}