common/reflect/ImmutableTypeToInstanceMapTest.java

/*
 * Copyright (C) 2012 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.reflect;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Maps;
import com.google.common.collect.testing.MapTestSuiteBuilder;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestMapGenerator;
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 junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Unit test for {@link ImmutableTypeToInstanceMap}.
 *
 * @author Ben Yu
 */
public class ImmutableTypeToInstanceMapTest extends TestCase {

  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTestSuite(ImmutableTypeToInstanceMapTest.class);

    suite.addTest(MapTestSuiteBuilder
        .using(new TestTypeToInstanceMapGenerator() {
          // 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<TypeToken, Object> create(Object... elements) {
            ImmutableTypeToInstanceMap.Builder<Object> builder
                = ImmutableTypeToInstanceMap.builder();
            for (Object object : elements) {
              Entry<TypeToken, Object> entry = (Entry<TypeToken, Object>) object;
              builder.put(entry.getKey(), entry.getValue());
            }
            return (Map) builder.build();
          }
        })
        .named("ImmutableTypeToInstanceMap")
        .withFeatures(
            MapFeature.REJECTS_DUPLICATES_AT_CREATION,
            MapFeature.RESTRICTS_KEYS,
            CollectionFeature.KNOWN_ORDER,
            CollectionSize.ANY,
            MapFeature.ALLOWS_ANY_NULL_QUERIES)
        .createTestSuite());

    return suite;
  }

  public void testEmpty() {
    assertEquals(0, ImmutableTypeToInstanceMap.of().size());
  }

  public void testPrimitiveAndWrapper() {
    ImmutableTypeToInstanceMap<Number> map = ImmutableTypeToInstanceMap.<Number>builder()
        .put(Integer.class, 0)
        .put(int.class, 1)
        .build();
    assertEquals(2, map.size());

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

  public void testParameterizedType() {
    TypeToken<ImmutableList<Integer>> type = new TypeToken<ImmutableList<Integer>>() {};
    ImmutableTypeToInstanceMap<Iterable<?>> map = ImmutableTypeToInstanceMap.<Iterable<?>>builder()
        .put(type, ImmutableList.of(1))
        .build();
    assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGeneriArrayType() {
    @SuppressWarnings("unchecked") // Trying to test generic array
    ImmutableList<Integer>[] array = new ImmutableList[] {ImmutableList.of(1)};
    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    ImmutableTypeToInstanceMap<Iterable<?>[]> map =
        ImmutableTypeToInstanceMap.<Iterable<?>[]>builder()
            .put(type, array)
            .build();
    assertEquals(1, map.size());
    assertThat(map.getInstance(type)).asList().has().exactly(array[0]).inOrder();
  }

  public void testWildcardType() {
    TypeToken<ImmutableList<?>> type = new TypeToken<ImmutableList<?>>() {};
    ImmutableTypeToInstanceMap<Iterable<?>> map = ImmutableTypeToInstanceMap.<Iterable<?>>builder()
            .put(type, ImmutableList.of(1))
            .build();
    assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGetInstance_containsTypeVariable() {
    ImmutableTypeToInstanceMap<Iterable<Number>> map = ImmutableTypeToInstanceMap.of();
    try {
      map.getInstance(this.<Number>anyIterableType());
      fail();
    } catch (IllegalArgumentException expected) {}
  }

  public void testPut_containsTypeVariable() {
    ImmutableTypeToInstanceMap.Builder<Iterable<Integer>> builder =
        ImmutableTypeToInstanceMap.builder();
    try {
      builder.put(this.<Integer>anyIterableType(), ImmutableList.of(1));
      fail();
    } catch (IllegalArgumentException expected) {}
  }

  private <T> TypeToken<Iterable<T>> anyIterableType() {
    return new TypeToken<Iterable<T>>() {};
  }

  abstract static class TestTypeToInstanceMapGenerator
      implements TestMapGenerator<TypeToken, Object> {

    @Override public TypeToken[] createKeyArray(int length) {
      return new TypeToken[length];
    }

    @Override public Object[] createValueArray(int length) {
      return new Object[length];
    }

    @Override
    public SampleElements<Entry<TypeToken, Object>> samples() {
      Entry<TypeToken, Object> entry1 =
          Maps.immutableEntry((TypeToken) TypeToken.of(Integer.class), (Object) 0);
      Entry<TypeToken, Object> entry2 =
          Maps.immutableEntry((TypeToken) TypeToken.of(Number.class), (Object) 1);
      Entry<TypeToken, Object> entry3 =
          Maps.immutableEntry((TypeToken) new TypeToken<ImmutableList<Integer>>() {},
              (Object) ImmutableList.of(2));
      Entry<TypeToken, Object> entry4 =
          Maps.immutableEntry((TypeToken) new TypeToken<int[]>() {}, (Object) new int[] {3});
      Entry<TypeToken, Object> entry5 =
          Maps.immutableEntry((TypeToken) new TypeToken<Iterable<?>>() {},
              (Object) ImmutableList.of("4"));
      return new SampleElements<Entry<TypeToken, Object>>(
          entry1, entry2, entry3, entry4, entry5
      );
    }

    @Override
    @SuppressWarnings("unchecked")
    public Entry<TypeToken, Object>[] createArray(int length) {
      return new Entry[length];
    }

    @Override
    public Iterable<Entry<TypeToken, Object>> order(List<Entry<TypeToken, Object>> insertionOrder) {
      return insertionOrder;
    }
  }
}