/*
    * Copyright (C) 2013 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 com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.AbstractMapTester;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.collect.testing.features.MapFeature;
  
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  /**
   * A generic JUnit test which tests {@code toString()} operations on a map. Can't be invoked
   * directly; please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
   *
   * @author Kevin Bourrillion
   * @author Louis Wasserman
   */
  @GwtCompatible
  public class MapToStringTester<K, V> extends AbstractMapTester<K, V> {
    public void testToString_minimal() {
      assertNotNull("toString() should not return null", getMap().toString());
    }
  
    @CollectionSize.Require(ZERO)
    public void testToString_size0() {
      assertEquals("emptyMap.toString should return {}", "{}", getMap().toString());
    }
  
    @CollectionSize.Require(ONE)
    public void testToString_size1() {
      assertEquals(
          "size1Map.toString should return {entry}", "{" + samples.e0 + "}", getMap().toString());
    }
  
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(ALLOWS_NULL_KEYS)
    public void testToStringWithNullKey() {
      initMapWithNullKey();
      testToString_formatting();
    }
  
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(ALLOWS_NULL_VALUES)
    public void testToStringWithNullValue() {
      initMapWithNullValue();
      testToString_formatting();
    }
  
    public void testToString_formatting() {
      assertEquals(
          "map.toString() incorrect", expectedToString(getMap().entrySet()), getMap().toString());
    }
  
    private String expectedToString(Set<Entry<K, V>> entries) {
      Map<K, V> reference = new LinkedHashMap<K, V>();
      for (Map.Entry<K, V> entry : entries) {
        reference.put(entry.getKey(), entry.getValue());
      }
      return reference.toString();
    }
  }