/*
    * Copyright (C) 2008 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.CollectionFeature.ALLOWS_NULL_VALUES;
  import static com.google.common.collect.testing.features.CollectionSize.ZERO;
  import static com.google.common.collect.testing.features.ListFeature.SUPPORTS_SET;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.annotations.GwtIncompatible;
  import com.google.common.collect.testing.Helpers;
  import com.google.common.collect.testing.features.CollectionFeature;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.collect.testing.features.ListFeature;
  
  import java.lang.reflect.Method;
  
  /**
   * A generic JUnit test which tests {@code set()} operations on a list. Can't be
   * invoked directly; please see
   * {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
   *
   * @author George van den Driessche
   */
  @GwtCompatible(emulated = true)
  public class ListSetTester<E> extends AbstractListTester<E> {
    @ListFeature.Require(SUPPORTS_SET)
    @CollectionSize.Require(absent = ZERO)
    public void testSet() {
      doTestSet(samples.e3);
    }
  
    @CollectionSize.Require(absent = ZERO)
    @CollectionFeature.Require(ALLOWS_NULL_VALUES)
    @ListFeature.Require(SUPPORTS_SET)
    public void testSet_null() {
      doTestSet(null);
    }
  
    @CollectionSize.Require(absent = ZERO)
    @CollectionFeature.Require(ALLOWS_NULL_VALUES)
    @ListFeature.Require(SUPPORTS_SET)
    public void testSet_replacingNull() {
      E[] elements = createSamplesArray();
      int i = aValidIndex();
      elements[i] = null;
      collection = getSubjectGenerator().create(elements);
  
      doTestSet(samples.e3);
    }
  
    private void doTestSet(E newValue) {
      int index = aValidIndex();
      E initialValue = getList().get(index);
      assertEquals("set(i, x) should return the old element at position i.",
          initialValue, getList().set(index, newValue));
      assertEquals("After set(i, x), get(i) should return x",
          newValue, getList().get(index));
      assertEquals("set() should not change the size of a list.",
          getNumElements(), getList().size());
    }
  
    @ListFeature.Require(SUPPORTS_SET)
    public void testSet_indexTooLow() {
      try {
        getList().set(-1, samples.e3);
        fail("set(-1) should throw IndexOutOfBoundsException");
      } catch (IndexOutOfBoundsException expected) {
      }
      expectUnchanged();
    }
  
    @ListFeature.Require(SUPPORTS_SET)
    public void testSet_indexTooHigh() {
      int index = getNumElements();
      try {
        getList().set(index, samples.e3);
        fail("set(size) should throw IndexOutOfBoundsException");
      } catch (IndexOutOfBoundsException expected) {
      }
      expectUnchanged();
    }
  
    @CollectionSize.Require(absent = ZERO)
    @ListFeature.Require(absent = SUPPORTS_SET)
   public void testSet_unsupported() {
     try {
       getList().set(aValidIndex(), samples.e3);
       fail("set() should throw UnsupportedOperationException");
     } catch (UnsupportedOperationException expected) {
     }
     expectUnchanged();
   }
 
   @CollectionSize.Require(ZERO)
   @ListFeature.Require(absent = SUPPORTS_SET)
   public void testSet_unsupportedByEmptyList() {
     try {
       getList().set(0, samples.e3);
       fail("set() should throw UnsupportedOperationException "
           + "or IndexOutOfBoundsException");
     } catch (UnsupportedOperationException tolerated) {
     } catch (IndexOutOfBoundsException tolerated) {
     }
     expectUnchanged();
   }
 
   @CollectionSize.Require(absent = ZERO)
   @ListFeature.Require(SUPPORTS_SET)
   @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
   public void testSet_nullUnsupported() {
     try {
       getList().set(aValidIndex(), null);
       fail("set(null) should throw NullPointerException");
     } catch (NullPointerException expected) {
     }
     expectUnchanged();
   }
 
   private int aValidIndex() {
     return getList().size() / 2;
   }
 
   /**
    * Returns the {@link java.lang.reflect.Method} instance for
    * {@link #testSet_null()} so that tests of {@link
    * java.util.Collections#checkedCollection(java.util.Collection, Class)} can
    * suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()}
    * until <a
    * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug
    * 6409434</a> is fixed. It's unclear whether nulls were to be permitted or
    * forbidden, but presumably the eventual fix will be to permit them, as it
    * seems more likely that code would depend on that behavior than on the
    * other. Thus, we say the bug is in set(), which fails to support null.
    */
   @GwtIncompatible("reflection")
   public static Method getSetNullSupportedMethod() {
     return Helpers.getMethod(ListSetTester.class, "testSet_null");
   }
 }