/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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 org.apache.commons.collections4;
  
  import static org.junit.jupiter.api.Assertions.assertInstanceOf;
  import static org.junit.jupiter.api.Assertions.assertSame;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import org.apache.commons.collections4.bag.HashBag;
  import org.apache.commons.collections4.bag.PredicatedBag;
  import org.apache.commons.collections4.bag.PredicatedSortedBag;
  import org.apache.commons.collections4.bag.SynchronizedBag;
  import org.apache.commons.collections4.bag.SynchronizedSortedBag;
  import org.apache.commons.collections4.bag.TransformedBag;
  import org.apache.commons.collections4.bag.TransformedSortedBag;
  import org.apache.commons.collections4.bag.TreeBag;
  import org.apache.commons.collections4.bag.UnmodifiableBag;
  import org.apache.commons.collections4.bag.UnmodifiableSortedBag;
  import org.apache.commons.collections4.functors.TruePredicate;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests for BagUtils factory methods.
   */
  public class BagUtilsTest {
  
      protected Predicate<Object> truePredicate = TruePredicate.truePredicate();
      protected Transformer<Object, Object> nopTransformer = TransformerUtils.nopTransformer();
  
      @Test
      public void testPredicatedBag() {
          final Bag<Object> bag = BagUtils.predicatedBag(new HashBag<>(), truePredicate);
          assertInstanceOf(PredicatedBag.class, bag, "Returned object should be a PredicatedBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.predicatedBag(null, truePredicate), "Expecting NullPointerException for null bag.");
          assertThrows(NullPointerException.class, () -> BagUtils.predicatedBag(new HashBag<>(), null), "Expecting NullPointerException for null predicate.");
      }
  
      @Test
      public void testPredicatedSortedBag() {
          final Bag<Object> bag = BagUtils.predicatedSortedBag(new TreeBag<>(), truePredicate);
          assertInstanceOf(PredicatedSortedBag.class, bag, "Returned object should be a PredicatedSortedBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.predicatedSortedBag(null, truePredicate), "Expecting NullPointerException for null bag.");
          assertThrows(NullPointerException.class, () -> BagUtils.predicatedSortedBag(new TreeBag<>(), null),
                  "Expecting NullPointerException for null predicate.");
      }
  
      @Test
      public void testSynchronizedBag() {
          final Bag<Object> bag = BagUtils.synchronizedBag(new HashBag<>());
          assertInstanceOf(SynchronizedBag.class, bag, "Returned object should be a SynchronizedBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.synchronizedBag(null), "Expecting NullPointerException for null bag.");
      }
  
      @Test
      public void testSynchronizedSortedBag() {
          final Bag<Object> bag = BagUtils.synchronizedSortedBag(new TreeBag<>());
          assertInstanceOf(SynchronizedSortedBag.class, bag, "Returned object should be a SynchronizedSortedBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.synchronizedSortedBag(null), "Expecting NullPointerException for null bag.");
      }
  
      @Test
      public void testTransformedBag() {
          final Bag<Object> bag = BagUtils.transformingBag(new HashBag<>(), nopTransformer);
          assertInstanceOf(TransformedBag.class, bag, "Returned object should be an TransformedBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.transformingBag(null, nopTransformer), "Expecting NullPointerException for null bag.");
          assertThrows(NullPointerException.class, () -> BagUtils.transformingBag(new HashBag<>(), null), "Expecting NullPointerException for null transformer.");
      }
  
      @Test
      public void testTransformedSortedBag() {
          final Bag<Object> bag = BagUtils.transformingSortedBag(new TreeBag<>(), nopTransformer);
          assertInstanceOf(TransformedSortedBag.class, bag, "Returned object should be an TransformedSortedBag");
          assertThrows(NullPointerException.class, () -> BagUtils.transformingSortedBag(null, nopTransformer), "Expecting NullPointerException for null bag.");
          assertThrows(NullPointerException.class, () -> BagUtils.transformingSortedBag(new TreeBag<>(), null),
                  "Expecting NullPointerException for null transformer.");
      }
  
      @Test
      public void testUnmodifiableBag() {
          final Bag<Object> bag = BagUtils.unmodifiableBag(new HashBag<>());
          assertInstanceOf(UnmodifiableBag.class, bag, "Returned object should be an UnmodifiableBag.");
          assertThrows(NullPointerException.class, () -> BagUtils.unmodifiableBag(null), "Expecting NullPointerException for null bag.");
          assertSame(bag, BagUtils.unmodifiableBag(bag), "UnmodifiableBag shall not be decorated");
      }
 
     @Test
     public void testUnmodifiableSortedBag() {
         final SortedBag<Object> bag = BagUtils.unmodifiableSortedBag(new TreeBag<>());
         assertInstanceOf(UnmodifiableSortedBag.class, bag, "Returned object should be an UnmodifiableSortedBag.");
         assertThrows(NullPointerException.class, () -> BagUtils.unmodifiableSortedBag(null), "Expecting NullPointerException for null bag.");
         assertSame(bag, BagUtils.unmodifiableSortedBag(bag), "UnmodifiableSortedBag shall not be decorated");
     }
 }