geode-core/src/test/java/org/apache/geode/internal/CopyOnWriteHashSetJUnitTest.java

/*
 * 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
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package org.apache.geode.internal;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.assertj.core.api.Assertions;
import org.junit.Test;


public class CopyOnWriteHashSetJUnitTest {

  @Test
  public void testSnapshot() {
    CopyOnWriteHashSet<String> set = new CopyOnWriteHashSet<String>();
    set.add("a");
    Set<String> snap = set.getSnapshot();
    Set<String> copy = new HashSet<String>(set);
    set.add("b");

    assertEquals(copy, snap);
  }

  @Test
  public void testIteratorRemove() {
    CopyOnWriteHashSet<String> startingCollection = new CopyOnWriteHashSet<String>();
    startingCollection.addAll(Arrays.asList("a", "b", "c", "d"));

    Iterator<String> iterator = startingCollection.iterator();
    while (iterator.hasNext()) {
      String element = iterator.next();

      if (element.equals("b")) {
        iterator.remove();
      }
    }

    assertEquals(3, startingCollection.size());

    Assertions.assertThat(startingCollection).containsExactly("a", "c", "d");
  }

  @Test
  public void testAllMethods() throws Exception {
    CopyOnWriteHashSet<String> set = new CopyOnWriteHashSet<String>();
    assertTrue(set.add("a"));
    assertFalse(set.add("a"));
    Iterator itr = set.iterator();
    assertTrue(itr.hasNext());
    assertEquals("a", itr.next());
    assertFalse(itr.hasNext());
    assertEquals(1, set.size());

    assertTrue(set.addAll(Arrays.asList(new String[] {"b", "c", "d"})));
    assertTrue(set.contains("b"));
    assertTrue(set.contains("c"));
    assertTrue(set.contains("d"));

    assertTrue(set.retainAll(Arrays.asList(new String[] {"a", "b", "c"})));
    assertFalse(set.retainAll(Arrays.asList(new String[] {"a", "b", "c"})));

    HashSet<String> test = new HashSet<String>();
    test.addAll(Arrays.asList(new String[] {"a", "b", "c"}));
    assertEquals(test, set);
    assertEquals(set, test);
    assertEquals(test.toString(), set.toString());
    assertEquals(Arrays.asList(test.toArray()), Arrays.asList(set.toArray()));
    assertEquals(Arrays.asList(test.toArray(new String[0])),
        Arrays.asList(set.toArray(new String[0])));

    assertTrue(set.containsAll(test));
    assertTrue(set.containsAll(test));

    set.remove("b");

    assertFalse(set.containsAll(test));

    set.clear();

    set.addAll(Arrays.asList(new String[] {"b", "c", "d"}));

    assertTrue(set.removeAll(Arrays.asList(new String[] {"b", "c"})));
    assertFalse(set.removeAll(Arrays.asList(new String[] {"b", "c"})));

    assertEquals(new HashSet(Arrays.asList(new String[] {"d"})), set);

    ByteArrayOutputStream boas = new ByteArrayOutputStream();
    ObjectOutputStream out = new ObjectOutputStream(boas);
    out.writeObject(set);
    ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(boas.toByteArray()));
    Set<String> result = (Set<String>) in.readObject();
    assertEquals(set, result);
    assertTrue(result instanceof CopyOnWriteHashSet);
  }

}