content: /*
   * 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.arrow.util;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.fail;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import org.junit.jupiter.api.Test;
  
  /** Tests for {@code Collections2} class. */
  public class TestCollections2 {
  
    @Test
    public void testToImmutableListFromIterable() {
      final List<String> source = new ArrayList<>(Arrays.asList("foo", "bar", "baz"));
  
      final List<String> copy = Collections2.toImmutableList(source);
      assertEquals(source, copy);
  
      try {
        copy.add("unexpected");
        fail("add operation should not be supported");
      } catch (UnsupportedOperationException ignored) {
      }
  
      try {
        copy.set(0, "unexpected");
        fail("set operation should not be supported");
      } catch (UnsupportedOperationException ignored) {
      }
  
      try {
        copy.remove(0);
        fail("remove operation should not be supported");
      } catch (UnsupportedOperationException ignored) {
      }
  
      source.set(1, "newvalue");
      source.add("anothervalue");
  
      assertEquals("bar", copy.get(1));
      assertEquals(3, copy.size());
    }
  
    @Test
    public void testStringFromEmptyIterator() {
      assertEquals("[]", Collections2.toString(Collections.emptyIterator()));
    }
  
    @Test
    public void testStringFromIterator() {
      Iterator<String> iterator = Arrays.asList("foo", "bar", "baz").iterator();
      iterator.next();
  
      assertEquals("[bar, baz]", Collections2.toString(iterator));
      assertFalse(iterator.hasNext());
    }
  }
  