core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ArrayUtilTest.java

/*******************************************************************************
 * Copyright (c) 2006, 2015 Wind River Systems, Inc. and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Markus Schorn - initial API and implementation
 *     Sergey Prigogin (Google)
 *******************************************************************************/
package org.eclipse.cdt.core.parser.tests;

import org.eclipse.cdt.core.parser.util.ArrayUtil;

import junit.framework.TestCase;

public class ArrayUtilTest extends TestCase {
	private final Object o1 = new Object();
	private final Object o2 = new Object();
	private final Object o3 = new Object();
	private final Object o4 = new Object();

	public void testAppend() {
		Object[] array = null;
		array = ArrayUtil.append(array, o1);
		array = ArrayUtil.append(array, o2);
		array = ArrayUtil.append(array, o3);
		assertEquals(o1, array[0]);
		assertEquals(o2, array[1]);
		assertEquals(o3, array[2]);

		array = ArrayUtil.appendAt(Object.class, null, 0, o1);
		array = ArrayUtil.appendAt(Object.class, array, 1, o2);
		array = ArrayUtil.appendAt(Object.class, array, 2, o3);
		assertEquals(o1, array[0]);
		assertEquals(o2, array[1]);
		assertEquals(o3, array[2]);
	}

	public void testPrepend() {
		Object[] array = null;
		array = ArrayUtil.prepend(Object.class, array, o1);
		array = ArrayUtil.prepend(Object.class, array, o2);
		array = ArrayUtil.prepend(Object.class, array, o3);
		assertEquals(o3, array[0]);
		assertEquals(o2, array[1]);
		assertEquals(o1, array[2]);
	}

	public void testTrim() {
		Object[] array = new Object[] { null, null };
		array = ArrayUtil.trim(Object.class, array);
		assertEquals(0, array.length);

		array = new Object[] { o1, null };
		array = ArrayUtil.trim(Object.class, array);
		assertEquals(1, array.length);
		assertEquals(o1, array[0]);

		array = new Object[] { o1, o2 };
		Object[] array2 = ArrayUtil.trim(Object.class, array);
		assertEquals(2, array2.length);
		assertSame(o1, array2[0]);
		assertSame(o2, array2[1]);
		assertSame(array, array2);

		array = new Object[] { null, null };
		array = ArrayUtil.trim(Object.class, array, true);
		assertEquals(0, array.length);

		array = new Object[] { o1, null };
		array = ArrayUtil.trim(Object.class, array, true);
		assertEquals(1, array.length);
		assertEquals(o1, array[0]);

		array = new Object[] { o1, o2 };
		array2 = ArrayUtil.trim(Object.class, array, true);
		assertEquals(2, array2.length);
		assertSame(o1, array2[0]);
		assertSame(o2, array2[1]);
		assertNotSame(array, array2);
	}

	public void testAddAll() {
		Object[] array1 = { o1, o2, null };
		Object[] array2 = { o3, null };
		Object[] result;

		result = ArrayUtil.addAll(Object.class, array2, array1);
		assertEquals(o3, result[0]);
		assertEquals(o1, result[1]);
		assertEquals(o2, result[2]);

		result = ArrayUtil.addAll(Object.class, array1, array2);
		assertEquals(o1, result[0]);
		assertEquals(o2, result[1]);
		assertEquals(o3, result[2]);
		assertSame(array1, result);

		array1 = new Object[] { o1, o2 };
		array2 = new Object[] { o3, null };

		result = ArrayUtil.addAll(Object.class, array2, array1);
		assertEquals(o3, result[0]);
		assertEquals(o1, result[1]);
		assertEquals(o2, result[2]);

		result = ArrayUtil.addAll(Object.class, array1, array2);
		assertEquals(o1, result[0]);
		assertEquals(o2, result[1]);
		assertEquals(o3, result[2]);

		array1 = new Object[] { o1, o2 };
		array2 = new Object[] { o3 };

		result = ArrayUtil.addAll(Object.class, array2, array1);
		assertEquals(o3, result[0]);
		assertEquals(o1, result[1]);
		assertEquals(o2, result[2]);

		result = ArrayUtil.addAll(Object.class, array1, array2);
		assertEquals(o1, result[0]);
		assertEquals(o2, result[1]);
		assertEquals(o3, result[2]);

		array1 = new Object[] { o1, o2 };
		array2 = new Object[] {};
		result = ArrayUtil.addAll(Object.class, array2, array1);
		assertEquals(o1, result[0]);
		assertEquals(o2, result[1]);
		assertNotSame(array1, result);

		result = ArrayUtil.addAll(Object.class, array1, array2);
		assertEquals(o1, result[0]);
		assertEquals(o2, result[1]);
		assertSame(array1, result);

		// Check that mismatched array types don't cause an ArrayStoreException.
		// See http://bugs.eclipse.org/481274
		array1 = new Integer[] { 1, 2 };
		array2 = new String[] { "s" };
		result = ArrayUtil.addAll(Object.class, array1, array2);
		assertEquals(3, result.length);
		assertEquals(1, result[0]);
		assertEquals(2, result[1]);
		assertEquals("s", result[2]);
	}

	public void testRemove() {
		Object[] array = new Object[] { o1, o2, o3, o4, null };
		ArrayUtil.remove(array, o3);
		assertSame(o1, array[0]);
		assertSame(o2, array[1]);
		assertSame(o4, array[2]);
		assertNull(array[3]);

		ArrayUtil.remove(array, o1);
		assertSame(o2, array[0]);
		assertSame(o4, array[1]);
		assertNull(array[2]);

		ArrayUtil.remove(array, o4);
		assertSame(o2, array[0]);
		assertNull(array[1]);

		ArrayUtil.remove(array, o2);
		assertNull(array[0]);

		array = new Object[] { o1, o2, o3, o4 };
		ArrayUtil.remove(array, o3);
		assertSame(o1, array[0]);
		assertSame(o2, array[1]);
		assertSame(o4, array[2]);
		assertNull(array[3]);

		ArrayUtil.remove(array, o1);
		assertSame(o2, array[0]);
		assertSame(o4, array[1]);
		assertNull(array[2]);

		ArrayUtil.remove(array, o4);
		assertSame(o2, array[0]);
		assertNull(array[1]);

		ArrayUtil.remove(array, o2);
		assertNull(array[0]);
	}

	public void testRemoveNulls() {
		Object[] array = new Object[0];
		Object[] result;

		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(0, result.length);
		assertSame(result, array);

		array = new Object[] { null };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(0, result.length);

		array = new Object[] { o1 };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(1, result.length);
		assertSame(result[0], o1);
		assertSame(result, array);

		array = new Object[] { o1, null };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(1, result.length);
		assertSame(result[0], o1);

		array = new Object[] { null, o1 };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(1, result.length);
		assertSame(result[0], o1);

		array = new Object[] { o1, o2 };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(2, result.length);
		assertSame(result[0], o1);
		assertSame(result[1], o2);
		assertSame(result, array);

		array = new Object[] { null, o1, o2 };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(2, result.length);
		assertSame(result[0], o1);
		assertSame(result[1], o2);

		array = new Object[] { o1, null, o2 };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(2, result.length);
		assertSame(result[0], o1);
		assertSame(result[1], o2);

		array = new Object[] { o1, o2, null };
		result = ArrayUtil.removeNulls(Object.class, array);
		assertEquals(2, result.length);
		assertSame(result[0], o1);
		assertSame(result[1], o2);
	}

	public void testRemoveDuplicates() {
		String[] array = { "1", "2", null, "3", "2", "1", "4", "3" };
		String[] result = ArrayUtil.removeDuplicates(array);
		assertEquals(4, result.length);
		assertEquals("1", result[0]);
		assertEquals("2", result[1]);
		assertEquals("3", result[2]);
		assertEquals("4", result[3]);

		// Test a long array.
		array = new String[100];
		for (int i = 0; i < array.length; i++) {
			array[i] = (i + 1) % 11 == 0 ? null : String.valueOf(i % 17);
		}
		result = ArrayUtil.removeDuplicates(array);
		assertEquals(17, result.length);
		for (int i = 0; i < result.length - 1; i++) {
			assertEquals(String.valueOf(i < 10 ? i : i < 16 ? i + 1 : 10), result[i]);
		}
	}
}