Add unit tests for ArrayUtils safeMultiply methods

These were migrated from SCIFIO, just like the methods they are testing.

Author: ctrueden

src/test/java/org/scijava/util/ArrayUtilsTest.java

@@ -0,0 +1,150 @@
+/*
+ * #%L
+ * SCIFIO library for reading and converting scientific file formats.
+ * %%
+ * Copyright (C) 2011 - 2014 Board of Regents of the University of
+ * Wisconsin-Madison
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.util;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import org.junit.Test;
+
+/** Unit tests for {@link ArrayUtils}. */
+public class ArrayUtilsTest {
+
+	@Test
+	public void testSafeMultiply32() {
+		// test vacuous edge cases
+		boolean ok = false;
+		try {
+			ArrayUtils.safeMultiply32(null);
+		}
+		catch (final NullPointerException e) {
+			ok = true;
+		}
+		if (!ok) fail("Expected NullPointerException");
+		assertSafeMultiply32Pass(0);
+
+		// test simple cases
+		assertSafeMultiply32Pass(1, 1);
+		assertSafeMultiply32Pass(54, 9, 6);
+		assertSafeMultiply32Pass(1037836800, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
+
+		// test invalid arguments
+		assertSafeMultiply32Fail("Invalid array size: -1", -1);
+		assertSafeMultiply32Fail("Invalid array size: 0", 0);
+
+		// test edge cases near Integer.MAX_VALUE
+		assertSafeMultiply32Pass(2147483646, Integer.MAX_VALUE / 2, 2);
+		assertSafeMultiply32Fail("Array size too large: 1073741824 x 2",
+			Integer.MAX_VALUE / 2 + 1, 2);
+		assertSafeMultiply32Pass(2147441940, 46340, 46341);
+		assertSafeMultiply32Fail("Array size too large: 46341 x 46341", 46341,
+			46341);
+		assertSafeMultiply32Fail("Array size too large: 46340 x 46342", 46340,
+			46342);
+		assertSafeMultiply32Pass(2147418112, 65536, 32767);
+		assertSafeMultiply32Pass(2147450880, 65535, 32768);
+		assertSafeMultiply32Fail("Array size too large: 65536 x 32768", 65536,
+			32768);
+	}
+
+	@Test
+	public void testSafeMultiply64() {
+		// test vacuous edge cases
+		boolean ok = false;
+		try {
+			ArrayUtils.safeMultiply64(null);
+		}
+		catch (final NullPointerException e) {
+			ok = true;
+		}
+		if (!ok) fail("Expected NullPointerException");
+		assertSafeMultiply64Pass(0);
+
+		// test simple cases
+		assertSafeMultiply64Pass(1, 1);
+		assertSafeMultiply64Pass(54, 9, 6);
+		assertSafeMultiply64Pass(3632428800L, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14);
+
+		// test invalid arguments
+		assertSafeMultiply64Fail("Invalid array size: -1", -1);
+		assertSafeMultiply64Fail("Invalid array size: 0", 0);
+
+		// test edge cases near Long.MAX_VALUE
+		assertSafeMultiply64Pass(9223372036854775806L, Long.MAX_VALUE / 6, 2, 3);
+		assertSafeMultiply64Fail(
+			"Array size too large: 1537228672809129302 x 2 x 3",
+			Long.MAX_VALUE / 6 + 1, 2, 3);
+		assertSafeMultiply64Pass(9223372033963249500L, 3037000499L, 3037000500L);
+		assertSafeMultiply64Fail("Array size too large: 3037000500 x 3037000500",
+			3037000500L, 3037000500L);
+		assertSafeMultiply64Fail("Array size too large: 3037000499 x 3037000501",
+			3037000499L, 3037000501L);
+	}
+
+	// -- Helper methods --
+
+	private void
+		assertSafeMultiply32Pass(final int expected, final long... sizes)
+	{
+		assertEquals(expected, ArrayUtils.safeMultiply32(sizes));
+	}
+
+	private void assertSafeMultiply32Fail(final String msg, final long... sizes) {
+		int actual;
+		try {
+			actual = ArrayUtils.safeMultiply32(sizes);
+		}
+		catch (final IllegalArgumentException e) {
+			assertEquals(e.getMessage(), msg);
+			return;
+		}
+		fail("Safe multiply succeeded with value: " + actual);
+	}
+
+	private void assertSafeMultiply64Pass(final long expected,
+		final long... sizes)
+	{
+		assertEquals(expected, ArrayUtils.safeMultiply64(sizes));
+	}
+
+	private void assertSafeMultiply64Fail(final String msg, final long... sizes) {
+		long actual;
+		try {
+			actual = ArrayUtils.safeMultiply64(sizes);
+		}
+		catch (final IllegalArgumentException e) {
+			assertEquals(e.getMessage(), msg);
+			return;
+		}
+		fail("Safe multiply succeeded with value: " + actual);
+	}
+
+}