| // Copyright 2020 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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 com.google.devtools.build.android.desugar.runtime; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.assertFalse; |
| |
| import java.util.Random; |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| import org.junit.runners.JUnit4; |
| |
| /** Tests for {@link UnsignedInts}. */ |
| @RunWith(JUnit4.class) |
| public class UnsignedIntsTest { |
| private static final long[] UNSIGNED_INTS = { |
| 0L, |
| 1L, |
| 2L, |
| 3L, |
| 0x12345678L, |
| 0x5a4316b8L, |
| 0x6cf78a4bL, |
| 0xff1a618bL, |
| 0xfffffffdL, |
| 0xfffffffeL, |
| 0xffffffffL |
| }; |
| |
| @Test |
| public void testToLong() { |
| for (long a : UNSIGNED_INTS) { |
| assertEquals(a, UnsignedInts.toLong((int) a)); |
| } |
| } |
| |
| @Test |
| public void testCompare() { |
| for (long a : UNSIGNED_INTS) { |
| for (long b : UNSIGNED_INTS) { |
| int cmpAsLongs = Long.compare(a, b); |
| int cmpAsUInt = UnsignedInts.compare((int) a, (int) b); |
| assertEquals(Integer.signum(cmpAsLongs), Integer.signum(cmpAsUInt)); |
| } |
| } |
| } |
| |
| @Test |
| public void testDivide() { |
| for (long a : UNSIGNED_INTS) { |
| for (long b : UNSIGNED_INTS) { |
| try { |
| assertEquals((int) (a / b), UnsignedInts.divide((int) a, (int) b)); |
| assertFalse(b == 0); |
| } catch (ArithmeticException e) { |
| assertEquals(0, b); |
| } |
| } |
| } |
| } |
| |
| @Test |
| public void testRemainder() { |
| for (long a : UNSIGNED_INTS) { |
| for (long b : UNSIGNED_INTS) { |
| try { |
| assertEquals((int) (a % b), UnsignedInts.remainder((int) a, (int) b)); |
| assertFalse(b == 0); |
| } catch (ArithmeticException e) { |
| assertEquals(0, b); |
| } |
| } |
| } |
| } |
| |
| @Test |
| public void testDivideRemainderEuclideanProperty() { |
| // Use a seed so that the test is deterministic: |
| Random r = new Random(0L); |
| for (int i = 0; i < 1000000; i++) { |
| int dividend = r.nextInt(); |
| int divisor = r.nextInt(); |
| // Test that the Euclidean property is preserved: |
| assertEquals( |
| 0, |
| dividend |
| - (divisor * UnsignedInts.divide(dividend, divisor) |
| + UnsignedInts.remainder(dividend, divisor))); |
| } |
| } |
| |
| @Test |
| public void testToString() { |
| int[] bases = {2, 5, 7, 8, 10, 16}; |
| for (long a : UNSIGNED_INTS) { |
| for (int base : bases) { |
| assertEquals(UnsignedInts.toString((int) a, base), Long.toString(a, base)); |
| } |
| } |
| } |
| } |