1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.math;
18
19import static com.google.common.math.MathTesting.ALL_BIGINTEGER_CANDIDATES;
20import static com.google.common.math.MathTesting.FINITE_DOUBLE_CANDIDATES;
21import static com.google.common.math.MathTesting.POSITIVE_FINITE_DOUBLE_CANDIDATES;
22
23import junit.framework.TestCase;
24
25import sun.misc.FpUtils;
26
27import java.math.BigInteger;
28
29/**
30 * Tests for {@link DoubleUtils}.
31 *
32 * @author Louis Wasserman
33 */
34public class DoubleUtilsTest extends TestCase {
35  public void testNextDown() {
36    for (double d : FINITE_DOUBLE_CANDIDATES) {
37      assertEquals(FpUtils.nextDown(d), DoubleUtils.nextDown(d));
38    }
39  }
40
41  public void testBigToDouble() {
42    for (BigInteger b : ALL_BIGINTEGER_CANDIDATES) {
43      assertEquals(b.doubleValue(), DoubleUtils.bigToDouble(b));
44    }
45  }
46
47  public void testEnsureNonNegative() {
48    assertEquals(0.0, DoubleUtils.ensureNonNegative(0.0));
49    for (double positiveValue : POSITIVE_FINITE_DOUBLE_CANDIDATES) {
50      assertEquals(positiveValue, DoubleUtils.ensureNonNegative(positiveValue));
51      assertEquals(0.0, DoubleUtils.ensureNonNegative(-positiveValue));
52    }
53    assertEquals(Double.POSITIVE_INFINITY, DoubleUtils.ensureNonNegative(Double.POSITIVE_INFINITY));
54    assertEquals(0.0, DoubleUtils.ensureNonNegative(Double.NEGATIVE_INFINITY));
55    try {
56      DoubleUtils.ensureNonNegative(Double.NaN);
57      fail("Expected IllegalArgumentException from ensureNonNegative(Double.NaN)");
58    } catch (IllegalArgumentException expected) {
59    }
60  }
61}
62