luni/src/test/java/libcore/java/math/BigIntegerTest.java

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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 libcore.java.math;

import java.math.BigInteger;

public class BigIntegerTest extends junit.framework.TestCase {
    // http://code.google.com/p/android/issues/detail?id=18452
    public void test_hashCode() {
        BigInteger firstBig  = new BigInteger("30003543667898318853");
        BigInteger secondBig = new BigInteger("3298535022597");
        BigInteger andedBigs = firstBig.and(secondBig);
        BigInteger toCompareBig = BigInteger.valueOf(andedBigs.longValue());
        assertEquals(andedBigs, toCompareBig);
        assertEquals(andedBigs.hashCode(), toCompareBig.hashCode());
    }

    // http://b/2981072 - off-by-one error in BigInteger.valueOf
    public void test_valueOf() {
        // I assume here that we'll never cache more than 1024 values.
        // (At the moment, we cache -1 to 10.)
        for (int i = -1024; i <= 1024; ++i) {
            assertEquals(i, BigInteger.valueOf(i).intValue());
        }
    }

    // http://code.google.com/p/android/issues/detail?id=7036
    public void test_invalidBigIntegerStringConversions() {
        // Check we don't disallow related reasonable strings...
        new BigInteger("1", 10);
        new BigInteger("1a", 16);
        new BigInteger("-1", 10);
        new BigInteger("-1a", 16);
        new BigInteger("\u0661", 10);
        new BigInteger("\u0661a", 16);
        new BigInteger("-\u0661", 10);
        new BigInteger("-\u0661a", 16);
        // This is allowed from Java 7 on.
        new BigInteger("+1");
        // Now check the invalid cases...
        try {
            new BigInteger("-a"); // no digits from other bases.
            fail();
        } catch (NumberFormatException expected) {
        }
        try {
            new BigInteger("-1a"); // no trailing digits from other bases.
            fail();
        } catch (NumberFormatException expected) {
        }
        try {
            new BigInteger("-1 hello"); // no trailing junk at all.
            fail();
        } catch (NumberFormatException expected) {
        }
        try {
            new BigInteger("--1"); // only one sign.
            fail();
        } catch (NumberFormatException expected) {
        }
        try {
            new BigInteger(""); // at least one digit.
            fail();
        } catch (NumberFormatException expected) {
        }
        try {
            new BigInteger("-"); // at least one digit, even after a sign.
            fail();
        } catch (NumberFormatException expected) {
        }
    }
}