NegateTests.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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/*
 * @test
 * @bug 6325535
 * @summary Test for the rounding behavior of negate(MathContext)
 * @author Joseph D. Darcy
 */

import java.math.*;

public class NegateTests {

    static BigDecimal negateThenRound(BigDecimal bd, MathContext mc) {
        return bd.negate().plus(mc);
    }


    static BigDecimal absThenRound(BigDecimal bd, MathContext mc) {
        return bd.abs().plus(mc);
    }


    static int negateTest(BigDecimal[][] testCases,  MathContext mc) {
        int failures = 0;

        for (BigDecimal [] testCase : testCases) {

            BigDecimal bd = testCase[0];
            BigDecimal neg1 = bd.negate(mc);
            BigDecimal neg2 = negateThenRound(bd, mc);
            BigDecimal expected = testCase[1];

            if (! neg1.equals(expected) ) {
                failures++;
                System.err.println("(" + bd + ").negate(" + mc + ") => " +
                                   neg1 + " != expected " + expected);
            }

            if (! neg1.equals(neg2) ) {
                failures++;
                System.err.println("(" + bd + ").negate(" + mc + ")  => " +
                                   neg1 + " != ntr " + neg2);
            }

            // Test abs consistency
            BigDecimal abs = bd.abs(mc);
            BigDecimal expectedAbs = absThenRound(bd,mc);
            if (! abs.equals(expectedAbs) ) {
                failures++;
                System.err.println("(" + bd + ").abs(" + mc + ")  => " +
                                   abs + " != atr " +  expectedAbs);
            }

        }

        return failures;
    }

    static int negateTests() {
        int failures = 0;
        BigDecimal [][] testCasesCeiling = {
            {new BigDecimal("1.3"),     new BigDecimal("-1")},
            {new BigDecimal("-1.3"),    new BigDecimal("2")},
        };

        failures += negateTest(testCasesCeiling,
                               new MathContext(1, RoundingMode.CEILING));

        BigDecimal [][] testCasesFloor = {
            {new BigDecimal("1.3"),     new BigDecimal("-2")},
            {new BigDecimal("-1.3"),    new BigDecimal("1")},
        };

        failures += negateTest(testCasesFloor,
                               new MathContext(1, RoundingMode.FLOOR));

        return failures;
    }

    public static void main(String argv[]) {
        int failures = 0;

        failures += negateTests();

        if (failures > 0 )
            throw new RuntimeException("Incurred " + failures + " failures" +
                                       " testing the negate and/or abs.");
    }
}