test/jdk/java/math/BigDecimal/LongValueExactTests.java

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/**
 * @test
 * @bug 6806261 8211936 8305343
 * @summary Tests of BigDecimal.longValueExact
 */
import java.math.*;
import java.util.List;
import java.util.Map;
import static java.util.Map.entry;

public class LongValueExactTests {
    public static void main(String... args) {
        int failures = 0;

        failures += longValueExactSuccessful();
        failures += longValueExactExceptional();
        failures += longValueExactExceptional8305343();

        if (failures > 0) {
            throw new RuntimeException("Incurred " + failures +
                                       " failures while testing longValueExact.");
        }
    }

    private static long simpleLongValueExact(BigDecimal bd) {
        return bd.toBigIntegerExact().longValue();
    }

    private static int longValueExactSuccessful() {
        int failures = 0;

        // Strings used to create BigDecimal instances on which invoking
        // longValueExact() will succeed.
        Map<BigDecimal, Long> successCases =
            Map.ofEntries(entry(new BigDecimal("9223372036854775807"),    Long.MAX_VALUE), // 2^63 -1
                          entry(new BigDecimal("9223372036854775807.0"),  Long.MAX_VALUE),
                          entry(new BigDecimal("9223372036854775807.00"), Long.MAX_VALUE),

                          entry(new BigDecimal("-9223372036854775808"),   Long.MIN_VALUE), // -2^63
                          entry(new BigDecimal("-9223372036854775808.0"), Long.MIN_VALUE),
                          entry(new BigDecimal("-9223372036854775808.00"),Long.MIN_VALUE),

                          entry(new BigDecimal("1e0"),    1L),
                          entry(new BigDecimal(BigInteger.ONE, -18),   1_000_000_000_000_000_000L),

                          entry(new BigDecimal("0e13"),   0L), // Fast path zero
                          entry(new BigDecimal("0e64"),   0L),
                          entry(new BigDecimal("0e1024"), 0L),

                          entry(new BigDecimal("10.000000000000000000000000000000000"), 10L));

        for (var testCase : successCases.entrySet()) {
            BigDecimal bd = testCase.getKey();
            long expected = testCase.getValue();
            try {
                long longValueExact = bd.longValueExact();
                if (expected != longValueExact ||
                    longValueExact != simpleLongValueExact(bd)) {
                    failures++;
                    System.err.println("Unexpected longValueExact result " + longValueExact +
                                       " on " + bd);
                }
            } catch (Exception e) {
                failures++;
                System.err.println("Error on " + bd + "\tException message:" + e.getMessage());
            }
        }
        return failures;
    }

    private static int longValueExactExceptional() {
        int failures = 0;
        List<BigDecimal> exceptionalCases =
            List.of(new BigDecimal("9223372036854775808"), // Long.MAX_VALUE + 1
                    new BigDecimal("9223372036854775808.0"),
                    new BigDecimal("9223372036854775808.00"),
                    new BigDecimal("-9223372036854775809"), // Long.MIN_VALUE - 1
                    new BigDecimal("-9223372036854775808.1"),
                    new BigDecimal("-9223372036854775808.01"),

                    new BigDecimal("9999999999999999999"),
                    new BigDecimal("10000000000000000000"),

                    new BigDecimal("0.99"),
                    new BigDecimal("0.999999999999999999999"));

        for (BigDecimal bd : exceptionalCases) {
            try {
                long longValueExact = bd.longValueExact();
                failures++;
                System.err.println("Unexpected non-exceptional longValueExact on " + bd);
            } catch (ArithmeticException e) {
                // Success;
            }
        }
        return failures;
    }

    private static int longValueExactExceptional8305343() {
        int failures = 0;
        List<BigDecimal> exceptionalCases =
                List.of(new BigDecimal("1e" + (Integer.MAX_VALUE - 1)),
                        new BigDecimal("1e" + (Integer.MAX_VALUE))
                );

        for (BigDecimal bd : exceptionalCases) {
            try {
                bd.longValueExact();
                failures++;
                System.err.println("Unexpected non-exceptional longValueExact on " + bd);
            } catch (ArithmeticException e) {
                if (!e.getMessage().toLowerCase().contains("overflow")) {
                    failures++;
                    System.err.println("Unexpected non-exceptional longValueExact on " + bd);
                }
            }
        }
        return failures;
    }

}