test/jdk/java/text/Format/NumberFormat/Bug4208135.java

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/*
 * @test
 * @summary Confirm that the decimal separator is shown when explicitly requested
 *          (or not shown if not requested). Tests against double, long, BigDecimal,
 *          and BigInteger with a combination of different patterns.
 * @bug 4208135
 * @run junit Bug4208135
 */

import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.DecimalFormat;
import java.util.Locale;
import java.util.stream.Stream;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class Bug4208135 {

    private static DecimalFormat df;
    // Save JVM default Locale
    private static final Locale savedLocale = Locale.getDefault();

    // Set JVM default locale to US
    @BeforeAll
    static void init() {
        Locale.setDefault(Locale.US);
    }

    // Restore JVM default locale
    @AfterAll
    static void tearDown() {
        Locale.setDefault(savedLocale);
    }

    // Confirm that decimal separator shown when formatting a number
    @ParameterizedTest
    @MethodSource("fractionalDigitsWithSeparatorProvider")
    public void fractionalDigitsWithSeparatorTest(Number num, String expected) {
        df = getDF("0.#E0", true);
        String actualFormatted = df.format(num);
        assertEquals(expected, actualFormatted, getErrMsg("0.#E0", true));
    }

    // Combination of numbers and a fractional exponent pattern with a separator
    private static Stream<Arguments> fractionalDigitsWithSeparatorProvider() {
        return Stream.of(
                Arguments.of(0.0, "0.E0"),
                Arguments.of(10.0, "1.E1"),
                Arguments.of(1000.0, "1.E3"),
                Arguments.of(0L, "0.E0"),
                Arguments.of(10L, "1.E1"),
                Arguments.of(1000L, "1.E3"),
                Arguments.of(new BigDecimal("0.0"), "0.E0"),
                Arguments.of(new BigDecimal("10.0"), "1.E1"),
                Arguments.of(new BigDecimal("1000.0"), "1.E3"),
                Arguments.of(new BigInteger("00"), "0.E0"),
                Arguments.of(new BigInteger("10"), "1.E1"),
                Arguments.of(new BigInteger("1000"), "1.E3")
        );
    }

    // Confirm that decimal separator not shown when formatting a number
    @ParameterizedTest
    @MethodSource("fractionalDigitsNoSeparatorProvider")
    public void fractionalDigitsNoSeparatorTest(Number num, String expected) {
        df = getDF("0.#E0", false);
        String actualFormatted = df.format(num);
        assertEquals(expected, actualFormatted, getErrMsg("0.#E0", false));
    }

    // Combination of numbers and a fractional exponent pattern with no separator
    private static Stream<Arguments> fractionalDigitsNoSeparatorProvider() {
        return Stream.of(
                Arguments.of(0.0, "0E0"),
                Arguments.of(10.0, "1E1"),
                Arguments.of(1000.0, "1E3"),
                Arguments.of(0L, "0E0"),
                Arguments.of(10L, "1E1"),
                Arguments.of(1000L, "1E3"),
                Arguments.of(new BigDecimal("0.0"), "0E0"),
                Arguments.of(new BigDecimal("10.0"), "1E1"),
                Arguments.of(new BigDecimal("1000.0"), "1E3"),
                Arguments.of(new BigInteger("00"), "0E0"),
                Arguments.of(new BigInteger("10"), "1E1"),
                Arguments.of(new BigInteger("1000"), "1E3")
        );
    }

    // Confirm that decimal separator shown when formatting a number
    @ParameterizedTest
    @MethodSource("noFractionalDigitsWithSeparatorProvider")
    public void noFractionalDigitsWithSeparatorTest(Number num, String expected) {
        df = getDF("0.###", true);
        String actualFormatted = df.format(num);
        assertEquals(expected, actualFormatted, getErrMsg("0.###", true));
    }

    // Combination of numbers and a non-fractional exponent pattern with a separator
    private static Stream<Arguments> noFractionalDigitsWithSeparatorProvider() {
        return Stream.of(
                Arguments.of(0.0, "0."),
                Arguments.of(10.0, "10."),
                Arguments.of(1000.0, "1000."),
                Arguments.of(0L, "0."),
                Arguments.of(10L, "10."),
                Arguments.of(1000L, "1000."),
                Arguments.of(new BigDecimal("0.0"), "0."),
                Arguments.of(new BigDecimal("10.0"), "10."),
                Arguments.of(new BigDecimal("1000.0"), "1000."),
                Arguments.of(new BigInteger("00"), "0."),
                Arguments.of(new BigInteger("10"), "10."),
                Arguments.of(new BigInteger("1000"), "1000.")
        );
    }

    // Confirm that decimal separator not shown when formatting a number
    @ParameterizedTest
    @MethodSource("noFractionalDigitsNoSeparatorProvider")
    public void noFractionalDigitsNoSeparatorTest(Number num, String expected) {
        df = getDF("0.###", false);
        String actualFormatted = df.format(num);
        assertEquals(expected, actualFormatted, getErrMsg("0.###", false));
    }

    // Combination of numbers and a non-fractional exponent pattern with no separator
    private static Stream<Arguments> noFractionalDigitsNoSeparatorProvider() {
        return Stream.of(
                Arguments.of(0.0, "0"),
                Arguments.of(10.0, "10"),
                Arguments.of(1000.0, "1000"),
                Arguments.of(0L, "0"),
                Arguments.of(10L, "10"),
                Arguments.of(1000L, "1000"),
                Arguments.of(new BigDecimal("0.0"), "0"),
                Arguments.of(new BigDecimal("10.0"), "10"),
                Arguments.of(new BigDecimal("1000.0"), "1000"),
                Arguments.of(new BigInteger("00"), "0"),
                Arguments.of(new BigInteger("10"), "10"),
                Arguments.of(new BigInteger("1000"), "1000")
        );
    }

    // Creates clean DF and sets the pattern and separatorShown value
    private static DecimalFormat getDF(String pattern, boolean separatorShown) {
        df = new DecimalFormat();
        df.applyPattern(pattern);
        df.setDecimalSeparatorAlwaysShown(separatorShown);
        return df;
    }

    // Utility to get a helpful error message when values are not as expected
    private static String getErrMsg(String pattern, boolean separatorShown) {
        return String.format("Fails with pattern= %s, with separatorShown = %s",
                pattern, separatorShown);
    }
}