test/jdk/java/util/TimeZone/AvailableIDsTest.java

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/*
 * @test
 * @bug 8347955
 * @summary Ensure underlying element equality of available tz ID methods
 * @run junit AvailableIDsTest
 */

import org.junit.jupiter.api.Test;

import java.util.TimeZone;

import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

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

public class AvailableIDsTest {

    // Validate the equality of the array and stream of available IDs
    @Test
    public void streamEqualsArrayTest() {
        String[] tzs = TimeZone.getAvailableIDs();
        assertArrayEquals(tzs, TimeZone.availableIDs().toArray(String[]::new),
                "availableIDs() and getAvailableIDs() do not have the same elements");
    }

    // Validate the equality of the array and stream of available IDs
    // when passed an offset. Tests various offsets.
    @ParameterizedTest
    @ValueSource(ints = {21600000, 25200000, 28800000}) // 6:00, 7:00, 8:00
    public void streamEqualsArrayWithOffsetTest(int offset) {
        String[] tzs = TimeZone.getAvailableIDs(offset);
        assertArrayEquals(tzs, TimeZone.availableIDs(offset).toArray(String[]::new),
                "availableIDs(int) and getAvailableIDs(int) do not have the same elements");
    }
}