LevenshteinComparatorTest.java

package io.dropwizard.configuration;

import org.junit.Test;

import java.util.Arrays;

import static org.assertj.core.api.Assertions.assertThat;

public class LevenshteinComparatorTest {
    private final ConfigurationParsingException.Builder.LevenshteinComparator c = new ConfigurationParsingException.Builder.LevenshteinComparator("base");

    /**
     * An "java.lang.IllegalArgumentException: Comparison method violates its general contract!"
     * is triggered by this test with a previous version of LevenshteinComparator
     *
     * It is triggered by a certain condition in TimSort that only happens if 32 or more
     * values are in an array. As such, it may not be a thorough test... it depends on the
     * specifics of the environment / JVM.
     */
    @Test
    public void testLevenshteinComparatorSort() {
        // no assertions, just making sure we don't violate the compare contract
        Arrays.sort(new String[]{
            "y", "w", "y", "e",
            "s", "u", "h", "o",
            "d", "t", "d", "f",
            "z", "j", "c", "k",
            "f", "z", "o", "e",
            "r", "t", "v", "d",
            "l", "r", "w", "u",
            "v", "a", "m", "o"}, c);
    }

    @Test
    public void testLevenshteinCompare() {
        assertThat(c.compare("z", "v")).isEqualTo(0);
        assertThat(c.compare("b", "v")).isEqualTo(-1);
        assertThat(c.compare("v", "b")).isEqualTo(1);
    }

}