FindFirstOccurrenceOfSubstringTest.java

import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class FindFirstOccurrenceOfSubstringTest {

    private int expected;
    private String string;
    private String substring;

    @Test
    public void findFirst1() {
        expected = 0;
        string = "abc";
        substring = "abc";

        test(expected, string, substring);
    }

    @Test
    public void findFirst2() {
        expected = 0;
        string = "abcabcabc";
        substring = "abc";

        test(expected, string, substring);
    }

    @Test
    public void findFirst3() {
        expected = 7;
        string = "aababcdabcdeabcdef";
        substring = "abcde";

        test(expected, string, substring);
    }

    @Test
    public void findFirst4() {
        expected = 12;
        string = "aababcdabcdeabcdef";
        substring = "abcdef";

        test(expected, string, substring);
    }

    private void test(int expected, String string, String substring) {
        assertEquals(expected, FindFirstOccurrenceOfSubstring.findFirst(string, substring));
    }

}