task_3.java

@RunWith(Parameterized.class)
public class CheckIsAdultTest {

    private final int age;
    private final boolean result;

    public CheckIsAdultTest(int age, boolean result) {
        this.age = age;
        this.result = result;
    }

    @Parameterized.Parameters
    public static Object[][] getTextData() {
        return new Object[][] {
                {18, true},
                {21, true},
                {17, false},
                {20, true},
        };
    }

    @Test
    public void checkIsAdultWhenAgeThenResult() {
        Program program = new Program();
        boolean isAdult = program.checkIsAdult(age);
        assertEquals("Пользователю не совершенолетный", result, isAdult);
    }
}