A Generic API Unit Test

TestMyObjectApi.java

/**
 * Name: MyObject
 * Date: 
 * Description: Tests used to create an empty API for an immutable type MyObject
 * using test driven design (TDD).
 *
 * API Specification:
 *
 * public class MyObject {
 *    public MyObject(Object[] objects)   // a general constructor description
 *    public           int someMethod()   // what someMethod does
 *    public int[] someOtherMethod()      // what someOtherMethod does
 * }
 * 
 * Corner Cases
 *   - Throw a java.lang.IllegalArgumentException if any argument is null.
 */
@DisplayName("MyObject Api")
class TestMyObjectApi {

    @DisplayName("Verify methods")
    @Test
    void should_verify_api_methods() {
        List<String> expected = expectedMethodNames();
        List<String> actual = actualMethodNames();
        assertEquals(expected, actual);
    }

    List<String> expectedMethodNames() {
        List<String> names = Arrays.asList("someMethod", "someOtherMethod");
        Collections.sort(names);
        return names;
    }

    List<String> actualMethodNames() {
        return Spy.publicMethodNames(MyObject.class)
                  .stream()
                  .filter(s -> !s.equals("main"))
                  .sorted()
                  .collect(Collectors.toList());
    }
}