java - JUnit - 针对不同实现的一项测试

Question

我在为我的程序编写测试时遇到了一点问题。我有一个 SortingAlgorithm 接口(interface)和一些实现，例如 BubbleSort、InsertionSort、QuickSort...

我不想为每个 SortingAlgorithms 实现都创建一个 TestCase。我想将每个算法类注入(inject)一个 TestCase，然后分别为每个算法运行 TestCase。

怎么做？

我的代码:

public class SortingAlorithmTest {

SortingAlgorithm sortingAlgorithm;
final int amount = 50000;
final int delayTime = 0;
int[] numbers;

public SortingAlorithmTest(SortingAlgorithm sortingAlgorithm){
    this.sortingAlgorithm = sortingAlgorithm;
}

@Before
public void setUp() throws Exception {
    Random random = new Random();
    numbers = new int[amount];

    for (int i = 0; i < amount; i++){
        numbers[i] = random.nextInt(Preferences.numberScope);
    }

    AlgorithmDelayer.setDelayTime(delayTime);
}

@Test(expected = NullPointerException.class)
public void passingNullValueTest(){
    sortingAlgorithm.sort(null);
}

@Test(timeout = 1000)
public void sortingSpeedTimeTest() {
    sortingAlgorithm.sort(numbers);
}

@Test
public void correctSortingTest(){
    sortingAlgorithm.sort(numbers);

    for (int i = 0; i < amount - 1; i++){
        assertTrue(numbers[i] <= numbers[i+1]);
    }
}

Answer 1

您可以使用 Parameterized测试:

@RunWith(Parameterized.class)
class MyTestClass {
  private final SortingAlgorithm algo;

  public MyTestClass(SortingAlgorithm algo) {
    this.algo = algo;
  }

  @Parameters 
  public static List<Object[]> getParameters() {
    List<Object[]> params = new ArrayList<>();
    // Build your list of parameters somehow.
    params.add(new Object[] { new BubbleSort() });
    params.add(new Object[] { new QuickSort() });
    // ...
    return params;
  }

  @Test
  public void test() {
    // Exercise your algorithm somehow.
  }
}