@Mock和@InjectMocks的区别

@Mock创建一个模拟。 创建类的实例，并将使用 （or ） 注释创建的模拟注入到此实例中。@InjectMocks@Mock@Spy

注意：您必须使用 或 来初始化这些模拟并注入它们 （JUnit 4）。@RunWith(MockitoJUnitRunner.class)Mockito.initMocks(this)

对于 JUnit 5，必须使用 .@ExtendWith(MockitoExtension.class)

@RunWith(MockitoJUnitRunner.class) // JUnit 4
// @ExtendWith(MockitoExtension.class) for JUnit 5
public class SomeManagerTest {

    @InjectMocks
    private SomeManager someManager;

    @Mock
    private SomeDependency someDependency; // this will be injected into someManager
 
     // tests...

}

这是一个关于如何工作的示例代码。@Mock@InjectMocks

说我们有和阶级。GamePlayer

class Game {

    private Player player;

    public Game(Player player) {
        this.player = player;
    }

    public String attack() {
        return "Player attack with: " + player.getWeapon();
    }

}

class Player {

    private String weapon;

    public Player(String weapon) {
        this.weapon = weapon;
    }

    String getWeapon() {
        return weapon;
    }
}

如您所见，类需要执行 .GamePlayerattack

@RunWith(MockitoJUnitRunner.class)
class GameTest {

    @Mock
    Player player;

    @InjectMocks
    Game game;

    @Test
    public void attackWithSwordTest() throws Exception {
        Mockito.when(player.getWeapon()).thenReturn("Sword");

        assertEquals("Player attack with: Sword", game.attack());
    }

}

Mockito将模拟玩家类及其行为使用和方法。最后，使用Mockito会将其放入.whenthenReturn@InjectMocksPlayerGame

请注意，您甚至不必创建对象。Mockito会为你注射它。new Game

// you don't have to do this
Game game = new Game(player);

我们还将使用注释获得相同的行为。即使属性名称不同。@Spy

@RunWith(MockitoJUnitRunner.class)
public class GameTest {

  @Mock Player player;

  @Spy List<String> enemies = new ArrayList<>();

  @InjectMocks Game game;

  @Test public void attackWithSwordTest() throws Exception {
    Mockito.when(player.getWeapon()).thenReturn("Sword");

    enemies.add("Dragon");
    enemies.add("Orc");

    assertEquals(2, game.numberOfEnemies());

    assertEquals("Player attack with: Sword", game.attack());
  }
}

class Game {

  private Player player;

  private List<String> opponents;

  public Game(Player player, List<String> opponents) {
    this.player = player;
    this.opponents = opponents;
  }

  public int numberOfEnemies() {
    return opponents.size();
  }

  // ...

这是因为 Mockito 将检查 Game 类，即 和 。Type SignaturePlayerList<String>