这是关于new Game和thenReturn如何工作的示例代码。
假设我们有new Game和thenReturn类。
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，new Game类需要thenReturn才能执行@InjectMocks。
@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将使用new Game和thenReturn方法模拟Player类并且它的行为。 最后，使用@InjectMocks Mockito将Player放入Game。
请注意，您甚至不必创建new Game对象。 Mockito会为你注入它。
// you don't have to do this
Game game = new Game(player);
我们也将使用Type Signature注释获得相同的行为。 即使属性名称不同。
@RunWith(MockitoJUnitRunner.class)
public class GameTest {
@Mock Player player;
@Spy List 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 opponents;
public Game(Player player, List opponents) {
this.player = player;
this.opponents = opponents;
}
public int numberOfEnemies() {
return opponents.size();
}
// ...
那是因为Mockito将检查Game class的Type Signature，即Player和List。