모의 객체(Mock)를 통해 Stub과 Spy 대체 - #71

- 모의 객체 생성,
- BDDMockito를 사용하여 Stub을 대체
- 모의 객체가 기대한 대로 불렸는지 검증
- Spy 대체

김정호/src/test/java/com/hou27/chap07/mock/EmailNotifier.java

@@ -0,0 +1,5 @@
+package com.hou27.chap07.mock;
+
+public interface EmailNotifier {
+  void sendRegisterEmail(String email);
+}

김정호/src/test/java/com/hou27/chap07/mock/UserRegister.java

@@ -0,0 +1,27 @@
+package com.hou27.chap07.mock;
+
+public class UserRegister {
+  private WeakPasswordChecker passwordChecker;
+  private UserRepository userRepository;
+  private EmailNotifier emailNotifier;
+
+  public UserRegister(WeakPasswordChecker passwordChecker,
+      EmailNotifier emailNotifier,
+      UserRepository userRepository) {
+    this.passwordChecker = passwordChecker;
+    this.emailNotifier = emailNotifier;
+    this.userRepository = userRepository;
+  }
+
+  public void register(String id, String pw, String email) {
+    if(passwordChecker.checkPasswordWeak(pw)) {
+      throw new WeakPasswordException();
+    }
+
+    User user = new User(id, pw, email);
+    userRepository.save(user);
+
+    emailNotifier.sendRegisterEmail(email);
+  }
+
+}

김정호/src/test/java/com/hou27/chap07/mock/UserRegisterMockTest.java

@@ -0,0 +1,64 @@
+package com.hou27.chap07.mock;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+public class UserRegisterMockTest {
+
+  private UserRegister userRegister;
+  private WeakPasswordChecker mockPasswordChecker
+      = Mockito.mock(WeakPasswordChecker.class);
+  private EmailNotifier mockEmailNotifier
+      = Mockito.mock(EmailNotifier.class);
+  private UserRepository fakeRepository
+      = new MemoryUserRepository();
+
+  @BeforeEach
+  void setUp() {
+    userRegister = new UserRegister(
+        mockPasswordChecker,
+        mockEmailNotifier,
+        fakeRepository
+    );
+  }
+
+  @Test
+  @DisplayName("약한 암호면 가입 실패")
+  void whenWeakPassword_thenFailRegister() {
+    BDDMockito.given(mockPasswordChecker.checkPasswordWeak("pw"))
+        .willReturn(true);
+
+    assertThrows(WeakPasswordException.class, () -> {
+      userRegister.register("id", "pw", "email");
+    });
+  }
+
+  @Test
+  @DisplayName("회원 가입 시 암호 검사 수행")
+  void whenRegister_thenCheckPassword() {
+    userRegister.register("id", "pw", "email");
+
+    BDDMockito.then(mockPasswordChecker)
+        .should()
+        .checkPasswordWeak("pw");
+  }
+
+  @Test
+  @DisplayName("가입 시 메일 전송")
+  void whenRegister_thenSendMail() {
+    userRegister.register("id", "pw", "[email protected]");
+
+    ArgumentCaptor<String> captor = ArgumentCaptor.forClass(String.class);
+    BDDMockito.then(mockEmailNotifier)
+        .should()
+        .sendRegisterEmail(captor.capture());
+
+    String realEmail = captor.getValue();
+    assertEquals("[email protected]", realEmail);
+  }
+}