Added new tests fixed some problem

pom.xml

@@ -105,6 +105,11 @@
             <artifactId>lombok</artifactId>
             <optional>true</optional>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa-test</artifactId>

src/main/java/auth_service/configuration/security/JwtService.java

@@ -1,5 +1,6 @@
 package auth_service.configuration.security;
 
+import auth_service.domain.login.service.TokenGenerator;
 import io.jsonwebtoken.Jwts;
 import io.jsonwebtoken.security.Keys;
 import org.springframework.stereotype.Service;
@@ -12,7 +13,7 @@ import java.util.Date;
  * Service responsible for generating and validating JSON Web Tokens (JWT).
  */
 @Service
-public class JwtService {
+public class JwtService implements TokenGenerator {
 
     // Token validity: 24 hours in milliseconds
     private static final long JWT_EXPIRATION_MS = 86400000;
@@ -24,10 +25,10 @@ public class JwtService {
 
     /**
      * Generates a secure JWT for the authenticated user.
-     * * @param user The authenticated user entity
      *
      * @return A signed JWT string
      */
+    @Override
     public String generateToken(String userId, String email) {
         return Jwts.builder()
                 .subject(email)

src/main/java/auth_service/domain/login/controller/LoginController.java

@@ -1,6 +1,5 @@
 package auth_service.domain.login.controller;
 
-import auth_service.configuration.security.JwtService;
 import auth_service.domain.login.controller.dto.request.LoginRequest;
 import auth_service.domain.login.controller.dto.response.LoginResponse;
 import auth_service.domain.login.controller.mapper.ApiMapper;
@@ -22,12 +21,11 @@ import org.springframework.web.bind.annotation.RestController;
 public class LoginController {
 
     private final LoginService loginService;
-    private final JwtService jwtService;
 
     /**
      * Authenticates a user based on email and password.
-     * * @param request The login credentials
      *
+     * @param request The login credentials
      * @return HTTP 200 on success, HTTP 401 on failure
      */
     @PostMapping("/login")
@@ -35,8 +33,7 @@ public class LoginController {
     public ResponseEntity<LoginResponse> login(@RequestBody LoginRequest request) {
 
         var user = ApiMapper.toModel(request);
-        var authenticatedUser = loginService.login(user);
-        var token = jwtService.generateToken(authenticatedUser.getId() + "", authenticatedUser.getEmail());
+        var token = loginService.login(user);
         return ResponseEntity.ok(new LoginResponse("Login successful", token));
     }
 }

src/main/java/auth_service/domain/login/controller/LoginExceptionController.java

@@ -1,6 +1,6 @@
 package auth_service.domain.login.controller;
 
-import auth_service.domain.login.controller.dto.response.ErrorResponse;
+import auth_service.shared.controller.dto.response.ErrorResponse;
 import auth_service.domain.login.exception.InvalidCredentialsException;
 import auth_service.domain.login.exception.UserNotFoundException;
 import lombok.NonNull;

src/main/java/auth_service/domain/login/controller/dto/response/ErrorResponse.java

@@ -1,4 +0,0 @@
-package auth_service.domain.login.controller.dto.response;
-
-public record ErrorResponse(String code, String message) {
-}

src/main/java/auth_service/domain/login/service/LoginService.java

@@ -15,19 +15,21 @@ import org.springframework.stereotype.Service;
 public class LoginService {
     private final MinimalUserRepository minimalUserRepository;
     private final PasswordEncoder passwordEncoder;
+    private final TokenGenerator tokenGenerator;
 
     /**
-     * Authenticates a user based on email and raw password.
+     * Authenticates a user and returns a token.
      *
-     * @return The authenticated User model
+     * @return The generated token
      */
-    public User login(User userToLogin) {
-        var foundUser = minimalUserRepository.findByEmail(userToLogin.getEmail()).orElseThrow(() -> new UserNotFoundException("User not found with given email"));
+    public String login(User userToLogin) {
+        var foundUser = minimalUserRepository.findByEmail(userToLogin.getEmail())
+                .orElseThrow(() -> new UserNotFoundException("User not found with given email"));
         var loginSuccessful = passwordEncoder.matches(userToLogin.getPassword(), foundUser.getPassword());
         if (!loginSuccessful) {
             throw new InvalidCredentialsException("Invalid credentials");
         }
         minimalUserRepository.updateLoginDate(foundUser.getId());
-        return foundUser;
+        return tokenGenerator.generateToken(String.valueOf(foundUser.getId()), foundUser.getEmail());
     }
 }

src/main/java/auth_service/domain/login/service/TokenGenerator.java

@@ -0,0 +1,16 @@
+package auth_service.domain.login.service;
+
+/**
+ * Port interface for token generation.
+ * Decouples the login service from specific token implementations (e.g. JWT).
+ */
+public interface TokenGenerator {
+    /**
+     * Generates a token for the given user.
+     *
+     * @param userId The unique identifier of the user.
+     * @param email  The email address of the user.
+     * @return The generated token string.
+     */
+    String generateToken(String userId, String email);
+}

src/main/java/auth_service/domain/registration/controller/RegistrationExceptionController.java

@@ -1,6 +1,6 @@
 package auth_service.domain.registration.controller;
 
-import auth_service.domain.registration.controller.dto.response.ErrorResponse;
+import auth_service.shared.controller.dto.response.ErrorResponse;
 import auth_service.domain.registration.exception.EmailAlreadyInUseException;
 import auth_service.domain.registration.exception.InvalidInvitationCodeException;
 import auth_service.domain.registration.exception.SteamIdAlreadyRegisteredException;

src/main/java/auth_service/domain/registration/controller/dto/response/ErrorResponse.java

@@ -1,4 +0,0 @@
-package auth_service.domain.registration.controller.dto.response;
-
-public record ErrorResponse(String code, String message) {
-}

src/main/java/auth_service/domain/registration/service/CodeValidationService.java

@@ -1,19 +1,19 @@
 package auth_service.domain.registration.service;
 
-import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
 @Service
-@RequiredArgsConstructor
 public class CodeValidationService {
 
-    private static final String RANDOM_INVITATION_CODE = "test-invite-code";
+    @Value("${auth.registration.invitation-code}")
+    private String invitationCode;
 
     public boolean isCodeValid(String code) {
         if (code == null || code.isEmpty()) {
             return false;
         }
 
-        return code.equals(RANDOM_INVITATION_CODE);
+        return code.equals(invitationCode);
     }
 }

src/main/java/auth_service/domain/user/controller/UserExceptionController.java

@@ -1,6 +1,6 @@
 package auth_service.domain.user.controller;
 
-import auth_service.domain.user.controller.dto.response.ErrorResponse;
+import auth_service.shared.controller.dto.response.ErrorResponse;
 import auth_service.domain.user.exception.UserNotFoundException;
 import lombok.NonNull;
 import lombok.extern.slf4j.Slf4j;

src/main/java/auth_service/domain/user/controller/dto/response/ErrorResponse.java

@@ -1,4 +0,0 @@
-package auth_service.domain.user.controller.dto.response;
-
-public record ErrorResponse(String code, String message) {
-}

src/main/java/auth_service/shared/controller/dto/response/ErrorResponse.java

@@ -0,0 +1,12 @@
+package auth_service.shared.controller.dto.response;
+
+import org.jspecify.annotations.NonNull;
+
+/**
+ * Shared error response record for all domains.
+ *
+ * @param code    A machine-readable error code.
+ * @param message A human-readable error message.
+ */
+public record ErrorResponse(@NonNull String code, @NonNull String message) {
+}

src/main/resources/application.yml

@@ -51,3 +51,8 @@ app:
   cors:
     # Production default: strictly allow only the frontend domain
     allowed-origins: "https://tbp.andreas-dahm.eu"
+
+# Registration settings
+auth:
+  registration:
+    invitation-code: ${AUTH_INVITATION_CODE}

src/test/java/auth_service/AuthServiceApplicationTests.java

@@ -1,25 +1,9 @@
 package auth_service;
 
+import auth_service.shared.test.AbstractIntegrationTest;
 import org.junit.jupiter.api.Test;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
-import org.testcontainers.containers.PostgreSQLContainer;
-import org.testcontainers.junit.jupiter.Container;
-import org.testcontainers.junit.jupiter.Testcontainers;
 
-@SpringBootTest
-@Testcontainers
-class AuthServiceApplicationTests {
-
-    /**
-     * Define the PostgreSQL container.
-     *
-     * @ServiceConnection automatically configures the application properties
-     * (URL, username, password) for this specific container.
-     */
-    @Container
-    @ServiceConnection
-    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:17.9");
+class AuthServiceApplicationTests extends AbstractIntegrationTest {
 
     @Test
     void contextLoads() {

src/test/java/auth_service/architecture/ArchitectureTest.java

@@ -1,5 +1,6 @@
 package auth_service.architecture;
 
+import auth_service.shared.test.AbstractArchitectureTest;
 import com.tngtech.archunit.core.importer.ImportOption;
 import com.tngtech.archunit.junit.AnalyzeClasses;
 import com.tngtech.archunit.junit.ArchTest;
@@ -14,7 +15,7 @@ import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.noClasses;
  * Analyzes all classes in the 'auth_service' package, ignoring test classes.
  */
 @AnalyzeClasses(packages = "auth_service", importOptions = ImportOption.DoNotIncludeTests.class)
-class ArchitectureTest {
+class ArchitectureTest extends AbstractArchitectureTest {
 
     // ===================================================================================
     // 1. DOMAIN INDEPENDENCE (Slices)
@@ -75,6 +76,24 @@ class ArchitectureTest {
             .should().dependOnClassesThat().resideInAPackage("..persistence..")
             .because("Controllers must delegate to Services and should not access Persistence directly.");
 
+    @ArchTest
+    static final ArchRule persistence_should_not_depend_on_controllers = noClasses()
+            .that().resideInAPackage("..persistence..")
+            .should().dependOnClassesThat().resideInAPackage("..controller..")
+            .because("Persistence layer must be independent of the Web/Controller layer.");
+
+    @ArchTest
+    static final ArchRule exceptions_should_be_isolated = noClasses()
+            .that().resideInAPackage("..exception..")
+            .should().dependOnClassesThat().resideInAnyPackage("..controller..", "..persistence.entities..")
+            .because("Exceptions should be part of the domain core and independent of infrastructure details.");
+
+    @ArchTest
+    static final ArchRule configuration_should_not_be_accessed_by_domain = noClasses()
+            .that().resideInAnyPackage("..domain..")
+            .should().dependOnClassesThat().resideInAPackage("auth_service.configuration..")
+            .because("Domain logic should not depend on Spring configuration classes.");
+
     @ArchTest
     static final ArchRule services_should_be_annotated = classes()
             .that().resideInAPackage("..service..")
@@ -82,6 +101,16 @@ class ArchitectureTest {
             .should().beAnnotatedWith(org.springframework.stereotype.Service.class)
             .because("Classes named *Service should be registered as Spring @Service beans.");
 
+    // ===================================================================================
+    // 5. SHARED PACKAGE RULES
+    // ===================================================================================
+
+    @ArchTest
+    static final ArchRule shared_should_not_depend_on_domains = noClasses()
+            .that().resideInAPackage("auth_service.shared..")
+            .should().dependOnClassesThat().resideInAPackage("auth_service.domain..")
+            .because("Shared classes should be independent of specific domains.");
+
     @ArchTest
     static final ArchRule controllers_should_be_annotated = classes()
             .that().resideInAPackage("..controller..")

src/test/java/auth_service/configuration/security/JwtServiceTest.java

@@ -1,10 +1,9 @@
 package auth_service.configuration.security;
 
+import auth_service.shared.test.AbstractUnitTest;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
 
 import static org.junit.jupiter.api.Assertions.*;
 import static org.mockito.Mockito.when;
@@ -12,8 +11,7 @@ import static org.mockito.Mockito.when;
 /**
  * Tests for JwtService.
  */
-@ExtendWith(MockitoExtension.class)
-class JwtServiceTest {
+class JwtServiceTest extends AbstractUnitTest {
 
     @Mock
     private JwtConfig jwtConfig;

src/test/java/auth_service/domain/login/controller/LoginControllerTest.java

@@ -1,11 +1,11 @@
 package auth_service.domain.login.controller;
 
 import auth_service.configuration.security.JwtAuthenticationFilter;
-import auth_service.configuration.security.JwtService;
 import auth_service.domain.login.controller.dto.request.LoginRequest;
 import auth_service.domain.login.exception.InvalidCredentialsException;
 import auth_service.domain.login.model.User;
 import auth_service.domain.login.service.LoginService;
+import auth_service.shared.test.AbstractWebMvcTest;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.json.AutoConfigureJsonTesters;
@@ -28,7 +28,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 @WebMvcTest(LoginController.class)
 @AutoConfigureMockMvc(addFilters = false) // Skip security filters for simple controller test
 @AutoConfigureJsonTesters
-class LoginControllerTest {
+class LoginControllerTest extends AbstractWebMvcTest {
 
     @Autowired
     private MockMvc mockMvc;
@@ -36,9 +36,6 @@ class LoginControllerTest {
     @MockitoBean
     private LoginService loginService;
 
-    @MockitoBean
-    private JwtService jwtService;
-
     @MockitoBean
     private JwtAuthenticationFilter jwtAuthenticationFilter; // Needed because it's used in SecurityConfig
 
@@ -49,9 +46,7 @@ class LoginControllerTest {
     void login_Success() throws Exception {
         // Arrange
         var request = new LoginRequest("test@example.com", "password");
-        var authenticatedUser = User.builder().id(815L).email("test@example.com").build();
-        when(loginService.login(any(User.class))).thenReturn(authenticatedUser);
-        when(jwtService.generateToken("815", "test@example.com")).thenReturn("mock-token");
+        when(loginService.login(any(User.class))).thenReturn("mock-token");
 
         // Act & Assert
         mockMvc.perform(post("/api/auth/login")

src/test/java/auth_service/domain/login/persistence/MinimalUserRepositoryTest.java

@@ -0,0 +1,60 @@
+package auth_service.domain.login.persistence;
+
+import auth_service.domain.login.persistence.entities.MinimalUserEntity;
+import auth_service.shared.test.AbstractPersistenceTest;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.jpa.test.autoconfigure.TestEntityManager;
+import org.springframework.context.annotation.Import;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@Import(MinimalUserRepositoryImpl.class)
+class MinimalUserRepositoryTest extends AbstractPersistenceTest {
+
+    @Autowired
+    private MinimalUserRepository minimalUserRepository;
+
+    @Autowired
+    private TestEntityManager entityManager;
+
+    @Test
+    void findByEmail_Success() {
+        // Arrange
+        var email = "minimal@example.com";
+        var entity = MinimalUserEntity.builder()
+                .email(email)
+                .password("password")
+                .enabled(true)
+                .build();
+        entityManager.persist(entity);
+        entityManager.flush();
+
+        // Act
+        var result = minimalUserRepository.findByEmail(email);
+
+        // Assert
+        assertTrue(result.isPresent());
+        assertEquals(email, result.get().getEmail());
+    }
+
+    @Test
+    void updateLoginDate_Success() {
+        // Arrange
+        var entity = MinimalUserEntity.builder()
+                .email("login@example.com")
+                .password("password")
+                .enabled(true)
+                .build();
+        entity = entityManager.persist(entity);
+        entityManager.flush();
+
+        // Act
+        minimalUserRepository.updateLoginDate(entity.getId());
+        entityManager.clear(); // Clear cache to force reload from DB
+
+        // Assert
+        var updated = entityManager.find(MinimalUserEntity.class, entity.getId());
+        assertNotNull(updated.getLastLoginDate());
+    }
+}

src/test/java/auth_service/domain/login/service/LoginServiceTest.java

@@ -4,12 +4,11 @@ import auth_service.domain.login.exception.InvalidCredentialsException;
 import auth_service.domain.login.exception.UserNotFoundException;
 import auth_service.domain.login.model.User;
 import auth_service.domain.login.persistence.MinimalUserRepository;
+import auth_service.shared.test.AbstractUnitTest;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
 import org.springframework.security.crypto.password.PasswordEncoder;
 
 import java.util.Optional;
@@ -21,8 +20,7 @@ import static org.mockito.Mockito.when;
 /**
  * Tests for LoginService.
  */
-@ExtendWith(MockitoExtension.class)
-class LoginServiceTest {
+class LoginServiceTest extends AbstractUnitTest {
 
     @Mock
     private MinimalUserRepository minimalUserRepository;
@@ -30,6 +28,9 @@ class LoginServiceTest {
     @Mock
     private PasswordEncoder passwordEncoder;
 
+    @Mock
+    private TokenGenerator tokenGenerator;
+
     @InjectMocks
     private LoginService loginService;
 
@@ -47,17 +48,19 @@ class LoginServiceTest {
     void login_Success() {
         // Arrange
         var dbUser = User.builder()
+                .id(815L)
                 .email("test@example.com")
                 .password("encodedPassword")
                 .build();
         when(minimalUserRepository.findByEmail(user.getEmail())).thenReturn(Optional.of(dbUser));
         when(passwordEncoder.matches(user.getPassword(), dbUser.getPassword())).thenReturn(true);
+        when(tokenGenerator.generateToken("815", "test@example.com")).thenReturn("mock-token");
 
         // Act
         var result = loginService.login(user);
 
         // Assert
-        assertEquals(dbUser, result);
+        assertEquals("mock-token", result);
     }
 
     @Test

src/test/java/auth_service/domain/registration/controller/RegistrationControllerTest.java

@@ -6,6 +6,7 @@ import auth_service.domain.registration.controller.dto.request.RegistrationReque
 import auth_service.domain.registration.exception.EmailAlreadyInUseException;
 import auth_service.domain.registration.model.Registration;
 import auth_service.domain.registration.service.RegistrationService;
+import auth_service.shared.test.AbstractWebMvcTest;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.json.AutoConfigureJsonTesters;
@@ -28,7 +29,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 @WebMvcTest(RegistrationController.class)
 @AutoConfigureMockMvc(addFilters = false) // Skip security filters for simple controller test
 @AutoConfigureJsonTesters
-class RegistrationControllerTest {
+class RegistrationControllerTest extends AbstractWebMvcTest {
 
     @Autowired
     private MockMvc mockMvc;

src/test/java/auth_service/domain/registration/persistence/RegisteredUserRepositoryTest.java

@@ -0,0 +1,78 @@
+package auth_service.domain.registration.persistence;
+
+import auth_service.domain.registration.model.Registration;
+import auth_service.domain.registration.persistence.entities.RegisteredUserEntity;
+import auth_service.shared.test.AbstractPersistenceTest;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.jpa.test.autoconfigure.TestEntityManager;
+import org.springframework.context.annotation.Import;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@Import(RegisteredUserRepositoryImpl.class)
+class RegisteredUserRepositoryTest extends AbstractPersistenceTest {
+
+    @Autowired
+    private RegisteredUserRepository registeredUserRepository;
+
+    @Autowired
+    private TestEntityManager entityManager;
+
+    @Test
+    void existsByEmail_Success() {
+        // Arrange
+        var email = "exists@example.com";
+        var entity = RegisteredUserEntity.builder()
+                .email(email)
+                .password("password")
+                .enabled(true)
+                .steamId(111L)
+                .registrationDate(java.time.LocalDateTime.now())
+                .build();
+        entityManager.persist(entity);
+        entityManager.flush();
+
+        // Act & Assert
+        assertTrue(registeredUserRepository.existsByEmail(email));
+        assertFalse(registeredUserRepository.existsByEmail("other@example.com"));
+    }
+
+    @Test
+    void existsBySteamId_Success() {
+        // Arrange
+        var steamId = 222L;
+        var entity = RegisteredUserEntity.builder()
+                .email("steam@example.com")
+                .password("password")
+                .enabled(true)
+                .steamId(steamId)
+                .registrationDate(java.time.LocalDateTime.now())
+                .build();
+        entityManager.persist(entity);
+        entityManager.flush();
+
+        // Act & Assert
+        assertTrue(registeredUserRepository.existsBySteamId(steamId));
+        assertFalse(registeredUserRepository.existsBySteamId(333L));
+    }
+
+    @Test
+    void save_Success() {
+        // Arrange
+        var registration = Registration.builder()
+                .email("save@example.com")
+                .encryptedPassword("hashed")
+                .steamId(444L)
+                .build();
+
+        // Act
+        long id = registeredUserRepository.save(registration);
+
+        // Assert
+        assertTrue(id > 0);
+        var saved = entityManager.find(RegisteredUserEntity.class, id);
+        assertNotNull(saved);
+        assertEquals("save@example.com", saved.getEmail());
+    }
+}

src/test/java/auth_service/domain/registration/service/RegistrationServiceTest.java

@@ -5,12 +5,11 @@ import auth_service.domain.registration.exception.InvalidInvitationCodeException
 import auth_service.domain.registration.exception.SteamIdAlreadyRegisteredException;
 import auth_service.domain.registration.model.Registration;
 import auth_service.domain.registration.persistence.RegisteredUserRepository;
+import auth_service.shared.test.AbstractUnitTest;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
 import org.springframework.security.crypto.password.PasswordEncoder;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -21,8 +20,7 @@ import static org.mockito.Mockito.*;
 /**
  * Tests for RegistrationService.
  */
-@ExtendWith(MockitoExtension.class)
-class RegistrationServiceTest {
+class RegistrationServiceTest extends AbstractUnitTest {
 
     @Mock
     private CodeValidationService codeValidationService;

src/test/java/auth_service/domain/user/controller/UserControllerTest.java

@@ -8,6 +8,7 @@ import auth_service.domain.user.exception.UserNotFoundException;
 import auth_service.domain.user.model.User;
 import auth_service.domain.user.model.UserSettings;
 import auth_service.domain.user.service.UserService;
+import auth_service.shared.test.AbstractWebMvcTest;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -34,7 +35,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 @WebMvcTest(UserController.class)
 @AutoConfigureMockMvc(addFilters = false)
 @AutoConfigureJsonTesters
-class UserControllerTest {
+class UserControllerTest extends AbstractWebMvcTest {
 
     @Autowired
     private MockMvc mockMvc;

src/test/java/auth_service/domain/user/persistence/UserRepositoryTest.java

@@ -0,0 +1,75 @@
+package auth_service.domain.user.persistence;
+
+import auth_service.domain.user.model.UserSettings;
+import auth_service.domain.user.persistence.entities.UserEntity;
+import auth_service.shared.test.AbstractPersistenceTest;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.jpa.test.autoconfigure.TestEntityManager;
+import org.springframework.context.annotation.Import;
+
+import java.time.LocalDateTime;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@Import(UserRepositoryImpl.class)
+class UserRepositoryTest extends AbstractPersistenceTest {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private TestEntityManager entityManager;
+
+    @Test
+    void findByEmail_Success() {
+        // Arrange
+        var email = "test@example.com";
+        var userEntity = UserEntity.builder()
+                .email(email)
+                .password("password")
+                .enabled(true)
+                .steamId(123456L)
+                .registrationDate(LocalDateTime.now())
+                .build();
+        entityManager.persist(userEntity);
+        entityManager.flush();
+
+        // Act
+        var result = userRepository.findByEmail(email);
+
+        // Assert
+        assertTrue(result.isPresent());
+        assertEquals(email, result.get().getEmail());
+    }
+
+    @Test
+    void updateSettings_Success() {
+        // Arrange
+        var email = "settings@example.com";
+        var userEntity = UserEntity.builder()
+                .email(email)
+                .password("password")
+                .enabled(true)
+                .steamId(123456L)
+                .registrationDate(LocalDateTime.now())
+                .build();
+        userEntity = entityManager.persist(userEntity);
+        entityManager.flush();
+
+        var settings = UserSettings.builder()
+                .language("de")
+                .theme("dark")
+                .build();
+
+        // Act
+        var updated = userRepository.updateSettings(userEntity.getId(), 654321L, settings);
+
+        // Assert
+        assertTrue(updated);
+        var updatedUser = entityManager.find(UserEntity.class, userEntity.getId());
+        assertEquals(654321L, updatedUser.getSteamId());
+        assertNotNull(updatedUser.getSettings());
+        assertEquals("de", updatedUser.getSettings().getLanguage());
+    }
+}

src/test/java/auth_service/domain/user/service/UserServiceTest.java

@@ -4,11 +4,10 @@ import auth_service.domain.user.exception.UserNotFoundException;
 import auth_service.domain.user.model.User;
 import auth_service.domain.user.model.UserSettings;
 import auth_service.domain.user.persistence.UserRepository;
+import auth_service.shared.test.AbstractUnitTest;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
 
 import java.util.Optional;
 
@@ -19,8 +18,7 @@ import static org.mockito.Mockito.*;
 /**
  * Tests for UserService.
  */
-@ExtendWith(MockitoExtension.class)
-class UserServiceTest {
+class UserServiceTest extends AbstractUnitTest {
 
     @Mock
     private UserRepository userRepository;

src/test/java/auth_service/shared/test/AbstractArchitectureTest.java

@@ -0,0 +1,10 @@
+package auth_service.shared.test;
+
+import org.junit.jupiter.api.Tag;
+
+/**
+ * Base class for ArchUnit tests.
+ */
+@Tag("ArchitectureTest")
+public abstract class AbstractArchitectureTest {
+}

src/test/java/auth_service/shared/test/AbstractIntegrationTest.java

@@ -0,0 +1,22 @@
+package auth_service.shared.test;
+
+import org.junit.jupiter.api.Tag;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+/**
+ * Base class for integration tests.
+ * Full Spring context with Testcontainers.
+ */
+@Tag("IntegrationTest")
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+@Testcontainers
+public abstract class AbstractIntegrationTest {
+
+    @Container
+    @ServiceConnection
+    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:17-alpine");
+}

src/test/java/auth_service/shared/test/AbstractPersistenceTest.java

@@ -0,0 +1,24 @@
+package auth_service.shared.test;
+
+import org.junit.jupiter.api.Tag;
+import org.springframework.boot.data.jpa.test.autoconfigure.DataJpaTest;
+import org.springframework.boot.jdbc.test.autoconfigure.AutoConfigureTestDatabase;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+/**
+ * Base class for persistence tests.
+ * Slices only the persistence layer with Testcontainers.
+ */
+@Tag("PersistenceTest")
+@DataJpaTest
+@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
+@Testcontainers
+public abstract class AbstractPersistenceTest {
+
+    @Container
+    @ServiceConnection
+    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:17-alpine");
+}

src/test/java/auth_service/shared/test/AbstractUnitTest.java

@@ -0,0 +1,14 @@
+package auth_service.shared.test;
+
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+/**
+ * Base class for unit tests.
+ * Isolated from Spring context.
+ */
+@Tag("UnitTest")
+@ExtendWith(MockitoExtension.class)
+public abstract class AbstractUnitTest {
+}

src/test/java/auth_service/shared/test/AbstractWebMvcTest.java

@@ -0,0 +1,13 @@
+package auth_service.shared.test;
+
+import org.junit.jupiter.api.Tag;
+import org.springframework.boot.webmvc.test.autoconfigure.WebMvcTest;
+
+/**
+ * Base class for WebMvc tests.
+ * Slices the web layer.
+ */
+@Tag("WebMvcTest")
+@WebMvcTest
+public abstract class AbstractWebMvcTest {
+}