Migrate register Student use case to command

Author: OctaviPascual

apps/main/tv/codely/apps/mooc/backend/controller/students/StudentsPutController.java

@@ -6,23 +6,34 @@
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RestController;
-import tv.codely.mooc.students.application.register.RegisterStudentRequest;
-import tv.codely.mooc.students.application.register.StudentRegistrar;
+import tv.codely.mooc.students.application.register.RegisterStudentCommand;
+import tv.codely.shared.domain.DomainError;
+import tv.codely.shared.domain.bus.command.CommandBus;
+import tv.codely.shared.domain.bus.query.QueryBus;
+import tv.codely.shared.infrastructure.spring.ApiController;
 
-@RestController
-public final class StudentsPutController {
+import java.util.HashMap;
 
-    private final StudentRegistrar registrar;
+@RestController
+public final class StudentsPutController extends ApiController {
 
-    public StudentsPutController(StudentRegistrar registrar) {
-        this.registrar = registrar;
+    public StudentsPutController(
+        QueryBus queryBus,
+        CommandBus commandBus
+    ) {
+        super(queryBus, commandBus);
     }
 
     @PutMapping(value = "/students/{id}")
     public ResponseEntity<String> index(@PathVariable String id, @RequestBody Request request) {
-        registrar.register(new RegisterStudentRequest(id, request.name(), request.surname(), request.email()));
+        dispatch(new RegisterStudentCommand(id, request.name(), request.surname(), request.email()));
         return new ResponseEntity<>(HttpStatus.CREATED);
     }
+
+    @Override
+    public HashMap<Class<? extends DomainError>, HttpStatus> errorMapping() {
+        return null;
+    }
 }
 
 final class Request {

src/mooc/main/tv/codely/mooc/students/application/register/RegisterStudentRequest.java renamed to src/mooc/main/tv/codely/mooc/students/application/register/RegisterStudentCommand.java

@@ -1,12 +1,14 @@
 package tv.codely.mooc.students.application.register;
 
-public final class RegisterStudentRequest {
+import tv.codely.shared.domain.bus.command.Command;
+
+public final class RegisterStudentCommand implements Command {
     private final String id;
     private final String name;
     private final String surname;
     private final String email;
 
-    public RegisterStudentRequest(String id, String name, String surname, String email) {
+    public RegisterStudentCommand(String id, String name, String surname, String email) {
         this.id      = id;
         this.name    = name;
         this.surname = surname;

src/mooc/main/tv/codely/mooc/students/application/register/RegisterStudentCommandHandler.java

@@ -0,0 +1,27 @@
+package tv.codely.mooc.students.application.register;
+
+import tv.codely.mooc.students.domain.StudentEmail;
+import tv.codely.mooc.students.domain.StudentId;
+import tv.codely.mooc.students.domain.StudentName;
+import tv.codely.mooc.students.domain.StudentSurname;
+import tv.codely.shared.domain.Service;
+import tv.codely.shared.domain.bus.command.CommandHandler;
+
+@Service
+public final class RegisterStudentCommandHandler implements CommandHandler<RegisterStudentCommand> {
+    private final StudentRegistrar registrar;
+
+    public RegisterStudentCommandHandler(StudentRegistrar registrar) {
+        this.registrar = registrar;
+    }
+
+    @Override
+    public void handle(RegisterStudentCommand command) {
+        StudentId      id      = new StudentId(command.id());
+        StudentName    name    = new StudentName(command.name());
+        StudentSurname surname = new StudentSurname(command.surname());
+        StudentEmail   email   = new StudentEmail(command.email());
+
+        registrar.register(id, name, surname, email);
+    }
+}

src/mooc/main/tv/codely/mooc/students/application/register/StudentRegistrar.java

@@ -14,13 +14,14 @@ public StudentRegistrar(StudentRepository repository, EventBus eventBus) {
         this.eventBus   = eventBus;
     }
 
-    public void register(RegisterStudentRequest request) {
-        Student student = Student.create(
-            new StudentId(request.id()),
-            new StudentName(request.name()),
-            new StudentSurname(request.surname()),
-            new StudentEmail(request.email())
-        );
+    public void register(
+        StudentId id,
+        StudentName name,
+        StudentSurname surname,
+        StudentEmail email
+    ) {
+        Student student = Student.create(id, name, surname, email);
+
         repository.register(student);
         eventBus.publish(student.pullDomainEvents());
     }

src/mooc/test/tv/codely/mooc/students/application/register/StudentRegistrarTestShould.java renamed to src/mooc/test/tv/codely/mooc/students/application/register/RegisterStudentCommandHandlerShould.java

@@ -8,23 +8,23 @@
 import tv.codely.mooc.students.domain.StudentRegisteredDomainEventMother;
 import tv.codely.shared.domain.student.StudentRegisteredDomainEvent;
 
-final class StudentRegistrarTestShould extends StudentsModuleUnitTestCase {
-    StudentRegistrar registrar;
+final class RegisterStudentCommandHandlerShould extends StudentsModuleUnitTestCase {
+    private RegisterStudentCommandHandler handler;
 
     @BeforeEach
     protected void setUp() {
         super.setUp();
 
-        registrar = new StudentRegistrar(repository, eventBus);
+        handler = new RegisterStudentCommandHandler(new StudentRegistrar(repository, eventBus));
     }
 
     @Test
     void register_a_valid_student() {
-        RegisterStudentRequest       request     = RegisterStudentRequestMother.random();
-        Student                      student     = StudentMother.fromRequest(request);
+        RegisterStudentCommand       command     = RegisterStudentCommandMother.random();
+        Student                      student     = StudentMother.fromCommand(command);
         StudentRegisteredDomainEvent domainEvent = StudentRegisteredDomainEventMother.fromStudent(student);
 
-        registrar.register(request);
+        handler.handle(command);
 
         shouldHaveSaved(student);
         shouldHavePublished(domainEvent);

src/mooc/test/tv/codely/mooc/students/application/register/RegisterStudentRequestMother.java renamed to src/mooc/test/tv/codely/mooc/students/application/register/RegisterStudentCommandMother.java

@@ -2,12 +2,12 @@
 
 import tv.codely.mooc.students.domain.*;
 
-public class RegisterStudentRequestMother {
-    public static RegisterStudentRequest create(StudentId id, StudentName name, StudentSurname surname, StudentEmail email) {
-        return new RegisterStudentRequest(id.value(), name.value(), surname.value(), email.value());
+public class RegisterStudentCommandMother {
+    public static RegisterStudentCommand create(StudentId id, StudentName name, StudentSurname surname, StudentEmail email) {
+        return new RegisterStudentCommand(id.value(), name.value(), surname.value(), email.value());
     }
 
-    public static RegisterStudentRequest random() {
+    public static RegisterStudentCommand random() {
         return create(
             StudentIdMother.random(),
             StudentNameMother.random(),

src/mooc/test/tv/codely/mooc/students/domain/StudentMother.java

@@ -1,13 +1,13 @@
 package tv.codely.mooc.students.domain;
 
-import tv.codely.mooc.students.application.register.RegisterStudentRequest;
+import tv.codely.mooc.students.application.register.RegisterStudentCommand;
 
 public class StudentMother {
     public static Student create(StudentId id, StudentName name, StudentSurname surname, StudentEmail email) {
         return new Student(id, name, surname, email);
     }
 
-    public static Student fromRequest(RegisterStudentRequest request) {
+    public static Student fromCommand(RegisterStudentCommand request) {
         return create(
             StudentIdMother.create(request.id()),
             StudentNameMother.create(request.name()),