Add conflict errors for duplicate registrations

common/errors/ConflictError.go

@@ -0,0 +1,8 @@
+package errors
+
+import "net/http"
+
+// An error that occurs when an incoming request tries to create a resource that already exists.
+func ConflictError(raw_error string, message string) ApiError {
+	return ApiError{Status: http.StatusConflict, Type: "CONFLICT_ERROR", Message: message, RawError: raw_error}
+}

services/registration/controller/controller.go

@@ -126,6 +126,10 @@ func CreateCurrentUserRegistration(w http.ResponseWriter, r *http.Request) {
 	err = service.CreateUserRegistration(id, user_registration)
 
 	if err != nil {
+		if err.Error() == service.RegistrationAlreadyExists {
+			errors.WriteError(w, r, errors.ConflictError(err.Error(), "Could not create user registration."))
+			return
+		}
 		errors.WriteError(w, r, errors.InternalError(err.Error(), "Could not create user registration."))
 		return
 	}
@@ -324,6 +328,10 @@ func CreateCurrentMentorRegistration(w http.ResponseWriter, r *http.Request) {
 	err = service.CreateMentorRegistration(id, mentor_registration)
 
 	if err != nil {
+		if err.Error() == service.RegistrationAlreadyExists {
+			errors.WriteError(w, r, errors.ConflictError(err.Error(), "Could not create mentor registration."))
+			return
+		}
 		errors.WriteError(w, r, errors.InternalError(err.Error(), "Could not create mentor registration."))
 		return
 	}

services/registration/service/registration_service.go

@@ -14,6 +14,8 @@ var validate *validator.Validate
 
 var db database.Database
 
+const RegistrationAlreadyExists = "Registration already exists."
+
 func Initialize() error {
 	if db != nil {
 		db.Close()
@@ -64,7 +66,7 @@ func CreateUserRegistration(id string, user_registration models.UserRegistration
 		if err != nil {
 			return err
 		}
-		return errors.New("Registration already exists.")
+		return errors.New(RegistrationAlreadyExists)
 	}
 
 	err = db.Insert("attendees", &user_registration)
@@ -189,7 +191,7 @@ func CreateMentorRegistration(id string, mentor_registration models.MentorRegist
 		if err != nil {
 			return err
 		}
-		return errors.New("Registration already exists")
+		return errors.New(RegistrationAlreadyExists)
 	}
 
 	err = db.Insert("mentors", &mentor_registration)