fix(backend): Insert weggewerkt

In de plaats optionele check aan DwengoEntityRepository.save(...) toegevoegd die eist dat de entity nog niet bestaat.

backend/src/data/dwengo-entity-repository.ts

@@ -1,8 +1,12 @@
-import { EntityRepository, FilterQuery } from '@mikro-orm/core';
+import {EntityRepository, FilterQuery} from '@mikro-orm/core';
+import {EntityAlreadyExistsException} from "../exceptions/entity-already-exists-exception";
 
 export abstract class DwengoEntityRepository<T extends object> extends EntityRepository<T> {
-    public async save(entity: T) {
-        await this.getEntityManager().insert(entity);
+    public async save(entity: T, options?: {preventOverwrite?: Boolean}): Promise<void> {
+        if (options?.preventOverwrite && await this.findOne(entity)) {
+            throw new EntityAlreadyExistsException(`A ${this.getEntityName()} with this identifier already exists.`);
+        }
+        await this.getEntityManager().persistAndFlush(entity);
     }
     public async deleteWhere(query: FilterQuery<T>) {
         const toDelete = await this.findOne(query);

backend/src/exceptions/entity-already-exists-exception.ts

@@ -0,0 +1,7 @@
+import {ConflictException} from "./conflict-exception";
+
+export class EntityAlreadyExistsException extends ConflictException {
+    constructor(message: string) {
+        super(message);
+    }
+}

backend/src/services/students.ts

@@ -5,9 +5,6 @@ import { GroupDTO, mapToGroupDTO, mapToGroupDTOId } from '../interfaces/group.js
 import { mapToStudent, mapToStudentDTO, StudentDTO } from '../interfaces/student.js';
 import { mapToSubmissionDTO, mapToSubmissionDTOId, SubmissionDTO, SubmissionDTOId } from '../interfaces/submission.js';
 import { getAllAssignments } from './assignments.js';
-import {UniqueConstraintViolationException} from "@mikro-orm/core";
-
-import {ConflictException} from "../exceptions/conflict-exception";
 
 export async function getAllStudents(full: boolean): Promise<StudentDTO[] | string[]> {
     const studentRepository = getStudentRepository();
@@ -29,16 +26,9 @@ export async function getStudent(username: string): Promise<StudentDTO | null> {
 export async function createStudent(userData: StudentDTO): Promise<StudentDTO | null> {
     const studentRepository = getStudentRepository();
 
-    try {
-        const newStudent = mapToStudent(userData);
-        await studentRepository.save(newStudent);
-        return mapToStudentDTO(newStudent);
-    } catch (e: unknown) {
-        if (e instanceof UniqueConstraintViolationException) {
-            throw new ConflictException(`There is already a user with username '${userData.username}'.`);
-        }
-        throw e;
-    }
+    const newStudent = mapToStudent(userData);
+    await studentRepository.save(newStudent, {preventOverwrite: true});
+    return mapToStudentDTO(newStudent);
 }
 
 export async function deleteStudent(username: string): Promise<StudentDTO | null> {

backend/src/services/teachers.ts

@@ -9,9 +9,6 @@ import { getClassStudents } from './classes.js';
 import { StudentDTO } from '../interfaces/student.js';
 import { mapToQuestionDTO, mapToQuestionId, QuestionDTO, QuestionId } from '../interfaces/question.js';
 import { mapToTeacher, mapToTeacherDTO, TeacherDTO } from '../interfaces/teacher.js';
-import {UniqueConstraintViolationException} from "@mikro-orm/core";
-
-import {ConflictException} from "../exceptions/conflict-exception";
 
 export async function getAllTeachers(full: boolean): Promise<TeacherDTO[] | string[]> {
     const teacherRepository = getTeacherRepository();
@@ -33,17 +30,10 @@ export async function getTeacher(username: string): Promise<TeacherDTO | null> {
 export async function createTeacher(userData: TeacherDTO): Promise<TeacherDTO | null> {
     const teacherRepository = getTeacherRepository();
 
-    try {
-        const newTeacher = teacherRepository.create(mapToTeacher(userData));
-        await teacherRepository.save(newTeacher);
+    const newTeacher = teacherRepository.create(mapToTeacher(userData));
+    await teacherRepository.save(newTeacher);
 
-        return mapToTeacherDTO(newTeacher);
-    } catch (e) {
-        if (e instanceof UniqueConstraintViolationException) {
-            throw new ConflictException(`There is already a user with username '${userData.username}'.`);
-        }
-        throw e;
-    }
+    return mapToTeacherDTO(newTeacher);
 }
 
 export async function deleteTeacher(username: string): Promise<TeacherDTO | null> {