fix: classes error handeling en return json

backend/src/controllers/classes.ts

@@ -1,44 +1,37 @@
 import { Request, Response } from 'express';
-import { createClass, getAllClasses, getClass, getClassStudents, getClassStudentsIds, getClassTeacherInvitations } from '../services/classes.js';
+import {
+    createClass,
+    getAllClasses,
+    getClass,
+    getClassStudents,
+    getClassTeacherInvitations,
+    getClassTeachers
+} from '../services/classes.js';
 import { ClassDTO } from '@dwengo-1/common/interfaces/class';
+import {requireFields} from "./error-helper";
 
 export async function getAllClassesHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
     const classes = await getAllClasses(full);
 
-    res.json({
-        classes: classes,
-    });
+    res.json({ classes });
 }
 
 export async function createClassHandler(req: Request, res: Response): Promise<void> {
+    const displayName= req.body.displayName;
+    requireFields({ displayName });
+
     const classData = req.body as ClassDTO;
-
-    if (!classData.displayName) {
-        res.status(400).json({
-            error: 'Missing one or more required fields: displayName',
-        });
-        return;
-    }
-
     const cls = await createClass(classData);
 
-    if (!cls) {
-        res.status(500).json({ error: 'Something went wrong while creating class' });
-        return;
-    }
-
-    res.status(201).json(cls);
+    res.json({ cls });
 }
 
 export async function getClassHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.id;
-    const cls = await getClass(classId);
+    requireFields({ classId });
 
-    if (!cls) {
-        res.status(404).json({ error: 'Class not found' });
-        return;
-    }
+    const cls = await getClass(classId);
 
     res.json(cls);
 }
@@ -46,21 +39,29 @@ export async function getClassHandler(req: Request, res: Response): Promise<void
 export async function getClassStudentsHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.id;
     const full = req.query.full === 'true';
+    requireFields({ classId });
 
-    const students = full ? await getClassStudents(classId) : await getClassStudentsIds(classId);
+    const students = await getClassStudents(classId, full);
 
-    res.json({
-        students: students,
-    });
+    res.json({ students });
+}
+
+export async function getClassTeachersHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const full = req.query.full === 'true';
+    requireFields({ classId });
+
+    const teachers = await getClassTeachers(classId, full);
+
+    res.json({ teachers });
 }
 
 export async function getTeacherInvitationsHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.id;
     const full = req.query.full === 'true';
+    requireFields({ classId });
 
     const invitations = await getClassTeacherInvitations(classId, full);
 
-    res.json({
-        invitations: invitations,
-    });
+    res.json({ invitations });
 }

backend/src/services/classes.ts

@@ -8,8 +8,10 @@ import { Class } from '../entities/classes/class.entity.js';
 import { ClassDTO } from '@dwengo-1/common/interfaces/class';
 import { TeacherInvitationDTO } from '@dwengo-1/common/interfaces/teacher-invitation';
 import { StudentDTO } from '@dwengo-1/common/interfaces/student';
-
-const logger = getLogger();
+import {fetchTeacher} from "./teachers";
+import {fetchStudent} from "./students";
+import {TeacherDTO} from "@dwengo-1/common/interfaces/teacher";
+import {mapToTeacherDTO} from "../interfaces/teacher";
 
 export async function fetchClass(classId: string): Promise<Class> {
     const classRepository = getClassRepository();
@@ -26,84 +28,56 @@ export async function getAllClasses(full: boolean): Promise<ClassDTO[] | string[
     const classRepository = getClassRepository();
     const classes = await classRepository.find({}, { populate: ['students', 'teachers'] });
 
-    if (!classes) {
-        return [];
-    }
-
     if (full) {
         return classes.map(mapToClassDTO);
     }
     return classes.map((cls) => cls.classId!);
 }
 
-export async function createClass(classData: ClassDTO): Promise<ClassDTO | null> {
-    const teacherRepository = getTeacherRepository();
+export async function createClass(classData: ClassDTO): Promise<ClassDTO> {
     const teacherUsernames = classData.teachers || [];
-    const teachers = (await Promise.all(teacherUsernames.map(async (id) => teacherRepository.findByUsername(id)))).filter(
-        (teacher) => teacher !== null
-    );
+    const teachers = (await Promise.all(teacherUsernames.map(async (id) => fetchTeacher(id) )));
 
-    const studentRepository = getStudentRepository();
     const studentUsernames = classData.students || [];
-    const students = (await Promise.all(studentUsernames.map(async (id) => studentRepository.findByUsername(id)))).filter(
-        (student) => student !== null
-    );
+    const students = (await Promise.all(studentUsernames.map(async (id) => fetchStudent(id) )));
 
     const classRepository = getClassRepository();
 
-    try {
-        const newClass = classRepository.create({
-            displayName: classData.displayName,
-            teachers: teachers,
-            students: students,
-        });
-        await classRepository.save(newClass);
+    const newClass = classRepository.create({
+        displayName: classData.displayName,
+        teachers: teachers,
+        students: students,
+    });
+    await classRepository.save(newClass, {preventOverwrite: true});
 
-        return mapToClassDTO(newClass);
-    } catch (e) {
-        logger.error(e);
-        return null;
-    }
+    return mapToClassDTO(newClass);
 }
 
-export async function getClass(classId: string): Promise<ClassDTO | null> {
-    const classRepository = getClassRepository();
-    const cls = await classRepository.findById(classId);
-
-    if (!cls) {
-        return null;
-    }
-
+export async function getClass(classId: string): Promise<ClassDTO> {
+    const cls = await fetchClass(classId);
     return mapToClassDTO(cls);
 }
 
-async function fetchClassStudents(classId: string): Promise<StudentDTO[]> {
-    const classRepository = getClassRepository();
-    const cls = await classRepository.findById(classId);
+export async function getClassStudents(classId: string, full: boolean): Promise<StudentDTO[] | string[]> {
+    const cls = await fetchClass(classId);
 
-    if (!cls) {
-        return [];
+    if (full){
+        return cls.students.map(mapToStudentDTO);
     }
-
-    return cls.students.map(mapToStudentDTO);
+    return cls.students.map((student) => student.username);
 }
 
-export async function getClassStudents(classId: string): Promise<StudentDTO[]> {
-    return await fetchClassStudents(classId);
-}
+export async function getClassTeachers(classId: string, full: boolean): Promise<TeacherDTO[] | string[]> {
+    const cls = await fetchClass(classId);
 
-export async function getClassStudentsIds(classId: string): Promise<string[]> {
-    const students: StudentDTO[] = await fetchClassStudents(classId);
-    return students.map((student) => student.username);
+    if (full){
+        return cls.teachers.map(mapToTeacherDTO);
+    }
+    return cls.teachers.map((student) => student.username);
 }
 
 export async function getClassTeacherInvitations(classId: string, full: boolean): Promise<TeacherInvitationDTO[]> {
-    const classRepository = getClassRepository();
-    const cls = await classRepository.findById(classId);
-
-    if (!cls) {
-        return [];
-    }
+    const cls = await fetchClass(classId);
 
     const teacherInvitationRepository = getTeacherInvitationRepository();
     const invitations = await teacherInvitationRepository.findAllInvitationsForClass(cls);