Merge remote-tracking branch 'origin/dev' into feat/endpoints-finaliseren-tests-backend-adriaan

# Conflicts:
#	backend/src/controllers/assignments.ts
#	backend/src/controllers/classes.ts
#	backend/src/controllers/groups.ts
#	backend/src/controllers/questions.ts
#	backend/src/controllers/submissions.ts
#	backend/src/data/assignments/submission-repository.ts
#	backend/src/data/users/student-repository.ts
#	backend/src/services/classes.ts
#	backend/src/services/submissions.ts
#	backend/tests/controllers/classes.test.ts

backend/.env.staging

@@ -0,0 +1,21 @@
+PORT=3000
+DWENGO_DB_HOST=db
+DWENGO_DB_PORT=5432
+DWENGO_DB_USERNAME=postgres
+DWENGO_DB_PASSWORD=postgres
+DWENGO_DB_UPDATE=false
+
+DWENGO_AUTH_STUDENT_URL=http://localhost/idp/realms/student
+DWENGO_AUTH_STUDENT_CLIENT_ID=dwengo
+DWENGO_AUTH_STUDENT_JWKS_ENDPOINT=http://idp:7080/idp/realms/student/protocol/openid-connect/certs
+DWENGO_AUTH_TEACHER_URL=http://localhost/idp/realms/teacher
+DWENGO_AUTH_TEACHER_CLIENT_ID=dwengo
+DWENGO_AUTH_TEACHER_JWKS_ENDPOINT=http://idp:7080/idp/realms/teacher/protocol/openid-connect/certs
+
+# Allow Vite dev-server to access the backend (for testing purposes). Don't forget to remove this in production!
+#DWENGO_CORS_ALLOWED_ORIGINS=http://localhost/,127.0.0.1:80,http://127.0.0.1,http://localhost:80,http://127.0.0.1:80,localhost
+DWENGO_CORS_ALLOWED_ORIGINS=http://localhost/*,http://idp:7080,https://idp:7080
+
+# Logging and monitoring
+
+LOKI_HOST=http://logging:3102

backend/.env.test

@@ -1,3 +1,22 @@
-PORT=3000
-DWENGO_DB_UPDATE=true
+#
+# Test environment configuration
+#
+# Should not need to be modified.
+# See .env.example for more information.
+#
+
+### Dwengo ###
+
+DWENGO_PORT=3000
+
 DWENGO_DB_NAME=":memory:"
+DWENGO_DB_UPDATE=true
+
+DWENGO_AUTH_STUDENT_URL=http://localhost:7080/realms/student
+DWENGO_AUTH_STUDENT_CLIENT_ID=dwengo
+DWENGO_AUTH_STUDENT_JWKS_ENDPOINT=http://localhost:7080/realms/student/protocol/openid-connect/certs
+DWENGO_AUTH_TEACHER_URL=http://localhost:7080/realms/teacher
+DWENGO_AUTH_TEACHER_CLIENT_ID=dwengo
+DWENGO_AUTH_TEACHER_JWKS_ENDPOINT=http://localhost:7080/realms/teacher/protocol/openid-connect/certs
+
+DWENGO_CORS_ALLOWED_ORIGINS=http://localhost:5173,http://localhost:3000,http://localhost:9876,*

backend/.env.test.example

@@ -1,13 +0,0 @@
-#
-# Test environment configuration
-#
-# Should not need to be modified.
-# See .env.example for more information.
-#
-
-### Dwengo ###
-
-DWENGO_PORT=3000
-
-DWENGO_DB_NAME=":memory:"
-DWENGO_DB_UPDATE=true

backend/Dockerfile

@@ -1,38 +1,51 @@
 FROM node:22 AS build-stage
 
-WORKDIR /app
+WORKDIR /app/dwengo
 
 # Install dependencies
 
 COPY package*.json ./
 COPY backend/package.json ./backend/
+# Backend depends on common and docs
+COPY common/package.json ./common/
+COPY docs/package.json ./docs/
 
 RUN npm install --silent
 
 # Build the backend
 
 # Root tsconfig.json
-COPY tsconfig.json ./
+COPY tsconfig.json tsconfig.build.json ./
 
-WORKDIR /app/backend
-
-COPY backend ./
-COPY docs /app/docs
+COPY backend ./backend
+COPY common ./common
+COPY docs ./docs
 
 RUN npm run build
 
 FROM node:22 AS production-stage
 
-WORKDIR /app
+WORKDIR /app/dwengo
 
-COPY package-lock.json backend/package.json ./
+# Copy static files
+
+COPY ./backend/i18n ./i18n
+
+# Copy built files
+
+COPY --from=build-stage /app/dwengo/common/dist ./common/dist
+COPY --from=build-stage /app/dwengo/backend/dist ./backend/dist
+COPY --from=build-stage /app/dwengo/docs/api/swagger.json ./docs/api/swagger.json
+
+COPY package*.json ./
+COPY backend/package.json ./backend/
+# Backend depends on common
+COPY common/package.json ./common/
 
 RUN npm install --silent --only=production
 
-COPY ./docs /docs
-COPY ./backend/i18n /app/i18n
-COPY --from=build-stage /app/backend/dist ./dist/
+COPY ./backend/i18n ./backend/i18n
 
 EXPOSE 3000
 
-CMD ["node", "--env-file=.env", "dist/app.js"]
+CMD ["node", "--env-file=/app/dwengo/backend/.env", "/app/dwengo/backend/dist/app.js"]

backend/README.md

@@ -34,7 +34,9 @@ npm run test:unit
 
 ```shell
 # Omgevingsvariabelen
-cp .env.development.example .env
+cp .env.example .env
+# Configureer de .env file met de juiste waarden!
+nano .env
 
 npm run build
 npm run start

backend/config.js

@@ -1,7 +0,0 @@
-// Can be placed in dotenv but found it redundant
-// Import dotenv from "dotenv";
-// Load .env file
-// Dotenv.config();
-export const DWENGO_API_BASE = 'https://dwengo.org/backend/api';
-export const FALLBACK_LANG = 'nl';
-export const FALLBACK_SEQ_NUM = 1;

backend/eslint.config.ts

@@ -8,14 +8,4 @@ export default [
             globals: globals.node,
         },
     },
-
-    {
-        files: ['tests/**/*.ts'],
-        languageOptions: {
-            globals: globals.node,
-        },
-        rules: {
-            'no-console': 'off',
-        },
-    },
 ];

backend/package.json

@@ -1,24 +1,28 @@
 {
-    "name": "dwengo-1-backend",
-    "version": "0.1.1",
+    "name": "@dwengo-1/backend",
+    "version": "0.2.0",
     "description": "Backend for Dwengo-1",
     "private": true,
     "type": "module",
+    "main": "dist/app.js",
     "scripts": {
-        "build": "cross-env NODE_ENV=production tsc --project tsconfig.json",
-        "dev": "cross-env NODE_ENV=development tsx watch --env-file=.env.development.local src/app.ts",
+        "build": "cross-env NODE_ENV=production tsc --build",
+        "predev": "tsc --build ../common/tsconfig.json",
+        "dev": "cross-env NODE_ENV=development tsx tool/seed.ts && tsx watch --env-file=.env.development.local src/app.ts",
         "start": "cross-env NODE_ENV=production node --env-file=.env dist/app.js",
         "format": "prettier --write src/",
         "format-check": "prettier --check src/",
         "lint": "eslint . --fix",
-        "test:unit": "vitest"
+        "pretest:unit": "tsx ../docs/api/generate.ts && npm run build",
+        "test:unit": "vitest --run",
+        "test:coverage": "vitest --run --coverage.enabled true"
     },
     "dependencies": {
-        "@mikro-orm/core": "6.4.9",
-        "@mikro-orm/knex": "6.4.9",
-        "@mikro-orm/postgresql": "6.4.9",
-        "@mikro-orm/reflection": "6.4.9",
-        "@mikro-orm/sqlite": "6.4.9",
+        "@mikro-orm/core": "6.4.12",
+        "@mikro-orm/knex": "6.4.12",
+        "@mikro-orm/postgresql": "6.4.12",
+        "@mikro-orm/reflection": "6.4.12",
+        "@mikro-orm/sqlite": "6.4.12",
         "axios": "^1.8.2",
         "cors": "^2.8.5",
         "cross": "^1.0.0",
@@ -33,6 +37,7 @@
         "jwks-rsa": "^3.1.0",
         "loki-logger-ts": "^1.0.2",
         "marked": "^15.0.7",
+        "nanoid": "^5.1.5",
         "response-time": "^2.3.3",
         "swagger-ui-express": "^5.0.1",
         "uuid": "^11.1.0",
@@ -40,7 +45,7 @@
         "winston-loki": "^6.1.3"
     },
     "devDependencies": {
-        "@mikro-orm/cli": "6.4.9",
+        "@mikro-orm/cli": "6.4.12",
         "@types/cors": "^2.8.17",
         "@types/express": "^5.0.0",
         "@types/js-yaml": "^4.0.9",

backend/src/app.ts

@@ -5,15 +5,16 @@ import cors from './middleware/cors.js';
 import { getLogger, Logger } from './logging/initalize.js';
 import { responseTimeLogger } from './logging/responseTimeLogger.js';
 import responseTime from 'response-time';
-import { EnvVars, getNumericEnvVar } from './util/envvars.js';
+import { envVars, getNumericEnvVar } from './util/envVars.js';
 import apiRouter from './routes/router.js';
 import swaggerMiddleware from './swagger.js';
 import swaggerUi from 'swagger-ui-express';
+import { errorHandler } from './middleware/error-handling/error-handler.js';
 
 const logger: Logger = getLogger();
 
 const app: Express = express();
-const port: string | number = getNumericEnvVar(EnvVars.Port);
+const port: string | number = getNumericEnvVar(envVars.Port);
 
 app.use(express.json());
 app.use(cors);
@@ -26,7 +27,9 @@ app.use('/api', apiRouter);
 // Swagger
 app.use('/api-docs', swaggerUi.serve, swaggerMiddleware);
 
-async function startServer() {
+app.use(errorHandler);
+
+async function startServer(): Promise<void> {
     await initORM();
 
     app.listen(port, () => {

backend/src/config.ts

@@ -1,7 +1,8 @@
-import { EnvVars, getEnvVar } from './util/envvars.js';
+import { envVars, getEnvVar } from './util/envVars.js';
 
 // API
-export const DWENGO_API_BASE = getEnvVar(EnvVars.LearningContentRepoApiBaseUrl);
-export const FALLBACK_LANG = getEnvVar(EnvVars.FallbackLanguage);
+export const DWENGO_API_BASE = getEnvVar(envVars.LearningContentRepoApiBaseUrl);
+export const FALLBACK_LANG = getEnvVar(envVars.FallbackLanguage);
 
 export const FALLBACK_SEQ_NUM = 1;
+export const FALLBACK_VERSION_NUM = 1;

backend/src/controllers/answers.ts

@@ -0,0 +1,99 @@
+import { Request, Response } from 'express';
+import { requireFields } from './error-helper.js';
+import { getLearningObjectId, getQuestionId } from './questions.js';
+import { createAnswer, deleteAnswer, getAnswer, getAnswersByQuestion, updateAnswer } from '../services/answers.js';
+import { FALLBACK_SEQ_NUM } from '../config.js';
+import { AnswerData } from '@dwengo-1/common/interfaces/answer';
+
+export async function getAllAnswersHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    const full = req.query.full === 'true';
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const answers = await getAnswersByQuestion(questionId, full);
+
+    res.json({ answers });
+}
+
+export async function getAnswerHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    const seqAnswer = req.params.seqAnswer;
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const sequenceNumber = Number(seqAnswer) || FALLBACK_SEQ_NUM;
+    const answer = await getAnswer(questionId, sequenceNumber);
+
+    res.json({ answer });
+}
+
+export async function createAnswerHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const author = req.body.author as string;
+    const content = req.body.content as string;
+    requireFields({ author, content });
+
+    const answerData = req.body as AnswerData;
+
+    const answer = await createAnswer(questionId, answerData);
+
+    res.json({ answer });
+}
+
+export async function deleteAnswerHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    const seqAnswer = req.params.seqAnswer;
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const sequenceNumber = Number(seqAnswer) || FALLBACK_SEQ_NUM;
+    const answer = await deleteAnswer(questionId, sequenceNumber);
+
+    res.json({ answer });
+}
+
+export async function updateAnswerHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    const seqAnswer = req.params.seqAnswer;
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const content = req.body.content as string;
+    requireFields({ content });
+
+    const answerData = req.body as AnswerData;
+
+    const sequenceNumber = Number(seqAnswer) || FALLBACK_SEQ_NUM;
+    const answer = await updateAnswer(questionId, sequenceNumber, answerData);
+
+    res.json({ answer });
+}

backend/src/controllers/assignments.ts

@@ -1,72 +1,93 @@
 import { Request, Response } from 'express';
-import { createAssignment, getAllAssignments, getAssignment, getAssignmentsSubmissions } from '../services/assignments.js';
-import { AssignmentDTO } from '../interfaces/assignment.js';
+import {
+    createAssignment,
+    deleteAssignment,
+    getAllAssignments,
+    getAssignment,
+    getAssignmentsQuestions,
+    getAssignmentsSubmissions,
+    putAssignment,
+} from '../services/assignments.js';
+import { AssignmentDTO } from '@dwengo-1/common/interfaces/assignment';
+import { requireFields } from './error-helper.js';
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+import { Assignment } from '../entities/assignments/assignment.entity.js';
+import { EntityDTO } from '@mikro-orm/core';
 
-// Typescript is annoy with with parameter forwarding from class.ts
-export async function getAllAssignmentsHandler(req: Request, res: Response): Promise<void> {
+function getAssignmentParams(req: Request): { classid: string; assignmentNumber: number; full: boolean } {
     const classid = req.params.classid;
+    const assignmentNumber = Number(req.params.id);
+    const full = req.query.full === 'true';
+    requireFields({ assignmentNumber, classid });
+
+    if (isNaN(assignmentNumber)) {
+        throw new BadRequestException('Assignment id should be a number');
+    }
+
+    return { classid, assignmentNumber, full };
+}
+
+export async function getAllAssignmentsHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.classid;
     const full = req.query.full === 'true';
 
-    const assignments = await getAllAssignments(classid, full);
+    const assignments = await getAllAssignments(classId, full);
 
-    res.json({
-        assignments: assignments,
-    });
+    res.json({ assignments });
 }
 
 export async function createAssignmentHandler(req: Request, res: Response): Promise<void> {
     const classid = req.params.classid;
+    const description = req.body.description;
+    const language = req.body.language;
+    const learningPath = req.body.learningPath;
+    const title = req.body.title;
+
+    requireFields({ description, language, learningPath, title });
+
     const assignmentData = req.body as AssignmentDTO;
-
-    if (!assignmentData.description || !assignmentData.language || !assignmentData.learningPath || !assignmentData.title) {
-        res.status(400).json({
-            error: 'Missing one or more required fields: title, description, learningPath, language',
-        });
-        return;
-    }
-
     const assignment = await createAssignment(classid, assignmentData);
 
-    if (!assignment) {
-        res.status(500).json({ error: 'Could not create assignment ' });
-        return;
-    }
-
-    res.status(201).json(assignment);
+    res.json({ assignment });
 }
 
 export async function getAssignmentHandler(req: Request, res: Response): Promise<void> {
-    const id = +req.params.id;
-    const classid = req.params.classid;
+    const { classid, assignmentNumber } = getAssignmentParams(req);
 
-    if (isNaN(id)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
-    }
+    const assignment = await getAssignment(classid, assignmentNumber);
 
-    const assignment = await getAssignment(classid, id);
+    res.json({ assignment });
+}
 
-    if (!assignment) {
-        res.status(404).json({ error: 'Assignment not found' });
-        return;
-    }
+export async function putAssignmentHandler(req: Request, res: Response): Promise<void> {
+    const { classid, assignmentNumber } = getAssignmentParams(req);
 
-    res.json(assignment);
+    const assignmentData = req.body as Partial<EntityDTO<Assignment>>;
+    const assignment = await putAssignment(classid, assignmentNumber, assignmentData);
+
+    res.json({ assignment });
+}
+
+export async function deleteAssignmentHandler(req: Request, res: Response): Promise<void> {
+    const { classid, assignmentNumber } = getAssignmentParams(req);
+
+    const assignment = await deleteAssignment(classid, assignmentNumber);
+
+    res.json({ assignment });
 }
 
 export async function getAssignmentsSubmissionsHandler(req: Request, res: Response): Promise<void> {
-    const classid = req.params.classid;
-    const assignmentNumber = +req.params.id;
-    const full = req.query.full === 'true';
-
-    if (isNaN(assignmentNumber)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
-    }
+    const { classid, assignmentNumber, full } = getAssignmentParams(req);
 
     const submissions = await getAssignmentsSubmissions(classid, assignmentNumber, full);
 
-    res.json({
-        submissions: submissions,
-    });
+    res.json({ submissions });
+}
+
+export async function getAssignmentQuestionsHandler(req: Request, res: Response): Promise<void> {
+    const { classid, assignmentNumber, full } = getAssignmentParams(req);
+
+    const questions = await getAssignmentsQuestions(classid, assignmentNumber, full);
+
+    res.json({ questions });
 }

backend/src/controllers/auth.ts

@@ -1,33 +1,62 @@
-import { EnvVars, getEnvVar } from '../util/envvars.js';
+import { UnauthorizedException } from '../exceptions/unauthorized-exception.js';
+import { getLogger } from '../logging/initalize.js';
+import { AuthenticatedRequest } from '../middleware/auth/authenticated-request.js';
+import { createOrUpdateStudent } from '../services/students.js';
+import { createOrUpdateTeacher } from '../services/teachers.js';
+import { envVars, getEnvVar } from '../util/envVars.js';
+import { Response } from 'express';
 
-type FrontendIdpConfig = {
+interface FrontendIdpConfig {
     authority: string;
     clientId: string;
     scope: string;
     responseType: string;
-};
+}
 
-type FrontendAuthConfig = {
+interface FrontendAuthConfig {
     student: FrontendIdpConfig;
     teacher: FrontendIdpConfig;
-};
+}
 
 const SCOPE = 'openid profile email';
 const RESPONSE_TYPE = 'code';
 
+const logger = getLogger();
+
 export function getFrontendAuthConfig(): FrontendAuthConfig {
     return {
         student: {
-            authority: getEnvVar(EnvVars.IdpStudentUrl),
-            clientId: getEnvVar(EnvVars.IdpStudentClientId),
+            authority: getEnvVar(envVars.IdpStudentUrl),
+            clientId: getEnvVar(envVars.IdpStudentClientId),
             scope: SCOPE,
             responseType: RESPONSE_TYPE,
         },
         teacher: {
-            authority: getEnvVar(EnvVars.IdpTeacherUrl),
-            clientId: getEnvVar(EnvVars.IdpTeacherClientId),
+            authority: getEnvVar(envVars.IdpTeacherUrl),
+            clientId: getEnvVar(envVars.IdpTeacherClientId),
             scope: SCOPE,
             responseType: RESPONSE_TYPE,
         },
     };
 }
+
+export async function postHelloHandler(req: AuthenticatedRequest, res: Response): Promise<void> {
+    const auth = req.auth;
+    if (!auth) {
+        throw new UnauthorizedException('Cannot say hello when not authenticated.');
+    }
+    const userData = {
+        id: auth.username,
+        username: auth.username,
+        firstName: auth.firstName ?? '',
+        lastName: auth.lastName ?? '',
+    };
+    if (auth.accountType === 'student') {
+        await createOrUpdateStudent(userData);
+        logger.debug(`Synchronized student ${userData.username} with IDP`);
+    } else {
+        await createOrUpdateTeacher(userData);
+        logger.debug(`Synchronized teacher ${userData.username} with IDP`);
+    }
+    res.status(200).send({ message: 'Welcome!' });
+}

backend/src/controllers/classes.ts

@@ -1,76 +1,132 @@
 import { Request, Response } from 'express';
-import { createClass, getAllClasses, getClass, getClassStudents, getClassTeacherInvitations } from '../services/class.js';
-import { ClassDTO } from '../interfaces/class.js';
+import {
+    addClassStudent,
+    addClassTeacher,
+    createClass,
+    deleteClass,
+    deleteClassStudent,
+    deleteClassTeacher,
+    getAllClasses,
+    getClass,
+    getClassStudents,
+    getClassTeacherInvitations,
+    getClassTeachers,
+    putClass,
+} from '../services/classes.js';
+import { ClassDTO } from '@dwengo-1/common/interfaces/class';
+import { requireFields } from './error-helper.js';
+import { EntityDTO } from '@mikro-orm/core';
+import { Class } from '../entities/classes/class.entity.js';
 
 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({ class: cls });
 }
 
 export async function getClassHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.id;
+    requireFields({ classId });
+
     const cls = await getClass(classId);
 
-    if (!cls) {
-        res.status(404).json({ error: 'Class not found' });
-        return;
-    }
+    res.json({ class: cls });
+}
 
-    res.json(cls);
+export async function putClassHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    requireFields({ classId });
+
+    const newData = req.body as Partial<EntityDTO<Class>>;
+    const cls = await putClass(classId, newData);
+
+    res.json({ class: cls });
+}
+
+export async function deleteClassHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const cls = await deleteClass(classId);
+
+    res.json({ class: cls });
 }
 
 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 = await getClassStudents(classId, full);
 
-	if (!students) {
-		res.status(404).json({ error: 'Class not found' });
-		return;
-	}
+    res.json({ students });
+}
 
-    res.json({
-        students: 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);
 
-    if (!invitations) {
-        res.status(404).json({ error: 'Class not found' });
-        return;
-    }
-
-    res.json({
-        invitations: invitations,
-    });
+    res.json({ invitations });
+}
+
+export async function deleteClassStudentHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const username = req.params.username;
+    requireFields({ classId, username });
+
+    const cls = await deleteClassStudent(classId, username);
+
+    res.json({ class: cls });
+}
+
+export async function deleteClassTeacherHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const username = req.params.username;
+    requireFields({ classId, username });
+
+    const cls = await deleteClassTeacher(classId, username);
+
+    res.json({ class: cls });
+}
+
+export async function addClassStudentHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const username = req.body.username;
+    requireFields({ classId, username });
+
+    const cls = await addClassStudent(classId, username);
+
+    res.json({ class: cls });
+}
+
+export async function addClassTeacherHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.id;
+    const username = req.body.username;
+    requireFields({ classId, username });
+
+    const cls = await addClassTeacher(classId, username);
+
+    res.json({ class: cls });
 }

backend/src/controllers/error-helper.ts

@@ -0,0 +1,18 @@
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+
+/**
+ * Checks for the presence of required fields and throws a BadRequestException
+ * if any are missing.
+ *
+ * @param fields - An object with key-value pairs to validate.
+ */
+export function requireFields(fields: Record<string, unknown>): void {
+    const missing = Object.entries(fields)
+        .filter(([_, value]) => value === undefined || value === null || value === '')
+        .map(([key]) => key);
+
+    if (missing.length > 0) {
+        const message = `Missing required field${missing.length > 1 ? 's' : ''}: ${missing.join(', ')}`;
+        throw new BadRequestException(message);
+    }
+}

backend/src/controllers/groups.ts

@@ -1,93 +1,120 @@
 import { Request, Response } from 'express';
-import { createGroup, getAllGroups, getGroup, getGroupSubmissions } from '../services/groups.js';
-import { GroupDTO } from '../interfaces/group.js';
+import { createGroup, deleteGroup, getAllGroups, getGroup, getGroupQuestions, getGroupSubmissions, putGroup } from '../services/groups.js';
+import { GroupDTO } from '@dwengo-1/common/interfaces/group';
+import { requireFields } from './error-helper.js';
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+
+function checkGroupFields(classId: string, assignmentId: number, groupId: number): void {
+    requireFields({ classId, assignmentId, groupId });
+
+    if (isNaN(assignmentId)) {
+        throw new BadRequestException('Assignment id must be a number');
+    }
+
+    if (isNaN(groupId)) {
+        throw new BadRequestException('Group id must be a number');
+    }
+}
 
 export async function getGroupHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.classid;
-    const full = req.query.full === 'true';
-    const assignmentId = +req.params.assignmentid;
+    const assignmentId = parseInt(req.params.assignmentid);
+    const groupId = parseInt(req.params.groupid);
+    checkGroupFields(classId, assignmentId, groupId);
 
-    if (isNaN(assignmentId)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
-    }
+    const group = await getGroup(classId, assignmentId, groupId);
 
-    const groupId = +req.params.groupid!; // Can't be undefined
+    res.json({ group });
+}
 
-    if (isNaN(groupId)) {
-        res.status(400).json({ error: 'Group id must be a number' });
-        return;
-    }
+export async function putGroupHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.classid;
+    const assignmentId = parseInt(req.params.assignmentid);
+    const groupId = parseInt(req.params.groupid);
+    checkGroupFields(classId, assignmentId, groupId);
 
-    const group = await getGroup(classId, assignmentId, groupId, full);
+    // Only members field can be changed
+    const members = req.body.members;
+    requireFields({ members });
 
-    if (!group) {
-        res.status(404).json({ error: 'Group not found' });
-        return;
-    }
+    const group = await putGroup(classId, assignmentId, groupId, { members } as Partial<GroupDTO>);
 
-    res.json(group);
+    res.json({ group });
+}
+
+export async function deleteGroupHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.classid;
+    const assignmentId = parseInt(req.params.assignmentid);
+    const groupId = parseInt(req.params.groupid);
+    checkGroupFields(classId, assignmentId, groupId);
+
+    const group = await deleteGroup(classId, assignmentId, groupId);
+
+    res.json({ group });
 }
 
 export async function getAllGroupsHandler(req: Request, res: Response): Promise<void> {
     const classId = req.params.classid;
+    const assignmentId = Number(req.params.assignmentid);
     const full = req.query.full === 'true';
-
-    const assignmentId = +req.params.assignmentid;
+    requireFields({ classId, assignmentId });
 
     if (isNaN(assignmentId)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
+        throw new BadRequestException('Assignment id must be a number');
     }
 
     const groups = await getAllGroups(classId, assignmentId, full);
 
-    res.json({
-        groups: groups,
-    });
+    res.json({ groups });
 }
 
 export async function createGroupHandler(req: Request, res: Response): Promise<void> {
     const classid = req.params.classid;
-    const assignmentId = +req.params.assignmentid;
+    const assignmentId = Number(req.params.assignmentid);
+    const members = req.body.members;
+    requireFields({ classid, assignmentId, members });
 
     if (isNaN(assignmentId)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
+        throw new BadRequestException('Assignment id must be a number');
     }
 
     const groupData = req.body as GroupDTO;
     const group = await createGroup(groupData, classid, assignmentId);
 
-    if (!group) {
-        res.status(500).json({ error: 'Something went wrong while creating group' });
-        return;
+    res.status(201).json({ group });
+}
+
+function getGroupParams(req: Request): { classId: string; assignmentId: number; groupId: number; full: boolean } {
+    const classId = req.params.classid;
+    const assignmentId = Number(req.params.assignmentid);
+    const groupId = Number(req.params.groupid);
+    const full = req.query.full === 'true';
+
+    requireFields({ classId, assignmentId, groupId });
+
+    if (isNaN(assignmentId)) {
+        throw new BadRequestException('Assignment id must be a number');
     }
 
-    res.status(201).json(group);
+    if (isNaN(groupId)) {
+        throw new BadRequestException('Group id must be a number');
+    }
+
+    return { classId, assignmentId, groupId, full };
 }
 
 export async function getGroupSubmissionsHandler(req: Request, res: Response): Promise<void> {
-    const classId = req.params.classid;
-    const full = req.query.full === 'true';
-
-    const assignmentId = +req.params.assignmentid;
-
-    if (isNaN(assignmentId)) {
-        res.status(400).json({ error: 'Assignment id must be a number' });
-        return;
-    }
-
-    const groupId = +req.params.groupid!; // Can't be undefined
-
-    if (isNaN(groupId)) {
-        res.status(400).json({ error: 'Group id must be a number' });
-        return;
-    }
+    const { classId, assignmentId, groupId, full } = getGroupParams(req);
 
     const submissions = await getGroupSubmissions(classId, assignmentId, groupId, full);
 
-    res.json({
-        submissions: submissions,
-    });
+    res.json({ submissions });
+}
+
+export async function getGroupQuestionsHandler(req: Request, res: Response): Promise<void> {
+    const { classId, assignmentId, groupId, full } = getGroupParams(req);
+
+    const questions = await getGroupQuestions(classId, assignmentId, groupId, full);
+
+    res.json({ questions });
 }

backend/src/controllers/learning-objects.ts

@@ -1,20 +1,20 @@
 import { Request, Response } from 'express';
 import { FALLBACK_LANG } from '../config.js';
-import { FilteredLearningObject, LearningObjectIdentifier, LearningPathIdentifier } from '../interfaces/learning-content.js';
 import learningObjectService from '../services/learning-objects/learning-object-service.js';
-import { EnvVars, getEnvVar } from '../util/envvars.js';
-import { Language } from '../entities/content/language.js';
-import { BadRequestException } from '../exceptions.js';
+import { Language } from '@dwengo-1/common/util/language';
 import attachmentService from '../services/learning-objects/attachment-service.js';
-import { NotFoundError } from '@mikro-orm/core';
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+import { NotFoundException } from '../exceptions/not-found-exception.js';
+import { envVars, getEnvVar } from '../util/envVars.js';
+import { FilteredLearningObject, LearningObjectIdentifierDTO, LearningPathIdentifier } from '@dwengo-1/common/interfaces/learning-content';
 
-function getLearningObjectIdentifierFromRequest(req: Request): LearningObjectIdentifier {
+function getLearningObjectIdentifierFromRequest(req: Request): LearningObjectIdentifierDTO {
     if (!req.params.hruid) {
         throw new BadRequestException('HRUID is required.');
     }
     return {
-        hruid: req.params.hruid as string,
-        language: (req.query.language || getEnvVar(EnvVars.FallbackLanguage)) as Language,
+        hruid: req.params.hruid,
+        language: (req.query.language || getEnvVar(envVars.FallbackLanguage)) as Language,
         version: parseInt(req.query.version as string),
     };
 }
@@ -24,7 +24,7 @@ function getLearningPathIdentifierFromRequest(req: Request): LearningPathIdentif
         throw new BadRequestException('HRUID is required.');
     }
     return {
-        hruid: req.params.hruid as string,
+        hruid: req.params.hruid,
         language: (req.query.language as Language) || FALLBACK_LANG,
     };
 }
@@ -47,6 +47,11 @@ export async function getLearningObject(req: Request, res: Response): Promise<vo
     const learningObjectId = getLearningObjectIdentifierFromRequest(req);
 
     const learningObject = await learningObjectService.getLearningObjectById(learningObjectId);
+
+    if (!learningObject) {
+        throw new NotFoundException('Learning object not found');
+    }
+
     res.json(learningObject);
 }
 
@@ -63,7 +68,7 @@ export async function getAttachment(req: Request, res: Response): Promise<void>
     const attachment = await attachmentService.getAttachment(learningObjectId, name);
 
     if (!attachment) {
-        throw new NotFoundError(`Attachment ${name} not found`);
+        throw new NotFoundException(`Attachment ${name} not found`);
     }
     res.setHeader('Content-Type', attachment.mimeType).send(attachment.content);
 }

backend/src/controllers/learning-paths.ts

@@ -2,13 +2,11 @@ import { Request, Response } from 'express';
 import { themes } from '../data/themes.js';
 import { FALLBACK_LANG } from '../config.js';
 import learningPathService from '../services/learning-paths/learning-path-service.js';
-import { BadRequestException, NotFoundException } from '../exceptions.js';
-import { Language } from '../entities/content/language.js';
-import {
-    PersonalizationTarget,
-    personalizedForGroup,
-    personalizedForStudent,
-} from '../services/learning-paths/learning-path-personalization-util.js';
+import { Language } from '@dwengo-1/common/util/language';
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+import { NotFoundException } from '../exceptions/not-found-exception.js';
+import { Group } from '../entities/assignments/group.entity.js';
+import { getAssignmentRepository, getGroupRepository } from '../data/repositories.js';
 
 /**
  * Fetch learning paths based on query parameters.
@@ -19,20 +17,20 @@ export async function getLearningPaths(req: Request, res: Response): Promise<voi
     const searchQuery = req.query.search as string;
     const language = (req.query.language as string) || FALLBACK_LANG;
 
-    const forStudent = req.query.forStudent as string;
     const forGroupNo = req.query.forGroup as string;
     const assignmentNo = req.query.assignmentNo as string;
     const classId = req.query.classId as string;
 
-    let personalizationTarget: PersonalizationTarget | undefined;
+    let forGroup: Group | undefined;
 
-    if (forStudent) {
-        personalizationTarget = await personalizedForStudent(forStudent);
-    } else if (forGroupNo) {
+    if (forGroupNo) {
         if (!assignmentNo || !classId) {
             throw new BadRequestException('If forGroupNo is specified, assignmentNo and classId must also be specified.');
         }
-        personalizationTarget = await personalizedForGroup(classId, parseInt(assignmentNo), parseInt(forGroupNo));
+        const assignment = await getAssignmentRepository().findByClassIdAndAssignmentId(classId, parseInt(assignmentNo));
+        if (assignment) {
+            forGroup = (await getGroupRepository().findByAssignmentAndGroupNumber(assignment, parseInt(forGroupNo))) ?? undefined;
+        }
     }
 
     let hruidList;
@@ -47,18 +45,13 @@ export async function getLearningPaths(req: Request, res: Response): Promise<voi
             throw new NotFoundException(`Theme "${themeKey}" not found.`);
         }
     } else if (searchQuery) {
-        const searchResults = await learningPathService.searchLearningPaths(searchQuery, language as Language, personalizationTarget);
+        const searchResults = await learningPathService.searchLearningPaths(searchQuery, language as Language, forGroup);
         res.json(searchResults);
         return;
     } else {
         hruidList = themes.flatMap((theme) => theme.hruids);
     }
 
-    const learningPaths = await learningPathService.fetchLearningPaths(
-        hruidList,
-        language as Language,
-        `HRUIDs: ${hruidList.join(', ')}`,
-        personalizationTarget
-    );
+    const learningPaths = await learningPathService.fetchLearningPaths(hruidList, language as Language, `HRUIDs: ${hruidList.join(', ')}`, forGroup);
     res.json(learningPaths.data);
 }

backend/src/controllers/questions.ts

@@ -1,34 +1,27 @@
 import { Request, Response } from 'express';
-import { createQuestion, deleteQuestion, getAllQuestions, getAnswersByQuestion, getQuestion } from '../services/questions.js';
-import { QuestionDTO, QuestionId } from '../interfaces/question.js';
-import { FALLBACK_LANG, FALLBACK_SEQ_NUM } from '../config.js';
+import {
+    createQuestion,
+    deleteQuestion,
+    getAllQuestions,
+    getQuestion,
+    getQuestionsAboutLearningObjectInAssignment,
+    updateQuestion,
+} from '../services/questions.js';
+import { FALLBACK_LANG, FALLBACK_SEQ_NUM, FALLBACK_VERSION_NUM } from '../config.js';
 import { LearningObjectIdentifier } from '../entities/content/learning-object-identifier.js';
-import { Language } from '../entities/content/language.js';
-
-function getObjectId(req: Request, res: Response): LearningObjectIdentifier | null {
-    const { hruid, version } = req.params;
-    const lang = req.query.lang;
-
-    if (!hruid || !version) {
-        res.status(400).json({ error: 'Missing required parameters.' });
-        return null;
-    }
+import { QuestionData, QuestionDTO, QuestionId } from '@dwengo-1/common/interfaces/question';
+import { Language } from '@dwengo-1/common/util/language';
+import { requireFields } from './error-helper.js';
 
+export function getLearningObjectId(hruid: string, version: string, lang: string): LearningObjectIdentifier {
     return {
         hruid,
-        language: (lang as Language) || FALLBACK_LANG,
-        version: +version,
+        language: (lang || FALLBACK_LANG) as Language,
+        version: Number(version) || FALLBACK_VERSION_NUM,
     };
 }
 
-function getQuestionId(req: Request, res: Response): QuestionId | null {
-    const seq = req.params.seq;
-    const learningObjectIdentifier = getObjectId(req, res);
-
-    if (!learningObjectIdentifier) {
-        return null;
-    }
-
+export function getQuestionId(learningObjectIdentifier: LearningObjectIdentifier, seq: string): QuestionId {
     return {
         learningObjectIdentifier,
         sequenceNumber: seq ? Number(seq) : FALLBACK_SEQ_NUM,
@@ -36,85 +29,96 @@ function getQuestionId(req: Request, res: Response): QuestionId | null {
 }
 
 export async function getAllQuestionsHandler(req: Request, res: Response): Promise<void> {
-    const objectId = getObjectId(req, res);
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = (req.query.lang ? req.query.lang : FALLBACK_LANG) as string;
     const full = req.query.full === 'true';
+    requireFields({ hruid });
 
-    if (!objectId) {
-        return;
-    }
+    const learningObjectId = getLearningObjectId(hruid, version, language);
 
-    const questions = await getAllQuestions(objectId, full);
-
-    if (!questions) {
-        res.status(404).json({ error: `Questions not found.` });
+    let questions: QuestionDTO[] | QuestionId[];
+    if (req.query.classId && req.query.assignmentId) {
+        questions = await getQuestionsAboutLearningObjectInAssignment(
+            learningObjectId,
+            req.query.classId as string,
+            parseInt(req.query.assignmentId as string),
+            full ?? false,
+            req.query.forStudent as string | undefined
+        );
     } else {
-        res.json({ questions: questions });
+        questions = await getAllQuestions(learningObjectId, full ?? false);
     }
+
+    res.json({ questions });
 }
 
 export async function getQuestionHandler(req: Request, res: Response): Promise<void> {
-    const questionId = getQuestionId(req, res);
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    requireFields({ hruid });
 
-    if (!questionId) {
-        return;
-    }
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
 
     const question = await getQuestion(questionId);
 
-    if (!question) {
-        res.status(404).json({ error: `Question not found.` });
-    } else {
-        res.json(question);
-    }
-}
-
-export async function getQuestionAnswersHandler(req: Request, res: Response): Promise<void> {
-    const questionId = getQuestionId(req, res);
-    const full = req.query.full === 'true';
-
-    if (!questionId) {
-        return;
-    }
-
-    const answers = await getAnswersByQuestion(questionId, full);
-
-    if (!answers) {
-        res.status(404).json({ error: `Questions not found` });
-    } else {
-        res.json({ answers: answers });
-    }
+    res.json({ question });
 }
 
 export async function createQuestionHandler(req: Request, res: Response): Promise<void> {
-    const questionDTO = req.body as QuestionDTO;
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    requireFields({ hruid });
 
-    if (!questionDTO.learningObjectIdentifier || !questionDTO.author || !questionDTO.content) {
-        res.status(400).json({ error: 'Missing required fields: identifier and content' });
-        return;
-    }
+    const loId = getLearningObjectId(hruid, version, language);
 
-    const question = await createQuestion(questionDTO);
+    const author = req.body.author as string;
+    const content = req.body.content as string;
+    const inGroup = req.body.inGroup;
+    requireFields({ author, content, inGroup });
 
-    if (!question) {
-        res.status(400).json({ error: 'Could not create question' });
-    } else {
-        res.json(question);
-    }
+    const questionData = req.body as QuestionData;
+
+    const question = await createQuestion(loId, questionData);
+
+    res.json({ question });
 }
 
 export async function deleteQuestionHandler(req: Request, res: Response): Promise<void> {
-    const questionId = getQuestionId(req, res);
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    requireFields({ hruid });
 
-    if (!questionId) {
-        res.json(404).json({ error: 'Question not found' });
-        return;
-    }
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
 
     const question = await deleteQuestion(questionId);
 
-    if (!question) {
-        res.status(404).json({ error: 'Could not find nor delete question' });
-    } else {
-        res.json(question);
-    }
+    res.json({ question });
+}
+
+export async function updateQuestionHandler(req: Request, res: Response): Promise<void> {
+    const hruid = req.params.hruid;
+    const version = req.params.version;
+    const language = req.query.lang as string;
+    const seq = req.params.seq;
+    requireFields({ hruid });
+
+    const learningObjectId = getLearningObjectId(hruid, version, language);
+    const questionId = getQuestionId(learningObjectId, seq);
+
+    const content = req.body.content as string;
+    requireFields({ content });
+
+    const questionData = req.body as QuestionData;
+
+    const question = await updateQuestion(questionId, questionData);
+
+    res.json({ question });
 }

backend/src/controllers/students.ts

@@ -1,101 +1,67 @@
 import { Request, Response } from 'express';
 import {
+    createClassJoinRequest,
     createStudent,
+    deleteClassJoinRequest,
     deleteStudent,
     getAllStudents,
+    getJoinRequestByStudentClass,
+    getJoinRequestsByStudent,
     getStudent,
     getStudentAssignments,
     getStudentClasses,
     getStudentGroups,
+    getStudentQuestions,
     getStudentSubmissions,
 } from '../services/students.js';
-import { StudentDTO } from '../interfaces/student.js';
+import { requireFields } from './error-helper.js';
+import { StudentDTO } from '@dwengo-1/common/interfaces/student';
 
-// TODO: accept arguments (full, ...)
-// TODO: endpoints
 export async function getAllStudentsHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
 
-    const students = await getAllStudents(full);
+    const students: StudentDTO[] | string[] = await getAllStudents(full);
 
-    if (!students) {
-        res.status(404).json({ error: `Student not found.` });
-        return;
-    }
-
-    res.json({ students: students });
+    res.json({ students });
 }
 
 export async function getStudentHandler(req: Request, res: Response): Promise<void> {
     const username = req.params.username;
+    requireFields({ username });
 
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
+    const student = await getStudent(username);
 
-    const user = await getStudent(username);
-
-    if (!user) {
-        res.status(404).json({
-            error: `User with username '${username}' not found.`,
-        });
-        return;
-    }
-
-    res.json(user);
+    res.json({ student });
 }
 
-export async function createStudentHandler(req: Request, res: Response) {
+export async function createStudentHandler(req: Request, res: Response): Promise<void> {
+    const username = req.body.username;
+    const firstName = req.body.firstName;
+    const lastName = req.body.lastName;
+    requireFields({ username, firstName, lastName });
+
     const userData = req.body as StudentDTO;
 
-    if (!userData.username || !userData.firstName || !userData.lastName) {
-        res.status(400).json({
-            error: 'Missing required fields: username, firstName, lastName',
-        });
-        return;
-    }
-
-    const newUser = await createStudent(userData);
-
-    if (!newUser) {
-        res.status(500).json({
-            error: 'Something went wrong while creating student'
-        });
-        return;
-    }
-
-    res.status(201).json(newUser);
+    const student = await createStudent(userData);
+    res.json({ student });
 }
 
-export async function deleteStudentHandler(req: Request, res: Response) {
+export async function deleteStudentHandler(req: Request, res: Response): Promise<void> {
     const username = req.params.username;
+    requireFields({ username });
 
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
-
-    const deletedUser = await deleteStudent(username);
-    if (!deletedUser) {
-        res.status(404).json({
-            error: `User with username '${username}' not found.`,
-        });
-        return;
-    }
-
-    res.status(200).json(deletedUser);
+    const student = await deleteStudent(username);
+    res.json({ student });
 }
 
 export async function getStudentClassesHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
-    const username = req.params.id;
+    const username = req.params.username;
+    requireFields({ username });
 
     const classes = await getStudentClasses(username, full);
 
-    res.json({
-        classes: classes,
-    });
+    res.json({ classes });
 }
 
 // TODO
@@ -104,33 +70,75 @@ export async function getStudentClassesHandler(req: Request, res: Response): Pro
 // Have this assignment.
 export async function getStudentAssignmentsHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
-    const username = req.params.id;
+    const username = req.params.username;
+    requireFields({ username });
 
-    const assignments = getStudentAssignments(username, full);
+    const assignments = await getStudentAssignments(username, full);
 
-    res.json({
-        assignments: assignments,
-    });
+    res.json({ assignments });
 }
 
 export async function getStudentGroupsHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
-    const username = req.params.id;
+    const username = req.params.username;
+    requireFields({ username });
 
     const groups = await getStudentGroups(username, full);
 
-    res.json({
-        groups: groups,
-    });
+    res.json({ groups });
 }
 
 export async function getStudentSubmissionsHandler(req: Request, res: Response): Promise<void> {
-    const username = req.params.id;
+    const username = req.params.username;
     const full = req.query.full === 'true';
+    requireFields({ username });
 
     const submissions = await getStudentSubmissions(username, full);
 
-    res.json({
-        submissions: submissions,
-    });
+    res.json({ submissions });
+}
+
+export async function getStudentQuestionsHandler(req: Request, res: Response): Promise<void> {
+    const full = req.query.full === 'true';
+    const username = req.params.username;
+    requireFields({ username });
+
+    const questions = await getStudentQuestions(username, full);
+
+    res.json({ questions });
+}
+
+export async function createStudentRequestHandler(req: Request, res: Response): Promise<void> {
+    const username = req.params.username;
+    const classId = req.body.classId;
+    requireFields({ username, classId });
+
+    const request = await createClassJoinRequest(username, classId);
+    res.json({ request });
+}
+
+export async function getStudentRequestsHandler(req: Request, res: Response): Promise<void> {
+    const username = req.params.username;
+    requireFields({ username });
+
+    const requests = await getJoinRequestsByStudent(username);
+    res.json({ requests });
+}
+
+export async function getStudentRequestHandler(req: Request, res: Response): Promise<void> {
+    const username = req.params.username;
+    const classId = req.params.classId;
+    requireFields({ username, classId });
+
+    const request = await getJoinRequestByStudentClass(username, classId);
+    res.json({ request });
+}
+
+export async function deleteClassJoinRequestHandler(req: Request, res: Response): Promise<void> {
+    const username = req.params.username;
+    const classId = req.params.classId;
+    requireFields({ username, classId });
+
+    const request = await deleteClassJoinRequest(username, classId);
+    res.json({ request });
 }

backend/src/controllers/submissions.ts

@@ -1,68 +1,86 @@
 import { Request, Response } from 'express';
-import { createSubmission, deleteSubmission, getAllSubmissions, getSubmission } from '../services/submissions.js';
-import { Language, languageMap } from '../entities/content/language.js';
-import { SubmissionDTO } from '../interfaces/submission';
+import {
+    createSubmission,
+    deleteSubmission,
+    getAllSubmissions,
+    getSubmission,
+    getSubmissionsForLearningObjectAndAssignment,
+} from '../services/submissions.js';
+import { SubmissionDTO } from '@dwengo-1/common/interfaces/submission';
+import { Language, languageMap } from '@dwengo-1/common/util/language';
+import { BadRequestException } from '../exceptions/bad-request-exception.js';
+import { requireFields } from './error-helper.js';
+import { LearningObjectIdentifier } from '../entities/content/learning-object-identifier.js';
+
+export async function getSubmissionsHandler(req: Request, res: Response): Promise<void> {
+    const loHruid = req.params.hruid;
+    const lang = languageMap[req.query.language as string] || Language.Dutch;
+    const version = parseInt(req.query.version as string) ?? 1;
+
+    const forGroup = req.query.forGroup as string | undefined;
+
+    const submissions: SubmissionDTO[] = await getSubmissionsForLearningObjectAndAssignment(
+        loHruid,
+        lang,
+        version,
+        req.query.classId as string,
+        parseInt(req.query.assignmentId as string),
+        forGroup ? parseInt(forGroup) : undefined
+    );
+
+    res.json({ submissions });
+}
 
 export async function getSubmissionHandler(req: Request, res: Response): Promise<void> {
     const lohruid = req.params.hruid;
-    const submissionNumber = +req.params.id;
-
-    if (isNaN(submissionNumber)) {
-        res.status(400).json({ error: 'Submission number is not a number' });
-        return;
-    }
-
-
     const lang = languageMap[req.query.language as string] || Language.Dutch;
     const version = (req.query.version || 1) as number;
+    const submissionNumber = Number(req.params.id);
+    requireFields({ lohruid, submissionNumber });
 
-    const submission = await getSubmission(lohruid, lang, version, submissionNumber);
-
-    if (!submission) {
-        res.status(404).json({ error: 'Submission not found' });
-        return;
+    if (isNaN(submissionNumber)) {
+        throw new BadRequestException('Submission number must be a number');
     }
 
-    res.json(submission);
+    const loId = new LearningObjectIdentifier(lohruid, lang, version);
+    const submission = await getSubmission(loId, submissionNumber);
+
+    res.json({ submission });
 }
 
 export async function getAllSubmissionsHandler(req: Request, res: Response): Promise<void> {
     const lohruid = req.params.hruid;
-
     const lang = languageMap[req.query.language as string] || Language.Dutch;
     const version = (req.query.version || 1) as number;
+    requireFields({ lohruid });
 
-    const submissions = await getAllSubmissions(lohruid, lang, version);
+    const loId = new LearningObjectIdentifier(lohruid, lang, version);
+    const submissions = await getAllSubmissions(loId);
 
-    res.json({ submissions: submissions });
+    res.json({ submissions });
 }
 
-export async function createSubmissionHandler(req: Request, res: Response) {
+// TODO: gerald moet nog dingen toevoegen aan de databank voor dat dit gefinaliseerd kan worden
+export async function createSubmissionHandler(req: Request, res: Response): Promise<void> {
     const submissionDTO = req.body as SubmissionDTO;
-
     const submission = await createSubmission(submissionDTO);
 
-    if (!submission) {
-        res.status(400).json({ error: 'Failed to create submission' });
-        return;
-    }
-
-    res.json(submission);
+    res.json({ submission });
 }
 
-export async function deleteSubmissionHandler(req: Request, res: Response) {
+export async function deleteSubmissionHandler(req: Request, res: Response): Promise<void> {
     const hruid = req.params.hruid;
-    const submissionNumber = +req.params.id;
-
     const lang = languageMap[req.query.language as string] || Language.Dutch;
     const version = (req.query.version || 1) as number;
+    const submissionNumber = Number(req.params.id);
+    requireFields({ hruid, submissionNumber });
 
-    const submission = await deleteSubmission(hruid, lang, version, submissionNumber);
-
-    if (!submission) {
-        res.status(404).json({ error: 'Submission not found' });
-        return;
+    if (isNaN(submissionNumber)) {
+        throw new BadRequestException('Submission number must be a number');
     }
 
-    res.json(submission);
+    const loId = new LearningObjectIdentifier(hruid, lang, version);
+    const submission = await deleteSubmission(loId, submissionNumber);
+
+    res.json({ submission });
 }

backend/src/controllers/teacher-invitations.ts

@@ -0,0 +1,66 @@
+import { Request, Response } from 'express';
+import { requireFields } from './error-helper.js';
+import { createInvitation, deleteInvitation, getAllInvitations, getInvitation, updateInvitation } from '../services/teacher-invitations.js';
+import { TeacherInvitationData } from '@dwengo-1/common/interfaces/teacher-invitation';
+
+export async function getAllInvitationsHandler(req: Request, res: Response): Promise<void> {
+    const username = req.params.username;
+    const by = req.query.sent === 'true';
+    requireFields({ username });
+
+    const invitations = await getAllInvitations(username, by);
+
+    res.json({ invitations });
+}
+
+export async function getInvitationHandler(req: Request, res: Response): Promise<void> {
+    const sender = req.params.sender;
+    const receiver = req.params.receiver;
+    const classId = req.params.classId;
+    requireFields({ sender, receiver, classId });
+
+    const invitation = await getInvitation(sender, receiver, classId);
+
+    res.json({ invitation });
+}
+
+export async function createInvitationHandler(req: Request, res: Response): Promise<void> {
+    const sender = req.body.sender;
+    const receiver = req.body.receiver;
+    const classId = req.body.class;
+    requireFields({ sender, receiver, classId });
+
+    const data = req.body as TeacherInvitationData;
+    const invitation = await createInvitation(data);
+
+    res.json({ invitation });
+}
+
+export async function updateInvitationHandler(req: Request, res: Response): Promise<void> {
+    const sender = req.body.sender;
+    const receiver = req.body.receiver;
+    const classId = req.body.class;
+    req.body.accepted = req.body.accepted !== false;
+    requireFields({ sender, receiver, classId });
+
+    const data = req.body as TeacherInvitationData;
+    const invitation = await updateInvitation(data);
+
+    res.json({ invitation });
+}
+
+export async function deleteInvitationHandler(req: Request, res: Response): Promise<void> {
+    const sender = req.params.sender;
+    const receiver = req.params.receiver;
+    const classId = req.params.classId;
+    requireFields({ sender, receiver, classId });
+
+    const data: TeacherInvitationData = {
+        sender,
+        receiver,
+        class: classId,
+    };
+    const invitation = await deleteInvitation(data);
+
+    res.json({ invitation });
+}

backend/src/controllers/teachers.ts

@@ -4,137 +4,96 @@ import {
     deleteTeacher,
     getAllTeachers,
     getClassesByTeacher,
-    getQuestionsByTeacher,
+    getJoinRequestsByClass,
     getStudentsByTeacher,
     getTeacher,
+    getTeacherQuestions,
+    updateClassJoinRequestStatus,
 } from '../services/teachers.js';
-import { TeacherDTO } from '../interfaces/teacher.js';
+import { requireFields } from './error-helper.js';
+import { TeacherDTO } from '@dwengo-1/common/interfaces/teacher';
 
 export async function getAllTeachersHandler(req: Request, res: Response): Promise<void> {
     const full = req.query.full === 'true';
 
-    const teachers = await getAllTeachers(full);
+    const teachers: TeacherDTO[] | string[] = await getAllTeachers(full);
 
-    if (!teachers) {
-        res.status(404).json({ error: `Teacher not found.` });
-        return;
-    }
-
-    res.json({ teachers: teachers });
+    res.json({ teachers });
 }
 
 export async function getTeacherHandler(req: Request, res: Response): Promise<void> {
     const username = req.params.username;
+    requireFields({ username });
 
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
+    const teacher = await getTeacher(username);
 
-    const user = await getTeacher(username);
-
-    if (!user) {
-        res.status(404).json({
-            error: `Teacher '${username}' not found.`,
-        });
-        return;
-    }
-
-    res.json(user);
+    res.json({ teacher });
 }
 
-export async function createTeacherHandler(req: Request, res: Response) {
+export async function createTeacherHandler(req: Request, res: Response): Promise<void> {
+    const username = req.body.username;
+    const firstName = req.body.firstName;
+    const lastName = req.body.lastName;
+    requireFields({ username, firstName, lastName });
+
     const userData = req.body as TeacherDTO;
 
-    if (!userData.username || !userData.firstName || !userData.lastName) {
-        res.status(400).json({
-            error: 'Missing required fields: username, firstName, lastName',
-        });
-        return;
-    }
-
-    const newUser = await createTeacher(userData);
-
-    if (!newUser) {
-        res.status(400).json({ error: 'Failed to create teacher' });
-        return;
-    }
-
-    res.status(201).json(newUser);
+    const teacher = await createTeacher(userData);
+    res.json({ teacher });
 }
 
-export async function deleteTeacherHandler(req: Request, res: Response) {
+export async function deleteTeacherHandler(req: Request, res: Response): Promise<void> {
     const username = req.params.username;
+    requireFields({ username });
 
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
-
-    const deletedUser = await deleteTeacher(username);
-    if (!deletedUser) {
-        res.status(404).json({
-            error: `User '${username}' not found.`,
-        });
-        return;
-    }
-
-    res.status(200).json(deletedUser);
+    const teacher = await deleteTeacher(username);
+    res.json({ teacher });
 }
 
 export async function getTeacherClassHandler(req: Request, res: Response): Promise<void> {
-    const username = req.params.username as string;
+    const username = req.params.username;
     const full = req.query.full === 'true';
-
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
+    requireFields({ username });
 
     const classes = await getClassesByTeacher(username, full);
 
-    if (!classes) {
-        res.status(404).json({ error: 'Teacher not found' });
-        return;
-    }
-
-    res.json({ classes: classes });
+    res.json({ classes });
 }
 
 export async function getTeacherStudentHandler(req: Request, res: Response): Promise<void> {
-    const username = req.params.username as string;
+    const username = req.params.username;
     const full = req.query.full === 'true';
-
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
+    requireFields({ username });
 
     const students = await getStudentsByTeacher(username, full);
 
-    if (!students) {
-        res.status(404).json({ error: 'Teacher not found' });
-        return;
-    }
-
-    res.json({ students: students });
+    res.json({ students });
 }
 
 export async function getTeacherQuestionHandler(req: Request, res: Response): Promise<void> {
-    const username = req.params.username as string;
+    const username = req.params.username;
     const full = req.query.full === 'true';
+    requireFields({ username });
 
-    if (!username) {
-        res.status(400).json({ error: 'Missing required field: username' });
-        return;
-    }
+    const questions = await getTeacherQuestions(username, full);
 
-    const questions = await getQuestionsByTeacher(username, full);
-
-    if (!questions) {
-        res.status(404).json({ error: 'Teacher not found' });
-        return;
-    }
-
-    res.json({ questions: questions });
+    res.json({ questions });
+}
+
+export async function getStudentJoinRequestHandler(req: Request, res: Response): Promise<void> {
+    const classId = req.params.classId;
+    requireFields({ classId });
+
+    const joinRequests = await getJoinRequestsByClass(classId);
+    res.json({ joinRequests });
+}
+
+export async function updateStudentJoinRequestHandler(req: Request, res: Response): Promise<void> {
+    const studentUsername = req.params.studentUsername;
+    const classId = req.params.classId;
+    const accepted = req.body.accepted !== 'false'; // Default = true
+    requireFields({ studentUsername, classId });
+
+    const request = await updateClassJoinRequestStatus(studentUsername, classId, accepted);
+    res.json({ request });
 }

backend/src/controllers/themes.ts

@@ -3,25 +3,23 @@ import { themes } from '../data/themes.js';
 import { loadTranslations } from '../util/translation-helper.js';
 
 interface Translations {
-    curricula_page: {
-        [key: string]: { title: string; description?: string };
-    };
+    curricula_page: Record<string, { title: string; description?: string }>;
 }
 
-export function getThemesHandler(req: Request, res: Response) {
-    const language = (req.query.language as string)?.toLowerCase() || 'nl';
+export function getThemesHandler(req: Request, res: Response): void {
+    const language = ((req.query.language as string) || 'nl').toLowerCase();
     const translations = loadTranslations<Translations>(language);
     const themeList = themes.map((theme) => ({
         key: theme.title,
-        title: translations.curricula_page[theme.title]?.title || theme.title,
-        description: translations.curricula_page[theme.title]?.description,
+        title: translations.curricula_page[theme.title].title || theme.title,
+        description: translations.curricula_page[theme.title].description,
         image: `https://dwengo.org/images/curricula/logo_${theme.title}.png`,
     }));
 
     res.json(themeList);
 }
 
-export function getHruidsByThemeHandler(req: Request, res: Response) {
+export function getHruidsByThemeHandler(req: Request, res: Response): void {
     const themeKey = req.params.theme;
 
     if (!themeKey) {

backend/src/data/assignments/assignment-repository.ts

@@ -3,13 +3,29 @@ import { Assignment } from '../../entities/assignments/assignment.entity.js';
 import { Class } from '../../entities/classes/class.entity.js';
 
 export class AssignmentRepository extends DwengoEntityRepository<Assignment> {
-    public findByClassAndId(within: Class, id: number): Promise<Assignment | null> {
-        return this.findOne({ within: within, id: id });
+    public async findByClassAndId(within: Class, id: number): Promise<Assignment | null> {
+        return this.findOne({ within: within, id: id }, { populate: ['groups', 'groups.members'] });
     }
-    public findAllAssignmentsInClass(within: Class): Promise<Assignment[]> {
-        return this.findAll({ where: { within: within } });
+    public async findByClassIdAndAssignmentId(withinClass: string, id: number): Promise<Assignment | null> {
+        return this.findOne({ within: { classId: withinClass }, id: id });
     }
-    public deleteByClassAndId(within: Class, id: number): Promise<void> {
+    public async findAllByResponsibleTeacher(teacherUsername: string): Promise<Assignment[]> {
+        return this.findAll({
+            where: {
+                within: {
+                    teachers: {
+                        $some: {
+                            username: teacherUsername,
+                        },
+                    },
+                },
+            },
+        });
+    }
+    public async findAllAssignmentsInClass(within: Class): Promise<Assignment[]> {
+        return this.findAll({ where: { within: within }, populate: ['groups', 'groups.members'] });
+    }
+    public async deleteByClassAndId(within: Class, id: number): Promise<void> {
         return this.deleteWhere({ within: within, id: id });
     }
 }

backend/src/data/assignments/group-repository.ts

@@ -4,7 +4,7 @@ import { Assignment } from '../../entities/assignments/assignment.entity.js';
 import { Student } from '../../entities/users/student.entity.js';
 
 export class GroupRepository extends DwengoEntityRepository<Group> {
-    public findByAssignmentAndGroupNumber(assignment: Assignment, groupNumber: number): Promise<Group | null> {
+    public async findByAssignmentAndGroupNumber(assignment: Assignment, groupNumber: number): Promise<Group | null> {
         return this.findOne(
             {
                 assignment: assignment,
@@ -13,16 +13,16 @@ export class GroupRepository extends DwengoEntityRepository<Group> {
             { populate: ['members'] }
         );
     }
-    public findAllGroupsForAssignment(assignment: Assignment): Promise<Group[]> {
+    public async findAllGroupsForAssignment(assignment: Assignment): Promise<Group[]> {
         return this.findAll({
             where: { assignment: assignment },
             populate: ['members'],
         });
     }
-    public findAllGroupsWithStudent(student: Student): Promise<Group[]> {
+    public async findAllGroupsWithStudent(student: Student): Promise<Group[]> {
         return this.find({ members: student }, { populate: ['members'] });
     }
-    public deleteByAssignmentAndGroupNumber(assignment: Assignment, groupNumber: number) {
+    public async deleteByAssignmentAndGroupNumber(assignment: Assignment, groupNumber: number): Promise<void> {
         return this.deleteWhere({
             assignment: assignment,
             groupNumber: groupNumber,

backend/src/data/assignments/submission-repository.ts

@@ -3,29 +3,30 @@ import { Group } from '../../entities/assignments/group.entity.js';
 import { Submission } from '../../entities/assignments/submission.entity.js';
 import { LearningObjectIdentifier } from '../../entities/content/learning-object-identifier.js';
 import { Student } from '../../entities/users/student.entity.js';
+import { Assignment } from '../../entities/assignments/assignment.entity';
 
 export class SubmissionRepository extends DwengoEntityRepository<Submission> {
-    public findSubmissionByLearningObjectAndSubmissionNumber(loId: LearningObjectIdentifier, submissionNumber: number): Promise<Submission | null> {
-        return this.findOne(
-            {
-                learningObjectHruid: loId.hruid,
-                learningObjectLanguage: loId.language,
-                learningObjectVersion: loId.version,
-                submissionNumber: submissionNumber,
-            },
-            { populate: ['submitter', 'onBehalfOf'] },
-        );  
+    public async findSubmissionByLearningObjectAndSubmissionNumber(
+        loId: LearningObjectIdentifier,
+        submissionNumber: number
+    ): Promise<Submission | null> {
+        return this.findOne({
+            learningObjectHruid: loId.hruid,
+            learningObjectLanguage: loId.language,
+            learningObjectVersion: loId.version,
+            submissionNumber: submissionNumber,
+        });
     }
 
-    public findSubmissionsByLearningObject(loId: LearningObjectIdentifier): Promise<Submission[]> {
+    public async findByLearningObject(loId: LearningObjectIdentifier): Promise<Submission[]> {
         return this.find({
             learningObjectHruid: loId.hruid,
             learningObjectLanguage: loId.language,
             learningObjectVersion: loId.version,
-        })
+        });
     }
 
-    public findMostRecentSubmissionForStudent(loId: LearningObjectIdentifier, submitter: Student): Promise<Submission | null> {
+    public async findMostRecentSubmissionForStudent(loId: LearningObjectIdentifier, submitter: Student): Promise<Submission | null> {
         return this.findOne(
             {
                 learningObjectHruid: loId.hruid,
@@ -37,7 +38,7 @@ export class SubmissionRepository extends DwengoEntityRepository<Submission> {
         );
     }
 
-    public findMostRecentSubmissionForGroup(loId: LearningObjectIdentifier, group: Group): Promise<Submission | null> {
+    public async findMostRecentSubmissionForGroup(loId: LearningObjectIdentifier, group: Group): Promise<Submission | null> {
         return this.findOne(
             {
                 learningObjectHruid: loId.hruid,
@@ -49,15 +50,60 @@ export class SubmissionRepository extends DwengoEntityRepository<Submission> {
         );
     }
 
-    public findAllSubmissionsForGroup(group: Group): Promise<Submission[]> {
-        return this.find({ onBehalfOf: group });
+    public async findAllSubmissionsForGroup(group: Group): Promise<Submission[]> {
+        return this.find(
+            { onBehalfOf: group },
+            {
+                populate: ['onBehalfOf.members'],
+            }
+        );
     }
 
-    public findAllSubmissionsForStudent(student: Student): Promise<Submission[]> {
-        return this.find({ submitter: student });
+    /**
+     * Looks up all submissions for the given learning object which were submitted as part of the given assignment.
+     */
+    public async findAllSubmissionsForLearningObjectAndAssignment(loId: LearningObjectIdentifier, assignment: Assignment): Promise<Submission[]> {
+        return this.findAll({
+            where: {
+                learningObjectHruid: loId.hruid,
+                learningObjectLanguage: loId.language,
+                learningObjectVersion: loId.version,
+                onBehalfOf: {
+                    assignment,
+                },
+            },
+        });
     }
 
-    public deleteSubmissionByLearningObjectAndSubmissionNumber(loId: LearningObjectIdentifier, submissionNumber: number): Promise<void> {
+    /**
+     * Looks up all submissions for the given learning object which were submitted by the given group
+     */
+    public async findAllSubmissionsForLearningObjectAndGroup(loId: LearningObjectIdentifier, group: Group): Promise<Submission[]> {
+        return this.findAll({
+            where: {
+                learningObjectHruid: loId.hruid,
+                learningObjectLanguage: loId.language,
+                learningObjectVersion: loId.version,
+                onBehalfOf: group,
+            },
+        });
+    }
+
+    public async findAllSubmissionsForStudent(student: Student): Promise<Submission[]> {
+        const result = await this.find(
+            { submitter: student },
+            {
+                populate: ['onBehalfOf.members'],
+            }
+        );
+
+        // Workaround: For some reason, without this MikroORM generates an UPDATE query with a syntax error in some tests
+        this.em.clear();
+
+        return result;
+    }
+
+    public async deleteSubmissionByLearningObjectAndSubmissionNumber(loId: LearningObjectIdentifier, submissionNumber: number): Promise<void> {
         return this.deleteWhere({
             learningObjectHruid: loId.hruid,
             learningObjectLanguage: loId.language,

backend/src/data/classes/class-join-request-repository.ts

@@ -2,15 +2,19 @@ import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { Class } from '../../entities/classes/class.entity.js';
 import { ClassJoinRequest } from '../../entities/classes/class-join-request.entity.js';
 import { Student } from '../../entities/users/student.entity.js';
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
 
 export class ClassJoinRequestRepository extends DwengoEntityRepository<ClassJoinRequest> {
-    public findAllRequestsBy(requester: Student): Promise<ClassJoinRequest[]> {
+    public async findAllRequestsBy(requester: Student): Promise<ClassJoinRequest[]> {
         return this.findAll({ where: { requester: requester } });
     }
-    public findAllOpenRequestsTo(clazz: Class): Promise<ClassJoinRequest[]> {
-        return this.findAll({ where: { class: clazz } });
+    public async findAllOpenRequestsTo(clazz: Class): Promise<ClassJoinRequest[]> {
+        return this.findAll({ where: { class: clazz, status: ClassStatus.Open } }); // TODO check if works like this
     }
-    public deleteBy(requester: Student, clazz: Class): Promise<void> {
+    public async findByStudentAndClass(requester: Student, clazz: Class): Promise<ClassJoinRequest | null> {
+        return this.findOne({ requester, class: clazz });
+    }
+    public async deleteBy(requester: Student, clazz: Class): Promise<void> {
         return this.deleteWhere({ requester: requester, class: clazz });
     }
 }

backend/src/data/classes/class-repository.ts

@@ -4,20 +4,20 @@ import { Student } from '../../entities/users/student.entity.js';
 import { Teacher } from '../../entities/users/teacher.entity';
 
 export class ClassRepository extends DwengoEntityRepository<Class> {
-    public findById(id: string): Promise<Class | null> {
+    public async findById(id: string): Promise<Class | null> {
         return this.findOne({ classId: id }, { populate: ['students', 'teachers'] });
     }
-    public deleteById(id: string): Promise<void> {
+    public async deleteById(id: string): Promise<void> {
         return this.deleteWhere({ classId: id });
     }
-    public findByStudent(student: Student): Promise<Class[]> {
+    public async findByStudent(student: Student): Promise<Class[]> {
         return this.find(
             { students: student },
             { populate: ['students', 'teachers'] } // Voegt student en teacher objecten toe
         );
     }
 
-    public findByTeacher(teacher: Teacher): Promise<Class[]> {
+    public async findByTeacher(teacher: Teacher): Promise<Class[]> {
         return this.find({ teachers: teacher }, { populate: ['students', 'teachers'] });
     }
 }

backend/src/data/classes/teacher-invitation-repository.ts

@@ -2,22 +2,30 @@ import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { Class } from '../../entities/classes/class.entity.js';
 import { TeacherInvitation } from '../../entities/classes/teacher-invitation.entity.js';
 import { Teacher } from '../../entities/users/teacher.entity.js';
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
 
 export class TeacherInvitationRepository extends DwengoEntityRepository<TeacherInvitation> {
-    public findAllInvitationsForClass(clazz: Class): Promise<TeacherInvitation[]> {
+    public async findAllInvitationsForClass(clazz: Class): Promise<TeacherInvitation[]> {
         return this.findAll({ where: { class: clazz } });
     }
-    public findAllInvitationsBy(sender: Teacher): Promise<TeacherInvitation[]> {
+    public async findAllInvitationsBy(sender: Teacher): Promise<TeacherInvitation[]> {
         return this.findAll({ where: { sender: sender } });
     }
-    public findAllInvitationsFor(receiver: Teacher): Promise<TeacherInvitation[]> {
-        return this.findAll({ where: { receiver: receiver } });
+    public async findAllInvitationsFor(receiver: Teacher): Promise<TeacherInvitation[]> {
+        return this.findAll({ where: { receiver: receiver, status: ClassStatus.Open } });
     }
-    public deleteBy(clazz: Class, sender: Teacher, receiver: Teacher): Promise<void> {
+    public async deleteBy(clazz: Class, sender: Teacher, receiver: Teacher): Promise<void> {
         return this.deleteWhere({
             sender: sender,
             receiver: receiver,
             class: clazz,
         });
     }
+    public async findBy(clazz: Class, sender: Teacher, receiver: Teacher): Promise<TeacherInvitation | null> {
+        return this.findOne({
+            sender: sender,
+            receiver: receiver,
+            class: clazz,
+        });
+    }
 }

backend/src/data/content/attachment-repository.ts

@@ -1,10 +1,10 @@
 import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { Attachment } from '../../entities/content/attachment.entity.js';
-import { Language } from '../../entities/content/language';
+import { Language } from '@dwengo-1/common/util/language';
 import { LearningObjectIdentifier } from '../../entities/content/learning-object-identifier';
 
 export class AttachmentRepository extends DwengoEntityRepository<Attachment> {
-    public findByLearningObjectIdAndName(learningObjectId: LearningObjectIdentifier, name: string): Promise<Attachment | null> {
+    public async findByLearningObjectIdAndName(learningObjectId: LearningObjectIdentifier, name: string): Promise<Attachment | null> {
         return this.findOne({
             learningObject: {
                 hruid: learningObjectId.hruid,
@@ -15,7 +15,11 @@ export class AttachmentRepository extends DwengoEntityRepository<Attachment> {
         });
     }
 
-    public findByMostRecentVersionOfLearningObjectAndName(hruid: string, language: Language, attachmentName: string): Promise<Attachment | null> {
+    public async findByMostRecentVersionOfLearningObjectAndName(
+        hruid: string,
+        language: Language,
+        attachmentName: string
+    ): Promise<Attachment | null> {
         return this.findOne(
             {
                 learningObject: {

backend/src/data/content/learning-object-repository.ts

@@ -1,11 +1,11 @@
 import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { LearningObject } from '../../entities/content/learning-object.entity.js';
 import { LearningObjectIdentifier } from '../../entities/content/learning-object-identifier.js';
-import { Language } from '../../entities/content/language.js';
+import { Language } from '@dwengo-1/common/util/language';
 import { Teacher } from '../../entities/users/teacher.entity.js';
 
 export class LearningObjectRepository extends DwengoEntityRepository<LearningObject> {
-    public findByIdentifier(identifier: LearningObjectIdentifier): Promise<LearningObject | null> {
+    public async findByIdentifier(identifier: LearningObjectIdentifier): Promise<LearningObject | null> {
         return this.findOne(
             {
                 hruid: identifier.hruid,
@@ -18,7 +18,7 @@ export class LearningObjectRepository extends DwengoEntityRepository<LearningObj
         );
     }
 
-    public findLatestByHruidAndLanguage(hruid: string, language: Language) {
+    public async findLatestByHruidAndLanguage(hruid: string, language: Language): Promise<LearningObject | null> {
         return this.findOne(
             {
                 hruid: hruid,
@@ -33,7 +33,7 @@ export class LearningObjectRepository extends DwengoEntityRepository<LearningObj
         );
     }
 
-    public findAllByTeacher(teacher: Teacher): Promise<LearningObject[]> {
+    public async findAllByTeacher(teacher: Teacher): Promise<LearningObject[]> {
         return this.find(
             { admins: teacher },
             { populate: ['admins'] } // Make sure to load admin relations

backend/src/data/content/learning-path-repository.ts

@@ -1,9 +1,13 @@
 import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { LearningPath } from '../../entities/content/learning-path.entity.js';
-import { Language } from '../../entities/content/language.js';
+import { Language } from '@dwengo-1/common/util/language';
+import { LearningPathNode } from '../../entities/content/learning-path-node.entity.js';
+import { RequiredEntityData } from '@mikro-orm/core';
+import { LearningPathTransition } from '../../entities/content/learning-path-transition.entity.js';
+import { EntityAlreadyExistsException } from '../../exceptions/entity-already-exists-exception.js';
 
 export class LearningPathRepository extends DwengoEntityRepository<LearningPath> {
-    public findByHruidAndLanguage(hruid: string, language: Language): Promise<LearningPath | null> {
+    public async findByHruidAndLanguage(hruid: string, language: Language): Promise<LearningPath | null> {
         return this.findOne({ hruid: hruid, language: language }, { populate: ['nodes', 'nodes.transitions'] });
     }
 
@@ -23,4 +27,27 @@ export class LearningPathRepository extends DwengoEntityRepository<LearningPath>
             populate: ['nodes', 'nodes.transitions'],
         });
     }
+
+    public createNode(nodeData: RequiredEntityData<LearningPathNode>): LearningPathNode {
+        return this.em.create(LearningPathNode, nodeData);
+    }
+
+    public createTransition(transitionData: RequiredEntityData<LearningPathTransition>): LearningPathTransition {
+        return this.em.create(LearningPathTransition, transitionData);
+    }
+
+    public async saveLearningPathNodesAndTransitions(
+        path: LearningPath,
+        nodes: LearningPathNode[],
+        transitions: LearningPathTransition[],
+        options?: { preventOverwrite?: boolean }
+    ): Promise<void> {
+        if (options?.preventOverwrite && (await this.findOne(path))) {
+            throw new EntityAlreadyExistsException('A learning path with this hruid/language combination already exists.');
+        }
+        const em = this.getEntityManager();
+        await em.persistAndFlush(path);
+        await Promise.all(nodes.map(async (it) => em.persistAndFlush(it)));
+        await Promise.all(transitions.map(async (it) => em.persistAndFlush(it)));
+    }
 }

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

@@ -1,12 +1,14 @@
 import { EntityRepository, FilterQuery } from '@mikro-orm/core';
+import { EntityAlreadyExistsException } from '../exceptions/entity-already-exists-exception.js';
 
 export abstract class DwengoEntityRepository<T extends object> extends EntityRepository<T> {
-    public async save(entity: T) {
-        const em = this.getEntityManager();
-        em.persist(entity);
-        await em.flush();
+    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>) {
+    public async deleteWhere(query: FilterQuery<T>): Promise<void> {
         const toDelete = await this.findOne(query);
         const em = this.getEntityManager();
         if (toDelete) {

backend/src/data/questions/answer-repository.ts

@@ -2,27 +2,43 @@ import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { Answer } from '../../entities/questions/answer.entity.js';
 import { Question } from '../../entities/questions/question.entity.js';
 import { Teacher } from '../../entities/users/teacher.entity.js';
+import { Loaded } from '@mikro-orm/core';
 
 export class AnswerRepository extends DwengoEntityRepository<Answer> {
-    public createAnswer(answer: { toQuestion: Question; author: Teacher; content: string }): Promise<Answer> {
+    public async createAnswer(answer: { toQuestion: Question; author: Teacher; content: string }): Promise<Answer> {
         const answerEntity = this.create({
             toQuestion: answer.toQuestion,
             author: answer.author,
             content: answer.content,
             timestamp: new Date(),
         });
-        return this.insert(answerEntity);
+        await this.insert(answerEntity);
+        answerEntity.toQuestion = answer.toQuestion;
+        answerEntity.author = answer.author;
+        answerEntity.content = answer.content;
+        return answerEntity;
     }
-    public findAllAnswersToQuestion(question: Question): Promise<Answer[]> {
+    public async findAllAnswersToQuestion(question: Question): Promise<Answer[]> {
         return this.findAll({
             where: { toQuestion: question },
             orderBy: { sequenceNumber: 'ASC' },
         });
     }
-    public removeAnswerByQuestionAndSequenceNumber(question: Question, sequenceNumber: number): Promise<void> {
+    public async findAnswer(question: Question, sequenceNumber: number): Promise<Loaded<Answer> | null> {
+        return this.findOne({
+            toQuestion: question,
+            sequenceNumber,
+        });
+    }
+    public async removeAnswerByQuestionAndSequenceNumber(question: Question, sequenceNumber: number): Promise<void> {
         return this.deleteWhere({
             toQuestion: question,
             sequenceNumber: sequenceNumber,
         });
     }
+    public async updateContent(answer: Answer, newContent: string): Promise<Answer> {
+        answer.content = newContent;
+        await this.save(answer);
+        return answer;
+    }
 }

backend/src/data/questions/question-repository.ts

@@ -3,14 +3,18 @@ import { Question } from '../../entities/questions/question.entity.js';
 import { LearningObjectIdentifier } from '../../entities/content/learning-object-identifier.js';
 import { Student } from '../../entities/users/student.entity.js';
 import { LearningObject } from '../../entities/content/learning-object.entity.js';
+import { Assignment } from '../../entities/assignments/assignment.entity.js';
+import { Loaded } from '@mikro-orm/core';
+import { Group } from '../../entities/assignments/group.entity';
 
 export class QuestionRepository extends DwengoEntityRepository<Question> {
-    public createQuestion(question: { loId: LearningObjectIdentifier; author: Student; content: string }): Promise<Question> {
+    public async createQuestion(question: { loId: LearningObjectIdentifier; author: Student; inGroup: Group; content: string }): Promise<Question> {
         const questionEntity = this.create({
             learningObjectHruid: question.loId.hruid,
             learningObjectLanguage: question.loId.language,
             learningObjectVersion: question.loId.version,
             author: question.author,
+            inGroup: question.inGroup,
             content: question.content,
             timestamp: new Date(),
         });
@@ -18,10 +22,11 @@ export class QuestionRepository extends DwengoEntityRepository<Question> {
         questionEntity.learningObjectLanguage = question.loId.language;
         questionEntity.learningObjectVersion = question.loId.version;
         questionEntity.author = question.author;
+        questionEntity.inGroup = question.inGroup;
         questionEntity.content = question.content;
-        return this.insert(questionEntity);
+        return await this.insert(questionEntity);
     }
-    public findAllQuestionsAboutLearningObject(loId: LearningObjectIdentifier): Promise<Question[]> {
+    public async findAllQuestionsAboutLearningObject(loId: LearningObjectIdentifier): Promise<Question[]> {
         return this.findAll({
             where: {
                 learningObjectHruid: loId.hruid,
@@ -33,7 +38,7 @@ export class QuestionRepository extends DwengoEntityRepository<Question> {
             },
         });
     }
-    public removeQuestionByLearningObjectAndSequenceNumber(loId: LearningObjectIdentifier, sequenceNumber: number): Promise<void> {
+    public async removeQuestionByLearningObjectAndSequenceNumber(loId: LearningObjectIdentifier, sequenceNumber: number): Promise<void> {
         return this.deleteWhere({
             learningObjectHruid: loId.hruid,
             learningObjectLanguage: loId.language,
@@ -54,4 +59,73 @@ export class QuestionRepository extends DwengoEntityRepository<Question> {
             orderBy: { timestamp: 'ASC' },
         });
     }
+
+    public async findAllByAssignment(assignment: Assignment): Promise<Question[]> {
+        return this.find({
+            inGroup: assignment.groups.getItems(),
+            learningObjectHruid: assignment.learningPathHruid,
+            learningObjectLanguage: assignment.learningPathLanguage,
+        });
+    }
+
+    public async findAllByAuthor(author: Student): Promise<Question[]> {
+        return this.findAll({
+            where: { author },
+            orderBy: { timestamp: 'DESC' }, // New to old
+        });
+    }
+
+    public async findAllByGroup(inGroup: Group): Promise<Question[]> {
+        return this.findAll({
+            where: { inGroup },
+            orderBy: { timestamp: 'DESC' },
+        });
+    }
+
+    /**
+     * Looks up all questions for the given learning object which were asked as part of the given assignment.
+     * When forStudentUsername is set, only the questions within the given user's group are shown.
+     */
+    public async findAllQuestionsAboutLearningObjectInAssignment(
+        loId: LearningObjectIdentifier,
+        assignment: Assignment,
+        forStudentUsername?: string
+    ): Promise<Question[]> {
+        const inGroup = forStudentUsername
+            ? {
+                  assignment,
+                  members: {
+                      $some: {
+                          username: forStudentUsername,
+                      },
+                  },
+              }
+            : {
+                  assignment,
+              };
+
+        return this.findAll({
+            where: {
+                learningObjectHruid: loId.hruid,
+                learningObjectLanguage: loId.language,
+                learningObjectVersion: loId.version,
+                inGroup,
+            },
+        });
+    }
+
+    public async findByLearningObjectAndSequenceNumber(loId: LearningObjectIdentifier, sequenceNumber: number): Promise<Loaded<Question> | null> {
+        return this.findOne({
+            learningObjectHruid: loId.hruid,
+            learningObjectLanguage: loId.language,
+            learningObjectVersion: loId.version,
+            sequenceNumber,
+        });
+    }
+
+    public async updateContent(question: Question, newContent: string): Promise<Question> {
+        question.content = newContent;
+        await this.save(question);
+        return question;
+    }
 }

backend/src/data/repositories.ts

@@ -34,8 +34,8 @@ let entityManager: EntityManager | undefined;
 /**
  * Execute all the database operations within the function f in a single transaction.
  */
-export function transactional<T>(f: () => Promise<T>) {
-    entityManager?.transactional(f);
+export async function transactional<T>(f: () => Promise<T>): Promise<void> {
+    await entityManager?.transactional(f);
 }
 
 function repositoryGetter<T extends AnyEntity, R extends EntityRepository<T>>(entity: EntityName<T>): () => R {

backend/src/data/themes.ts

@@ -1,7 +1,4 @@
-export interface Theme {
-    title: string;
-    hruids: string[];
-}
+import { Theme } from '@dwengo-1/common/interfaces/theme';
 
 export const themes: Theme[] = [
     {

backend/src/data/users/student-repository.ts

@@ -1,18 +1,11 @@
-import { Class } from '../../entities/classes/class.entity.js';
 import { Student } from '../../entities/users/student.entity.js';
 import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
-// Import { UserRepository } from './user-repository.js';
-
-// Export class StudentRepository extends UserRepository<Student> {}
 
 export class StudentRepository extends DwengoEntityRepository<Student> {
-    public findByUsername(username: string): Promise<Student | null> {
+    public async findByUsername(username: string): Promise<Student | null> {
         return this.findOne({ username: username });
     }
-    public findByClass(cls: Class): Promise<Student[]> {
-        return this.find({ classes: cls });
-    }
-    public deleteByUsername(username: string): Promise<void> {
+    public async deleteByUsername(username: string): Promise<void> {
         return this.deleteWhere({ username: username });
     }
 }

backend/src/data/users/teacher-repository.ts

@@ -2,10 +2,10 @@ import { Teacher } from '../../entities/users/teacher.entity.js';
 import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 
 export class TeacherRepository extends DwengoEntityRepository<Teacher> {
-    public findByUsername(username: string): Promise<Teacher | null> {
+    public async findByUsername(username: string): Promise<Teacher | null> {
         return this.findOne({ username: username });
     }
-    public deleteByUsername(username: string): Promise<void> {
+    public async deleteByUsername(username: string): Promise<void> {
         return this.deleteWhere({ username: username });
     }
 }

backend/src/data/users/user-repository.ts

@@ -2,10 +2,10 @@ import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
 import { User } from '../../entities/users/user.entity.js';
 
 export class UserRepository<T extends User> extends DwengoEntityRepository<T> {
-    public findByUsername(username: string): Promise<T | null> {
+    public async findByUsername(username: string): Promise<T | null> {
         return this.findOne({ username } as Partial<T>);
     }
-    public deleteByUsername(username: string): Promise<void> {
+    public async deleteByUsername(username: string): Promise<void> {
         return this.deleteWhere({ username } as Partial<T>);
     }
 }

backend/src/entities/assignments/assignment.entity.ts

@@ -1,7 +1,7 @@
-import { Entity, Enum, ManyToOne, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
+import { Cascade, Collection, Entity, Enum, ManyToOne, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
 import { Class } from '../classes/class.entity.js';
 import { Group } from './group.entity.js';
-import { Language } from '../content/language.js';
+import { Language } from '@dwengo-1/common/util/language';
 import { AssignmentRepository } from '../../data/assignments/assignment-repository.js';
 
 @Entity({
@@ -14,7 +14,7 @@ export class Assignment {
     })
     within!: Class;
 
-    @PrimaryKey({ type: 'number', autoincrement: true })
+    @PrimaryKey({ type: 'integer', autoincrement: true })
     id?: number;
 
     @Property({ type: 'string' })
@@ -34,6 +34,7 @@ export class Assignment {
     @OneToMany({
         entity: () => Group,
         mappedBy: 'assignment',
+        cascade: [Cascade.ALL],
     })
-    groups!: Group[];
+    groups: Collection<Group> = new Collection<Group>(this);
 }

backend/src/entities/assignments/group.entity.ts

@@ -1,4 +1,4 @@
-import { Entity, ManyToMany, ManyToOne, PrimaryKey } from '@mikro-orm/core';
+import { Collection, Entity, ManyToMany, ManyToOne, PrimaryKey } from '@mikro-orm/core';
 import { Assignment } from './assignment.entity.js';
 import { Student } from '../users/student.entity.js';
 import { GroupRepository } from '../../data/assignments/group-repository.js';
@@ -7,17 +7,23 @@ import { GroupRepository } from '../../data/assignments/group-repository.js';
     repository: () => GroupRepository,
 })
 export class Group {
+    /*
+     WARNING: Don't move the definition of groupNumber! If it does not come before the definition of assignment,
+     creating groups fails because of a MikroORM bug!
+     */
+    @PrimaryKey({ type: 'integer', autoincrement: true })
+    groupNumber?: number;
+
     @ManyToOne({
         entity: () => Assignment,
         primary: true,
     })
     assignment!: Assignment;
 
-    @PrimaryKey({ type: 'integer', autoincrement: true })
-    groupNumber?: number;
-
     @ManyToMany({
         entity: () => Student,
+        owner: true,
+        inversedBy: 'groups',
     })
-    members!: Student[];
+    members: Collection<Student> = new Collection<Student>(this);
 }

backend/src/entities/assignments/submission.entity.ts

@@ -1,11 +1,14 @@
 import { Student } from '../users/student.entity.js';
 import { Group } from './group.entity.js';
-import { Entity, Enum, ManyToOne, PrimaryKey, Property } from '@mikro-orm/core';
-import { Language } from '../content/language.js';
+import { Entity, Enum, ManyToOne, PrimaryKey, Property, Cascade } from '@mikro-orm/core';
 import { SubmissionRepository } from '../../data/assignments/submission-repository.js';
+import { Language } from '@dwengo-1/common/util/language';
 
 @Entity({ repository: () => SubmissionRepository })
 export class Submission {
+    @PrimaryKey({ type: 'integer', autoincrement: true })
+    submissionNumber?: number;
+
     @PrimaryKey({ type: 'string' })
     learningObjectHruid!: string;
 
@@ -15,11 +18,13 @@ export class Submission {
     })
     learningObjectLanguage!: Language;
 
-    @PrimaryKey({ type: 'numeric' })
-    learningObjectVersion: number = 1;
+    @PrimaryKey({ type: 'numeric', autoincrement: false })
+    learningObjectVersion = 1;
 
-    @PrimaryKey({ type: 'integer', autoincrement: true })
-    submissionNumber?: number;
+    @ManyToOne(() => Group, {
+        cascade: [Cascade.REMOVE],
+    })
+    onBehalfOf!: Group;
 
     @ManyToOne({
         entity: () => Student,
@@ -29,12 +34,6 @@ export class Submission {
     @Property({ type: 'datetime' })
     submissionTime!: Date;
 
-    @ManyToOne({
-        entity: () => Group,
-        nullable: true,
-    })
-    onBehalfOf?: Group;
-
     @Property({ type: 'json' })
     content!: string;
 }

backend/src/entities/classes/class-join-request.entity.ts

@@ -2,12 +2,7 @@ import { Entity, Enum, ManyToOne } from '@mikro-orm/core';
 import { Student } from '../users/student.entity.js';
 import { Class } from './class.entity.js';
 import { ClassJoinRequestRepository } from '../../data/classes/class-join-request-repository.js';
-
-export enum ClassJoinRequestStatus {
-    Open = 'open',
-    Accepted = 'accepted',
-    Declined = 'declined',
-}
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
 
 @Entity({
     repository: () => ClassJoinRequestRepository,
@@ -25,6 +20,6 @@ export class ClassJoinRequest {
     })
     class!: Class;
 
-    @Enum(() => ClassJoinRequestStatus)
-    status!: ClassJoinRequestStatus;
-}
+    @Enum(() => ClassStatus)
+    status!: ClassStatus;
+}

backend/src/entities/classes/class.entity.ts

@@ -1,22 +1,24 @@
 import { Collection, Entity, ManyToMany, PrimaryKey, Property } from '@mikro-orm/core';
-import { v4 } from 'uuid';
 import { Teacher } from '../users/teacher.entity.js';
 import { Student } from '../users/student.entity.js';
 import { ClassRepository } from '../../data/classes/class-repository.js';
+import { customAlphabet } from 'nanoid';
+
+const generateClassId = customAlphabet('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789', 6);
 
 @Entity({
     repository: () => ClassRepository,
 })
 export class Class {
     @PrimaryKey()
-    classId? = v4();
+    classId? = generateClassId();
 
     @Property({ type: 'string' })
     displayName!: string;
 
-    @ManyToMany(() => Teacher)
+    @ManyToMany({ entity: () => Teacher, owner: true, inversedBy: 'classes' })
     teachers!: Collection<Teacher>;
 
-    @ManyToMany(() => Student)
+    @ManyToMany({ entity: () => Student, owner: true, inversedBy: 'classes' })
     students!: Collection<Student>;
 }

backend/src/entities/classes/teacher-invitation.entity.ts

@@ -1,7 +1,8 @@
-import { Entity, ManyToOne } from '@mikro-orm/core';
+import { Entity, Enum, ManyToOne } from '@mikro-orm/core';
 import { Teacher } from '../users/teacher.entity.js';
 import { Class } from './class.entity.js';
 import { TeacherInvitationRepository } from '../../data/classes/teacher-invitation-repository.js';
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
 
 /**
  * Invitation of a teacher into a class (in order to teach it).
@@ -25,4 +26,7 @@ export class TeacherInvitation {
         primary: true,
     })
     class!: Class;
+
+    @Enum(() => ClassStatus)
+    status!: ClassStatus;
 }

backend/src/entities/content/educational-goal.entity.ts

@@ -0,0 +1,10 @@
+import { Embeddable, Property } from '@mikro-orm/core';
+
+@Embeddable()
+export class EducationalGoal {
+    @Property({ type: 'string' })
+    source!: string;
+
+    @Property({ type: 'string' })
+    id!: string;
+}

backend/src/entities/content/language.ts

@@ -1,193 +0,0 @@
-export enum Language {
-    Afar = 'aa',
-    Abkhazian = 'ab',
-    Afrikaans = 'af',
-    Akan = 'ak',
-    Albanian = 'sq',
-    Amharic = 'am',
-    Arabic = 'ar',
-    Aragonese = 'an',
-    Armenian = 'hy',
-    Assamese = 'as',
-    Avaric = 'av',
-    Avestan = 'ae',
-    Aymara = 'ay',
-    Azerbaijani = 'az',
-    Bashkir = 'ba',
-    Bambara = 'bm',
-    Basque = 'eu',
-    Belarusian = 'be',
-    Bengali = 'bn',
-    Bihari = 'bh',
-    Bislama = 'bi',
-    Bosnian = 'bs',
-    Breton = 'br',
-    Bulgarian = 'bg',
-    Burmese = 'my',
-    Catalan = 'ca',
-    Chamorro = 'ch',
-    Chechen = 'ce',
-    Chinese = 'zh',
-    ChurchSlavic = 'cu',
-    Chuvash = 'cv',
-    Cornish = 'kw',
-    Corsican = 'co',
-    Cree = 'cr',
-    Czech = 'cs',
-    Danish = 'da',
-    Divehi = 'dv',
-    Dutch = 'nl',
-    Dzongkha = 'dz',
-    English = 'en',
-    Esperanto = 'eo',
-    Estonian = 'et',
-    Ewe = 'ee',
-    Faroese = 'fo',
-    Fijian = 'fj',
-    Finnish = 'fi',
-    French = 'fr',
-    Frisian = 'fy',
-    Fulah = 'ff',
-    Georgian = 'ka',
-    German = 'de',
-    Gaelic = 'gd',
-    Irish = 'ga',
-    Galician = 'gl',
-    Manx = 'gv',
-    Greek = 'el',
-    Guarani = 'gn',
-    Gujarati = 'gu',
-    Haitian = 'ht',
-    Hausa = 'ha',
-    Hebrew = 'he',
-    Herero = 'hz',
-    Hindi = 'hi',
-    HiriMotu = 'ho',
-    Croatian = 'hr',
-    Hungarian = 'hu',
-    Igbo = 'ig',
-    Icelandic = 'is',
-    Ido = 'io',
-    SichuanYi = 'ii',
-    Inuktitut = 'iu',
-    Interlingue = 'ie',
-    Interlingua = 'ia',
-    Indonesian = 'id',
-    Inupiaq = 'ik',
-    Italian = 'it',
-    Javanese = 'jv',
-    Japanese = 'ja',
-    Kalaallisut = 'kl',
-    Kannada = 'kn',
-    Kashmiri = 'ks',
-    Kanuri = 'kr',
-    Kazakh = 'kk',
-    Khmer = 'km',
-    Kikuyu = 'ki',
-    Kinyarwanda = 'rw',
-    Kirghiz = 'ky',
-    Komi = 'kv',
-    Kongo = 'kg',
-    Korean = 'ko',
-    Kuanyama = 'kj',
-    Kurdish = 'ku',
-    Lao = 'lo',
-    Latin = 'la',
-    Latvian = 'lv',
-    Limburgan = 'li',
-    Lingala = 'ln',
-    Lithuanian = 'lt',
-    Luxembourgish = 'lb',
-    LubaKatanga = 'lu',
-    Ganda = 'lg',
-    Macedonian = 'mk',
-    Marshallese = 'mh',
-    Malayalam = 'ml',
-    Maori = 'mi',
-    Marathi = 'mr',
-    Malay = 'ms',
-    Malagasy = 'mg',
-    Maltese = 'mt',
-    Mongolian = 'mn',
-    Nauru = 'na',
-    Navajo = 'nv',
-    SouthNdebele = 'nr',
-    NorthNdebele = 'nd',
-    Ndonga = 'ng',
-    Nepali = 'ne',
-    NorwegianNynorsk = 'nn',
-    NorwegianBokmal = 'nb',
-    Norwegian = 'no',
-    Chichewa = 'ny',
-    Occitan = 'oc',
-    Ojibwa = 'oj',
-    Oriya = 'or',
-    Oromo = 'om',
-    Ossetian = 'os',
-    Punjabi = 'pa',
-    Persian = 'fa',
-    Pali = 'pi',
-    Polish = 'pl',
-    Portuguese = 'pt',
-    Pashto = 'ps',
-    Quechua = 'qu',
-    Romansh = 'rm',
-    Romanian = 'ro',
-    Rundi = 'rn',
-    Russian = 'ru',
-    Sango = 'sg',
-    Sanskrit = 'sa',
-    Sinhala = 'si',
-    Slovak = 'sk',
-    Slovenian = 'sl',
-    NorthernSami = 'se',
-    Samoan = 'sm',
-    Shona = 'sn',
-    Sindhi = 'sd',
-    Somali = 'so',
-    Sotho = 'st',
-    Spanish = 'es',
-    Sardinian = 'sc',
-    Serbian = 'sr',
-    Swati = 'ss',
-    Sundanese = 'su',
-    Swahili = 'sw',
-    Swedish = 'sv',
-    Tahitian = 'ty',
-    Tamil = 'ta',
-    Tatar = 'tt',
-    Telugu = 'te',
-    Tajik = 'tg',
-    Tagalog = 'tl',
-    Thai = 'th',
-    Tibetan = 'bo',
-    Tigrinya = 'ti',
-    Tonga = 'to',
-    Tswana = 'tn',
-    Tsonga = 'ts',
-    Turkmen = 'tk',
-    Turkish = 'tr',
-    Twi = 'tw',
-    Uighur = 'ug',
-    Ukrainian = 'uk',
-    Urdu = 'ur',
-    Uzbek = 'uz',
-    Venda = 've',
-    Vietnamese = 'vi',
-    Volapuk = 'vo',
-    Welsh = 'cy',
-    Walloon = 'wa',
-    Wolof = 'wo',
-    Xhosa = 'xh',
-    Yiddish = 'yi',
-    Yoruba = 'yo',
-    Zhuang = 'za',
-    Zulu = 'zu',
-}
-
-export const languageMap: Record<string, Language> = {
-    nl: Language.Dutch,
-    fr: Language.French,
-    en: Language.English,
-    de: Language.German,
-};

backend/src/entities/content/learning-object-identifier.ts

@@ -1,9 +1,11 @@
-import { Language } from './language.js';
+import { Language } from '@dwengo-1/common/util/language';
 
 export class LearningObjectIdentifier {
     constructor(
         public hruid: string,
         public language: Language,
         public version: number
-    ) {}
+    ) {
+        // Do nothing
+    }
 }

backend/src/entities/content/learning-object.entity.ts

@@ -1,28 +1,12 @@
-import { Embeddable, Embedded, Entity, Enum, ManyToMany, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
-import { Language } from './language.js';
+import { ArrayType, Embedded, Entity, Enum, ManyToMany, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
 import { Attachment } from './attachment.entity.js';
 import { Teacher } from '../users/teacher.entity.js';
 import { DwengoContentType } from '../../services/learning-objects/processing/content-type.js';
 import { v4 } from 'uuid';
 import { LearningObjectRepository } from '../../data/content/learning-object-repository.js';
-
-@Embeddable()
-export class EducationalGoal {
-    @Property({ type: 'string' })
-    source!: string;
-
-    @Property({ type: 'string' })
-    id!: string;
-}
-
-@Embeddable()
-export class ReturnValue {
-    @Property({ type: 'string' })
-    callbackUrl!: string;
-
-    @Property({ type: 'json' })
-    callbackSchema!: string;
-}
+import { EducationalGoal } from './educational-goal.entity.js';
+import { ReturnValue } from './return-value.entity.js';
+import { Language } from '@dwengo-1/common/util/language';
 
 @Entity({ repository: () => LearningObjectRepository })
 export class LearningObject {
@@ -36,7 +20,7 @@ export class LearningObject {
     language!: Language;
 
     @PrimaryKey({ type: 'number' })
-    version: number = 1;
+    version = 1;
 
     @Property({ type: 'uuid', unique: true })
     uuid = v4();
@@ -58,11 +42,11 @@ export class LearningObject {
     @Property({ type: 'array' })
     keywords: string[] = [];
 
-    @Property({ type: 'array', nullable: true })
+    @Property({ type: new ArrayType((i) => Number(i)), nullable: true })
     targetAges?: number[] = [];
 
     @Property({ type: 'bool' })
-    teacherExclusive: boolean = false;
+    teacherExclusive = false;
 
     @Property({ type: 'array' })
     skosConcepts: string[] = [];
@@ -74,10 +58,10 @@ export class LearningObject {
     educationalGoals: EducationalGoal[] = [];
 
     @Property({ type: 'string' })
-    copyright: string = '';
+    copyright = '';
 
     @Property({ type: 'string' })
-    license: string = '';
+    license = '';
 
     @Property({ type: 'smallint', nullable: true })
     difficulty?: number;
@@ -91,7 +75,7 @@ export class LearningObject {
     returnValue!: ReturnValue;
 
     @Property({ type: 'bool' })
-    available: boolean = true;
+    available = true;
 
     @Property({ type: 'string', nullable: true })
     contentLocation?: string;

backend/src/entities/content/learning-path-node.entity.ts

@@ -1,16 +1,16 @@
-import { Entity, Enum, ManyToOne, OneToMany, PrimaryKey, Property, Rel } from '@mikro-orm/core';
-import { Language } from './language.js';
+import { Collection, Entity, Enum, ManyToOne, OneToMany, PrimaryKey, Property, Rel } from '@mikro-orm/core';
 import { LearningPath } from './learning-path.entity.js';
 import { LearningPathTransition } from './learning-path-transition.entity.js';
+import { Language } from '@dwengo-1/common/util/language';
 
 @Entity()
 export class LearningPathNode {
+    @PrimaryKey({ type: 'integer', autoincrement: true })
+    nodeNumber?: number;
+
     @ManyToOne({ entity: () => LearningPath, primary: true })
     learningPath!: Rel<LearningPath>;
 
-    @PrimaryKey({ type: 'integer', autoincrement: true })
-    nodeNumber!: number;
-
     @Property({ type: 'string' })
     learningObjectHruid!: string;
 
@@ -27,7 +27,7 @@ export class LearningPathNode {
     startNode!: boolean;
 
     @OneToMany({ entity: () => LearningPathTransition, mappedBy: 'node' })
-    transitions: LearningPathTransition[] = [];
+    transitions!: Collection<LearningPathTransition>;
 
     @Property({ length: 3 })
     createdAt: Date = new Date();

backend/src/entities/content/learning-path-transition.entity.ts

@@ -3,12 +3,12 @@ import { LearningPathNode } from './learning-path-node.entity.js';
 
 @Entity()
 export class LearningPathTransition {
-    @ManyToOne({ entity: () => LearningPathNode, primary: true })
-    node!: Rel<LearningPathNode>;
-
     @PrimaryKey({ type: 'numeric' })
     transitionNumber!: number;
 
+    @ManyToOne({ entity: () => LearningPathNode, primary: true })
+    node!: Rel<LearningPathNode>;
+
     @Property({ type: 'string' })
     condition!: string;
 

backend/src/entities/content/learning-path.entity.ts

@@ -1,8 +1,8 @@
-import { Entity, Enum, ManyToMany, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
-import { Language } from './language.js';
+import { Collection, Entity, Enum, ManyToMany, OneToMany, PrimaryKey, Property } from '@mikro-orm/core';
 import { Teacher } from '../users/teacher.entity.js';
 import { LearningPathRepository } from '../../data/content/learning-path-repository.js';
 import { LearningPathNode } from './learning-path-node.entity.js';
+import { Language } from '@dwengo-1/common/util/language';
 
 @Entity({ repository: () => LearningPathRepository })
 export class LearningPath {
@@ -25,5 +25,5 @@ export class LearningPath {
     image: Buffer | null = null;
 
     @OneToMany({ entity: () => LearningPathNode, mappedBy: 'learningPath' })
-    nodes: LearningPathNode[] = [];
+    nodes: Collection<LearningPathNode> = new Collection<LearningPathNode>(this);
 }

backend/src/entities/content/return-value.entity.ts

@@ -0,0 +1,10 @@
+import { Embeddable, Property } from '@mikro-orm/core';
+
+@Embeddable()
+export class ReturnValue {
+    @Property({ type: 'string' })
+    callbackUrl!: string;
+
+    @Property({ type: 'json' })
+    callbackSchema!: string;
+}

backend/src/entities/questions/question.entity.ts

@@ -1,7 +1,8 @@
 import { Entity, Enum, ManyToOne, PrimaryKey, Property } from '@mikro-orm/core';
-import { Language } from '../content/language.js';
 import { Student } from '../users/student.entity.js';
 import { QuestionRepository } from '../../data/questions/question-repository.js';
+import { Language } from '@dwengo-1/common/util/language';
+import { Group } from '../assignments/group.entity.js';
 
 @Entity({ repository: () => QuestionRepository })
 export class Question {
@@ -15,11 +16,14 @@ export class Question {
     learningObjectLanguage!: Language;
 
     @PrimaryKey({ type: 'number' })
-    learningObjectVersion: number = 1;
+    learningObjectVersion = 1;
 
     @PrimaryKey({ type: 'integer', autoincrement: true })
     sequenceNumber?: number;
 
+    @ManyToOne({ entity: () => Group })
+    inGroup!: Group;
+
     @ManyToOne({
         entity: () => Student,
     })

backend/src/entities/users/student.entity.ts

@@ -8,17 +8,9 @@ import { StudentRepository } from '../../data/users/student-repository.js';
     repository: () => StudentRepository,
 })
 export class Student extends User {
-    @ManyToMany(() => Class)
+    @ManyToMany({ entity: () => Class, mappedBy: 'students' })
     classes!: Collection<Class>;
 
-    @ManyToMany(() => Group)
-    groups!: Collection<Group>;
-
-    constructor(
-        public username: string,
-        public firstName: string,
-        public lastName: string
-    ) {
-        super();
-    }
+    @ManyToMany({ entity: () => Group, mappedBy: 'members' })
+    groups: Collection<Group> = new Collection<Group>(this);
 }

backend/src/entities/users/teacher.entity.ts

@@ -5,14 +5,6 @@ import { TeacherRepository } from '../../data/users/teacher-repository.js';
 
 @Entity({ repository: () => TeacherRepository })
 export class Teacher extends User {
-    @ManyToMany(() => Class)
+    @ManyToMany({ entity: () => Class, mappedBy: 'teachers' })
     classes!: Collection<Class>;
-
-    constructor(
-        public username: string,
-        public firstName: string,
-        public lastName: string
-    ) {
-        super();
-    }
 }

backend/src/entities/users/user.entity.ts

@@ -6,8 +6,8 @@ export abstract class User {
     username!: string;
 
     @Property()
-    firstName: string = '';
+    firstName = '';
 
     @Property()
-    lastName: string = '';
+    lastName = '';
 }

backend/src/exceptions.ts

@@ -1,42 +0,0 @@
-/**
- * Exception for HTTP 400 Bad Request
- */
-export class BadRequestException extends Error {
-    public status = 400;
-
-    constructor(error: string) {
-        super(error);
-    }
-}
-
-/**
- * Exception for HTTP 401 Unauthorized
- */
-export class UnauthorizedException extends Error {
-    status = 401;
-    constructor(message: string = 'Unauthorized') {
-        super(message);
-    }
-}
-
-/**
- * Exception for HTTP 403 Forbidden
- */
-export class ForbiddenException extends Error {
-    status = 403;
-
-    constructor(message: string = 'Forbidden') {
-        super(message);
-    }
-}
-
-/**
- * Exception for HTTP 404 Not Found
- */
-export class NotFoundException extends Error {
-    public status = 404;
-
-    constructor(error: string) {
-        super(error);
-    }
-}

backend/src/exceptions/bad-request-exception.ts

@@ -0,0 +1,10 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 400 Bad Request
+ */
+export class BadRequestException extends ExceptionWithHttpState {
+    constructor(error: string) {
+        super(400, error);
+    }
+}

backend/src/exceptions/conflict-exception.ts

@@ -0,0 +1,12 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 409 Conflict
+ */
+export class ConflictException extends ExceptionWithHttpState {
+    public status = 409;
+
+    constructor(error: string) {
+        super(409, error);
+    }
+}

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

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

backend/src/exceptions/exception-with-http-state.ts

@@ -0,0 +1,13 @@
+import { HasStatusCode } from './has-status-code';
+
+/**
+ * Exceptions which are associated with a HTTP error code.
+ */
+export abstract class ExceptionWithHttpState extends Error implements HasStatusCode {
+    constructor(
+        public status: number,
+        public error: string
+    ) {
+        super(error);
+    }
+}

backend/src/exceptions/forbidden-exception.ts

@@ -0,0 +1,12 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 403 Forbidden
+ */
+export class ForbiddenException extends ExceptionWithHttpState {
+    status = 403;
+
+    constructor(message = 'Forbidden') {
+        super(403, message);
+    }
+}

backend/src/exceptions/has-status-code.ts

@@ -0,0 +1,6 @@
+export interface HasStatusCode {
+    status: number;
+}
+export function hasStatusCode(err: unknown): err is HasStatusCode {
+    return typeof err === 'object' && err !== null && 'status' in err && typeof (err as HasStatusCode)?.status === 'number';
+}

backend/src/exceptions/not-found-exception.ts

@@ -0,0 +1,12 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 404 Not Found
+ */
+export class NotFoundException extends ExceptionWithHttpState {
+    public status = 404;
+
+    constructor(error: string) {
+        super(404, error);
+    }
+}

backend/src/exceptions/server-error-exception.ts

@@ -0,0 +1,12 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 500 Internal Server Error
+ */
+export class ServerErrorException extends ExceptionWithHttpState {
+    status = 500;
+
+    constructor(message = 'Internal server error, something went wrong') {
+        super(500, message);
+    }
+}

backend/src/exceptions/unauthorized-exception.ts

@@ -0,0 +1,10 @@
+import { ExceptionWithHttpState } from './exception-with-http-state.js';
+
+/**
+ * Exception for HTTP 401 Unauthorized
+ */
+export class UnauthorizedException extends ExceptionWithHttpState {
+    constructor(message = 'Unauthorized') {
+        super(401, message);
+    }
+}

backend/src/interfaces/answer.ts

@@ -1,21 +1,14 @@
-import { mapToUserDTO, UserDTO } from './user.js';
-import { mapToQuestionDTO, mapToQuestionId, QuestionDTO, QuestionId } from './question.js';
+import { mapToQuestionDTO, mapToQuestionDTOId } from './question.js';
 import { Answer } from '../entities/questions/answer.entity.js';
-
-export interface AnswerDTO {
-    author: UserDTO;
-    toQuestion: QuestionDTO;
-    sequenceNumber: number;
-    timestamp: string;
-    content: string;
-}
+import { AnswerDTO, AnswerId } from '@dwengo-1/common/interfaces/answer';
+import { mapToTeacherDTO } from './teacher.js';
 
 /**
  * Convert a Question entity to a DTO format.
  */
 export function mapToAnswerDTO(answer: Answer): AnswerDTO {
     return {
-        author: mapToUserDTO(answer.author),
+        author: mapToTeacherDTO(answer.author),
         toQuestion: mapToQuestionDTO(answer.toQuestion),
         sequenceNumber: answer.sequenceNumber!,
         timestamp: answer.timestamp.toISOString(),
@@ -23,16 +16,10 @@ export function mapToAnswerDTO(answer: Answer): AnswerDTO {
     };
 }
 
-export interface AnswerId {
-    author: string;
-    toQuestion: QuestionId;
-    sequenceNumber: number;
-}
-
-export function mapToAnswerId(answer: AnswerDTO): AnswerId {
+export function mapToAnswerDTOId(answer: Answer): AnswerId {
     return {
         author: answer.author.username,
-        toQuestion: mapToQuestionId(answer.toQuestion),
-        sequenceNumber: answer.sequenceNumber,
+        toQuestion: mapToQuestionDTOId(answer.toQuestion),
+        sequenceNumber: answer.sequenceNumber!,
     };
 }

backend/src/interfaces/assignment.ts

@@ -1,50 +1,36 @@
-import { FALLBACK_LANG } from '../config.js';
+import { languageMap } from '@dwengo-1/common/util/language';
 import { Assignment } from '../entities/assignments/assignment.entity.js';
 import { Class } from '../entities/classes/class.entity.js';
-import { languageMap } from '../entities/content/language.js';
-import { GroupDTO } from './group.js';
+import { AssignmentDTO, AssignmentDTOId } from '@dwengo-1/common/interfaces/assignment';
+import { mapToGroupDTO } from './group.js';
+import { getAssignmentRepository } from '../data/repositories.js';
 
-export interface AssignmentDTO {
-    id: number;
-    class: string; // Id of class 'within'
-    title: string;
-    description: string;
-    learningPath: string;
-    language: string;
-    groups?: GroupDTO[] | string[]; // TODO
-}
-
-export function mapToAssignmentDTOId(assignment: Assignment): AssignmentDTO {
+export function mapToAssignmentDTOId(assignment: Assignment): AssignmentDTOId {
     return {
         id: assignment.id!,
-        class: assignment.within.classId!,
-        title: assignment.title,
-        description: assignment.description,
-        learningPath: assignment.learningPathHruid,
-        language: assignment.learningPathLanguage,
-        // Groups: assignment.groups.map(group => group.groupNumber),
+        within: assignment.within.classId!,
     };
 }
 
 export function mapToAssignmentDTO(assignment: Assignment): AssignmentDTO {
     return {
         id: assignment.id!,
-        class: assignment.within.classId!,
+        within: assignment.within.classId!,
         title: assignment.title,
         description: assignment.description,
         learningPath: assignment.learningPathHruid,
         language: assignment.learningPathLanguage,
-        // Groups: assignment.groups.map(mapToGroupDTO),
+        groups: assignment.groups.map((group) => mapToGroupDTO(group, assignment.within)),
     };
 }
 
 export function mapToAssignment(assignmentData: AssignmentDTO, cls: Class): Assignment {
-    const assignment = new Assignment();
-    assignment.title = assignmentData.title;
-    assignment.description = assignmentData.description;
-    assignment.learningPathHruid = assignmentData.learningPath;
-    assignment.learningPathLanguage = languageMap[assignmentData.language] || FALLBACK_LANG;
-    assignment.within = cls;
-
-    return assignment;
+    return getAssignmentRepository().create({
+        within: cls,
+        title: assignmentData.title,
+        description: assignmentData.description,
+        learningPathHruid: assignmentData.learningPath,
+        learningPathLanguage: languageMap[assignmentData.language],
+        groups: [],
+    });
 }

backend/src/interfaces/class.ts

@@ -2,14 +2,7 @@ import { Collection } from '@mikro-orm/core';
 import { Class } from '../entities/classes/class.entity.js';
 import { Student } from '../entities/users/student.entity.js';
 import { Teacher } from '../entities/users/teacher.entity.js';
-
-export interface ClassDTO {
-    id: string;
-    displayName: string;
-    teachers: string[];
-    students: string[];
-    joinRequests: string[];
-}
+import { ClassDTO } from '@dwengo-1/common/interfaces/class';
 
 export function mapToClassDTO(cls: Class): ClassDTO {
     return {
@@ -17,7 +10,6 @@ export function mapToClassDTO(cls: Class): ClassDTO {
         displayName: cls.displayName,
         teachers: cls.teachers.map((teacher) => teacher.username),
         students: cls.students.map((student) => student.username),
-        joinRequests: [], // TODO
     };
 }
 

backend/src/interfaces/group.ts

@@ -1,23 +1,46 @@
 import { Group } from '../entities/assignments/group.entity.js';
-import { AssignmentDTO, mapToAssignmentDTO } from './assignment.js';
-import { mapToStudentDTO, StudentDTO } from './student.js';
+import { mapToAssignment } from './assignment.js';
+import { mapToStudent } from './student.js';
+import { mapToStudentDTO } from './student.js';
+import { GroupDTO, GroupDTOId } from '@dwengo-1/common/interfaces/group';
+import { getGroupRepository } from '../data/repositories.js';
+import { AssignmentDTO } from '@dwengo-1/common/interfaces/assignment';
+import { Class } from '../entities/classes/class.entity.js';
+import { StudentDTO } from '@dwengo-1/common/interfaces/student';
 
-export interface GroupDTO {
-    assignment: number | AssignmentDTO;
-    groupNumber: number;
-    members: string[] | StudentDTO[];
+export function mapToGroup(groupDto: GroupDTO, clazz: Class): Group {
+    const assignmentDto = groupDto.assignment as AssignmentDTO;
+
+    return getGroupRepository().create({
+        groupNumber: groupDto.groupNumber,
+        assignment: mapToAssignment(assignmentDto, clazz),
+        members: groupDto.members!.map((studentDto) => mapToStudent(studentDto as StudentDTO)),
+    });
 }
 
-export function mapToGroupDTO(group: Group): GroupDTO {
+export function mapToGroupDTO(group: Group, cls: Class): GroupDTO {
     return {
-        assignment: mapToAssignmentDTO(group.assignment), // ERROR: , group.assignment.within),
+        class: cls.classId!,
+        assignment: group.assignment.id!,
         groupNumber: group.groupNumber!,
         members: group.members.map(mapToStudentDTO),
     };
 }
 
-export function mapToGroupDTOId(group: Group): GroupDTO {
+export function mapToGroupDTOId(group: Group, cls: Class): GroupDTOId {
     return {
+        class: cls.classId!,
+        assignment: group.assignment.id!,
+        groupNumber: group.groupNumber!,
+    };
+}
+
+/**
+ * Map to group DTO where other objects are only referenced by their id.
+ */
+export function mapToShallowGroupDTO(group: Group): GroupDTO {
+    return {
+        class: group.assignment.within.classId!,
         assignment: group.assignment.id!,
         groupNumber: group.groupNumber!,
         members: group.members.map((member) => member.username),

backend/src/interfaces/learning-content.ts

@@ -1,112 +0,0 @@
-import { Language } from '../entities/content/language';
-
-export interface Transition {
-    default: boolean;
-    _id: string;
-    next: {
-        _id: string;
-        hruid: string;
-        version: number;
-        language: string;
-    };
-}
-
-export interface LearningObjectIdentifier {
-    hruid: string;
-    language: Language;
-    version?: number;
-}
-
-export interface LearningObjectNode {
-    _id: string;
-    learningobject_hruid: string;
-    version: number;
-    language: Language;
-    start_node?: boolean;
-    transitions: Transition[];
-    created_at: string;
-    updatedAt: string;
-    done?: boolean; // True if a submission exists for this node by the user for whom the learning path is customized.
-}
-
-export interface LearningPath {
-    _id: string;
-    language: string;
-    hruid: string;
-    title: string;
-    description: string;
-    image?: string; // Image might be missing, so it's optional
-    num_nodes: number;
-    num_nodes_left: number;
-    nodes: LearningObjectNode[];
-    keywords: string;
-    target_ages: number[];
-    min_age: number;
-    max_age: number;
-    __order: number;
-}
-
-export interface LearningPathIdentifier {
-    hruid: string;
-    language: Language;
-}
-
-export interface EducationalGoal {
-    source: string;
-    id: string;
-}
-
-export interface ReturnValue {
-    callback_url: string;
-    callback_schema: Record<string, any>;
-}
-
-export interface LearningObjectMetadata {
-    _id: string;
-    uuid: string;
-    hruid: string;
-    version: number;
-    language: Language;
-    title: string;
-    description: string;
-    difficulty: number;
-    estimated_time: number;
-    available: boolean;
-    teacher_exclusive: boolean;
-    educational_goals: EducationalGoal[];
-    keywords: string[];
-    target_ages: number[];
-    content_type: string; // Markdown, image, etc.
-    content_location?: string;
-    skos_concepts?: string[];
-    return_value?: ReturnValue;
-}
-
-export interface FilteredLearningObject {
-    key: string;
-    _id: string;
-    uuid: string;
-    version: number;
-    title: string;
-    htmlUrl: string;
-    language: Language;
-    difficulty: number;
-    estimatedTime?: number;
-    available: boolean;
-    teacherExclusive: boolean;
-    educationalGoals: EducationalGoal[];
-    keywords: string[];
-    description: string;
-    targetAges: number[];
-    contentType: string;
-    contentLocation?: string;
-    skosConcepts?: string[];
-    returnValue?: ReturnValue;
-}
-
-export interface LearningPathResponse {
-    success: boolean;
-    source: string;
-    data: LearningPath[] | null;
-    message?: string;
-}

backend/src/interfaces/question.ts

@@ -1,42 +1,47 @@
 import { Question } from '../entities/questions/question.entity.js';
+import { mapToStudentDTO } from './student.js';
+import { QuestionDTO, QuestionId } from '@dwengo-1/common/interfaces/question';
+import { LearningObjectIdentifierDTO } from '@dwengo-1/common/interfaces/learning-content';
 import { LearningObjectIdentifier } from '../entities/content/learning-object-identifier.js';
-import { mapToStudentDTO, StudentDTO } from './student.js';
+import { mapToGroupDTOId } from './group.js';
 
-export interface QuestionDTO {
-    learningObjectIdentifier: LearningObjectIdentifier;
-    sequenceNumber?: number;
-    author: StudentDTO;
-    timestamp?: string;
-    content: string;
+function getLearningObjectIdentifier(question: Question): LearningObjectIdentifierDTO {
+    return {
+        hruid: question.learningObjectHruid,
+        language: question.learningObjectLanguage,
+        version: question.learningObjectVersion,
+    };
+}
+
+export function mapToLearningObjectID(loID: LearningObjectIdentifierDTO): LearningObjectIdentifier {
+    return {
+        hruid: loID.hruid,
+        language: loID.language,
+        version: loID.version ?? 1,
+    };
 }
 
 /**
  * Convert a Question entity to a DTO format.
  */
 export function mapToQuestionDTO(question: Question): QuestionDTO {
-    const learningObjectIdentifier = {
-        hruid: question.learningObjectHruid,
-        language: question.learningObjectLanguage,
-        version: question.learningObjectVersion,
-    };
+    const learningObjectIdentifier = getLearningObjectIdentifier(question);
 
     return {
         learningObjectIdentifier,
         sequenceNumber: question.sequenceNumber!,
         author: mapToStudentDTO(question.author),
+        inGroup: mapToGroupDTOId(question.inGroup, question.inGroup.assignment?.within),
         timestamp: question.timestamp.toISOString(),
         content: question.content,
     };
 }
 
-export interface QuestionId {
-    learningObjectIdentifier: LearningObjectIdentifier;
-    sequenceNumber: number;
-}
+export function mapToQuestionDTOId(question: Question): QuestionId {
+    const learningObjectIdentifier = getLearningObjectIdentifier(question);
 
-export function mapToQuestionId(question: QuestionDTO): QuestionId {
     return {
-        learningObjectIdentifier: question.learningObjectIdentifier,
+        learningObjectIdentifier,
         sequenceNumber: question.sequenceNumber!,
     };
 }

backend/src/interfaces/student-request.ts

@@ -0,0 +1,23 @@
+import { mapToStudentDTO } from './student.js';
+import { ClassJoinRequest } from '../entities/classes/class-join-request.entity.js';
+import { getClassJoinRequestRepository } from '../data/repositories.js';
+import { Student } from '../entities/users/student.entity.js';
+import { Class } from '../entities/classes/class.entity.js';
+import { ClassJoinRequestDTO } from '@dwengo-1/common/interfaces/class-join-request';
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
+
+export function mapToStudentRequestDTO(request: ClassJoinRequest): ClassJoinRequestDTO {
+    return {
+        requester: mapToStudentDTO(request.requester),
+        class: request.class.classId!,
+        status: request.status,
+    };
+}
+
+export function mapToStudentRequest(student: Student, cls: Class): ClassJoinRequest {
+    return getClassJoinRequestRepository().create({
+        requester: student,
+        class: cls,
+        status: ClassStatus.Open,
+    });
+}

backend/src/interfaces/student.ts

@@ -1,17 +1,6 @@
 import { Student } from '../entities/users/student.entity.js';
-
-export interface StudentDTO {
-    id: string;
-    username: string;
-    firstName: string;
-    lastName: string;
-    endpoints?: {
-        classes: string;
-        questions: string;
-        invitations: string;
-        groups: string;
-    };
-}
+import { getStudentRepository } from '../data/repositories.js';
+import { StudentDTO } from '@dwengo-1/common/interfaces/student';
 
 export function mapToStudentDTO(student: Student): StudentDTO {
     return {
@@ -23,7 +12,9 @@ export function mapToStudentDTO(student: Student): StudentDTO {
 }
 
 export function mapToStudent(studentData: StudentDTO): Student {
-    const student = new Student(studentData.username, studentData.firstName, studentData.lastName);
-
-    return student;
+    return getStudentRepository().create({
+        username: studentData.username,
+        firstName: studentData.firstName,
+        lastName: studentData.lastName,
+    });
 }

backend/src/interfaces/submission.ts

@@ -1,26 +1,10 @@
 import { Submission } from '../entities/assignments/submission.entity.js';
-import { Language } from '../entities/content/language.js';
-import { GroupDTO, mapToGroupDTO } from './group.js';
-import { mapToStudent, mapToStudentDTO, StudentDTO } from './student.js';
-import { LearningObjectIdentifier } from './learning-content.js';
-
-export interface SubmissionDTO {
-    learningObjectIdentifier: LearningObjectIdentifier;
-
-    submissionNumber?: number;
-    submitter: StudentDTO;
-    time?: Date;
-    group?: GroupDTO;
-    content: string;
-}
-
-export interface SubmissionDTOId {
-    learningObjectHruid: string;
-    learningObjectLanguage: Language;
-    learningObjectVersion: number;
-
-    submissionNumber?: number;
-}
+import { mapToGroupDTOId } from './group.js';
+import { mapToStudentDTO } from './student.js';
+import { SubmissionDTO, SubmissionDTOId } from '@dwengo-1/common/interfaces/submission';
+import { getSubmissionRepository } from '../data/repositories.js';
+import { Student } from '../entities/users/student.entity.js';
+import { Group } from '../entities/assignments/group.entity.js';
 
 export function mapToSubmissionDTO(submission: Submission): SubmissionDTO {
     return {
@@ -29,11 +13,10 @@ export function mapToSubmissionDTO(submission: Submission): SubmissionDTO {
             language: submission.learningObjectLanguage,
             version: submission.learningObjectVersion,
         },
-
         submissionNumber: submission.submissionNumber,
         submitter: mapToStudentDTO(submission.submitter),
         time: submission.submissionTime,
-        group: submission.onBehalfOf ? mapToGroupDTO(submission.onBehalfOf) : undefined,
+        group: submission.onBehalfOf ? mapToGroupDTOId(submission.onBehalfOf, submission.onBehalfOf.assignment.within) : undefined,
         content: submission.content,
     };
 }
@@ -48,17 +31,14 @@ export function mapToSubmissionDTOId(submission: Submission): SubmissionDTOId {
     };
 }
 
-export function mapToSubmission(submissionDTO: SubmissionDTO): Submission {
-    const submission = new Submission();
-    submission.learningObjectHruid = submissionDTO.learningObjectIdentifier.hruid;
-    submission.learningObjectLanguage = submissionDTO.learningObjectIdentifier.language;
-    submission.learningObjectVersion = submissionDTO.learningObjectIdentifier.version!;
-    // Submission.submissionNumber = submissionDTO.submissionNumber;
-    submission.submitter = mapToStudent(submissionDTO.submitter);
-    // Submission.submissionTime = submissionDTO.time;
-    // Submission.onBehalfOf =  submissionDTO.group!;
-    // TODO fix group
-    submission.content = submissionDTO.content;
-
-    return submission;
+export function mapToSubmission(submissionDTO: SubmissionDTO, submitter: Student, onBehalfOf: Group): Submission {
+    return getSubmissionRepository().create({
+        learningObjectHruid: submissionDTO.learningObjectIdentifier.hruid,
+        learningObjectLanguage: submissionDTO.learningObjectIdentifier.language,
+        learningObjectVersion: submissionDTO.learningObjectIdentifier.version || 1,
+        submitter: submitter,
+        submissionTime: new Date(),
+        content: submissionDTO.content,
+        onBehalfOf: onBehalfOf,
+    });
 }

backend/src/interfaces/teacher-invitation.ts

@@ -1,18 +1,17 @@
 import { TeacherInvitation } from '../entities/classes/teacher-invitation.entity.js';
-import { ClassDTO, mapToClassDTO } from './class.js';
-import { mapToUserDTO, UserDTO } from './user.js';
-
-export interface TeacherInvitationDTO {
-    sender: string | UserDTO;
-    receiver: string | UserDTO;
-    class: string | ClassDTO;
-}
+import { mapToUserDTO } from './user.js';
+import { TeacherInvitationDTO } from '@dwengo-1/common/interfaces/teacher-invitation';
+import { getTeacherInvitationRepository } from '../data/repositories.js';
+import { Teacher } from '../entities/users/teacher.entity.js';
+import { Class } from '../entities/classes/class.entity.js';
+import { ClassStatus } from '@dwengo-1/common/util/class-join-request';
 
 export function mapToTeacherInvitationDTO(invitation: TeacherInvitation): TeacherInvitationDTO {
     return {
         sender: mapToUserDTO(invitation.sender),
         receiver: mapToUserDTO(invitation.receiver),
-        class: mapToClassDTO(invitation.class),
+        classId: invitation.class.classId!,
+        status: invitation.status,
     };
 }
 
@@ -20,6 +19,16 @@ export function mapToTeacherInvitationDTOIds(invitation: TeacherInvitation): Tea
     return {
         sender: invitation.sender.username,
         receiver: invitation.receiver.username,
-        class: invitation.class.classId!,
+        classId: invitation.class.classId!,
+        status: invitation.status,
     };
 }
+
+export function mapToInvitation(sender: Teacher, receiver: Teacher, cls: Class): TeacherInvitation {
+    return getTeacherInvitationRepository().create({
+        sender,
+        receiver,
+        class: cls,
+        status: ClassStatus.Open,
+    });
+}

backend/src/interfaces/teacher.ts

@@ -1,17 +1,6 @@
 import { Teacher } from '../entities/users/teacher.entity.js';
-
-export interface TeacherDTO {
-    id: string;
-    username: string;
-    firstName: string;
-    lastName: string;
-    endpoints?: {
-        classes: string;
-        questions: string;
-        invitations: string;
-        groups: string;
-    };
-}
+import { getTeacherRepository } from '../data/repositories.js';
+import { TeacherDTO } from '@dwengo-1/common/interfaces/teacher';
 
 export function mapToTeacherDTO(teacher: Teacher): TeacherDTO {
     return {
@@ -22,8 +11,10 @@ export function mapToTeacherDTO(teacher: Teacher): TeacherDTO {
     };
 }
 
-export function mapToTeacher(TeacherData: TeacherDTO): Teacher {
-    const teacher = new Teacher(TeacherData.username, TeacherData.firstName, TeacherData.lastName);
-
-    return teacher;
+export function mapToTeacher(teacherData: TeacherDTO): Teacher {
+    return getTeacherRepository().create({
+        username: teacherData.username,
+        firstName: teacherData.firstName,
+        lastName: teacherData.lastName,
+    });
 }

backend/src/interfaces/user.ts

@@ -1,17 +1,5 @@
 import { User } from '../entities/users/user.entity.js';
-
-export interface UserDTO {
-    id?: string;
-    username: string;
-    firstName: string;
-    lastName: string;
-    endpoints?: {
-        self: string;
-        classes: string;
-        questions: string;
-        invitations: string;
-    };
-}
+import { UserDTO } from '@dwengo-1/common/interfaces/user';
 
 export function mapToUserDTO(user: User): UserDTO {
     return {

backend/src/logging/initalize.ts

@@ -1,7 +1,7 @@
 import { createLogger, format, Logger as WinstonLogger, transports } from 'winston';
 import LokiTransport from 'winston-loki';
 import { LokiLabels } from 'loki-logger-ts';
-import { EnvVars, getEnvVar } from '../util/envvars.js';
+import { envVars, getEnvVar } from '../util/envVars.js';
 
 export class Logger extends WinstonLogger {
     constructor() {
@@ -9,7 +9,7 @@ export class Logger extends WinstonLogger {
     }
 }
 
-const Labels: LokiLabels = {
+const lokiLabels: LokiLabels = {
     source: 'Dwengo-Backend',
     service: 'API',
     host: 'localhost',
@@ -22,28 +22,30 @@ function initializeLogger(): Logger {
         return logger;
     }
 
-    const logLevel = getEnvVar(EnvVars.LogLevel);
+    const logLevel = getEnvVar(envVars.LogLevel);
 
     const consoleTransport = new transports.Console({
-        level: getEnvVar(EnvVars.LogLevel),
-        format: format.combine(format.cli(), format.colorize()),
+        level: getEnvVar(envVars.LogLevel),
+        format: format.combine(format.cli(), format.simple()),
     });
 
-    if (getEnvVar(EnvVars.RunMode) === 'dev') {
-        return createLogger({
+    if (getEnvVar(envVars.RunMode) === 'dev') {
+        logger = createLogger({
             transports: [consoleTransport],
         });
+        logger.debug(`Logger initialized with level ${logLevel} to console`);
+        return logger;
     }
 
-    const lokiHost = getEnvVar(EnvVars.LokiHost);
+    const lokiHost = getEnvVar(envVars.LokiHost);
 
     const lokiTransport: LokiTransport = new LokiTransport({
         host: lokiHost,
-        labels: Labels,
+        labels: lokiLabels,
         level: logLevel,
         json: true,
         format: format.combine(format.timestamp(), format.json()),
-        onConnectionError: (err) => {
+        onConnectionError: (err): void => {
             // eslint-disable-next-line no-console
             console.error(`Connection error: ${err}`);
         },

backend/src/logging/mikroOrmLogger.ts

@@ -5,35 +5,54 @@ import { LokiLabels } from 'loki-logger-ts';
 export class MikroOrmLogger extends DefaultLogger {
     private logger: Logger = getLogger();
 
-    log(namespace: LoggerNamespace, message: string, context?: LogContext) {
+    static createMessage(namespace: LoggerNamespace, messageArg: string, context?: LogContext): unknown {
+        const labels: LokiLabels = {
+            service: 'ORM',
+        };
+
+        let message: string;
+        if (context !== undefined && context.labels !== undefined) {
+            message = `[${namespace}] (${context.label}) ${messageArg}`;
+        } else {
+            message = `[${namespace}] ${messageArg}`;
+        }
+
+        return {
+            message: message,
+            labels: labels,
+            context: context,
+        };
+    }
+
+    log(namespace: LoggerNamespace, message: string, context?: LogContext): void {
         if (!this.isEnabled(namespace, context)) {
             return;
         }
 
         switch (namespace) {
             case 'query':
-                this.logger.debug(this.createMessage(namespace, message, context));
+                this.logger.debug(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             case 'query-params':
                 // TODO Which log level should this be?
-                this.logger.info(this.createMessage(namespace, message, context));
+                this.logger.info(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             case 'schema':
-                this.logger.info(this.createMessage(namespace, message, context));
+                this.logger.info(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             case 'discovery':
-                this.logger.debug(this.createMessage(namespace, message, context));
+                this.logger.debug(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             case 'info':
-                this.logger.info(this.createMessage(namespace, message, context));
+                this.logger.info(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             case 'deprecated':
-                this.logger.warn(this.createMessage(namespace, message, context));
+                this.logger.warn(MikroOrmLogger.createMessage(namespace, message, context));
                 break;
             default:
                 switch (context?.level) {
                     case 'info':
-                        this.logger.info(this.createMessage(namespace, message, context));
+                        this.logger.info(MikroOrmLogger.createMessage(namespace, message, context));
                         break;
                     case 'warning':
                         this.logger.warn(message);
@@ -47,23 +66,4 @@ export class MikroOrmLogger extends DefaultLogger {
                 }
         }
     }
-
-    private createMessage(namespace: LoggerNamespace, messageArg: string, context?: LogContext) {
-        const labels: LokiLabels = {
-            service: 'ORM',
-        };
-
-        let message: string;
-        if (context?.label) {
-            message = `[${namespace}] (${context?.label}) ${messageArg}`;
-        } else {
-            message = `[${namespace}] ${messageArg}`;
-        }
-
-        return {
-            message: message,
-            labels: labels,
-            context: context,
-        };
-    }
 }

backend/src/logging/responseTimeLogger.ts

@@ -1,7 +1,7 @@
 import { getLogger, Logger } from './initalize.js';
 import { Request, Response } from 'express';
 
-export function responseTimeLogger(req: Request, res: Response, time: number) {
+export function responseTimeLogger(req: Request, res: Response, time: number): void {
     const logger: Logger = getLogger();
 
     const method = req.method;

backend/src/middleware/auth/auth.ts

@@ -1,12 +1,13 @@
-import { EnvVars, getEnvVar } from '../../util/envvars.js';
+import { envVars, getEnvVar } from '../../util/envVars.js';
 import { expressjwt } from 'express-jwt';
+import * as jwt from 'jsonwebtoken';
 import { JwtPayload } from 'jsonwebtoken';
 import jwksClient from 'jwks-rsa';
 import * as express from 'express';
-import * as jwt from 'jsonwebtoken';
 import { AuthenticatedRequest } from './authenticated-request.js';
 import { AuthenticationInfo } from './authentication-info.js';
-import { ForbiddenException, UnauthorizedException } from '../../exceptions.js';
+import { UnauthorizedException } from '../../exceptions/unauthorized-exception.js';
+import { ForbiddenException } from '../../exceptions/forbidden-exception.js';
 
 const JWKS_CACHE = true;
 const JWKS_RATE_LIMIT = true;
@@ -32,12 +33,12 @@ function createJwksClient(uri: string): jwksClient.JwksClient {
 
 const idpConfigs = {
     student: {
-        issuer: getEnvVar(EnvVars.IdpStudentUrl),
-        jwksClient: createJwksClient(getEnvVar(EnvVars.IdpStudentJwksEndpoint)),
+        issuer: getEnvVar(envVars.IdpStudentUrl),
+        jwksClient: createJwksClient(getEnvVar(envVars.IdpStudentJwksEndpoint)),
     },
     teacher: {
-        issuer: getEnvVar(EnvVars.IdpTeacherUrl),
-        jwksClient: createJwksClient(getEnvVar(EnvVars.IdpTeacherJwksEndpoint)),
+        issuer: getEnvVar(envVars.IdpTeacherUrl),
+        jwksClient: createJwksClient(getEnvVar(envVars.IdpTeacherJwksEndpoint)),
     },
 };
 
@@ -47,14 +48,14 @@ const idpConfigs = {
 const verifyJwtToken = expressjwt({
     secret: async (_: express.Request, token: jwt.Jwt | undefined) => {
         if (!token?.payload || !(token.payload as JwtPayload).iss) {
-            throw new Error('Invalid token');
+            throw new UnauthorizedException('Invalid token.');
         }
 
         const issuer = (token.payload as JwtPayload).iss;
 
         const idpConfig = Object.values(idpConfigs).find((config) => config.issuer === issuer);
         if (!idpConfig) {
-            throw new Error('Issuer not accepted.');
+            throw new UnauthorizedException('Issuer not accepted.');
         }
 
         const signingKey = await idpConfig.jwksClient.getSigningKey(token.header.kid);
@@ -63,7 +64,7 @@ const verifyJwtToken = expressjwt({
         }
         return signingKey.getPublicKey();
     },
-    audience: getEnvVar(EnvVars.IdpAudience),
+    audience: getEnvVar(envVars.IdpAudience),
     algorithms: [JWT_ALGORITHM],
     credentialsRequired: false,
     requestProperty: REQUEST_PROPERTY_FOR_JWT_PAYLOAD,
@@ -74,7 +75,7 @@ const verifyJwtToken = expressjwt({
  */
 function getAuthenticationInfo(req: AuthenticatedRequest): AuthenticationInfo | undefined {
     if (!req.jwtPayload) {
-        return;
+        return undefined;
     }
     const issuer = req.jwtPayload.iss;
     let accountType: 'student' | 'teacher';
@@ -84,8 +85,9 @@ function getAuthenticationInfo(req: AuthenticatedRequest): AuthenticationInfo |
     } else if (issuer === idpConfigs.teacher.issuer) {
         accountType = 'teacher';
     } else {
-        return;
+        return undefined;
     }
+
     return {
         accountType: accountType,
         username: req.jwtPayload[JWT_PROPERTY_NAMES.username]!,
@@ -100,10 +102,10 @@ function getAuthenticationInfo(req: AuthenticatedRequest): AuthenticationInfo |
  * Add the AuthenticationInfo object with the information about the current authentication to the request in order
  * to avoid that the routers have to deal with the JWT token.
  */
-const addAuthenticationInfo = (req: AuthenticatedRequest, res: express.Response, next: express.NextFunction) => {
+function addAuthenticationInfo(req: AuthenticatedRequest, _res: express.Response, next: express.NextFunction): void {
     req.auth = getAuthenticationInfo(req);
     next();
-};
+}
 
 export const authenticateUser = [verifyJwtToken, addAuthenticationInfo];
 
@@ -113,9 +115,8 @@ export const authenticateUser = [verifyJwtToken, addAuthenticationInfo];
  * @param accessCondition Predicate over the current AuthenticationInfo. Access is only granted when this evaluates
  *                        to true.
  */
-export const authorize =
-    (accessCondition: (auth: AuthenticationInfo) => boolean) =>
-    (req: AuthenticatedRequest, res: express.Response, next: express.NextFunction): void => {
+export function authorize(accessCondition: (auth: AuthenticationInfo) => boolean) {
+    return (req: AuthenticatedRequest, _res: express.Response, next: express.NextFunction): void => {
         if (!req.auth) {
             throw new UnauthorizedException();
         } else if (!accessCondition(req.auth)) {
@@ -124,6 +125,7 @@ export const authorize =
             next();
         }
     };
+}
 
 /**
  * Middleware which rejects all unauthenticated users, but accepts all authenticated users.

backend/src/middleware/auth/authentication-info.d.ts

@@ -1,11 +1,11 @@
 /**
  * Object with information about the user who is currently logged in.
  */
-export type AuthenticationInfo = {
+export interface AuthenticationInfo {
     accountType: 'student' | 'teacher';
     username: string;
     name?: string;
     firstName?: string;
     lastName?: string;
     email?: string;
-};
+}

backend/src/middleware/cors.ts

@@ -1,7 +1,7 @@
 import cors from 'cors';
-import { EnvVars, getEnvVar } from '../util/envvars.js';
+import { envVars, getEnvVar } from '../util/envVars.js';
 
 export default cors({
-    origin: getEnvVar(EnvVars.CorsAllowedOrigins).split(','),
-    allowedHeaders: getEnvVar(EnvVars.CorsAllowedHeaders).split(','),
+    origin: getEnvVar(envVars.CorsAllowedOrigins).split(','),
+    allowedHeaders: getEnvVar(envVars.CorsAllowedHeaders).split(','),
 });

backend/src/middleware/error-handling/error-handler.ts

@@ -0,0 +1,15 @@
+import { NextFunction, Request, Response } from 'express';
+import { getLogger, Logger } from '../../logging/initalize.js';
+import { hasStatusCode } from '../../exceptions/has-status-code.js';
+
+const logger: Logger = getLogger();
+
+export function errorHandler(err: unknown, _req: Request, res: Response, _: NextFunction): void {
+    if (hasStatusCode(err)) {
+        logger.warn(`An error occurred while handling a request: ${err} (-> HTTP ${err.status})`);
+        res.status(err.status).json(err);
+    } else {
+        logger.error(`Unexpected error occurred while handing a request: ${(err as { stack: string })?.stack ?? JSON.stringify(err)}`);
+        res.status(500).json(err);
+    }
+}

backend/src/mikro-orm.config.ts

@@ -1,6 +1,6 @@
 import { LoggerOptions, Options } from '@mikro-orm/core';
 import { PostgreSqlDriver } from '@mikro-orm/postgresql';
-import { EnvVars, getEnvVar, getNumericEnvVar } from './util/envvars.js';
+import { envVars, getEnvVar, getNumericEnvVar } from './util/envVars.js';
 import { SqliteDriver } from '@mikro-orm/sqlite';
 import { MikroOrmLogger } from './logging/mikroOrmLogger.js';
 
@@ -42,33 +42,35 @@ const entities = [
     Question,
 ];
 
-function config(testingMode: boolean = false): Options {
+function config(testingMode = false): Options {
     if (testingMode) {
         return {
             driver: SqliteDriver,
-            dbName: getEnvVar(EnvVars.DbName),
+            dbName: getEnvVar(envVars.DbName),
             subscribers: [new SqliteAutoincrementSubscriber()],
             entities: entities,
+            persistOnCreate: false, // Do not implicitly save entities when they are created via `create`.
             // EntitiesTs: entitiesTs,
 
             // Workaround: vitest: `TypeError: Unknown file extension ".ts"` (ERR_UNKNOWN_FILE_EXTENSION)
             // (see https://mikro-orm.io/docs/guide/project-setup#testing-the-endpoint)
-            dynamicImportProvider: (id) => import(id),
+            dynamicImportProvider: async (id) => import(id),
         };
     }
 
     return {
         driver: PostgreSqlDriver,
-        host: getEnvVar(EnvVars.DbHost),
-        port: getNumericEnvVar(EnvVars.DbPort),
-        dbName: getEnvVar(EnvVars.DbName),
-        user: getEnvVar(EnvVars.DbUsername),
-        password: getEnvVar(EnvVars.DbPassword),
+        host: getEnvVar(envVars.DbHost),
+        port: getNumericEnvVar(envVars.DbPort),
+        dbName: getEnvVar(envVars.DbName),
+        user: getEnvVar(envVars.DbUsername),
+        password: getEnvVar(envVars.DbPassword),
         entities: entities,
+        persistOnCreate: false, // Do not implicitly save entities when they are created via `create`.
         // EntitiesTs: entitiesTs,
 
         // Logging
-        debug: getEnvVar(EnvVars.LogLevel) === 'debug',
+        debug: getEnvVar(envVars.LogLevel) === 'debug',
         loggerFactory: (options: LoggerOptions) => new MikroOrmLogger(options),
     };
 }

backend/src/orm.ts

@@ -1,10 +1,10 @@
-import { EntityManager, MikroORM } from '@mikro-orm/core';
+import { EntityManager, IDatabaseDriver, MikroORM } from '@mikro-orm/core';
 import config from './mikro-orm.config.js';
-import { EnvVars, getEnvVar } from './util/envvars.js';
+import { envVars, getEnvVar } from './util/envVars.js';
 import { getLogger, Logger } from './logging/initalize.js';
 
 let orm: MikroORM | undefined;
-export async function initORM(testingMode: boolean = false) {
+export async function initORM(testingMode = false): Promise<MikroORM<IDatabaseDriver, EntityManager>> {
     const logger: Logger = getLogger();
 
     logger.info('Initializing ORM');
@@ -12,7 +12,7 @@ export async function initORM(testingMode: boolean = false) {
 
     orm = await MikroORM.init(config(testingMode));
     // Update the database scheme if necessary and enabled.
-    if (getEnvVar(EnvVars.DbUpdate)) {
+    if (getEnvVar(envVars.DbUpdate)) {
         await orm.schema.updateSchema();
     } else {
         const diff = await orm.schema.getUpdateSchemaSQL();
@@ -25,6 +25,8 @@ export async function initORM(testingMode: boolean = false) {
             );
         }
     }
+
+    return orm;
 }
 export function forkEntityManager(): EntityManager {
     if (!orm) {

backend/src/routes/answers.ts

@@ -0,0 +1,16 @@
+import express from 'express';
+import { createAnswerHandler, deleteAnswerHandler, getAnswerHandler, getAllAnswersHandler, updateAnswerHandler } from '../controllers/answers.js';
+
+const router = express.Router({ mergeParams: true });
+
+router.get('/', getAllAnswersHandler);
+
+router.post('/', createAnswerHandler);
+
+router.get('/:seqAnswer', getAnswerHandler);
+
+router.delete('/:seqAnswer', deleteAnswerHandler);
+
+router.put('/:seqAnswer', updateAnswerHandler);
+
+export default router;

backend/src/routes/assignments.ts

@@ -1,29 +1,30 @@
 import express from 'express';
 import {
     createAssignmentHandler,
+    deleteAssignmentHandler,
     getAllAssignmentsHandler,
     getAssignmentHandler,
+    getAssignmentQuestionsHandler,
     getAssignmentsSubmissionsHandler,
+    putAssignmentHandler,
 } from '../controllers/assignments.js';
 import groupRouter from './groups.js';
 
 const router = express.Router({ mergeParams: true });
 
-// Root endpoint used to search objects
 router.get('/', getAllAssignmentsHandler);
 
 router.post('/', createAssignmentHandler);
 
-// Information about an assignment with id 'id'
 router.get('/:id', getAssignmentHandler);
 
+router.put('/:id', putAssignmentHandler);
+
+router.delete('/:id', deleteAssignmentHandler);
+
 router.get('/:id/submissions', getAssignmentsSubmissionsHandler);
 
-router.get('/:id/questions', (req, res) => {
-    res.json({
-        questions: ['0'],
-    });
-});
+router.get('/:id/questions', getAssignmentQuestionsHandler);
 
 router.use('/:assignmentid/groups', groupRouter);
 

backend/src/routes/auth.ts

@@ -1,26 +1,28 @@
 import express from 'express';
-import { getFrontendAuthConfig } from '../controllers/auth.js';
+import { getFrontendAuthConfig, postHelloHandler } from '../controllers/auth.js';
 import { authenticatedOnly, studentsOnly, teachersOnly } from '../middleware/auth/auth.js';
 const router = express.Router();
 
 // Returns auth configuration for frontend
-router.get('/config', (req, res) => {
+router.get('/config', (_req, res) => {
     res.json(getFrontendAuthConfig());
 });
 
-router.get('/testAuthenticatedOnly', authenticatedOnly, (req, res) => {
+router.get('/testAuthenticatedOnly', authenticatedOnly, (_req, res) => {
     /* #swagger.security = [{ "student": [ ] }, { "teacher": [ ] }] */
     res.json({ message: 'If you see this, you should be authenticated!' });
 });
 
-router.get('/testStudentsOnly', studentsOnly, (req, res) => {
+router.get('/testStudentsOnly', studentsOnly, (_req, res) => {
     /* #swagger.security = [{ "student": [ ] }] */
     res.json({ message: 'If you see this, you should be a student!' });
 });
 
-router.get('/testTeachersOnly', teachersOnly, (req, res) => {
+router.get('/testTeachersOnly', teachersOnly, (_req, res) => {
     /* #swagger.security = [{ "teacher": [ ] }] */
     res.json({ message: 'If you see this, you should be a teacher!' });
 });
 
+router.post('/hello', authenticatedOnly, postHelloHandler);
+
 export default router;

backend/src/routes/classes.ts

@@ -1,10 +1,17 @@
 import express from 'express';
 import {
+    addClassStudentHandler,
+    addClassTeacherHandler,
     createClassHandler,
+    deleteClassHandler,
+    deleteClassStudentHandler,
+    deleteClassTeacherHandler,
     getAllClassesHandler,
     getClassHandler,
     getClassStudentsHandler,
+    getClassTeachersHandler,
     getTeacherInvitationsHandler,
+    putClassHandler,
 } from '../controllers/classes.js';
 import assignmentRouter from './assignments.js';
 
@@ -15,13 +22,26 @@ router.get('/', getAllClassesHandler);
 
 router.post('/', createClassHandler);
 
-// Information about an class with id 'id'
 router.get('/:id', getClassHandler);
 
+router.put('/:id', putClassHandler);
+
+router.delete('/:id', deleteClassHandler);
+
 router.get('/:id/teacher-invitations', getTeacherInvitationsHandler);
 
 router.get('/:id/students', getClassStudentsHandler);
 
+router.post('/:id/students', addClassStudentHandler);
+
+router.delete('/:id/students/:username', deleteClassStudentHandler);
+
+router.get('/:id/teachers', getClassTeachersHandler);
+
+router.post('/:id/teachers', addClassTeacherHandler);
+
+router.delete('/:id/teachers/:username', deleteClassTeacherHandler);
+
 router.use('/:classid/assignments', assignmentRouter);
 
 export default router;

backend/src/routes/groups.ts

@@ -1,5 +1,13 @@
 import express from 'express';
-import { createGroupHandler, getAllGroupsHandler, getGroupHandler, getGroupSubmissionsHandler } from '../controllers/groups.js';
+import {
+    createGroupHandler,
+    deleteGroupHandler,
+    getAllGroupsHandler,
+    getGroupHandler,
+    getGroupQuestionsHandler,
+    getGroupSubmissionsHandler,
+    putGroupHandler,
+} from '../controllers/groups.js';
 
 const router = express.Router({ mergeParams: true });
 
@@ -8,16 +16,14 @@ router.get('/', getAllGroupsHandler);
 
 router.post('/', createGroupHandler);
 
-// Information about a group (members, ... [TODO DOC])
 router.get('/:groupid', getGroupHandler);
 
-router.get('/:groupid', getGroupSubmissionsHandler);
+router.put('/:groupid', putGroupHandler);
 
-// The list of questions a group has made
-router.get('/:id/questions', (req, res) => {
-    res.json({
-        questions: ['0'],
-    });
-});
+router.delete('/:groupid', deleteGroupHandler);
+
+router.get('/:groupid/submissions', getGroupSubmissionsHandler);
+
+router.get('/:groupid/questions', getGroupQuestionsHandler);
 
 export default router;

backend/src/routes/questions.ts

@@ -1,11 +1,7 @@
 import express from 'express';
-import {
-    createQuestionHandler,
-    deleteQuestionHandler,
-    getAllQuestionsHandler,
-    getQuestionAnswersHandler,
-    getQuestionHandler,
-} from '../controllers/questions.js';
+import { createQuestionHandler, deleteQuestionHandler, getAllQuestionsHandler, getQuestionHandler } from '../controllers/questions.js';
+import answerRoutes from './answers.js';
+
 const router = express.Router({ mergeParams: true });
 
 // Query language
@@ -20,6 +16,6 @@ router.delete('/:seq', deleteQuestionHandler);
 // Information about a question with id
 router.get('/:seq', getQuestionHandler);
 
-router.get('/answers/:seq', getQuestionAnswersHandler);
+router.use('/:seq/answers', answerRoutes);
 
 export default router;

backend/src/routes/student-join-requests.ts

@@ -0,0 +1,19 @@
+import express from 'express';
+import {
+    createStudentRequestHandler,
+    deleteClassJoinRequestHandler,
+    getStudentRequestHandler,
+    getStudentRequestsHandler,
+} from '../controllers/students.js';
+
+const router = express.Router({ mergeParams: true });
+
+router.get('/', getStudentRequestsHandler);
+
+router.post('/', createStudentRequestHandler);
+
+router.get('/:classId', getStudentRequestHandler);
+
+router.delete('/:classId', deleteClassJoinRequestHandler);
+
+export default router;

backend/src/routes/students.ts

@@ -7,8 +7,11 @@ import {
     getStudentClassesHandler,
     getStudentGroupsHandler,
     getStudentHandler,
+    getStudentQuestionsHandler,
     getStudentSubmissionsHandler,
 } from '../controllers/students.js';
+import joinRequestRouter from './student-join-requests.js';
+
 const router = express.Router();
 
 // Root endpoint used to search objects
@@ -16,30 +19,26 @@ router.get('/', getAllStudentsHandler);
 
 router.post('/', createStudentHandler);
 
-router.delete('/', deleteStudentHandler);
-
 router.delete('/:username', deleteStudentHandler);
 
 // Information about a student's profile
 router.get('/:username', getStudentHandler);
 
 // The list of classes a student is in
-router.get('/:id/classes', getStudentClassesHandler);
+router.get('/:username/classes', getStudentClassesHandler);
 
 // The list of submissions a student has made
-router.get('/:id/submissions', getStudentSubmissionsHandler);
+router.get('/:username/submissions', getStudentSubmissionsHandler);
 
 // The list of assignments a student has
-router.get('/:id/assignments', getStudentAssignmentsHandler);
+router.get('/:username/assignments', getStudentAssignmentsHandler);
 
 // The list of groups a student is in
-router.get('/:id/groups', getStudentGroupsHandler);
+router.get('/:username/groups', getStudentGroupsHandler);
 
 // A list of questions a user has created
-router.get('/:id/questions', (req, res) => {
-    res.json({
-        questions: ['0'],
-    });
-});
+router.get('/:username/questions', getStudentQuestionsHandler);
+
+router.use('/:username/joinRequests', joinRequestRouter);
 
 export default router;

backend/src/routes/submissions.ts

@@ -1,15 +1,11 @@
 import express from 'express';
-import { createSubmissionHandler, deleteSubmissionHandler, getSubmissionHandler } from '../controllers/submissions.js';
+import { createSubmissionHandler, deleteSubmissionHandler, getSubmissionHandler, getSubmissionsHandler } from '../controllers/submissions.js';
 const router = express.Router({ mergeParams: true });
 
 // Root endpoint used to search objects
-router.get('/', (req, res) => {
-    res.json({
-        submissions: ['0', '1'],
-    });
-});
+router.get('/', getSubmissionsHandler);
 
-router.post('/:id', createSubmissionHandler);
+router.post('/', createSubmissionHandler);
 
 // Information about an submission with id 'id'
 router.get('/:id', getSubmissionHandler);

backend/src/routes/teacher-invitations.ts

@@ -0,0 +1,22 @@
+import express from 'express';
+import {
+    createInvitationHandler,
+    deleteInvitationHandler,
+    getAllInvitationsHandler,
+    getInvitationHandler,
+    updateInvitationHandler,
+} from '../controllers/teacher-invitations.js';
+
+const router = express.Router({ mergeParams: true });
+
+router.get('/:username', getAllInvitationsHandler);
+
+router.get('/:sender/:receiver/:classId', getInvitationHandler);
+
+router.post('/', createInvitationHandler);
+
+router.put('/', updateInvitationHandler);
+
+router.delete('/:sender/:receiver/:classId', deleteInvitationHandler);
+
+export default router;