Solved the same bug but for the e-mail

src/pages/api/assignments/index.ts

@@ -1,14 +1,23 @@
 // Next.js API route support: https://nextjs.org/docs/api-routes/introduction
 import type { NextApiRequest, NextApiResponse } from "next";
 import { app } from "@/firebase";
-import {getFirestore, collection, getDocs, query, where, setDoc, doc, getDoc} from "firebase/firestore";
+import {
+  getFirestore,
+  collection,
+  getDocs,
+  query,
+  where,
+  setDoc,
+  doc,
+  getDoc,
+} from "firebase/firestore";
 import { withIronSessionApiRoute } from "iron-session/next";
 import { sessionOptions } from "@/lib/session";
 import { uuidv4 } from "@firebase/util";
 import { Module } from "@/interfaces";
 import { getExams } from "@/utils/exams.be";
 import { Exam, Variant } from "@/interfaces/exam";
-import {capitalize, flatten} from "lodash";
+import { capitalize, flatten, uniqBy } from "lodash";
 import { User } from "@/interfaces/user";
 import moment from "moment";
 import { sendEmail } from "@/email";
@@ -60,10 +69,17 @@ const generateExams = async (
 ): Promise<ExamWithUser[]> => {
   if (generateMultiple) {
     // for optimization purposes, it would be better to create a new endpoint that returned the answers for all users at once
-		const allExams = await assignees.map(async (assignee) => {
+    const allExams = assignees.map(async (assignee) => {
-			const selectedModulePromises = await selectedModules.map(async (module: Module) => {
+      const selectedModulePromises = selectedModules.map(
+        async (module: Module) => {
           try {
-					const exams: Exam[] = await getExams(db, module, "true", assignee, variant);
+            const exams: Exam[] = await getExams(
+              db,
+              module,
+              "true",
+              assignee,
+              variant,
+            );
 
             const exam = exams[getRandomIndex(exams)];
             if (exam) {
@@ -74,17 +90,21 @@ const generateExams = async (
             console.error(e);
             return null;
           }
-			}, []);
+        },
+        [],
+      );
       const newModules = await Promise.all(selectedModulePromises);
 
       return newModules;
     }, []);
 
-		const exams = flatten(await Promise.all(allExams)).filter((x) => x !== null) as ExamWithUser[];
+    const exams = flatten(await Promise.all(allExams)).filter(
+      (x) => x !== null,
+    ) as ExamWithUser[];
     return exams;
   }
 
-	const selectedModulePromises = await selectedModules.map(async (module: Module) => {
+  const selectedModulePromises = selectedModules.map(async (module: Module) => {
     const exams: Exam[] = await getExams(db, module, "false", undefined);
     const exam = exams[getRandomIndex(exams)];
 
@@ -96,7 +116,11 @@ const generateExams = async (
 
   const exams = await Promise.all(selectedModulePromises);
   const examesFiltered = exams.filter((x) => x !== null) as ExamWithUser[];
-	return flatten(assignees.map((assignee) => examesFiltered.map((exam) => ({...exam, assignee}))));
+  return flatten(
+    assignees.map((assignee) =>
+      examesFiltered.map((exam) => ({ ...exam, assignee })),
+    ),
+  );
 };
 
 async function POST(req: NextApiRequest, res: NextApiResponse) {
@@ -118,10 +142,17 @@ async function POST(req: NextApiRequest, res: NextApiResponse) {
     variant?: Variant;
   };
 
-	const exams: ExamWithUser[] = await generateExams(generateMultiple, selectedModules, assignees, variant);
+  const exams: ExamWithUser[] = await generateExams(
+    generateMultiple,
+    selectedModules,
+    assignees,
+    variant,
+  );
 
   if (exams.length === 0) {
-		res.status(400).json({ok: false, error: "No exams found for the selected modules"});
+    res
+      .status(400)
+      .json({ ok: false, error: "No exams found for the selected modules" });
     return;
   }
 
@@ -142,13 +173,24 @@ async function POST(req: NextApiRequest, res: NextApiResponse) {
     const assignee = { id: assigneeID, ...assigneeSnapshot.data() } as User;
     const name = body.name;
     const teacher = req.session.user!;
-		const examModulesLabel = exams.map((x) => capitalize(x.module)).join(", ");
+    const examModulesLabel = uniqBy(exams, (x) => x.module)
+      .map((x) => capitalize(x.module))
+      .join(", ");
     const startDate = moment(body.startDate).format("DD/MM/YYYY - HH:mm");
     const endDate = moment(body.endDate).format("DD/MM/YYYY - HH:mm");
 
     await sendEmail(
       "assignment",
-			{user: {name: assignee.name}, assignment: {name, startDate, endDate, modules: examModulesLabel, assigner: teacher.name}},
+      {
+        user: { name: assignee.name },
+        assignment: {
+          name,
+          startDate,
+          endDate,
+          modules: examModulesLabel,
+          assigner: teacher.name,
+        },
+      },
       [assignee.email],
       "EnCoach - New Assignment!",
     );