style: fix linting issues met ESLint

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

@@ -8,9 +8,7 @@ import { TeacherInvitationRepository } from '../../data/classes/teacher-invitati
  */
 @Entity({ repository: () => TeacherInvitationRepository })
 @Entity({
-    repository: () => {
+    repository: () => TeacherInvitationRepository,
-        return TeacherInvitationRepository;
-    },
 })
 export class TeacherInvitation {
     @ManyToOne({

backend/src/sqlite-autoincrement-workaround.ts

@@ -25,7 +25,7 @@ export class SqliteAutoincrementSubscriber implements EventSubscriber {
             return; // If there is not a composite primary key, autoincrement works fine with SQLite anyway.
         }
 
-        for (let prop of Object.values(args.meta.properties)) {
+        for (const prop of Object.values(args.meta.properties)) {
             const property = prop as EntityProperty<T>;
             if (property.primary && property.autoincrement && !(args.entity as Record<string, any>)[property.name]) {
                 // Obtain and increment sequence number of this entity.

backend/tests/test_assets/content/learning-paths.testdata.ts

@@ -72,8 +72,8 @@ export function makeTestLearningPaths(
     learningPathNode05.version = 1;
 
     const nodes01: Array<LearningPathNode> = [
-        // learningPathNode01,
+        // LearningPathNode01,
-        // learningPathNode02,
+        // LearningPathNode02,
     ];
     const learningPath01 = em.create(LearningPath, {
         hruid: 'id01',
@@ -86,9 +86,9 @@ export function makeTestLearningPaths(
     });
 
     const nodes02: Array<LearningPathNode> = [
-        // learningPathNode03,
+        // LearningPathNode03,
-        // learningPathNode04,
+        // LearningPathNode04,
-        // learningPathNode05,
+        // LearningPathNode05,
     ];
     const learningPath02 = em.create(LearningPath, {
         hruid: 'id02',

backend/tests/test_assets/users/students.testdata.ts

@@ -40,7 +40,7 @@ export function makeTestStudents(
         lastName: 'Morisson',
     });
 
-    // do not use for any tests, gets deleted in a unit test
+    // Do not use for any tests, gets deleted in a unit test
     const student07 = em.create(Student, {
         username: 'Nirvana',
         firstName: 'Kurt',

backend/tests/test_assets/users/teachers.testdata.ts

@@ -22,7 +22,7 @@ export function makeTestTeachers(
         lastName: 'Lewis',
     });
 
-    // should not be used, gets deleted in a unit test
+    // Should not be used, gets deleted in a unit test
     const teacher04 = em.create(Teacher, {
         username: 'ZesdeMetaal',
         firstName: 'Wannes',