fix(repository): Move backend code into subdirectory

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

backend/src/permissions/note-group-permission.entity.ts

@@ -0,0 +1,52 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  Column,
+  Entity,
+  Index,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
+
+import { Group } from '../groups/group.entity';
+import { Note } from '../notes/note.entity';
+
+@Entity()
+@Index(['group', 'note'], { unique: true })
+export class NoteGroupPermission {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @ManyToOne((_) => Group, {
+    onDelete: 'CASCADE', // This deletes the NoteGroupPermission, when the associated Group is deleted
+    orphanedRowAction: 'delete', // This ensures the row of the NoteGroupPermission is deleted when no group references it anymore
+  })
+  group: Promise<Group>;
+
+  @ManyToOne((_) => Note, (note) => note.groupPermissions, {
+    onDelete: 'CASCADE', // This deletes the NoteGroupPermission, when the associated Note is deleted
+    orphanedRowAction: 'delete', // This ensures the row of the NoteGroupPermission is deleted when no note references it anymore
+  })
+  note: Promise<Note>;
+
+  @Column()
+  canEdit: boolean;
+
+  // eslint-disable-next-line @typescript-eslint/no-empty-function
+  private constructor() {}
+
+  public static create(
+    group: Group,
+    note: Note,
+    canEdit: boolean,
+  ): NoteGroupPermission {
+    const groupPermission = new NoteGroupPermission();
+    groupPermission.group = Promise.resolve(group);
+    groupPermission.note = Promise.resolve(note);
+    groupPermission.canEdit = canEdit;
+    return groupPermission;
+  }
+}