From 65b21fe9048b670ee39b700901630a1cde16b516 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 10:16:37 +0100
Subject: [PATCH 1/9] perf(assignments-service): Add extra indexes on
 Assignee.solution and Evaluation.solution

---
 services/apps/assignments/src/assignee/assignee.schema.ts     | 2 +-
 services/apps/assignments/src/evaluation/evaluation.schema.ts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/services/apps/assignments/src/assignee/assignee.schema.ts b/services/apps/assignments/src/assignee/assignee.schema.ts
index 4e7be9380..bd1e50b79 100644
--- a/services/apps/assignments/src/assignee/assignee.schema.ts
+++ b/services/apps/assignments/src/assignee/assignee.schema.ts
@@ -35,7 +35,7 @@ export class Assignee {
   @IsMongoId()
   assignment: string;
 
-  @Prop()
+  @Prop({index: 1})
   @ApiProperty()
   @IsMongoId()
   solution: string;
diff --git a/services/apps/assignments/src/evaluation/evaluation.schema.ts b/services/apps/assignments/src/evaluation/evaluation.schema.ts
index b5177a66b..76a7e6873 100644
--- a/services/apps/assignments/src/evaluation/evaluation.schema.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.schema.ts
@@ -98,7 +98,7 @@ export class Evaluation {
   @IsMongoId()
   assignment: string;
 
-  @Prop()
+  @Prop({index: 1})
   @ApiProperty()
   @IsMongoId()
   solution: string;

From 2e4ec089eaead4491229959fbf3d2c6c1e8ac5b4 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 10:41:45 +0100
Subject: [PATCH 2/9] refactor(assignments-service): Make Assignee.assignment
 and Assignee.solution ObjectId

---
 .../src/assignee/assignee.controller.ts       | 25 ++++++++++---------
 .../src/assignee/assignee.handler.ts          |  6 ++++-
 .../src/assignee/assignee.schema.ts           | 17 ++++++-------
 .../assignments/src/course/course.service.ts  | 13 +++++-----
 .../src/solution/solution.service.ts          |  8 +++---
 5 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/services/apps/assignments/src/assignee/assignee.controller.ts b/services/apps/assignments/src/assignee/assignee.controller.ts
index e2f328562..fbd2d8711 100644
--- a/services/apps/assignments/src/assignee/assignee.controller.ts
+++ b/services/apps/assignments/src/assignee/assignee.controller.ts
@@ -1,10 +1,11 @@
-import {NotFound} from '@mean-stream/nestx';
+import {NotFound, ObjectIdPipe} from '@mean-stream/nestx';
 import {Body, Controller, Delete, Get, Param, Patch, Put} from '@nestjs/common';
 import {ApiOkResponse, ApiOperation, ApiTags} from '@nestjs/swagger';
 import {AssignmentAuth} from '../assignment/assignment-auth.decorator';
 import {BulkUpdateAssigneeDto, PatchAssigneeDto, UpdateAssigneeDto} from './assignee.dto';
 import {Assignee} from './assignee.schema';
 import {AssigneeService} from './assignee.service';
+import {Types} from "mongoose";
 
 const forbiddenResponse = 'Not owner of assignment, or invalid Assignment-Token';
 
@@ -20,7 +21,7 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: [Assignee]})
   async findAll(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
   ): Promise<Assignee[]> {
     return this.assigneeService.findAll({assignment}, {sort: {assignee: 1}});
   }
@@ -30,7 +31,7 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({isArray: true})
   async findUnique(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
     @Param('field') field: string,
   ): Promise<unknown[]> {
     return this.assigneeService.model.distinct(field, {assignment}).exec();
@@ -40,7 +41,7 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: Assignee})
   async updateMany(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
     @Body() dtos: BulkUpdateAssigneeDto[],
   ): Promise<Assignee[]> {
     return Promise.all(dtos.map(dto => this.assigneeService.upsert({assignment, solution: dto.solution}, dto)));
@@ -51,8 +52,8 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: Assignee})
   async findOne(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
   ) {
     return this.assigneeService.findOne({assignment, solution});
   }
@@ -61,8 +62,8 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: Assignee})
   async update(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
     @Body() dto: UpdateAssigneeDto,
   ) {
     return this.assigneeService.upsert({assignment, solution}, dto);
@@ -72,8 +73,8 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: Assignee})
   async patch(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
     @Body() dto: PatchAssigneeDto,
   ) {
     return this.assigneeService.updateOne({assignment, solution}, dto);
@@ -84,8 +85,8 @@ export class AssigneeController {
   @AssignmentAuth({forbiddenResponse})
   @ApiOkResponse({type: Assignee})
   async remove(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
   ) {
     return this.assigneeService.deleteOne({assignment, solution});
   }
diff --git a/services/apps/assignments/src/assignee/assignee.handler.ts b/services/apps/assignments/src/assignee/assignee.handler.ts
index 5fcc8db23..e47eba4b2 100644
--- a/services/apps/assignments/src/assignee/assignee.handler.ts
+++ b/services/apps/assignments/src/assignee/assignee.handler.ts
@@ -2,6 +2,7 @@ import {Injectable} from '@nestjs/common';
 import {OnEvent} from '@nestjs/event-emitter';
 import {SolutionDocument} from '../solution/solution.schema';
 import {AssigneeService} from './assignee.service';
+import {Types} from "mongoose";
 
 @Injectable()
 export class AssigneeHandler {
@@ -12,6 +13,9 @@ export class AssigneeHandler {
 
   @OnEvent('assignments.*.solutions.*.deleted')
   async onSolutionDeleted(solution: SolutionDocument) {
-    await this.assigneeService.deleteOne({assignment: solution.assignment, solution: solution.id});
+    await this.assigneeService.deleteOne({
+      assignment: new Types.ObjectId(solution.assignment),
+      solution: solution._id,
+    });
   }
 }
diff --git a/services/apps/assignments/src/assignee/assignee.schema.ts b/services/apps/assignments/src/assignee/assignee.schema.ts
index bd1e50b79..241b03ae2 100644
--- a/services/apps/assignments/src/assignee/assignee.schema.ts
+++ b/services/apps/assignments/src/assignee/assignee.schema.ts
@@ -1,8 +1,9 @@
 import {Prop, Schema, SchemaFactory} from '@nestjs/mongoose';
 import {ApiProperty, ApiPropertyOptional} from '@nestjs/swagger';
-import {IsIn, IsMongoId, IsNotEmpty, IsOptional, IsPositive, IsString, ValidateNested} from 'class-validator';
-import {Document} from 'mongoose';
+import {IsIn, IsNotEmpty, IsOptional, IsPositive, IsString, ValidateNested} from 'class-validator';
+import {Document, Types} from 'mongoose';
 import {Type} from "class-transformer";
+import {Ref} from "@mean-stream/nestx";
 
 const OPTIONS = [1, 2, 3, 4];
 
@@ -30,15 +31,11 @@ export class Feedback {
 
 @Schema({id: false, _id: false})
 export class Assignee {
-  @Prop({index: 1})
-  @ApiProperty()
-  @IsMongoId()
-  assignment: string;
+  @Ref('Assignment', {index: 1})
+  assignment: Types.ObjectId;
 
-  @Prop({index: 1})
-  @ApiProperty()
-  @IsMongoId()
-  solution: string;
+  @Ref('Solution', {index: 1})
+  solution: Types.ObjectId;
 
   @Prop()
   @ApiProperty()
diff --git a/services/apps/assignments/src/course/course.service.ts b/services/apps/assignments/src/course/course.service.ts
index 9409e1420..6bfb6dd83 100644
--- a/services/apps/assignments/src/course/course.service.ts
+++ b/services/apps/assignments/src/course/course.service.ts
@@ -35,12 +35,11 @@ export class CourseService extends MongooseRepository<Course> {
 
     const students = new Map<string, CourseStudent>();
     const solutions = await this.solutionService.model.aggregate([
-      {$match: {assignment: {$in: courseAssignmentsWhereUserIsMember}}},
-      {$addFields: {id: {$toString: '$_id'}}},
+      {$match: {assignment: {$in: courseAssignmentsWhereUserIsMember.map(o => o.toString())}}},
       {
         $lookup: {
           from: 'assignees',
-          localField: 'id',
+          localField: '_id',
           foreignField: 'solution',
           as: '_assignees',
         },
@@ -101,12 +100,12 @@ export class CourseService extends MongooseRepository<Course> {
     return Array.from(new Set(students.values()));
   }
 
-  private async getCourseAssignmentsWhereUserIsMember(course: CourseDocument, user: string) {
+  private async getCourseAssignmentsWhereUserIsMember(course: CourseDocument, user: string): Promise<Types.ObjectId[]> {
     const userMembers = await this.memberService.findAll({
       parent: {$in: course.assignments.map(a => new Types.ObjectId(a))},
       user,
     });
-    return userMembers.map(m => m.parent.toString());
+    return userMembers.map(m => m.parent);
   }
 
   async getAssignees(id: Types.ObjectId, user: string): Promise<CourseAssignee[]> {
@@ -124,7 +123,7 @@ export class CourseService extends MongooseRepository<Course> {
     for await (const aggregateElement of this.assigneeService.model.aggregate<{
       _id: {
         assignee: string,
-        assignment: string,
+        assignment: Types.ObjectId,
       },
       solutions: number,
       duration: number,
@@ -159,7 +158,7 @@ export class CourseService extends MongooseRepository<Course> {
         };
         assigneeMap.set(assignee, courseAssignee);
       }
-      const index = course.assignments.indexOf(assignment);
+      const index = course.assignments.indexOf(assignment.toString());
       courseAssignee.assignments[index] = rest;
       courseAssignee.solutions += rest.solutions;
       courseAssignee.duration += rest.duration;
diff --git a/services/apps/assignments/src/solution/solution.service.ts b/services/apps/assignments/src/solution/solution.service.ts
index 56fc5f098..42ff4ce54 100644
--- a/services/apps/assignments/src/solution/solution.service.ts
+++ b/services/apps/assignments/src/solution/solution.service.ts
@@ -48,17 +48,17 @@ export class SolutionService {
       {
         $match: preFilter,
       },
-      {
-        $addFields: {id: {$toString: '$_id'}},
-      },
       {
         $lookup: {
           from: 'assignees',
-          localField: 'id',
+          localField: '_id',
           foreignField: 'solution',
           as: '_assignee',
         },
       },
+      {
+        $addFields: {id: {$toString: '$_id'}},
+      },
       {
         $lookup: {
           from: 'evaluations',

From e2fa563845ab30a52e82d10c9c11ee9ee9386b45 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 10:47:41 +0100
Subject: [PATCH 3/9] refactor(assignments-service): Add solution sort
 constants

---
 .../apps/assignments/src/course/course.service.ts     |  9 +++------
 .../apps/assignments/src/solution/solution.schema.ts  | 11 +++++++++++
 .../apps/assignments/src/solution/solution.service.ts | 10 +---------
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/services/apps/assignments/src/course/course.service.ts b/services/apps/assignments/src/course/course.service.ts
index 6bfb6dd83..716d4e137 100644
--- a/services/apps/assignments/src/course/course.service.ts
+++ b/services/apps/assignments/src/course/course.service.ts
@@ -2,7 +2,7 @@ import {EventRepository, EventService, MongooseRepository} from '@mean-stream/ne
 import {Injectable} from '@nestjs/common';
 import {InjectModel} from '@nestjs/mongoose';
 import {Model, Types} from 'mongoose';
-import {AuthorInfo} from '../solution/solution.schema';
+import {AuthorInfo, SOLUTION_COLLATION, SOLUTION_SORT} from '../solution/solution.schema';
 import {SolutionService} from '../solution/solution.service';
 import {CourseAssignee, CourseStudent} from './course.dto';
 import {Course, CourseDocument} from './course.schema';
@@ -55,12 +55,9 @@ export class CourseService extends MongooseRepository<Course> {
           feedback: 1,
         },
       },
-      {$sort: {'author.name': 1, 'author.github': 1}},
+      {$sort: SOLUTION_SORT},
     ], {
-      collation: {
-        locale: 'en',
-        caseFirst: 'off',
-      },
+      collation: SOLUTION_COLLATION,
     });
 
     const keys: (keyof AuthorInfo)[] = ['studentId', 'email', 'github', 'name'];
diff --git a/services/apps/assignments/src/solution/solution.schema.ts b/services/apps/assignments/src/solution/solution.schema.ts
index 2cc4bdac1..e2eca417d 100644
--- a/services/apps/assignments/src/solution/solution.schema.ts
+++ b/services/apps/assignments/src/solution/solution.schema.ts
@@ -141,3 +141,14 @@ export const SolutionSchema = SchemaFactory.createForClass(Solution)
   .index({assignment: 1, 'author.github': 1})
   .index({assignment: 1, 'timestamp': 1})
 ;
+
+export const SOLUTION_SORT = {
+  'author.name': 1,
+  'author.github': 1,
+  timestamp: 1,
+} as const;
+
+export const SOLUTION_COLLATION = {
+  locale: 'en',
+  caseFirst: 'off',
+} as const;
diff --git a/services/apps/assignments/src/solution/solution.service.ts b/services/apps/assignments/src/solution/solution.service.ts
index 42ff4ce54..3decfc2e5 100644
--- a/services/apps/assignments/src/solution/solution.service.ts
+++ b/services/apps/assignments/src/solution/solution.service.ts
@@ -5,15 +5,7 @@ import {InjectModel} from '@nestjs/mongoose';
 import {FilterQuery, Model, UpdateQuery} from 'mongoose';
 import {generateToken} from '../utils';
 import {BatchUpdateSolutionDto, CreateSolutionDto, RichSolutionDto, UpdateSolutionDto} from './solution.dto';
-import {Solution, SolutionDocument} from './solution.schema';
-
-const SOLUTION_SORT = {
-  'author.name': 1,
-  'author.github': 1,
-  timestamp: 1,
-} as const;
-
-const SOLUTION_COLLATION = {locale: 'en', caseFirst: 'off'};
+import {Solution, SOLUTION_COLLATION, SOLUTION_SORT, SolutionDocument} from './solution.schema';
 
 @Injectable()
 export class SolutionService {

From ce454a1c7756a3b70cdc512d6182d71b90609bf3 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 11:06:27 +0100
Subject: [PATCH 4/9] fix(assignments-service): Correctly typed
 Evaluation.codeSearch.origin

---
 .../assignments/src/evaluation/evaluation.schema.ts   | 11 +++++------
 .../assignments/src/evaluation/evaluation.service.ts  |  6 +++---
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/services/apps/assignments/src/evaluation/evaluation.schema.ts b/services/apps/assignments/src/evaluation/evaluation.schema.ts
index 76a7e6873..afcbf6dd2 100644
--- a/services/apps/assignments/src/evaluation/evaluation.schema.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.schema.ts
@@ -14,7 +14,8 @@ import {
   Min,
   ValidateNested,
 } from 'class-validator';
-import {Document} from 'mongoose';
+import {Document, Types} from 'mongoose';
+import {OptionalRef} from "@mean-stream/nestx";
 
 export class Location {
   @Prop()
@@ -66,11 +67,9 @@ export class Snippet {
 }
 
 export class CodeSearchInfo {
-  @Prop()
   @ApiPropertyOptional({description: 'Only in GET responses'})
-  @IsOptional()
-  @IsMongoId()
-  origin?: string;
+  @OptionalRef('Evaluation')
+  origin?: Types.ObjectId;
 
   @ApiPropertyOptional({description: 'Only in POST response'})
   @IsOptional()
@@ -91,7 +90,7 @@ export class CodeSearchInfo {
 @Schema({timestamps: true})
 export class Evaluation {
   @ApiProperty()
-  _id: string;
+  _id: Types.ObjectId;
 
   @Prop()
   @ApiProperty()
diff --git a/services/apps/assignments/src/evaluation/evaluation.service.ts b/services/apps/assignments/src/evaluation/evaluation.service.ts
index c68c58129..0d402c32d 100644
--- a/services/apps/assignments/src/evaluation/evaluation.service.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.service.ts
@@ -1,7 +1,7 @@
 import {EventService} from '@mean-stream/nestx';
 import {Injectable} from '@nestjs/common';
 import {InjectModel} from '@nestjs/mongoose';
-import {FilterQuery, Model, UpdateQuery} from 'mongoose';
+import {FilterQuery, Model, Types, UpdateQuery} from 'mongoose';
 import {AssignmentService} from '../assignment/assignment.service';
 import {SearchService} from '../search/search.service';
 import {CreateEvaluationDto, RemarkDto, UpdateEvaluationDto} from './evaluation.dto';
@@ -156,7 +156,7 @@ export class EvaluationService {
       ;
   }
 
-  private async codeSearchCreate(assignment: string, origin: any, dto: CreateEvaluationDto): Promise<CodeSearchInfo> {
+  private async codeSearchCreate(assignment: string, origin: Types.ObjectId, dto: CreateEvaluationDto): Promise<CodeSearchInfo> {
     const solutions = await this.codeSearch(assignment, dto.task, dto.snippets);
     const result = await this.model.bulkWrite(solutions.filter(s => s[1]).map(([solution, snippets]) => {
       const newEvaluation: UpdateQuery<Evaluation> = {
@@ -181,7 +181,7 @@ export class EvaluationService {
     return {created: result.upsertedCount};
   }
 
-  private async codeSearchUpdate(assignment: string, task: string, origin: any, dto: UpdateEvaluationDto): Promise<Partial<CodeSearchInfo>> {
+  private async codeSearchUpdate(assignment: string, task: string, origin: Types.ObjectId, dto: UpdateEvaluationDto): Promise<Partial<CodeSearchInfo>> {
     const solutions = await this.codeSearch(assignment, task, dto.snippets!);
     let deleted = 0;
     let updated = 0;

From 1aaa6c5b7b1c5be96ea6abdf2b92db9a68f4ad57 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 11:21:42 +0100
Subject: [PATCH 5/9] refactor(assignments-service): Make Evaluation.assignment
 and Evaluation.solution ObjectId

---
 .../src/assignment/assignment.service.ts      |  4 ++--
 .../src/evaluation/evaluation.controller.ts   | 22 +++++++++----------
 .../src/evaluation/evaluation.handler.ts      |  6 ++++-
 .../src/evaluation/evaluation.schema.ts       | 14 +++++-------
 .../src/evaluation/evaluation.service.ts      | 16 +++++++-------
 .../src/solution/solution.service.ts          |  6 +----
 .../src/statistics/statistics.service.ts      | 11 +++++-----
 7 files changed, 38 insertions(+), 41 deletions(-)

diff --git a/services/apps/assignments/src/assignment/assignment.service.ts b/services/apps/assignments/src/assignment/assignment.service.ts
index e8f5ddb2d..a62544642 100644
--- a/services/apps/assignments/src/assignment/assignment.service.ts
+++ b/services/apps/assignments/src/assignment/assignment.service.ts
@@ -2,7 +2,7 @@ import {EventService} from '@mean-stream/nestx';
 import {UserToken} from '@app/keycloak-auth';
 import {Injectable} from '@nestjs/common';
 import {InjectModel} from '@nestjs/mongoose';
-import {FilterQuery, Model, UpdateQuery} from 'mongoose';
+import {FilterQuery, Model, Types, UpdateQuery} from 'mongoose';
 import {generateToken} from '../utils';
 import {CreateAssignmentDto, ReadAssignmentDto, ReadTaskDto, UpdateAssignmentDto} from './assignment.dto';
 import {Assignment, AssignmentDocument, Task} from './assignment.schema';
@@ -48,7 +48,7 @@ export class AssignmentService {
     }).exec();
   }
 
-  async findOne(id: string): Promise<AssignmentDocument | null> {
+  async findOne(id: string | Types.ObjectId): Promise<AssignmentDocument | null> {
     return this.model.findById(id).exec();
   }
 
diff --git a/services/apps/assignments/src/evaluation/evaluation.controller.ts b/services/apps/assignments/src/evaluation/evaluation.controller.ts
index 8a8e9e39d..9bb4ad3bf 100644
--- a/services/apps/assignments/src/evaluation/evaluation.controller.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.controller.ts
@@ -1,5 +1,5 @@
 import {AuthUser, UserToken} from '@app/keycloak-auth';
-import {NotFound} from '@mean-stream/nestx';
+import {NotFound, ObjectIdPipe} from '@mean-stream/nestx';
 import {Body, Controller, Delete, Get, Headers, MessageEvent, Param, Patch, Post, Query, Sse} from '@nestjs/common';
 import {ApiCreatedResponse, ApiOkResponse, ApiOperation, ApiTags} from '@nestjs/swagger';
 import {FilterQuery, Types} from 'mongoose';
@@ -22,7 +22,7 @@ export class EvaluationController {
   ) {
   }
 
-  private toQuery(assignment: string, solution?: string, params: FilterEvaluationParams = {}): FilterQuery<Evaluation> {
+  private toQuery(assignment: Types.ObjectId, solution?: Types.ObjectId, params: FilterEvaluationParams = {}): FilterQuery<Evaluation> {
     const query: FilterQuery<Evaluation> = {assignment};
     solution && (query.solution = solution);
     params.file && (query['snippets.file'] = params.file);
@@ -38,7 +38,7 @@ export class EvaluationController {
   @AssignmentAuth({forbiddenResponse: forbiddenAssignmentResponse})
   @ApiOkResponse({type: [Evaluation]})
   async findByAssignment(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
     @Query() params?: FilterEvaluationParams,
   ): Promise<Evaluation[]> {
     return this.evaluationService.findAll(this.toQuery(assignment, undefined, params));
@@ -49,7 +49,7 @@ export class EvaluationController {
   @AssignmentAuth({forbiddenResponse: forbiddenAssignmentResponse})
   @ApiOkResponse({isArray: true})
   async findUnique(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
     @Param('field') field: string,
     @Query() params?: FilterEvaluationParams,
   ): Promise<unknown[]> {
@@ -61,7 +61,7 @@ export class EvaluationController {
   @AssignmentAuth({forbiddenResponse: forbiddenAssignmentResponse})
   @ApiOkResponse({type: [RemarkDto]})
   async findRemarks(
-    @Param('assignment') assignment: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
     @Query() params?: FilterEvaluationParams,
   ): Promise<RemarkDto[]> {
     return this.evaluationService.findRemarks(this.toQuery(assignment, undefined, params));
@@ -71,8 +71,8 @@ export class EvaluationController {
   @AssignmentAuth({forbiddenResponse: forbiddenAssignmentResponse})
   @ApiCreatedResponse({type: Evaluation})
   async create(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
     @Body() dto: CreateEvaluationDto,
     @AuthUser() user?: UserToken,
   ): Promise<Evaluation> {
@@ -83,8 +83,8 @@ export class EvaluationController {
   @SolutionAuth({forbiddenResponse})
   @ApiOkResponse({type: [Evaluation]})
   async findAll(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
     @Query() params?: FilterEvaluationParams,
   ): Promise<Evaluation[]> {
     return this.evaluationService.findAll(this.toQuery(assignment, solution, params));
@@ -94,8 +94,8 @@ export class EvaluationController {
   @SolutionAuth({forbiddenResponse})
   @ApiOkResponse({type: Evaluation})
   stream(
-    @Param('assignment') assignment: string,
-    @Param('solution') solution: string,
+    @Param('assignment', ObjectIdPipe) assignment: Types.ObjectId,
+    @Param('solution', ObjectIdPipe) solution: Types.ObjectId,
     @AuthUser() user?: UserToken,
     @Headers('assignment-token') assignmentToken?: string,
     @Headers('solution-token') solutionToken?: string,
diff --git a/services/apps/assignments/src/evaluation/evaluation.handler.ts b/services/apps/assignments/src/evaluation/evaluation.handler.ts
index e1b8ce414..9947524c0 100644
--- a/services/apps/assignments/src/evaluation/evaluation.handler.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.handler.ts
@@ -2,6 +2,7 @@ import {Injectable} from '@nestjs/common';
 import {OnEvent} from '@nestjs/event-emitter';
 import {SolutionDocument} from '../solution/solution.schema';
 import {EvaluationService} from './evaluation.service';
+import {Types} from "mongoose";
 
 @Injectable()
 export class EvaluationHandler {
@@ -12,6 +13,9 @@ export class EvaluationHandler {
 
   @OnEvent('assignments.*.solutions.*.deleted')
   async onSolutionDeleted(solution: SolutionDocument) {
-    await this.evaluationService.removeAll({assignment: solution.assignment, solution: solution.id});
+    await this.evaluationService.removeAll({
+      assignment: new Types.ObjectId(solution.assignment),
+      solution: solution._id,
+    });
   }
 }
diff --git a/services/apps/assignments/src/evaluation/evaluation.schema.ts b/services/apps/assignments/src/evaluation/evaluation.schema.ts
index afcbf6dd2..6e249a0f5 100644
--- a/services/apps/assignments/src/evaluation/evaluation.schema.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.schema.ts
@@ -15,7 +15,7 @@ import {
   ValidateNested,
 } from 'class-validator';
 import {Document, Types} from 'mongoose';
-import {OptionalRef} from "@mean-stream/nestx";
+import {OptionalRef, Ref} from "@mean-stream/nestx";
 
 export class Location {
   @Prop()
@@ -92,15 +92,11 @@ export class Evaluation {
   @ApiProperty()
   _id: Types.ObjectId;
 
-  @Prop()
-  @ApiProperty()
-  @IsMongoId()
-  assignment: string;
+  @Ref('Assignment')
+  assignment: Types.ObjectId;
 
-  @Prop({index: 1})
-  @ApiProperty()
-  @IsMongoId()
-  solution: string;
+  @Ref('Solution', {index: 1})
+  solution: Types.ObjectId;
 
   @Prop()
   @ApiProperty()
diff --git a/services/apps/assignments/src/evaluation/evaluation.service.ts b/services/apps/assignments/src/evaluation/evaluation.service.ts
index 0d402c32d..4e21237f2 100644
--- a/services/apps/assignments/src/evaluation/evaluation.service.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.service.ts
@@ -21,12 +21,12 @@ export class EvaluationService {
     this.eventService.emit(`assignments.${evaluation.assignment}.solutions.${evaluation.solution}.evaluations.${evaluation.id}.${event}`, evaluation);
   }
 
-  subscribe(assignment: string, solution: string, evaluation: string, event: string, user?: string) {
+  subscribe(assignment: Types.ObjectId, solution: Types.ObjectId, evaluation: Types.ObjectId | '*', event: string, user?: string) {
     // TODO only emit to users that have access to the assignment or solution
     return this.eventService.subscribe<Evaluation>(`assignments.${assignment}.solutions.${solution}.evaluations.${evaluation}.${event}`, user);
   }
 
-  async create(assignment: string, solution: string, dto: CreateEvaluationDto, createdBy?: string): Promise<Evaluation> {
+  async create(assignment: Types.ObjectId, solution: Types.ObjectId, dto: CreateEvaluationDto, createdBy?: string): Promise<Evaluation> {
     const {codeSearch, ...rest} = dto;
     const evaluation = await this.model.findOneAndUpdate({
       assignment,
@@ -121,11 +121,11 @@ export class EvaluationService {
     return evaluations;
   }
 
-  private async codeSearch(assignmentId: string, taskId: string, snippets: Snippet[]): Promise<[string, Snippet[] | undefined][]> {
+  private async codeSearch(assignmentId: Types.ObjectId, taskId: string, snippets: Snippet[]): Promise<[Types.ObjectId, Snippet[] | undefined][]> {
     const assignment = await this.assignmentService.findOne(assignmentId);
     const task = assignment && this.assignmentService.findTask(assignment.tasks, taskId);
     const resultsBySnippet = await Promise.all(snippets.map(async snippet => {
-      const results = await this.searchService.find(assignmentId, {
+      const results = await this.searchService.find(assignmentId.toString(), {
         q: snippet.pattern || snippet.code,
         glob: task?.glob,
         wildcard: '***',
@@ -149,14 +149,14 @@ export class EvaluationService {
       .map(solution => {
         if (solutionMatches[solution] !== snippets.length) {
           // remove solutions where any original snippet was not found
-          return [solution, undefined];
+          return [new Types.ObjectId(solution), undefined];
         }
-        return [solution, solutionSnippets[solution]];
+        return [new Types.ObjectId(solution), solutionSnippets[solution]];
       })
       ;
   }
 
-  private async codeSearchCreate(assignment: string, origin: Types.ObjectId, dto: CreateEvaluationDto): Promise<CodeSearchInfo> {
+  private async codeSearchCreate(assignment: Types.ObjectId, origin: Types.ObjectId, dto: CreateEvaluationDto): Promise<CodeSearchInfo> {
     const solutions = await this.codeSearch(assignment, dto.task, dto.snippets);
     const result = await this.model.bulkWrite(solutions.filter(s => s[1]).map(([solution, snippets]) => {
       const newEvaluation: UpdateQuery<Evaluation> = {
@@ -181,7 +181,7 @@ export class EvaluationService {
     return {created: result.upsertedCount};
   }
 
-  private async codeSearchUpdate(assignment: string, task: string, origin: Types.ObjectId, dto: UpdateEvaluationDto): Promise<Partial<CodeSearchInfo>> {
+  private async codeSearchUpdate(assignment: Types.ObjectId, task: string, origin: Types.ObjectId, dto: UpdateEvaluationDto): Promise<Partial<CodeSearchInfo>> {
     const solutions = await this.codeSearch(assignment, task, dto.snippets!);
     let deleted = 0;
     let updated = 0;
diff --git a/services/apps/assignments/src/solution/solution.service.ts b/services/apps/assignments/src/solution/solution.service.ts
index 3decfc2e5..739e65d07 100644
--- a/services/apps/assignments/src/solution/solution.service.ts
+++ b/services/apps/assignments/src/solution/solution.service.ts
@@ -48,13 +48,10 @@ export class SolutionService {
           as: '_assignee',
         },
       },
-      {
-        $addFields: {id: {$toString: '$_id'}},
-      },
       {
         $lookup: {
           from: 'evaluations',
-          localField: 'id',
+          localField: '_id',
           foreignField: 'solution',
           as: '_evaluations',
           pipeline: [
@@ -111,7 +108,6 @@ export class SolutionService {
       },
       {
         $project: {
-          id: 0,
           _evaluations: 0,
           _assignee: 0,
         },
diff --git a/services/apps/assignments/src/statistics/statistics.service.ts b/services/apps/assignments/src/statistics/statistics.service.ts
index 2a3d79d31..03feece67 100644
--- a/services/apps/assignments/src/statistics/statistics.service.ts
+++ b/services/apps/assignments/src/statistics/statistics.service.ts
@@ -11,6 +11,7 @@ import {
   TaskStatistics,
   TimeStatistics
 } from './statistics.dto';
+import {Types} from "mongoose";
 
 const outlierDuration = 60;
 
@@ -59,10 +60,10 @@ export class StatisticsService {
       solutions,
       ,
     ] = await Promise.all([
-      this.timeStatistics(assignment, taskStats, tasks),
+      this.timeStatistics(assignmentDoc._id, taskStats, tasks),
       this.countComments(assignment),
       this.solutionStatistics(assignmentDoc),
-      this.fillEvaluationStatistics(assignment, taskStats, tasks, evaluations, weightedEvaluations),
+      this.fillEvaluationStatistics(assignmentDoc._id, taskStats, tasks, evaluations, weightedEvaluations),
     ]);
 
     // needs to happen after timeStatistics and fillEvaluationStatistics
@@ -80,7 +81,7 @@ export class StatisticsService {
     };
   }
 
-  private async fillEvaluationStatistics(assignment: string, taskStats: Map<string, TaskStatistics>, tasks: Map<string, Task>, evaluationStatistics: EvaluationStatistics, weightedEvaluationStatistics: EvaluationStatistics) {
+  private async fillEvaluationStatistics(assignment: Types.ObjectId, taskStats: Map<string, TaskStatistics>, tasks: Map<string, Task>, evaluationStatistics: EvaluationStatistics, weightedEvaluationStatistics: EvaluationStatistics) {
     for await (const {
       codeSearch,
       points,
@@ -115,7 +116,7 @@ export class StatisticsService {
     }
   }
 
-  private async timeStatistics(assignment: string, taskStats: Map<string, TaskStatistics>, tasks: Map<string, Task>): Promise<TimeStatistics> {
+  private async timeStatistics(assignment: Types.ObjectId, taskStats: Map<string, TaskStatistics>, tasks: Map<string, Task>): Promise<TimeStatistics> {
     let eventCount = 0;
     let totalTime = 0;
     let weightedTime = 0;
@@ -182,7 +183,7 @@ export class StatisticsService {
       }
       passed++;
     }
-    const evaluated = (await this.evaluationService.findUnique('solution', {assignment: assignment.id})).length;
+    const evaluated = (await this.evaluationService.findUnique('solution', {assignment: assignment._id})).length;
     return {
       total,
       evaluated,

From d812418d2029161250cc69951d363bb0bffdb808 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 11:50:25 +0100
Subject: [PATCH 6/9] refactor(assignments-service): Use Nestx Doc

---
 services/apps/assignments/src/assignee/assignee.schema.ts | 6 +++---
 .../apps/assignments/src/assignee/assignee.service.ts     | 2 +-
 .../apps/assignments/src/assignment/assignment.schema.ts  | 5 +++--
 .../apps/assignments/src/assignment/assignment.service.ts | 2 +-
 .../apps/assignments/src/classroom/classroom.service.ts   | 4 ++--
 services/apps/assignments/src/comment/comment.schema.ts   | 4 ++--
 services/apps/assignments/src/course/course.schema.ts     | 5 +++--
 .../apps/assignments/src/evaluation/evaluation.schema.ts  | 7 +++----
 services/apps/assignments/src/solution/solution.schema.ts | 8 +++++---
 9 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/services/apps/assignments/src/assignee/assignee.schema.ts b/services/apps/assignments/src/assignee/assignee.schema.ts
index 241b03ae2..3999b94f8 100644
--- a/services/apps/assignments/src/assignee/assignee.schema.ts
+++ b/services/apps/assignments/src/assignee/assignee.schema.ts
@@ -1,9 +1,9 @@
 import {Prop, Schema, SchemaFactory} from '@nestjs/mongoose';
 import {ApiProperty, ApiPropertyOptional} from '@nestjs/swagger';
 import {IsIn, IsNotEmpty, IsOptional, IsPositive, IsString, ValidateNested} from 'class-validator';
-import {Document, Types} from 'mongoose';
+import {Types} from 'mongoose';
 import {Type} from "class-transformer";
-import {Ref} from "@mean-stream/nestx";
+import {Doc, Ref} from "@mean-stream/nestx";
 
 const OPTIONS = [1, 2, 3, 4];
 
@@ -57,7 +57,7 @@ export class Assignee {
   feedback?: Feedback;
 }
 
-export type AssigneeDocument = Assignee & Document;
+export type AssigneeDocument = Doc<Assignee, never>;
 
 export const AssigneeSchema = SchemaFactory.createForClass(Assignee)
   .index({assignment: 1, solution: 1}, {unique: true});
diff --git a/services/apps/assignments/src/assignee/assignee.service.ts b/services/apps/assignments/src/assignee/assignee.service.ts
index f03f7f7e8..5910600d0 100644
--- a/services/apps/assignments/src/assignee/assignee.service.ts
+++ b/services/apps/assignments/src/assignee/assignee.service.ts
@@ -8,7 +8,7 @@ import {Assignee, AssigneeDocument} from './assignee.schema';
 @Injectable()
 export class AssigneeService extends MongooseRepository<Assignee, never, AssigneeDocument> {
   constructor(
-    @InjectModel(Assignee.name) public model: Model<Assignee>,
+    @InjectModel(Assignee.name) public model: Model<Assignee, object, object, object, AssigneeDocument>,
     private eventService: EventService,
   ) {
     super(model);
diff --git a/services/apps/assignments/src/assignment/assignment.schema.ts b/services/apps/assignments/src/assignment/assignment.schema.ts
index 707dd003f..27fbfa927 100644
--- a/services/apps/assignments/src/assignment/assignment.schema.ts
+++ b/services/apps/assignments/src/assignment/assignment.schema.ts
@@ -16,8 +16,9 @@ import {
   IsUrl,
   ValidateNested,
 } from 'class-validator';
-import {Document, Types} from 'mongoose';
+import {Types} from 'mongoose';
 import {MOSS_LANGUAGES} from "../search/search.constants";
+import {Doc} from "@mean-stream/nestx";
 
 @Schema({id: false, _id: false})
 export class Task {
@@ -192,6 +193,6 @@ export class Assignment {
   tasks: Task[];
 }
 
-export type AssignmentDocument = Assignment & Document;
+export type AssignmentDocument = Doc<Assignment>;
 
 export const AssignmentSchema = SchemaFactory.createForClass(Assignment);
diff --git a/services/apps/assignments/src/assignment/assignment.service.ts b/services/apps/assignments/src/assignment/assignment.service.ts
index a62544642..2ba6f4d65 100644
--- a/services/apps/assignments/src/assignment/assignment.service.ts
+++ b/services/apps/assignments/src/assignment/assignment.service.ts
@@ -68,7 +68,7 @@ export class AssignmentService {
     };
   }
 
-  async update(id: string, dto: UpdateAssignmentDto | UpdateQuery<Assignment>): Promise<Assignment | null> {
+  async update(id: string | Types.ObjectId, dto: UpdateAssignmentDto | UpdateQuery<Assignment>): Promise<Assignment | null> {
     const {token, classroom, ...rest} = dto;
     const update: UpdateQuery<Assignment> = rest;
     if (token) {
diff --git a/services/apps/assignments/src/classroom/classroom.service.ts b/services/apps/assignments/src/classroom/classroom.service.ts
index 64bef76b4..b70782c2d 100644
--- a/services/apps/assignments/src/classroom/classroom.service.ts
+++ b/services/apps/assignments/src/classroom/classroom.service.ts
@@ -150,7 +150,7 @@ export class ClassroomService {
       const upsertedId = solutions.upsertedIds[i];
       if (commit && upsertedId) {
         const zip = await this.getRepoZip(assignment, this.getGithubName(repo, assignment), commit);
-        return zip ? this.fileService.importZipEntries(zip, assignment._id, upsertedId, commit) : [];
+        return zip ? this.fileService.importZipEntries(zip, assignment._id.toString(), upsertedId, commit) : [];
       } else {
         return [];
       }
@@ -239,7 +239,7 @@ export class ClassroomService {
 
   private createImportSolution(assignment: AssignmentDocument, repo: RepositoryInfo, commit: string | undefined): ImportSolution {
     return {
-      assignment: assignment._id,
+      assignment: assignment._id.toString(),
       author: {
         name: '',
         email: '',
diff --git a/services/apps/assignments/src/comment/comment.schema.ts b/services/apps/assignments/src/comment/comment.schema.ts
index 5b0e3751a..819797f73 100644
--- a/services/apps/assignments/src/comment/comment.schema.ts
+++ b/services/apps/assignments/src/comment/comment.schema.ts
@@ -1,7 +1,7 @@
 import {Prop, Schema, SchemaFactory} from '@nestjs/mongoose';
 import {ApiProperty} from '@nestjs/swagger';
 import {IsBoolean, IsDateString, IsEmail, IsMongoId, IsNotEmpty, IsString} from 'class-validator';
-import {Document} from 'mongoose';
+import {Doc} from "@mean-stream/nestx";
 
 @Schema()
 export class Comment {
@@ -47,7 +47,7 @@ export class Comment {
   distinguished: boolean;
 }
 
-export type CommentDocument = Comment & Document;
+export type CommentDocument = Doc<Comment>;
 
 export const CommentSchema = SchemaFactory.createForClass(Comment)
   .index({assignment: 1, solution: 1})
diff --git a/services/apps/assignments/src/course/course.schema.ts b/services/apps/assignments/src/course/course.schema.ts
index 24a99c066..3380896ee 100644
--- a/services/apps/assignments/src/course/course.schema.ts
+++ b/services/apps/assignments/src/course/course.schema.ts
@@ -1,7 +1,8 @@
 import {Prop, Schema, SchemaFactory} from '@nestjs/mongoose';
 import {ApiProperty, ApiPropertyOptional} from '@nestjs/swagger';
 import {IsArray, IsMongoId, IsNotEmpty, IsOptional, IsString, IsUUID} from 'class-validator';
-import {Document, Types} from 'mongoose';
+import {Types} from 'mongoose';
+import {Doc} from "@mean-stream/nestx";
 
 @Schema()
 export class Course {
@@ -32,6 +33,6 @@ export class Course {
   assignments: string[];
 }
 
-export type CourseDocument = Course & Document;
+export type CourseDocument = Doc<Course>;
 
 export const CourseSchema = SchemaFactory.createForClass(Course);
diff --git a/services/apps/assignments/src/evaluation/evaluation.schema.ts b/services/apps/assignments/src/evaluation/evaluation.schema.ts
index 6e249a0f5..da659e773 100644
--- a/services/apps/assignments/src/evaluation/evaluation.schema.ts
+++ b/services/apps/assignments/src/evaluation/evaluation.schema.ts
@@ -4,7 +4,6 @@ import {Type} from 'class-transformer';
 import {
   IsAlphanumeric,
   IsInt,
-  IsMongoId,
   IsNotEmpty,
   IsNumber,
   IsOptional,
@@ -14,8 +13,8 @@ import {
   Min,
   ValidateNested,
 } from 'class-validator';
-import {Document, Types} from 'mongoose';
-import {OptionalRef, Ref} from "@mean-stream/nestx";
+import {Types} from 'mongoose';
+import {Doc, OptionalRef, Ref} from "@mean-stream/nestx";
 
 export class Location {
   @Prop()
@@ -152,7 +151,7 @@ export class Evaluation {
   codeSearch?: CodeSearchInfo;
 }
 
-export type EvaluationDocument = Evaluation & Document;
+export type EvaluationDocument = Doc<Evaluation>;
 
 export const EvaluationSchema = SchemaFactory.createForClass(Evaluation)
   .index({assignment: 1, solution: 1})
diff --git a/services/apps/assignments/src/solution/solution.schema.ts b/services/apps/assignments/src/solution/solution.schema.ts
index e2eca417d..182e93535 100644
--- a/services/apps/assignments/src/solution/solution.schema.ts
+++ b/services/apps/assignments/src/solution/solution.schema.ts
@@ -5,7 +5,8 @@ import {
   IsBoolean,
   IsDateString,
   IsEmail,
-  IsHash, IsIn,
+  IsHash,
+  IsIn,
   IsMongoId,
   IsNumber,
   IsOptional,
@@ -13,7 +14,8 @@ import {
   IsUUID,
   ValidateNested,
 } from 'class-validator';
-import {Document, Types} from 'mongoose';
+import {Types} from 'mongoose';
+import {Doc} from "@mean-stream/nestx";
 
 export class Consent {
   @Prop()
@@ -134,7 +136,7 @@ export class Solution {
   points?: number;
 }
 
-export type SolutionDocument = Solution & Document;
+export type SolutionDocument = Doc<Solution>;
 
 export const SolutionSchema = SchemaFactory.createForClass(Solution)
   .index({assignment: 1, 'author.name': 1})

From e123894c4937673487a21299ce01ce593dc26356 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 11:54:35 +0100
Subject: [PATCH 7/9] refactor(assignments-service): Course students Solution
 _id

---
 services/apps/assignments/src/course/course.dto.ts     | 4 +---
 services/apps/assignments/src/course/course.service.ts | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/services/apps/assignments/src/course/course.dto.ts b/services/apps/assignments/src/course/course.dto.ts
index e3552728e..53f40364c 100644
--- a/services/apps/assignments/src/course/course.dto.ts
+++ b/services/apps/assignments/src/course/course.dto.ts
@@ -12,11 +12,9 @@ export class UpdateCourseDto extends PartialType(CreateCourseDto) {
 }
 
 export class SolutionSummary extends PickType(Solution, [
+  '_id',
   'points',
 ] as const) {
-  @ApiProperty()
-  _id: string;
-
   @ApiPropertyOptional()
   assignee?: string;
 }
diff --git a/services/apps/assignments/src/course/course.service.ts b/services/apps/assignments/src/course/course.service.ts
index 716d4e137..00c640ed2 100644
--- a/services/apps/assignments/src/course/course.service.ts
+++ b/services/apps/assignments/src/course/course.service.ts
@@ -86,7 +86,7 @@ export class CourseService extends MongooseRepository<Course> {
 
       const index = course.assignments.indexOf(assignment);
       student.solutions[index] = {
-        _id: _id.toString(),
+        _id,
         points,
         assignee,
       };

From 5d0ec5fe182252c55819d4c88d947ee965129bd6 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 12:04:34 +0100
Subject: [PATCH 8/9] perf(assignments-service): Optimize solution sort index

---
 .../apps/assignments/src/solution/solution.schema.ts   | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/services/apps/assignments/src/solution/solution.schema.ts b/services/apps/assignments/src/solution/solution.schema.ts
index 182e93535..2313b8344 100644
--- a/services/apps/assignments/src/solution/solution.schema.ts
+++ b/services/apps/assignments/src/solution/solution.schema.ts
@@ -138,12 +138,6 @@ export class Solution {
 
 export type SolutionDocument = Doc<Solution>;
 
-export const SolutionSchema = SchemaFactory.createForClass(Solution)
-  .index({assignment: 1, 'author.name': 1})
-  .index({assignment: 1, 'author.github': 1})
-  .index({assignment: 1, 'timestamp': 1})
-;
-
 export const SOLUTION_SORT = {
   'author.name': 1,
   'author.github': 1,
@@ -154,3 +148,7 @@ export const SOLUTION_COLLATION = {
   locale: 'en',
   caseFirst: 'off',
 } as const;
+
+export const SolutionSchema = SchemaFactory.createForClass(Solution)
+  .index({assignment: 1, ...SOLUTION_SORT}, {collation: SOLUTION_COLLATION})
+;

From c51514b9520122923c02fc38d275f378d368e378 Mon Sep 17 00:00:00 2001
From: Adrian Kunz <a.kunz@uni-kassel.de>
Date: Wed, 15 Nov 2023 12:15:17 +0100
Subject: [PATCH 9/9] perf(assignments-service): Better assignment sort index

---
 .../assignments/src/assignment/assignment.schema.ts | 13 ++++++++++++-
 .../src/assignment/assignment.service.ts            |  8 ++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/services/apps/assignments/src/assignment/assignment.schema.ts b/services/apps/assignments/src/assignment/assignment.schema.ts
index 27fbfa927..343b424c8 100644
--- a/services/apps/assignments/src/assignment/assignment.schema.ts
+++ b/services/apps/assignments/src/assignment/assignment.schema.ts
@@ -195,4 +195,15 @@ export class Assignment {
 
 export type AssignmentDocument = Doc<Assignment>;
 
-export const AssignmentSchema = SchemaFactory.createForClass(Assignment);
+export const ASSIGNMENT_SORT = {
+  title: 1,
+} as const;
+
+export const ASSIGNMENT_COLLATION = {
+  locale: 'en',
+  numericOrdering: true,
+} as const;
+
+export const AssignmentSchema = SchemaFactory.createForClass(Assignment)
+  .index(ASSIGNMENT_SORT, {collation: ASSIGNMENT_COLLATION})
+;
diff --git a/services/apps/assignments/src/assignment/assignment.service.ts b/services/apps/assignments/src/assignment/assignment.service.ts
index 2ba6f4d65..adda46584 100644
--- a/services/apps/assignments/src/assignment/assignment.service.ts
+++ b/services/apps/assignments/src/assignment/assignment.service.ts
@@ -5,7 +5,7 @@ import {InjectModel} from '@nestjs/mongoose';
 import {FilterQuery, Model, Types, UpdateQuery} from 'mongoose';
 import {generateToken} from '../utils';
 import {CreateAssignmentDto, ReadAssignmentDto, ReadTaskDto, UpdateAssignmentDto} from './assignment.dto';
-import {Assignment, AssignmentDocument, Task} from './assignment.schema';
+import {Assignment, ASSIGNMENT_COLLATION, ASSIGNMENT_SORT, AssignmentDocument, Task} from './assignment.schema';
 import {MemberService} from "@app/member";
 
 @Injectable()
@@ -42,9 +42,9 @@ export class AssignmentService {
   }
 
   async findAll(where: FilterQuery<Assignment> = {}): Promise<AssignmentDocument[]> {
-    return this.model.find(where).sort({title: 1}).collation({
-      locale: 'en',
-      numericOrdering: true,
+    return this.model.find(where, undefined,{
+      sort: ASSIGNMENT_SORT,
+      collation: ASSIGNMENT_COLLATION,
     }).exec();
   }