Refactor student homework logic (#1650)

I made the code less complex and changed `List` to `IList` everywhere.
This is a step to using (parts of) the logic for parents and teachers.

app/lib/homework/student/src/open_homework_list.dart

@@ -44,7 +44,7 @@ class OpenHomeworkList extends StatelessWidget {
   Widget build(BuildContext context) {
     final bloc = BlocProvider.of<HomeworkPageBloc>(context);
 
-    if (_nullOrEmpty(homeworkListView.sections)) return Container();
+    if (homeworkListView.sections.isEmpty) return Container();
     return GlowingOverscrollColorChanger(
       color: overscrollColor,
       child: AnimatedStaggeredScrollView(
@@ -72,7 +72,4 @@ class OpenHomeworkList extends StatelessWidget {
       ),
     );
   }
-
-  bool _nullOrEmpty(List<HomeworkSectionView> homeworkSections) =>
-      homeworkSections.isEmpty;
 }

app/lib/homework/teacher/src/teacher_open_homework_list.dart

@@ -29,7 +29,7 @@ class TeacherOpenHomeworkList extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    if (_nullOrEmpty(homeworkListView.sections)) return Container();
+    if (homeworkListView.sections.isEmpty) return Container();
     return GlowingOverscrollColorChanger(
         color: overscrollColor,
         child: AnimatedStaggeredScrollView(
@@ -48,7 +48,4 @@ class TeacherOpenHomeworkList extends StatelessWidget {
           ],
         ));
   }
-
-  bool _nullOrEmpty(List<TeacherHomeworkSectionView> homeworkSections) =>
-      homeworkSections.isEmpty;
 }

app/test/homework/teacher/teacher_homework_page_widget_test.dart

@@ -13,6 +13,7 @@ import 'package:analytics/null_analytics_backend.dart';
 import 'package:bloc_provider/bloc_provider.dart';
 import 'package:bloc_provider/multi_bloc_provider.dart';
 import 'package:common_domain_models/common_domain_models.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:flutter/material.dart' as flutter show Color;
 import 'package:flutter/material.dart' hide Color;
 import 'package:flutter_test/flutter_test.dart';
@@ -161,16 +162,22 @@ void main() {
           bloc: homeworkPageBloc, initialTab: HomeworkTab.open);
 
       homeworkPageBloc.emitNewState(Success(
-        TeacherOpenHomeworkListView([
-          TeacherHomeworkSectionView('Section 1', [
-            randomHomeworkViewWith(title: 'HW in first Section'),
-          ]),
-          TeacherHomeworkSectionView('Section 2', [
-            randomHomeworkViewWith(title: 'HW in second Section'),
-          ]),
-        ], sorting: HomeworkSort.subjectSmallestDateAndTitleSort),
+        TeacherOpenHomeworkListView(
+            IList([
+              TeacherHomeworkSectionView(
+                  'Section 1',
+                  IListConst([
+                    randomHomeworkViewWith(title: 'HW in first Section'),
+                  ])),
+              TeacherHomeworkSectionView(
+                  'Section 2',
+                  IList([
+                    randomHomeworkViewWith(title: 'HW in second Section'),
+                  ])),
+            ]),
+            sorting: HomeworkSort.subjectSmallestDateAndTitleSort),
         TeacherArchivedHomeworkListView(
-          [],
+          const IListConst([]),
           loadedAllArchivedHomeworks: true,
         ),
       ));
@@ -242,7 +249,7 @@ void main() {
       await pumpHomeworkPage(tester,
           bloc: homeworkPageBloc, initialTab: HomeworkTab.archived);
 
-      final firstHomeworkBatch = generateRandomHomeworks(count: 30);
+      final firstHomeworkBatch = generateRandomHomeworks(count: 30).toIList();
 
       homeworkPageBloc.emitNewState(
         Success(
@@ -274,10 +281,8 @@ void main() {
           reason:
               "After scrolling down to near the last loaded homework the bloc should've received the event to load the next archived homeworks (as there are more to load in this test).");
 
-      final allLoadedHomeworks = [
-        ...firstHomeworkBatch,
-        ...generateRandomHomeworks(count: 10)
-      ];
+      final allLoadedHomeworks =
+          IList([...firstHomeworkBatch, ...generateRandomHomeworks(count: 10)]);
 
       homeworkPageBloc.emitNewState(
         Success(
@@ -362,11 +367,13 @@ void main() {
           bloc: homeworkPageBloc, initialTab: HomeworkTab.open);
 
       homeworkPageBloc.emitNewState(Success(
-        TeacherOpenHomeworkListView([
-          TeacherHomeworkSectionView('Section 1', views),
-        ], sorting: HomeworkSort.subjectSmallestDateAndTitleSort),
+        TeacherOpenHomeworkListView(
+            IList([
+              TeacherHomeworkSectionView('Section 1', views.toIList()),
+            ]),
+            sorting: HomeworkSort.subjectSmallestDateAndTitleSort),
         TeacherArchivedHomeworkListView(
-          [],
+          const IListConst([]),
           loadedAllArchivedHomeworks: true,
         ),
       ));
@@ -416,7 +423,7 @@ void main() {
         _noOpenHomeworks,
         TeacherArchivedHomeworkListView(
           // No homeworks loaded already
-          [],
+          const IListConst([]),
           // but there are homeworks to load
           loadedAllArchivedHomeworks: false,
         ),
@@ -489,32 +496,37 @@ TeacherHomeworkView randomHomeworkViewWith({
 
 Success _openHomeworksWith(HomeworkSort sort) {
   return Success(
-    TeacherOpenHomeworkListView([
-      TeacherHomeworkSectionView('Heute', [
-        randomHomeworkViewWith(title: 'S. 32'),
-        randomHomeworkViewWith(title: 'S. 34'),
-        randomHomeworkViewWith(title: 'S. 31'),
-      ])
-    ], sorting: sort),
+    TeacherOpenHomeworkListView(
+        IList([
+          TeacherHomeworkSectionView(
+              'Heute',
+              IList([
+                randomHomeworkViewWith(title: 'S. 32'),
+                randomHomeworkViewWith(title: 'S. 34'),
+                randomHomeworkViewWith(title: 'S. 31'),
+              ])),
+        ]),
+        sorting: sort),
     _noArchivedHomeworks,
   );
 }
 
 final _noHomeworks = Success(
   TeacherOpenHomeworkListView(
-    [],
+    const IListConst([]),
     sorting: HomeworkSort.smallestDateSubjectAndTitle,
   ),
   TeacherArchivedHomeworkListView(
-    [],
+    const IListConst([]),
     loadedAllArchivedHomeworks: true,
   ),
 );
 
-final _noOpenHomeworks = TeacherOpenHomeworkListView([],
+final _noOpenHomeworks = TeacherOpenHomeworkListView(const IListConst([]),
     sorting: HomeworkSort.smallestDateSubjectAndTitle);
-final _noArchivedHomeworks =
-    TeacherArchivedHomeworkListView([], loadedAllArchivedHomeworks: true);
+final _noArchivedHomeworks = TeacherArchivedHomeworkListView(
+    const IListConst([]),
+    loadedAllArchivedHomeworks: true);
 
 Future<void> _pumpHomeworkPageWithNoHomeworks(
   WidgetTester tester, {

lib/firebase_hausaufgabenheft_logik/lib/src/firestore_homework_data_source.dart

@@ -10,6 +10,7 @@ import 'dart:async';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:common_domain_models/common_domain_models.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
 import 'homework_transformation.dart';
 
@@ -24,7 +25,7 @@ class FirestoreHomeworkDataSource extends HomeworkDataSource {
       this.createLazyLoadingController, this._homeworkTransformer);
 
   @override
-  Stream<List<HomeworkReadModel>> get openHomeworks {
+  Stream<IList<HomeworkReadModel>> get openHomeworks {
     return _homeworkCollection
         .where("assignedUserArrays.openStudentUids", arrayContains: uid)
         .snapshots()
@@ -37,12 +38,12 @@ class FirestoreHomeworkDataSource extends HomeworkDataSource {
     return homework;
   }
 
-  Future<List<HomeworkId>> getCurrentOpenOverdueHomeworkIds() async {
+  Future<IList<HomeworkId>> getCurrentOpenOverdueHomeworkIds() async {
     final open = await openHomeworks.first;
     final overdue = open
         .where((homeworks) => homeworks.isOverdueRelativeTo(Date.now()))
         .toList();
-    final overdueIds = overdue.map((hws) => hws.id).toList();
+    final overdueIds = overdue.map((hws) => hws.id).toIList();
     return overdueIds;
   }
 

lib/firebase_hausaufgabenheft_logik/lib/src/firestore_realtime_completed_homework_loader.dart

@@ -7,6 +7,7 @@
 // SPDX-License-Identifier: EUPL-1.2
 
 import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
 
 import 'homework_transformation.dart';
@@ -22,7 +23,7 @@ class FirestoreRealtimeCompletedHomeworkLoader
       this._homeworkCollection, this._userId, this._homeworkTransformer);
 
   @override
-  Stream<List<HomeworkReadModel>> loadMostRecentHomeworks(
+  Stream<IList<HomeworkReadModel>> loadMostRecentHomeworks(
       int numberOfHomeworks) {
     return _homeworkCollection
         .where('assignedUserArrays.completedStudentUids',

lib/firebase_hausaufgabenheft_logik/lib/src/homework_transformation.dart

@@ -11,6 +11,7 @@ import 'dart:developer';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:common_domain_models/common_domain_models.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:hausaufgabenheft_logik/color.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
 
@@ -19,25 +20,25 @@ import 'homework_dto.dart';
 typedef CourseColorRetriever = FutureOr<int> Function(String courseId);
 
 class HomeworkTransformer extends StreamTransformerBase<
-    QuerySnapshot<Map<String, dynamic>>, List<HomeworkReadModel>> {
+    QuerySnapshot<Map<String, dynamic>>, IList<HomeworkReadModel>> {
   final String userId;
   final CourseColorRetriever getCourseColorHexValue;
 
   HomeworkTransformer(this.userId, {required this.getCourseColorHexValue});
 
   @override
-  Stream<List<HomeworkReadModel>> bind(Stream<QuerySnapshot> stream) {
+  Stream<IList<HomeworkReadModel>> bind(Stream<QuerySnapshot> stream) {
     return stream.asyncMap(querySnapshotToHomeworks);
   }
 
-  Future<List<HomeworkReadModel>> querySnapshotToHomeworks(
+  Future<IList<HomeworkReadModel>> querySnapshotToHomeworks(
       QuerySnapshot querySnapshot) async {
-    final homeworks = <HomeworkReadModel>[];
+    IList<HomeworkReadModel> homeworks = const IListConst([]);
     for (final document in querySnapshot.docs) {
       final homework = await tryToConvertToHomework(document, userId,
           getCourseColorHexValue: getCourseColorHexValue);
       if (homework != null) {
-        homeworks.add(homework);
+        homeworks = homeworks.add(homework);
       }
     }
     return homeworks;

lib/firebase_hausaufgabenheft_logik/lib/src/realtime_completed_homework_loader.dart

@@ -6,9 +6,10 @@
 //
 // SPDX-License-Identifier: EUPL-1.2
 
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
 
 abstract class RealtimeCompletedHomeworkLoader {
-  Stream<List<HomeworkReadModel>> loadMostRecentHomeworks(
+  Stream<IList<HomeworkReadModel>> loadMostRecentHomeworks(
       int numberOfHomeworks);
 }

lib/firebase_hausaufgabenheft_logik/pubspec.yaml

@@ -25,6 +25,7 @@ dependencies:
   time:
     path: ../time
   cloud_firestore: ^4.17.2
+  fast_immutable_collections: ^9.1.5
   flutter:
     sdk: flutter
   clock: ^1.1.1

lib/firebase_hausaufgabenheft_logik/test/in_memory_homework_loader.dart

@@ -6,17 +6,18 @@
 //
 // SPDX-License-Identifier: EUPL-1.2
 
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:firebase_hausaufgabenheft_logik/src/realtime_completed_homework_loader.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
 import 'package:rxdart/subjects.dart';
 
 class InMemoryHomeworkLoader extends RealtimeCompletedHomeworkLoader {
-  final BehaviorSubject<List<HomeworkReadModel>> _completedHomeworksSubject;
+  final BehaviorSubject<IList<HomeworkReadModel>> _completedHomeworksSubject;
 
   InMemoryHomeworkLoader(this._completedHomeworksSubject);
 
   @override
-  Stream<List<HomeworkReadModel>> loadMostRecentHomeworks(
+  Stream<IList<HomeworkReadModel>> loadMostRecentHomeworks(
       int numberOfHomeworks) {
     return _completedHomeworksSubject.map((homeworks) {
       if (homeworks.length < numberOfHomeworks) return homeworks;

lib/firebase_hausaufgabenheft_logik/test/lazy_loading_controller_test.dart

@@ -10,6 +10,7 @@ import 'dart:async';
 
 import 'package:clock/clock.dart';
 import 'package:common_domain_models/common_domain_models.dart';
+import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:firebase_hausaufgabenheft_logik/src/realtime_updating_lazy_loading_controller.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:hausaufgabenheft_logik/hausaufgabenheft_logik.dart';
@@ -22,14 +23,14 @@ class ReportingInMemoryHomeworkLoader extends InMemoryHomeworkLoader {
 
   bool wasInvoked = false;
   @override
-  Stream<List<HomeworkReadModel>> loadMostRecentHomeworks(
+  Stream<IList<HomeworkReadModel>> loadMostRecentHomeworks(
       int numberOfHomeworks) {
     wasInvoked = true;
     return super.loadMostRecentHomeworks(numberOfHomeworks);
   }
 }
 
-List<HomeworkReadModel> listOfHomeworksWithLength(int length) => List.generate(
+IList<HomeworkReadModel> listOfHomeworksWithLength(int length) => List.generate(
       length,
       (index) => HomeworkReadModel(
           id: HomeworkId("$index"),
@@ -38,29 +39,29 @@ List<HomeworkReadModel> listOfHomeworksWithLength(int length) => List.generate(
           subject: Subject("Mathe", abbreviation: 'Ma'),
           title: const Title("ABC"),
           withSubmissions: false),
-    );
+    ).toIList();
 
-Stream<List<HomeworkReadModel>> getHomeworkResultsAsStream(
+Stream<IList<HomeworkReadModel>> getHomeworkResultsAsStream(
         Stream<LazyLoadingResult> resultStream) =>
     resultStream.map((res) => res.homeworks);
 
 void main() {
   group('LazyLoadingController', () {
     late ReportingInMemoryHomeworkLoader homeworkLoader;
-    late rx.BehaviorSubject<List<HomeworkReadModel>> homeworkSubject;
+    late rx.BehaviorSubject<IList<HomeworkReadModel>> homeworkSubject;
 
-    void addToDataSource(List<HomeworkReadModel> homeworks) {
-      final hws = homeworkSubject.valueOrNull;
+    void addToDataSource(IList<HomeworkReadModel> homeworks) {
+      var hws = homeworkSubject.valueOrNull;
       if (hws != null) {
-        hws.addAll(homeworks);
+        hws = hws.addAll(homeworks);
         homeworkSubject.add(hws);
       } else {
         homeworkSubject.add(homeworks);
       }
     }
 
     setUp(() {
-      homeworkSubject = rx.BehaviorSubject<List<HomeworkReadModel>>();
+      homeworkSubject = rx.BehaviorSubject<IList<HomeworkReadModel>>();
       homeworkLoader = ReportingInMemoryHomeworkLoader(homeworkSubject);
     });