From 73f9db5fabd6ff85c13c207f24894474bfc61c1e Mon Sep 17 00:00:00 2001
From: Vishesh Handa <me@vhanda.in>
Date: Mon, 17 May 2021 18:15:47 +0200
Subject: [PATCH] Core: Null Safety++

This is a rather huge change. I hope I haven't broken anything.
---
 lib/core/note.dart            | 101 +++++++++++++++++-----------------
 lib/core/note_notifier.dart   |  41 +++++++-------
 lib/core/note_serializer.dart |   8 +--
 lib/core/notes_folder_fs.dart |  21 +++----
 lib/core/sorting_mode.dart    |  10 ++--
 lib/error_reporting.dart      |  23 ++++----
 lib/folder_views/common.dart  |   8 +--
 lib/settings.dart             |   2 +-
 8 files changed, 100 insertions(+), 114 deletions(-)

diff --git a/lib/core/note.dart b/lib/core/note.dart
index 50f4e27b..98595c56 100644
--- a/lib/core/note.dart
+++ b/lib/core/note.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
 /*
 Copyright 2020-2021 Vishesh Handa <me@vhanda.in>
 
@@ -86,31 +84,31 @@ enum NoteFileFormat {
 
 class Note with NotesNotifier {
   NotesFolderFS parent;
-  String _filePath;
+  String? _filePath;
 
   String _title = "";
-  DateTime _created;
-  DateTime _modified;
+  DateTime? _created;
+  DateTime? _modified;
   String _body = "";
   NoteType _type = NoteType.Unknown;
   Set<String> _tags = {};
   Map<String, dynamic> _extraProps = {};
 
-  NoteFileFormat _fileFormat;
+  NoteFileFormat? _fileFormat;
 
   MdYamlDoc _data = MdYamlDoc();
-  NoteSerializer noteSerializer;
+  late NoteSerializer noteSerializer;
 
-  DateTime fileLastModified;
+  DateTime? fileLastModified;
 
   var _loadState = NoteLoadState.None;
   var _serializer = MarkdownYAMLCodec();
 
   // Computed from body
-  String _summary;
-  List<Link> _links;
-  Set<String> _inlineTags;
-  Set<NoteImage> _images;
+  String? _summary;
+  List<Link>? _links;
+  Set<String>? _inlineTags;
+  Set<NoteImage>? _images;
 
   static final _mdYamlDocLoader = MdYamlDocLoader();
   static final _linksLoader = LinksLoader();
@@ -150,58 +148,61 @@ class Note with NotesNotifier {
 
   String get filePath {
     if (_filePath == null) {
+      var fp = "";
       try {
-        _filePath = p.join(parent.folderPath, _buildFileName());
+        fp = p.join(parent.folderPath, _buildFileName());
       } catch (e, stackTrace) {
         Log.e("_buildFileName: $e");
         logExceptionWarning(e, stackTrace);
-        _filePath = p.join(parent.folderPath, const Uuid().v4());
+        fp = p.join(parent.folderPath, const Uuid().v4());
       }
       switch (_fileFormat) {
         case NoteFileFormat.OrgMode:
-          if (!_filePath.toLowerCase().endsWith('.org')) {
-            _filePath += '.org';
+          if (!fp.toLowerCase().endsWith('.org')) {
+            fp += '.org';
           }
           break;
 
         case NoteFileFormat.Txt:
-          if (!_filePath.toLowerCase().endsWith('.txt')) {
-            _filePath += '.txt';
+          if (!fp.toLowerCase().endsWith('.txt')) {
+            fp += '.txt';
           }
           break;
 
         case NoteFileFormat.Markdown:
         default:
-          if (!_filePath.toLowerCase().endsWith('.md')) {
-            _filePath += '.md';
+          if (!fp.toLowerCase().endsWith('.md')) {
+            fp += '.md';
           }
           break;
       }
+
+      _filePath = fp;
     }
 
-    return _filePath;
+    return _filePath as String;
   }
 
   String get fileName {
     return p.basename(filePath);
   }
 
-  DateTime get created {
+  DateTime? get created {
     return _created;
   }
 
-  set created(DateTime dt) {
+  set created(DateTime? dt) {
     if (!canHaveMetadata) return;
 
     _created = dt;
     _notifyModified();
   }
 
-  DateTime get modified {
+  DateTime? get modified {
     return _modified;
   }
 
-  set modified(DateTime dt) {
+  set modified(DateTime? dt) {
     if (!canHaveMetadata) return;
 
     _modified = dt;
@@ -255,7 +256,6 @@ class Note with NotesNotifier {
   }
 
   set tags(Set<String> tags) {
-    assert(tags != null);
     if (!canHaveMetadata) return;
 
     _tags = tags;
@@ -270,16 +270,16 @@ class Note with NotesNotifier {
       var p = InlineTagsProcessor(tagPrefixes: tagPrefixes);
       _inlineTags = p.extractTags(body);
     }
-    return _inlineTags;
+    return _inlineTags!;
   }
 
   Set<NoteImage> get images {
     if (_loadState != NoteLoadState.Loaded) return {};
 
     var p = ImageExtractor();
-    _images ??= p.extract(body);
+    _images = p.extract(body);
 
-    return _images;
+    return _images!;
   }
 
   Map<String, dynamic> get extraProps {
@@ -317,7 +317,7 @@ class Note with NotesNotifier {
     return body.isEmpty;
   }
 
-  String get summary {
+  String? get summary {
     if (_loadState != NoteLoadState.Loaded) return "";
 
     _summary ??= stripMarkdownFormatting(body);
@@ -330,13 +330,13 @@ class Note with NotesNotifier {
 
   Future<NoteLoadState> load() async {
     assert(_filePath != null);
-    assert(_filePath.isNotEmpty);
+    assert(_filePath!.isNotEmpty);
 
     if (_loadState == NoteLoadState.Loading) {
       return _loadState;
     }
 
-    final file = File(_filePath);
+    final file = File(_filePath!);
     if (_loadState == NoteLoadState.Loaded) {
       try {
         var fileLastModified = file.lastModifiedSync();
@@ -346,7 +346,7 @@ class Note with NotesNotifier {
         this.fileLastModified = fileLastModified;
       } catch (e, stackTrace) {
         if (e is FileSystemException &&
-            e.osError.errorCode == 2 /* File Not Found */) {
+            e.osError!.errorCode == 2 /* File Not Found */) {
           _loadState = NoteLoadState.NotExists;
           _notifyModified();
           return _loadState;
@@ -360,14 +360,15 @@ class Note with NotesNotifier {
       Log.d("Note modified: $_filePath");
     }
 
-    var fpLowerCase = _filePath.toLowerCase();
+    var fpLowerCase = _filePath!.toLowerCase();
     var isMarkdown = fpLowerCase.endsWith('.md');
     var isTxt = fpLowerCase.endsWith('.txt');
     var isOrg = fpLowerCase.endsWith('.org');
 
     if (isMarkdown) {
       try {
-        data = await _mdYamlDocLoader.loadDoc(_filePath);
+        var dataMaybe = await _mdYamlDocLoader.loadDoc(_filePath!);
+        data = dataMaybe!;
         _fileFormat = NoteFileFormat.Markdown;
       } on MdYamlDocNotFoundException catch (_) {
         _loadState = NoteLoadState.NotExists;
@@ -382,7 +383,7 @@ class Note with NotesNotifier {
       }
     } else if (isTxt) {
       try {
-        body = await File(_filePath).readAsString();
+        body = await File(_filePath!).readAsString();
         _fileFormat = NoteFileFormat.Txt;
       } catch (e, stackTrace) {
         logExceptionWarning(e, stackTrace);
@@ -393,7 +394,7 @@ class Note with NotesNotifier {
       }
     } else if (isOrg) {
       try {
-        body = await File(_filePath).readAsString();
+        body = await File(_filePath!).readAsString();
         _fileFormat = NoteFileFormat.OrgMode;
       } catch (e, stackTrace) {
         logExceptionWarning(e, stackTrace);
@@ -417,10 +418,6 @@ class Note with NotesNotifier {
 
   // FIXME: What about error handling?
   Future<void> save() async {
-    assert(_data != null);
-    assert(_data.body != null);
-    assert(_data.props != null);
-
     var file = File(filePath);
     var contents = _serializer.encode(data);
     // Make sure all docs end with a \n
@@ -439,7 +436,7 @@ class Note with NotesNotifier {
   Future<void> remove() async {
     assert(_filePath != null);
 
-    var file = File(_filePath);
+    var file = File(filePath);
     await file.delete();
   }
 
@@ -537,8 +534,12 @@ class Note with NotesNotifier {
     if (imageSpec == '.') {
       baseFolder = parent.folderPath;
     } else {
-      baseFolder = parent.rootFolder.getFolderWithSpec(imageSpec).folderPath;
-      baseFolder ??= parent.folderPath;
+      var folder = parent.rootFolder.getFolderWithSpec(imageSpec);
+      if (folder != null) {
+        baseFolder = folder.folderPath;
+      } else {
+        baseFolder = parent.folderPath;
+      }
     }
 
     var imageFileName = p.basename(file.path);
@@ -567,9 +568,6 @@ class Note with NotesNotifier {
   }
 
   String pathSpec() {
-    if (parent == null) {
-      return fileName;
-    }
     return p.join(parent.pathSpec(), fileName);
   }
 
@@ -590,7 +588,6 @@ class Note with NotesNotifier {
         } else {
           return toSimpleDateTime(date);
         }
-        break;
       case NoteFileNameFormat.Iso8601:
         return toIso8601(date);
       case NoteFileNameFormat.Iso8601WithTimeZone:
@@ -606,20 +603,20 @@ class Note with NotesNotifier {
     return date.toString();
   }
 
-  Future<List<Link>> fetchLinks() async {
+  Future<List<Link>?> fetchLinks() async {
     if (_links != null) {
       return _links;
     }
 
-    _links = await _linksLoader.parseLinks(body: _body, filePath: _filePath);
+    _links = await _linksLoader.parseLinks(body: _body, filePath: _filePath!);
     return _links;
   }
 
-  List<Link> links() {
+  List<Link>? links() {
     return _links;
   }
 
-  NoteFileFormat get fileFormat {
+  NoteFileFormat? get fileFormat {
     return _fileFormat;
   }
 }
diff --git a/lib/core/note_notifier.dart b/lib/core/note_notifier.dart
index 042eb676..9dc444f5 100644
--- a/lib/core/note_notifier.dart
+++ b/lib/core/note_notifier.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
@@ -9,25 +7,27 @@ typedef NoteModificationCallback = void Function(Note note);
 typedef NoteRenameCallback = void Function(Note note, String oldPath);
 
 class NotesNotifier implements ChangeNotifier {
-  var _modListeners = ObserverList<NoteModificationCallback>();
-  var _renameListeners = ObserverList<NoteRenameCallback>();
+  ObserverList<NoteModificationCallback>? _modListeners =
+      ObserverList<NoteModificationCallback>();
+  ObserverList<NoteRenameCallback>? _renameListeners =
+      ObserverList<NoteRenameCallback>();
 
   void addModifiedListener(NoteModificationCallback listener) {
-    _modListeners.add(listener);
+    _modListeners?.add(listener);
   }
 
   void removeModifiedListener(NoteModificationCallback listener) {
-    assert(_modListeners.contains(listener));
-    _modListeners.remove(listener);
+    assert(_modListeners!.contains(listener));
+    _modListeners?.remove(listener);
   }
 
   void addRenameListener(NoteRenameCallback listener) {
-    _renameListeners.add(listener);
+    _renameListeners?.add(listener);
   }
 
   void removeRenameListener(NoteRenameCallback listener) {
-    assert(_renameListeners.contains(listener));
-    _renameListeners.remove(listener);
+    assert(_renameListeners!.contains(listener));
+    _renameListeners?.remove(listener);
   }
 
   @mustCallSuper
@@ -42,7 +42,7 @@ class NotesNotifier implements ChangeNotifier {
   //
   // ChangeNotifier implementation - How to not duplicate this?
   //
-  ObserverList<VoidCallback> _listeners = ObserverList<VoidCallback>();
+  ObserverList<VoidCallback>? _listeners = ObserverList<VoidCallback>();
 
   bool _debugAssertNotDisposed() {
     assert(() {
@@ -77,7 +77,7 @@ class NotesNotifier implements ChangeNotifier {
   @override
   bool get hasListeners {
     assert(_debugAssertNotDisposed());
-    return _listeners.isNotEmpty;
+    return _listeners!.isNotEmpty;
   }
 
   /// Register a closure to be called when the object changes.
@@ -86,7 +86,7 @@ class NotesNotifier implements ChangeNotifier {
   @override
   void addListener(VoidCallback listener) {
     assert(_debugAssertNotDisposed());
-    _listeners.add(listener);
+    _listeners!.add(listener);
   }
 
   /// Remove a previously registered closure from the list of closures that are
@@ -111,7 +111,7 @@ class NotesNotifier implements ChangeNotifier {
   @override
   void removeListener(VoidCallback listener) {
     assert(_debugAssertNotDisposed());
-    _listeners.remove(listener);
+    _listeners!.remove(listener);
   }
 
   /// Call all the registered listeners.
@@ -136,10 +136,10 @@ class NotesNotifier implements ChangeNotifier {
     assert(_debugAssertNotDisposed());
     if (_listeners != null) {
       final List<VoidCallback> localListeners =
-          List<VoidCallback>.from(_listeners);
+          List<VoidCallback>.from(_listeners!);
       for (VoidCallback listener in localListeners) {
         try {
-          if (_listeners.contains(listener)) {
+          if (_listeners!.contains(listener)) {
             listener();
           }
         } catch (exception, stack) {
@@ -165,10 +165,11 @@ class NotesNotifier implements ChangeNotifier {
   void notifyModifiedListeners(Note note) {
     assert(_debugAssertNotDisposed());
     if (_modListeners != null) {
-      final localListeners = List<NoteModificationCallback>.from(_modListeners);
+      final localListeners =
+          List<NoteModificationCallback>.from(_modListeners!);
       for (var listener in localListeners) {
         try {
-          if (_modListeners.contains(listener)) {
+          if (_modListeners!.contains(listener)) {
             listener(note);
           }
         } catch (exception, stack) {
@@ -194,10 +195,10 @@ class NotesNotifier implements ChangeNotifier {
   void notifyRenameListeners(Note note, String oldPath) {
     assert(_debugAssertNotDisposed());
     if (_renameListeners != null) {
-      final localListeners = List<NoteRenameCallback>.from(_renameListeners);
+      final localListeners = List<NoteRenameCallback>.from(_renameListeners!);
       for (var listener in localListeners) {
         try {
-          if (_renameListeners.contains(listener)) {
+          if (_renameListeners!.contains(listener)) {
             listener(note, oldPath);
           }
         } catch (exception, stack) {
diff --git a/lib/core/note_serializer.dart b/lib/core/note_serializer.dart
index 5e03676b..1d10f852 100644
--- a/lib/core/note_serializer.dart
+++ b/lib/core/note_serializer.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
 /*
 Copyright 2020-2021 Vishesh Handa <me@vhanda.in>
 
@@ -65,18 +63,18 @@ class NoteSerializer implements NoteSerializerInterface {
     data.body = emojiParser.unemojify(note.body);
 
     if (note.created != null) {
-      data.props[settings.createdKey] = toIso8601WithTimezone(note.created);
+      data.props[settings.createdKey] = toIso8601WithTimezone(note.created!);
     } else {
       data.props.remove(settings.createdKey);
     }
 
     if (note.modified != null) {
-      data.props[settings.modifiedKey] = toIso8601WithTimezone(note.modified);
+      data.props[settings.modifiedKey] = toIso8601WithTimezone(note.modified!);
     } else {
       data.props.remove(settings.modifiedKey);
     }
 
-    if (note.title != null) {
+    if (note.title.isNotEmpty) {
       var title = emojiParser.unemojify(note.title.trim());
       if (settings.titleSettings == SettingsTitle.InH1) {
         if (title.isNotEmpty) {
diff --git a/lib/core/notes_folder_fs.dart b/lib/core/notes_folder_fs.dart
index 2b12d784..4a164b9a 100644
--- a/lib/core/notes_folder_fs.dart
+++ b/lib/core/notes_folder_fs.dart
@@ -1,10 +1,7 @@
-// @dart=2.9
-
 import 'dart:collection';
 import 'dart:io';
 
 import 'package:easy_localization/easy_localization.dart';
-import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;
 import 'package:path/path.dart';
 import 'package:synchronized/synchronized.dart';
@@ -24,7 +21,7 @@ class IgnoredFile {
   String filePath;
   IgnoreReason reason;
 
-  IgnoredFile({@required this.filePath, @required this.reason});
+  IgnoredFile({required this.filePath, required this.reason});
 
   String get fileName {
     return p.basename(filePath);
@@ -32,7 +29,7 @@ class IgnoredFile {
 }
 
 class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
-  final NotesFolderFS _parent;
+  final NotesFolderFS? _parent;
   String _folderPath;
   var _lock = Lock();
 
@@ -54,9 +51,9 @@ class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
   }
 
   @override
-  NotesFolder get parent => _parent;
+  NotesFolder? get parent => _parent;
 
-  NotesFolderFS get parentFS => _parent;
+  NotesFolderFS? get parentFS => _parent;
 
   void _entityChanged() {
     notifyListeners();
@@ -190,7 +187,7 @@ class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
       futures.add(f);
     }
 
-    return Future.wait(futures);
+    await Future.wait(futures);
   }
 
   Future<void> load() async {
@@ -418,7 +415,7 @@ class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
     if (parent == null) {
       return "";
     }
-    return p.join(parent.pathSpec(), name);
+    return p.join(parent!.pathSpec(), name);
   }
 
   @override
@@ -448,7 +445,7 @@ class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
     return this;
   }
 
-  NotesFolderFS getFolderWithSpec(String spec) {
+  NotesFolderFS? getFolderWithSpec(String spec) {
     if (pathSpec() == spec) {
       return this;
     }
@@ -465,12 +462,12 @@ class NotesFolderFS with NotesFolderNotifier implements NotesFolder {
   NotesFolderFS get rootFolder {
     var folder = this;
     while (folder.parent != null) {
-      folder = folder.parent;
+      folder = folder.parent as NotesFolderFS;
     }
     return folder;
   }
 
-  Note getNoteWithSpec(String spec) {
+  Note? getNoteWithSpec(String spec) {
     var parts = spec.split(p.separator);
     var folder = this;
     while (parts.length != 1) {
diff --git a/lib/core/sorting_mode.dart b/lib/core/sorting_mode.dart
index 72e3487b..73b564e5 100644
--- a/lib/core/sorting_mode.dart
+++ b/lib/core/sorting_mode.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
 import 'package:easy_localization/easy_localization.dart';
 
 import 'package:gitjournal/core/note.dart';
@@ -160,7 +158,7 @@ int _sortCreatedDesc(Note a, Note b) {
   if (bDt == null && aDt == null) {
     return a.fileName.compareTo(b.fileName);
   }
-  return bDt.compareTo(aDt);
+  return bDt!.compareTo(aDt!);
 }
 
 int _sortModifiedDesc(Note a, Note b) {
@@ -175,12 +173,12 @@ int _sortModifiedDesc(Note a, Note b) {
   if (bDt == null && aDt == null) {
     return a.fileName.compareTo(b.fileName);
   }
-  return bDt.compareTo(aDt);
+  return bDt!.compareTo(aDt!);
 }
 
 int _sortTitleAsc(Note a, Note b) {
-  var aTitleExists = a.title != null && a.title.isNotEmpty;
-  var bTitleExists = b.title != null && b.title.isNotEmpty;
+  var aTitleExists = a.title.isNotEmpty;
+  var bTitleExists = b.title.isNotEmpty;
 
   if (!aTitleExists && bTitleExists) {
     return 1;
diff --git a/lib/error_reporting.dart b/lib/error_reporting.dart
index bb6d3871..1ecb151d 100644
--- a/lib/error_reporting.dart
+++ b/lib/error_reporting.dart
@@ -1,5 +1,3 @@
-// @dart=2.9
-
 import 'dart:async';
 import 'dart:io';
 
@@ -30,8 +28,8 @@ Future<void> initSentry() async {
 Future<SentryEvent> get _environmentEvent async {
   final packageInfo = await PackageInfo.fromPlatform();
   final deviceInfoPlugin = DeviceInfoPlugin();
-  SentryOperatingSystem os;
-  SentryDevice device;
+  SentryOperatingSystem? os;
+  SentryDevice? device;
   if (Platform.isAndroid) {
     final androidInfo = await deviceInfoPlugin.androidInfo;
     os = SentryOperatingSystem(
@@ -77,19 +75,19 @@ void flutterOnErrorHandler(FlutterErrorDetails details) {
   if (reportCrashes == true) {
     // vHanda: This doesn't always call our zone error handler, why?
     // Zone.current.handleUncaughtError(details.exception, details.stack);
-    reportError(details.exception, details.stack);
+    reportError(details.exception, details.stack ?? StackTrace.current);
   } else {
     FlutterError.dumpErrorToConsole(details);
   }
 }
 
 bool get reportCrashes => _reportCrashes ??= _initReportCrashes();
-bool _reportCrashes;
+bool? _reportCrashes;
 bool _initReportCrashes() {
   return !JournalApp.isInDebugMode && AppSettings.instance.collectCrashReports;
 }
 
-Future<void> reportError(Object error, StackTrace stackTrace) async {
+Future<void> reportError(dynamic error, StackTrace stackTrace) async {
   Log.e("Uncaught Exception", ex: error, stacktrace: stackTrace);
 
   if (reportCrashes) {
@@ -124,8 +122,8 @@ Future<void> logExceptionWarning(Object e, StackTrace stackTrace) async {
 List<Breadcrumb> breadcrumbs = [];
 
 void captureErrorBreadcrumb({
-  @required String name,
-  Map<String, String> parameters,
+  required String name,
+  required Map<String, String> parameters,
 }) {
   var b = Breadcrumb(
     message: name,
@@ -136,19 +134,20 @@ void captureErrorBreadcrumb({
 }
 
 Future<void> captureSentryException(
-  Object exception,
+  dynamic exception,
   StackTrace stackTrace, {
   SentryLevel level = SentryLevel.error,
 }) async {
   try {
     await initSentry();
     final event = (await _environmentEvent).copyWith(
-      exception: exception,
+      throwable: exception,
       breadcrumbs: breadcrumbs,
       level: level,
     );
 
-    return Sentry.captureEvent(event, stackTrace: Trace.from(stackTrace).terse);
+    await Sentry.captureEvent(event, stackTrace: Trace.from(stackTrace).terse);
+    return;
   } catch (e) {
     print("Failed to report with Sentry: $e");
   }
diff --git a/lib/folder_views/common.dart b/lib/folder_views/common.dart
index 81bd51a6..46112ee8 100644
--- a/lib/folder_views/common.dart
+++ b/lib/folder_views/common.dart
@@ -16,14 +16,10 @@ import 'package:gitjournal/screens/note_editor.dart';
 import 'package:gitjournal/settings.dart';
 import 'package:gitjournal/utils.dart';
 import 'package:gitjournal/utils/logger.dart';
+import 'common_types.dart';
 import 'standard_view.dart';
 
-enum FolderViewType {
-  Standard,
-  Journal,
-  Card,
-  Grid,
-}
+export 'common_types.dart';
 
 Widget buildFolderView({
   @required FolderViewType viewType,
diff --git a/lib/settings.dart b/lib/settings.dart
index 46675acb..efda65e6 100644
--- a/lib/settings.dart
+++ b/lib/settings.dart
@@ -29,7 +29,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 import 'package:uuid/uuid.dart';
 
 import 'package:gitjournal/core/sorting_mode.dart';
-import 'package:gitjournal/folder_views/common.dart';
+import 'package:gitjournal/folder_views/common_types.dart';
 import 'package:gitjournal/screens/note_editor.dart';
 
 const DEFAULT_ID = "0";