chore: strict casts

analysis_options.yaml

@@ -11,7 +11,7 @@ linter:
 
 analyzer:
   language:
-    strict-casts: false
+    strict-casts: true
     strict-inference: true
     strict-raw-types: true
   errors:

lib/fake_matrix_api.dart

@@ -31,12 +31,12 @@ import 'package:matrix_api_lite/matrix_api_lite.dart';
 
 Map<String, dynamic> decodeJson(dynamic data) {
   if (data is String) {
-    return json.decode(data);
+    return json.decode(data) as Map<String, dynamic>;
   }
   if (data is Map && data.isEmpty) {
     return <String, dynamic>{};
   }
-  return data;
+  return data as Map<String, dynamic>;
 }
 
 T? tryCast<T>(dynamic object) => object is T ? object : null;

lib/src/matrix_api.dart

@@ -47,7 +47,10 @@ class MatrixApi extends Api {
   @override
   Never unexpectedResponse(http.BaseResponse response, Uint8List body) {
     if (response.statusCode >= 400 && response.statusCode < 500) {
-      throw MatrixException.fromJson(json.decode(utf8.decode(body)));
+      final resp = json.decode(utf8.decode(body));
+      if (resp is Map<String, dynamic>) {
+        throw MatrixException.fromJson(resp);
+      }
     }
     super.unexpectedResponse(response, body);
   }
@@ -164,7 +167,7 @@ class MatrixApi extends Api {
         },
       },
     );
-    return Map<String, int>.from(response['one_time_key_counts']);
+    return Map<String, int>.from(response['one_time_key_counts'] as Map);
   }
 
   /// This endpoint allows the creation, modification and deletion of pushers

lib/src/model/auth/authentication_data.dart

@@ -30,8 +30,8 @@ class AuthenticationData {
   AuthenticationData({this.type, this.session});
 
   AuthenticationData.fromJson(Map<String, dynamic> json)
-      : type = json['type'],
+      : type = json['type'] as String?,
-        session = json['session'];
+        session = json['session'] as String?;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/auth/authentication_identifier.dart

@@ -32,7 +32,7 @@ class AuthenticationIdentifier {
   AuthenticationIdentifier({required this.type});
 
   AuthenticationIdentifier.fromJson(Map<String, dynamic> json)
-      : type = json['type'];
+      : type = json['type'] as String;
 
   factory AuthenticationIdentifier.subFromJson(Map<String, dynamic> json) {
     switch (json['type']) {

lib/src/model/auth/authentication_password.dart

@@ -41,8 +41,9 @@ class AuthenticationPassword extends AuthenticationData {
         );
 
   AuthenticationPassword.fromJson(Map<String, dynamic> json)
-      : password = json['password'],
+      : password = json['password'] as String,
-        identifier = AuthenticationIdentifier.subFromJson(json['identifier']),
+        identifier = AuthenticationIdentifier.subFromJson(
+            json['identifier'] as Map<String, dynamic>),
         super.fromJson(json);
 
   @override

lib/src/model/auth/authentication_phone_identifier.dart

@@ -32,8 +32,8 @@ class AuthenticationPhoneIdentifier extends AuthenticationIdentifier {
       : super(type: AuthenticationIdentifierTypes.phone);
 
   AuthenticationPhoneIdentifier.fromJson(Map<String, dynamic> json)
-      : country = json['country'],
+      : country = json['country'] as String,
-        phone = json['phone'],
+        phone = json['phone'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/auth/authentication_recaptcha.dart

@@ -34,7 +34,7 @@ class AuthenticationRecaptcha extends AuthenticationData {
         );
 
   AuthenticationRecaptcha.fromJson(Map<String, dynamic> json)
-      : response = json['response'],
+      : response = json['response'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/auth/authentication_third_party_identifier.dart

@@ -33,8 +33,8 @@ class AuthenticationThirdPartyIdentifier extends AuthenticationIdentifier {
       : super(type: AuthenticationIdentifierTypes.thirdParty);
 
   AuthenticationThirdPartyIdentifier.fromJson(Map<String, dynamic> json)
-      : medium = json['medium'],
+      : medium = json['medium'] as String,
-        address = json['address'],
+        address = json['address'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/auth/authentication_three_pid_creds.dart

@@ -66,10 +66,10 @@ class ThreepidCreds {
       this.idAccessToken});
 
   ThreepidCreds.fromJson(Map<String, dynamic> json)
-      : sid = json['sid'],
+      : sid = json['sid'] as String,
-        clientSecret = json['client_secret'],
+        clientSecret = json['client_secret'] as String,
-        idServer = json['id_server'],
+        idServer = json['id_server'] as String?,
-        idAccessToken = json['id_access_token'];
+        idAccessToken = json['id_access_token'] as String?;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/auth/authentication_token.dart

@@ -37,8 +37,8 @@ class AuthenticationToken extends AuthenticationData {
         );
 
   AuthenticationToken.fromJson(Map<String, dynamic> json)
-      : token = json['token'],
+      : token = json['token'] as String,
-        txnId = json['txn_id'],
+        txnId = json['txn_id'] as String?,
         super.fromJson(json);
 
   @override

lib/src/model/auth/authentication_user_identifier.dart

@@ -31,7 +31,7 @@ class AuthenticationUserIdentifier extends AuthenticationIdentifier {
       : super(type: AuthenticationIdentifierTypes.userId);
 
   AuthenticationUserIdentifier.fromJson(Map<String, dynamic> json)
-      : user = json['user'],
+      : user = json['user'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/basic_event.dart

@@ -33,7 +33,7 @@ class BasicEvent {
   });
 
   BasicEvent.fromJson(Map<String, dynamic> json)
-      : type = json['type'],
+      : type = json['type'] as String,
         content = (json['content'] as Map<String, dynamic>).copy();
 
   Map<String, dynamic> toJson() {

lib/src/model/basic_event_with_sender.dart

@@ -33,7 +33,7 @@ class BasicEventWithSender extends BasicEvent {
       : super(type: type, content: content);
 
   BasicEventWithSender.fromJson(Map<String, dynamic> json)
-      : senderId = json['sender'],
+      : senderId = json['sender'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/basic_room_event.dart

@@ -36,7 +36,7 @@ class BasicRoomEvent extends BasicEvent {
         );
 
   BasicRoomEvent.fromJson(Map<String, dynamic> json)
-      : roomId = json['room_id'],
+      : roomId = json['room_id'] as String?,
         super.fromJson(json);
 
   @override

lib/src/model/children_state.dart

@@ -39,8 +39,8 @@ class ChildrenState extends StrippedStateEvent {
             stateKey: stateKey);
 
   ChildrenState.fromJson(Map<String, dynamic> json)
-      : originServerTs =
+      : originServerTs = DateTime.fromMillisecondsSinceEpoch(
-            DateTime.fromMillisecondsSinceEpoch(json['origin_server_ts']),
+            json['origin_server_ts'] as int),
         super.fromJson(json);
 
   @override

lib/src/model/events/image_pack_content.dart

@@ -78,15 +78,19 @@ class ImagePackContent {
             (e) => !['images', 'pack', 'emoticons', 'short'].contains(e.key))),
         pack = ImagePackPackContent.fromJson(
             json.tryGetMap<String, dynamic>('pack') ?? {}),
-        images = json.tryGetMap<String, dynamic>('images')?.catchMap(
+        images = json.tryGetMap<String, dynamic>('images')?.catchMap((k, v) =>
-                (k, v) => MapEntry(k, ImagePackImageContent.fromJson(v))) ??
+                MapEntry(
+                    k,
+                    ImagePackImageContent.fromJson(
+                        v as Map<String, dynamic>))) ??
             // the "emoticons" key needs a small migration on the key, ":string:" --> "string"
             json.tryGetMap<String, dynamic>('emoticons')?.catchMap((k, v) =>
                 MapEntry(
                     k.startsWith(':') && k.endsWith(':')
                         ? k.substring(1, k.length - 1)
                         : k,
-                    ImagePackImageContent.fromJson(v))) ??
+                    ImagePackImageContent.fromJson(
+                        v as Map<String, dynamic>))) ??
             // the "short" key was still just a map from shortcode to mxc uri
             json.tryGetMap<String, String>('short')?.catchMap((k, v) =>
                 MapEntry(
@@ -118,7 +122,7 @@ class ImagePackImageContent {
   ImagePackImageContent.fromJson(Map<String, dynamic> json)
       : _json = Map.fromEntries(json.entries
             .where((e) => !['url', 'body', 'info'].contains(e.key))),
-        url = Uri.parse(json['url']),
+        url = Uri.parse(json['url'] as String),
         body = json.tryGet('body'),
         info = json.tryGetMap<String, dynamic>('info'),
         usage = imagePackUsageFromJson(json.tryGetList<String>('usage'));

lib/src/model/events/room_encrypted_content.dart

@@ -49,7 +49,8 @@ class RoomEncryptedContent {
         // filter out invalid/incomplete CiphertextInfos
         ciphertextOlm = json
             .tryGet<Map<String, dynamic>>('ciphertext', TryGet.silent)
-            ?.catchMap((k, v) => MapEntry(k, CiphertextInfo.fromJson(v)));
+            ?.catchMap((k, v) => MapEntry(
+                k, CiphertextInfo.fromJson(v as Map<String, dynamic>)));
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -81,8 +82,8 @@ class CiphertextInfo {
   int type;
 
   CiphertextInfo.fromJson(Map<String, dynamic> json)
-      : body = json['body'],
+      : body = json['body'] as String,
-        type = json['type'];
+        type = json['type'] as int;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/matrix_event.dart

@@ -50,13 +50,13 @@ class MatrixEvent extends StrippedStateEvent {
             stateKey: stateKey);
 
   MatrixEvent.fromJson(Map<String, dynamic> json)
-      : eventId = json['event_id'],
+      : eventId = json['event_id'] as String,
-        roomId = json['room_id'],
+        roomId = json['room_id'] as String?,
-        originServerTs =
+        originServerTs = DateTime.fromMillisecondsSinceEpoch(
-            DateTime.fromMillisecondsSinceEpoch(json['origin_server_ts']),
+            json['origin_server_ts'] as int),
         unsigned = (json['unsigned'] as Map<String, dynamic>?)?.copy(),
         prevContent = (json['prev_content'] as Map<String, dynamic>?)?.copy(),
-        redacts = json['redacts'],
+        redacts = json['redacts'] as String?,
         super.fromJson(json);
 
   @override

lib/src/model/matrix_exception.dart

@@ -65,12 +65,12 @@ class MatrixException implements Exception {
 
   /// The unique identifier for this error.
   String get errcode =>
-      raw['errcode'] ??
+      raw['errcode'] as String? ??
       (requireAdditionalAuthentication ? 'M_FORBIDDEN' : 'M_UNKNOWN');
 
   /// A human readable error description.
   String get errorMessage =>
-      raw['error'] ??
+      raw['error'] as String? ??
       (requireAdditionalAuthentication
           ? 'Require additional authentication'
           : 'Unknown error');
@@ -79,7 +79,7 @@ class MatrixException implements Exception {
   http.Response? response;
 
   MatrixException(http.Response this.response)
-      : raw = json.decode(response.body);
+      : raw = json.decode(response.body) as Map<String, dynamic>;
 
   MatrixException.fromJson(Map<String, dynamic> content) : raw = content;
 
@@ -91,11 +91,11 @@ class MatrixException implements Exception {
       (e) => e.toString() == 'MatrixError.${(raw["errcode"] ?? "")}',
       orElse: () => MatrixError.M_UNKNOWN);
 
-  int? get retryAfterMs => raw['retry_after_ms'];
+  int? get retryAfterMs => raw['retry_after_ms'] as int?;
 
   /// This is a session identifier that the client must pass back to the homeserver, if one is provided,
   /// in subsequent attempts to authenticate in the same API call.
-  String? get session => raw['session'];
+  String? get session => raw['session'] as String?;
 
   /// Returns true if the server requires additional authentication.
   bool get requireAdditionalAuthentication => response != null
@@ -119,11 +119,12 @@ class MatrixException implements Exception {
   /// This section contains any information that the client will need to know in order to use a given type
   /// of authentication. For each authentication type presented, that type may be present as a key in this
   /// dictionary. For example, the public part of an OAuth client ID could be given here.
-  Map<String, dynamic>? get authenticationParams => raw['params'];
+  Map<String, dynamic>? get authenticationParams =>
+      raw['params'] as Map<String, dynamic>?;
 
   /// Returns the list of already completed authentication flows from previous requests.
   List<String> get completedAuthenticationFlows =>
-      List<String>.from(raw['completed'] ?? []);
+      List<String>.from(raw['completed'] as List<String>? ?? []);
 }
 
 /// For each endpoint, a server offers one or more 'flows' that the client can use

lib/src/model/matrix_keys.dart

@@ -21,7 +21,7 @@
 * SOFTWARE.
 */
 
-import '../utils/map_copy_extension.dart';
+import 'package:matrix_api_lite/matrix_api_lite.dart';
 
 abstract class MatrixSignableKey {
   String userId;
@@ -39,14 +39,11 @@ abstract class MatrixSignableKey {
 
   MatrixSignableKey.fromJson(Map<String, dynamic> json)
       : _json = json,
-        userId = json['user_id'],
+        userId = json['user_id'] as String,
-        keys = Map<String, String>.from(json['keys']),
+        keys = Map<String, String>.from(json['keys'] as Map<String, dynamic>),
         // we need to manually copy to ensure that our map is Map<String, Map<String, String>>
-        signatures = json['signatures'] is Map
+        signatures = json.tryGetMap<String, Map<String, String>>('signatures'),
-            ? Map<String, Map<String, String>>.from((json['signatures'] as Map)
+        unsigned = json.tryGetMap<String, dynamic>('unsigned');
-                .map((k, v) => MapEntry(k, Map<String, String>.from(v))))
-            : null,
-        unsigned = (json['unsigned'] as Map<String, dynamic>?)?.copy();
 
   Map<String, dynamic> toJson() {
     final data = _json ?? <String, dynamic>{};
@@ -81,7 +78,7 @@ class MatrixCrossSigningKey extends MatrixSignableKey {
 
   @override
   MatrixCrossSigningKey.fromJson(Map<String, dynamic> json)
-      : usage = List<String>.from(json['usage']),
+      : usage = json.tryGetList<String>('usage') ?? [],
         super.fromJson(json);
 
   @override
@@ -97,7 +94,7 @@ class MatrixDeviceKeys extends MatrixSignableKey {
   List<String> algorithms;
 
   String? get deviceDisplayName =>
-      unsigned != null ? unsigned!['device_display_name'] : null;
+      unsigned?.tryGet<String>('device_display_name');
 
   MatrixDeviceKeys(
     String userId,
@@ -113,8 +110,8 @@ class MatrixDeviceKeys extends MatrixSignableKey {
 
   @override
   MatrixDeviceKeys.fromJson(Map<String, dynamic> json)
-      : algorithms = (json['algorithms'] as List).cast<String>(),
+      : algorithms = json.tryGetList<String>('algorithms') ?? [],
-        deviceId = json['device_id'],
+        deviceId = json['device_id'] as String,
         super.fromJson(json);
 
   @override

lib/src/model/presence.dart

@@ -28,6 +28,7 @@ class Presence extends BasicEventWithSender {
   PresenceContent presence;
 
   Presence.fromJson(Map<String, dynamic> json)
-      : presence = PresenceContent.fromJson(json['content']),
+      : presence =
+            PresenceContent.fromJson(json['content'] as Map<String, dynamic>),
         super.fromJson(json);
 }

lib/src/model/presence_content.dart

@@ -21,7 +21,7 @@
 * SOFTWARE.
 */
 
-import '../generated/model.dart';
+import 'package:matrix_api_lite/matrix_api_lite.dart';
 
 class PresenceContent {
   PresenceType presence;
@@ -32,9 +32,9 @@ class PresenceContent {
   PresenceContent.fromJson(Map<String, dynamic> json)
       : presence = PresenceType.values.firstWhere(
             (p) => p.toString().split('.').last == json['presence']),
-        lastActiveAgo = json['last_active_ago'],
+        lastActiveAgo = json.tryGet<int>('last_active_ago'),
-        statusMsg = json['status_msg'],
+        statusMsg = json.tryGet<String>('status_msg'),
-        currentlyActive = json['currently_active'];
+        currentlyActive = json.tryGet<bool>('currently_active');
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/room_keys_keys.dart

@@ -21,6 +21,8 @@
 * SOFTWARE.
 */
 
+import 'package:matrix_api_lite/matrix_api_lite.dart';
+
 class RoomKeysSingleKey {
   int firstMessageIndex;
   int forwardedCount;
@@ -34,10 +36,10 @@ class RoomKeysSingleKey {
       required this.sessionData});
 
   RoomKeysSingleKey.fromJson(Map<String, dynamic> json)
-      : firstMessageIndex = json['first_message_index'],
+      : firstMessageIndex = json['first_message_index'] as int,
-        forwardedCount = json['forwarded_count'],
+        forwardedCount = json['forwarded_count'] as int,
-        isVerified = json['is_verified'],
+        isVerified = json['is_verified'] as bool,
-        sessionData = json['session_data'];
+        sessionData = json['session_data'] as Map<String, dynamic>;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -55,8 +57,8 @@ class RoomKeysRoom {
   RoomKeysRoom({required this.sessions});
 
   RoomKeysRoom.fromJson(Map<String, dynamic> json)
-      : sessions = (json['sessions'] as Map)
+      : sessions = (json['sessions'] as Map<String, dynamic>).map((k, v) =>
-            .map((k, v) => MapEntry(k, RoomKeysSingleKey.fromJson(v)));
+            MapEntry(k, RoomKeysSingleKey.fromJson(v as Map<String, dynamic>)));
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -70,8 +72,9 @@ class RoomKeysUpdateResponse {
   int count;
 
   RoomKeysUpdateResponse.fromJson(Map<String, dynamic> json)
-      : etag = json['etag'], // synapse replies an int but docs say string?
+      : etag = json.tryGet<String>('etag') ??
-        count = json['count'];
+            '', // synapse replies an int but docs say string?
+        count = json.tryGet<int>('count') ?? 0;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/room_summary.dart

@@ -28,10 +28,10 @@ class RoomSummary {
 
   RoomSummary.fromJson(Map<String, dynamic> json)
       : mHeroes = json['m.heroes'] != null
-            ? List<String>.from(json['m.heroes'])
+            ? List<String>.from(json['m.heroes'] as List)
             : null,
-        mJoinedMemberCount = json['m.joined_member_count'],
+        mJoinedMemberCount = json['m.joined_member_count'] as int?,
-        mInvitedMemberCount = json['m.invited_member_count'];
+        mInvitedMemberCount = json['m.invited_member_count'] as int?;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/model/stripped_state_event.dart

@@ -21,7 +21,7 @@
 * SOFTWARE.
 */
 
-import 'basic_event_with_sender.dart';
+import 'package:matrix_api_lite/matrix_api_lite.dart';
 
 class StrippedStateEvent extends BasicEventWithSender {
   String? stateKey;
@@ -34,7 +34,7 @@ class StrippedStateEvent extends BasicEventWithSender {
       : super(type: type, content: content, senderId: senderId);
 
   StrippedStateEvent.fromJson(Map<String, dynamic> json)
-      : stateKey = json['state_key'],
+      : stateKey = json.tryGet<String>('state_key'),
         super.fromJson(json);
 
   @override

lib/src/model/sync_update.dart

@@ -21,13 +21,7 @@
 * SOFTWARE.
 */
 
-import 'basic_event.dart';
+import 'package:matrix_api_lite/matrix_api_lite.dart';
-import 'basic_event_with_sender.dart';
-import 'basic_room_event.dart';
-import 'matrix_event.dart';
-import 'presence.dart';
-import 'room_summary.dart';
-import 'stripped_state_event.dart';
 
 class SyncUpdate {
   String nextBatch;
@@ -51,32 +45,34 @@ class SyncUpdate {
   });
 
   SyncUpdate.fromJson(Map<String, dynamic> json)
-      : nextBatch = json['next_batch'],
+      : nextBatch = json['next_batch'] as String,
-        rooms =
+        rooms = (() {
-            json['rooms'] != null ? RoomsUpdate.fromJson(json['rooms']) : null,
+          final temp = json.tryGetMap<String, dynamic>('rooms');
-        presence = ((json['presence'] as Map?)?['events'] as List?)
+          return temp != null ? RoomsUpdate.fromJson(temp) : null;
-            ?.map((i) => Presence.fromJson(i))
+        }()),
+        presence = json
+            .tryGetMap<String, List<dynamic>>('presence')?['events']
+            ?.map((i) => Presence.fromJson(i as Map<String, dynamic>))
             .toList(),
-        accountData = ((json['account_data'] as Map?)?['events'] as List?)
+        accountData = json
-            ?.map((i) => BasicEvent.fromJson(i))
+            .tryGetMap<String, List<dynamic>>('account_data')?['events']
+            ?.map((i) => BasicEvent.fromJson(i as Map<String, dynamic>))
             .toList(),
-        toDevice = ((json['to_device'] as Map?)?['events'] as List?)
+        toDevice = json
-            ?.map((i) => BasicEventWithSender.fromJson(i))
+            .tryGetMap<String, List<dynamic>>('to_device')?['events']
+            ?.map(
+                (i) => BasicEventWithSender.fromJson(i as Map<String, dynamic>))
             .toList(),
-        deviceLists = json['device_lists'] != null
+        deviceLists = (() {
-            ? DeviceListsUpdate.fromJson(json['device_lists'])
+          final temp = json.tryGetMap<String, dynamic>('device_lists');
-            : null,
+          return temp != null ? DeviceListsUpdate.fromJson(temp) : null;
-        deviceOneTimeKeysCount = json['device_one_time_keys_count'] != null
+        }()),
-            ? Map<String, int>.from(json['device_one_time_keys_count'])
+        deviceOneTimeKeysCount =
-            : null,
+            json.tryGetMap<String, int>('device_one_time_keys_count'),
-        deviceUnusedFallbackKeyTypes = (json[
+        deviceUnusedFallbackKeyTypes =
-                        'device_unused_fallback_key_types'] ??
+            json.tryGetList<String>('device_unused_fallback_key_types') ??
-                    json[
+                json.tryGetList<String>(
-                        'org.matrix.msc2732.device_unused_fallback_key_types']) !=
+                    'org.matrix.msc2732.device_unused_fallback_key_types');
-                null
-            ? List<String>.from(json['device_unused_fallback_key_types'] ??
-                json['org.matrix.msc2732.device_unused_fallback_key_types'])
-            : null;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -126,18 +122,12 @@ class RoomsUpdate {
   });
 
   RoomsUpdate.fromJson(Map<String, dynamic> json) {
-    join = json['join'] != null
+    join = json.tryGetMap<String, dynamic>('join')?.catchMap((k, v) =>
-        ? (json['join'] as Map)
+        MapEntry(k, JoinedRoomUpdate.fromJson(v as Map<String, dynamic>)));
-            .map((k, v) => MapEntry(k, JoinedRoomUpdate.fromJson(v)))
+    invite = json.tryGetMap<String, dynamic>('invite')?.catchMap((k, v) =>
-        : null;
+        MapEntry(k, InvitedRoomUpdate.fromJson(v as Map<String, dynamic>)));
-    invite = json['invite'] != null
+    leave = json.tryGetMap<String, dynamic>('leave')?.catchMap((k, v) =>
-        ? (json['invite'] as Map)
+        MapEntry(k, LeftRoomUpdate.fromJson(v as Map<String, dynamic>)));
-            .map((k, v) => MapEntry(k, InvitedRoomUpdate.fromJson(v)))
-        : null;
-    leave = json['leave'] != null
-        ? (json['leave'] as Map)
-            .map((k, v) => MapEntry(k, LeftRoomUpdate.fromJson(v)))
-        : null;
   }
 
   Map<String, dynamic> toJson() {
@@ -175,24 +165,22 @@ class JoinedRoomUpdate extends SyncRoomUpdate {
   });
 
   JoinedRoomUpdate.fromJson(Map<String, dynamic> json)
-      : summary = json['summary'] != null
+      : summary = json.tryGetFromJson('summary', RoomSummary.fromJson),
-            ? RoomSummary.fromJson(json['summary'])
+        state = json
-            : null,
+            .tryGetMap<String, List<dynamic>>('state')?['events']
-        state = ((json['state'] as Map?)?['events'] as List?)
+            ?.map((i) => MatrixEvent.fromJson(i as Map<String, dynamic>))
-            ?.map((i) => MatrixEvent.fromJson(i))
             .toList(),
-        timeline = json['timeline'] != null
+        timeline = json.tryGetFromJson('timeline', TimelineUpdate.fromJson),
-            ? TimelineUpdate.fromJson(json['timeline'])
+        ephemeral = json
-            : null,
+            .tryGetMap<String, List<dynamic>>('ephemeral')?['events']
-        ephemeral = ((json['ephemeral'] as Map?)?['events'] as List?)
+            ?.map((i) => BasicRoomEvent.fromJson(i as Map<String, dynamic>))
-            ?.map((i) => BasicRoomEvent.fromJson(i))
             .toList(),
-        accountData = ((json['account_data'] as Map?)?['events'] as List?)
+        accountData = json
-            ?.map((i) => BasicRoomEvent.fromJson(i))
+            .tryGetMap<String, List<dynamic>>('account_data')?['events']
+            ?.map((i) => BasicRoomEvent.fromJson(i as Map<String, dynamic>))
             .toList(),
-        unreadNotifications = json['unread_notifications'] != null
+        unreadNotifications = json.tryGetFromJson(
-            ? UnreadNotificationCounts.fromJson(json['unread_notifications'])
+            'unread_notifications', UnreadNotificationCounts.fromJson);
-            : null;
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -230,8 +218,9 @@ class InvitedRoomUpdate extends SyncRoomUpdate {
   InvitedRoomUpdate({this.inviteState});
 
   InvitedRoomUpdate.fromJson(Map<String, dynamic> json)
-      : inviteState = ((json['invite_state'] as Map?)?['events'] as List?)
+      : inviteState = json
-            ?.map((i) => StrippedStateEvent.fromJson(i))
+            .tryGetMap<String, List<dynamic>>('invite_state')?['events']
+            ?.map((i) => StrippedStateEvent.fromJson(i as Map<String, dynamic>))
             .toList();
 
   Map<String, dynamic> toJson() {
@@ -257,14 +246,14 @@ class LeftRoomUpdate extends SyncRoomUpdate {
   });
 
   LeftRoomUpdate.fromJson(Map<String, dynamic> json)
-      : state = ((json['state'] as Map?)?['events'] as List?)
+      : state = json
-            ?.map((i) => MatrixEvent.fromJson(i))
+            .tryGetMap<String, List<dynamic>>('state')?['events']
+            ?.map((i) => MatrixEvent.fromJson(i as Map<String, dynamic>))
             .toList(),
-        timeline = json['timeline'] != null
+        timeline = json.tryGetFromJson('timeline', TimelineUpdate.fromJson),
-            ? TimelineUpdate.fromJson(json['timeline'])
+        accountData = json
-            : null,
+            .tryGetMap<String, List<dynamic>>('account_data')?['events']
-        accountData = ((json['account_data'] as Map?)?['events'] as List?)
+            ?.map((i) => BasicRoomEvent.fromJson(i as Map<String, dynamic>))
-            ?.map((i) => BasicRoomEvent.fromJson(i))
             .toList();
 
   Map<String, dynamic> toJson() {
@@ -297,13 +286,13 @@ class TimelineUpdate {
     this.prevBatch,
   });
 
-  TimelineUpdate.fromJson(Map<String, dynamic> json) {
+  TimelineUpdate.fromJson(Map<String, dynamic> json)
-    events = json['events'] != null
+      : events = json
-        ? (json['events'] as List).map((i) => MatrixEvent.fromJson(i)).toList()
+            .tryGetList<Map<String, dynamic>>('events')
-        : null;
+            ?.map((v) => MatrixEvent.fromJson(v))
-    limited = json['limited'];
+            .toList(),
-    prevBatch = json['prev_batch'];
+        limited = json.tryGet<bool>('limited'),
-  }
+        prevBatch = json.tryGet<String>('prev_batch');
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -329,10 +318,9 @@ class UnreadNotificationCounts {
     this.highlightCount,
   });
 
-  UnreadNotificationCounts.fromJson(Map<String, dynamic> json) {
+  UnreadNotificationCounts.fromJson(Map<String, dynamic> json)
-    highlightCount = json['highlight_count'];
+      : highlightCount = json.tryGet<int>('highlight_count'),
-    notificationCount = json['notification_count'];
+        notificationCount = json.tryGet<int>('notification_count');
-  }
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};
@@ -355,10 +343,9 @@ class DeviceListsUpdate {
     this.left,
   });
 
-  DeviceListsUpdate.fromJson(Map<String, dynamic> json) {
+  DeviceListsUpdate.fromJson(Map<String, dynamic> json)
-    changed = List<String>.from(json['changed'] ?? []);
+      : changed = json.tryGetList<String>('changed') ?? [],
-    left = List<String>.from(json['left'] ?? []);
+        left = json.tryGetList<String>('left') ?? [];
-  }
 
   Map<String, dynamic> toJson() {
     final data = <String, dynamic>{};

lib/src/utils/try_get_map_extension.dart

@@ -100,6 +100,13 @@ extension TryGetMapExtension on Map<String, dynamic> {
       return null;
     }
   }
+
+  A? tryGetFromJson<A>(String key, A Function(Map<String, dynamic>) fromJson,
+      [TryGet log = TryGet.optional]) {
+    final value = tryGetMap<String, dynamic>(key, log);
+
+    return value != null ? fromJson(value) : null;
+  }
 }
 
 extension on StackTrace {

test/event_content_test.dart

@@ -43,7 +43,7 @@ void main() {
         'type': 'm.room.encryption',
         'unsigned': {'age': 1234}
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(MatrixEvent.fromJson(json!).parsedRoomEncryptionContent.toJson(),
           json['content']);
     });
@@ -63,7 +63,7 @@ void main() {
         'type': 'm.room.encrypted',
         'unsigned': {'age': 1234}
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(MatrixEvent.fromJson(json!).parsedRoomEncryptedContent.toJson(),
           json['content']);
       json = <String, dynamic>{
@@ -84,7 +84,7 @@ void main() {
         'type': 'm.room.encrypted',
         'unsigned': {'age': 1234}
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(MatrixEvent.fromJson(json!).parsedRoomEncryptedContent.toJson(),
           json['content']);
     });
@@ -98,7 +98,7 @@ void main() {
         },
         'type': 'm.room_key'
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(BasicEvent.fromJson(json!).parsedRoomKeyContent.toJson(),
           json['content']);
     });
@@ -111,7 +111,7 @@ void main() {
         },
         'type': 'm.room_key_request'
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(BasicEvent.fromJson(json!).parsedRoomKeyRequestContent.toJson(),
           json['content']);
       json = <String, dynamic>{
@@ -128,7 +128,7 @@ void main() {
         },
         'type': 'm.room_key_request'
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(BasicEvent.fromJson(json!).parsedRoomKeyRequestContent.toJson(),
           json['content']);
     });
@@ -148,7 +148,7 @@ void main() {
         },
         'type': 'm.forwarded_room_key'
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(BasicEvent.fromJson(json!).parsedForwardedRoomKeyContent.toJson(),
           json['content']);
     });
@@ -164,7 +164,7 @@ void main() {
         'recipient_keys': {'ed25519': '<our_ed25519_key>'},
         'keys': {'ed25519': '<sender_ed25519_key>'}
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>?;
       expect(OlmPlaintextPayload.fromJson(json!).toJson(), json);
     });
     test('Image Pack Content', () {
@@ -190,7 +190,7 @@ void main() {
           'org.custom': 'blah',
         },
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>;
       expect(BasicEvent.fromJson(json).parsedImagePackContent.toJson(),
           json['content']);
 
@@ -205,7 +205,7 @@ void main() {
           },
         },
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>;
       expect(
           BasicEvent.fromJson(json)
               .parsedImagePackContent
@@ -223,7 +223,7 @@ void main() {
           },
         },
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>;
       expect(
           BasicEvent.fromJson(json)
               .parsedImagePackContent
@@ -242,7 +242,7 @@ void main() {
           },
         },
       };
-      json = jsonDecode(jsonEncode(json));
+      json = jsonDecode(jsonEncode(json)) as Map<String, dynamic>;
       expect(BasicEvent.fromJson(json).parsedImagePackContent.images['emote'],
           null);
     });