diff --git a/lib/router.dart b/lib/router.dart
index b8d25646..196bd3ef 100644
--- a/lib/router.dart
+++ b/lib/router.dart
@@ -154,7 +154,8 @@ class GithubRouter {
   });
   static final repo = RouterScreen('/:owner/:name', (context, parameters) {
     if (parameters['ref'] == null) {
-      return GhRepoScreen(parameters['owner']!.first, parameters['name']!.first);
+      return GhRepoScreen(
+          parameters['owner']!.first, parameters['name']!.first);
     } else {
       return GhRepoScreen(parameters['owner']!.first, parameters['name']!.first,
           branch: parameters['ref']!.first);
@@ -182,8 +183,8 @@ class GithubRouter {
   });
   static final issues = RouterScreen(
       '/:owner/:name/issues',
-      (context, parameters) =>
-          GhIssuesScreen(parameters['owner']!.first, parameters['name']!.first));
+      (context, parameters) => GhIssuesScreen(
+          parameters['owner']!.first, parameters['name']!.first));
   static final pulls = RouterScreen(
       '/:owner/:name/pulls',
       (context, parameters) =>
@@ -263,8 +264,10 @@ class GitlabRouter {
     GitlabRouter.issueAdd,
     GitlabRouter.issue,
   ];
-  static final user = RouterScreen('/user/:id',
-      (context, parameters) => GlUserScreen(int.parse(parameters['id']!.first)));
+  static final user = RouterScreen(
+      '/user/:id',
+      (context, parameters) =>
+          GlUserScreen(int.parse(parameters['id']!.first)));
   static final group = RouterScreen(
       '/group/:id',
       (context, parameters) =>
@@ -316,8 +319,8 @@ class GitlabRouter {
   });
   static final commit = RouterScreen(
       '/projects/:id/commit/:sha',
-      (context, parameters) =>
-          GlCommitScreen(parameters['id']!.first, sha: parameters['sha']!.first));
+      (context, parameters) => GlCommitScreen(parameters['id']!.first,
+          sha: parameters['sha']!.first));
   static final projectMembers = RouterScreen(
       '/projects/:id/members',
       (context, parameters) =>
@@ -412,12 +415,12 @@ class GiteaRouter {
   });
   static final commits = RouterScreen(
       '/:owner/:name/commits',
-      (context, parameters) =>
-          GtCommitsScreen(parameters['owner']!.first, parameters['name']!.first));
+      (context, parameters) => GtCommitsScreen(
+          parameters['owner']!.first, parameters['name']!.first));
   static final issues = RouterScreen(
       '/:owner/:name/issues',
-      (context, parameters) =>
-          GtIssuesScreen(parameters['owner']!.first, parameters['name']!.first));
+      (context, parameters) => GtIssuesScreen(
+          parameters['owner']!.first, parameters['name']!.first));
   static final pulls = RouterScreen(
       '/:owner/:name/pulls',
       (context, parameters) => GtIssuesScreen(
@@ -458,7 +461,8 @@ class BitbucketRouter {
           isTeam: parameters['team']!.first == '1'));
   static final repo = RouterScreen('/:owner/:name', (context, parameters) {
     if (parameters['branch'] == null) {
-      return BbRepoScreen(parameters['owner']!.first, parameters['name']!.first);
+      return BbRepoScreen(
+          parameters['owner']!.first, parameters['name']!.first);
     } else {
       return BbRepoScreen(parameters['owner']!.first, parameters['name']!.first,
           branch: parameters['branch']!.first);
@@ -475,8 +479,8 @@ class BitbucketRouter {
   );
   static final issues = RouterScreen(
       '/:owner/:name/issues',
-      (context, parameters) =>
-          BbIssuesScreen(parameters['owner']!.first, parameters['name']!.first));
+      (context, parameters) => BbIssuesScreen(
+          parameters['owner']!.first, parameters['name']!.first));
   static final commits = RouterScreen(
       '/:owner/:name/commits/:ref',
       (context, parameters) => BbCommitsScreen(parameters['owner']!.first,
@@ -549,7 +553,8 @@ class GiteeRouter {
         return GeRepoScreen(
             parameters['owner']!.first, parameters['name']!.first);
       } else {
-        return GeRepoScreen(parameters['owner']!.first, parameters['name']!.first,
+        return GeRepoScreen(
+            parameters['owner']!.first, parameters['name']!.first,
             branch: parameters['branch']!.first);
       }
     },
@@ -597,7 +602,8 @@ class GiteeRouter {
   static final issues = RouterScreen(
     '/:owner/:name/issues',
     (context, parameters) {
-      return GeIssuesScreen(parameters['owner']!.first, parameters['name']!.first,
+      return GeIssuesScreen(
+          parameters['owner']!.first, parameters['name']!.first,
           isPr: false);
     },
   );
@@ -610,7 +616,8 @@ class GiteeRouter {
   static final pulls = RouterScreen(
     '/:owner/:name/pulls',
     (context, parameters) {
-      return GePullsScreen(parameters['owner']!.first, parameters['name']!.first,
+      return GePullsScreen(
+          parameters['owner']!.first, parameters['name']!.first,
           isPr: true);
     },
   );
@@ -701,7 +708,8 @@ class GogsRouter {
         return GoRepoScreen(
             parameters['owner']!.first, parameters['name']!.first);
       } else {
-        return GoRepoScreen(parameters['owner']!.first, parameters['name']!.first,
+        return GoRepoScreen(
+            parameters['owner']!.first, parameters['name']!.first,
             branch: parameters['branch']!.first);
       }
     },
@@ -722,6 +730,6 @@ class GogsRouter {
           branch: parameters['ref']?.first));
   static final issues = RouterScreen(
       '/:owner/:name/issues',
-      (context, parameters) =>
-          GoIssuesScreen(parameters['owner']!.first, parameters['name']!.first));
+      (context, parameters) => GoIssuesScreen(
+          parameters['owner']!.first, parameters['name']!.first));
 }
diff --git a/lib/screens/ge_search.dart b/lib/screens/ge_search.dart
index 0c14b68d..9c850137 100644
--- a/lib/screens/ge_search.dart
+++ b/lib/screens/ge_search.dart
@@ -25,7 +25,7 @@ class _GeSearchScreenState extends State<GeSearchScreen> {
   List<List> _payloads = [[], [], []];
 
   TextEditingController? _controller;
-  String get _keyword => _controller!.text?.trim() ?? '';
+  String get _keyword => _controller!.text.trim();
 
   @override
   void initState() {
diff --git a/lib/screens/gh_events.dart b/lib/screens/gh_events.dart
index 6fe28d1b..46f1ab61 100644
--- a/lib/screens/gh_events.dart
+++ b/lib/screens/gh_events.dart
@@ -22,7 +22,8 @@ class GhEventsScreen extends StatelessWidget {
         page = page ?? 1;
         final events = await context.read<AuthModel>().ghClient!.getJSON(
             '/users/$login/events?page=$page&per_page=$pageSize',
-            convert: (dynamic vs) => [for (var v in vs) GithubEvent.fromJson(v)]);
+            convert: (dynamic vs) =>
+                [for (var v in vs) GithubEvent.fromJson(v)]);
         return ListPayload(
           cursor: page + 1,
           hasMore: events.length == pageSize,
diff --git a/lib/screens/gh_issue.dart b/lib/screens/gh_issue.dart
index 6d757d3e..c8769688 100644
--- a/lib/screens/gh_issue.dart
+++ b/lib/screens/gh_issue.dart
@@ -102,11 +102,11 @@ class GhIssueScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return LongListStatefulScaffold<GIssueData_repository, dynamic>(
+    return LongListStatefulScaffold<GIssueData_repository?, dynamic>(
       title: Text('$owner/$name #$number'),
       trailingBuilder: (p) {
-        if (p.issueOrPullRequest!.G__typename == 'Issue') {
-          final d = p.issueOrPullRequest
+        if (p?.issueOrPullRequest!.G__typename == 'Issue') {
+          final d = p?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asIssue;
           return ActionButton(
             title: 'Actions',
@@ -126,7 +126,7 @@ class GhIssueScreen extends StatelessWidget {
             ],
           );
         } else {
-          final d = p.issueOrPullRequest
+          final d = p?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asPullRequest;
           return ActionButton(
             title: 'Actions',
@@ -138,8 +138,8 @@ class GhIssueScreen extends StatelessWidget {
       },
       headerBuilder: (p) {
         final theme = Provider.of<ThemeModel>(context);
-        if (p.issueOrPullRequest!.G__typename == 'Issue') {
-          final issue = p.issueOrPullRequest
+        if (p?.issueOrPullRequest!.G__typename == 'Issue') {
+          final issue = p?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asIssue;
 
           return _buildHeader(
@@ -204,7 +204,7 @@ class GhIssueScreen extends StatelessWidget {
             }),
           );
         } else {
-          final pr = p.issueOrPullRequest
+          final pr = p?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asPullRequest;
           return _buildHeader(
             context,
@@ -257,10 +257,9 @@ class GhIssueScreen extends StatelessWidget {
       },
       itemBuilder: (p) => TimelineItem(p),
       onRefresh: () async {
-        final res =
-            await (_queryIssue(context) as Future<GIssueData_repository>);
-        if (res.issueOrPullRequest!.G__typename == 'Issue') {
-          final issue = res.issueOrPullRequest
+        final res = await _queryIssue(context);
+        if (res?.issueOrPullRequest!.G__typename == 'Issue') {
+          final issue = res?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asIssue;
           return LongListPayload(
             header: res,
@@ -270,7 +269,7 @@ class GhIssueScreen extends StatelessWidget {
             trailingItems: [],
           );
         } else {
-          final pr = res.issueOrPullRequest
+          final pr = res?.issueOrPullRequest
               as GIssueData_repository_issueOrPullRequest__asPullRequest;
           return LongListPayload(
             header: res,
diff --git a/lib/screens/gh_repo.dart b/lib/screens/gh_repo.dart
index 78d5896a..dea0265e 100644
--- a/lib/screens/gh_repo.dart
+++ b/lib/screens/gh_repo.dart
@@ -170,7 +170,7 @@ class GhRepoScreen extends StatelessWidget {
                     SizedBox(width: 8),
                     MutationButton(
                       active: repo.viewerHasStarred,
-                      text: repo.viewerHasStarred? 'Unstar' : 'Star',
+                      text: repo.viewerHasStarred ? 'Unstar' : 'Star',
                       onTap: () async {
                         final activityApi =
                             context.read<AuthModel>().ghClient!.activity;
@@ -232,7 +232,7 @@ class GhRepoScreen extends StatelessWidget {
                 for (var edge in repo.languages!.edges!)
                   LanguageBarItem(
                     name: edge.node.name,
-                    ratio: edge.size/ repo.languages!.totalSize,
+                    ratio: edge.size / repo.languages!.totalSize,
                     hexColor: edge.node.color,
                   )
               ]),
@@ -270,7 +270,7 @@ class GhRepoScreen extends StatelessWidget {
                     leftIconData: Octicons.history,
                     text: Text(AppLocalizations.of(context)!.commits),
                     rightWidget: Text(
-                        ((ref.target as GRepoCommit).history?.totalCount ?? 0)
+                        ((ref.target as GRepoCommit).history.totalCount)
                             .toString()),
                     url: '/github/$owner/$name/commits/${ref.name}',
                   ),
@@ -278,7 +278,7 @@ class GhRepoScreen extends StatelessWidget {
                     TableViewItem(
                       leftIconData: Octicons.git_branch,
                       text: Text(AppLocalizations.of(context)!.branches),
-                      rightWidget: Text(ref.name+
+                      rightWidget: Text(ref.name +
                           ' • ' +
                           numberFormat.format(repo.refs!.totalCount)),
                       onTap: () async {
diff --git a/lib/screens/gh_search.dart b/lib/screens/gh_search.dart
index 53464266..bd48733b 100644
--- a/lib/screens/gh_search.dart
+++ b/lib/screens/gh_search.dart
@@ -25,7 +25,7 @@ class _GhSearchScreenState extends State<GhSearchScreen> {
 
   TextEditingController? _controller;
 
-  String get _keyword => _controller!.text?.trim() ?? '';
+  String get _keyword => _controller!.text.trim();
 
   @override
   void initState() {
diff --git a/lib/screens/gh_user.dart b/lib/screens/gh_user.dart
index 48c56a48..0d762dae 100644
--- a/lib/screens/gh_user.dart
+++ b/lib/screens/gh_user.dart
@@ -319,7 +319,8 @@ class GhUser extends StatelessWidget {
               if (p.viewerCanFollow)
                 MutationButton(
                   active: p.viewerIsFollowing,
-                  text: p.viewerIsFollowing? AppLocalizations.of(context)!.unfollow
+                  text: p.viewerIsFollowing
+                      ? AppLocalizations.of(context)!.unfollow
                       : AppLocalizations.of(context)!.follow,
                   onTap: () async {
                     if (p.viewerIsFollowing) {
diff --git a/lib/screens/gl_issue.dart b/lib/screens/gl_issue.dart
index 62ebc497..3d3f4e16 100644
--- a/lib/screens/gl_issue.dart
+++ b/lib/screens/gl_issue.dart
@@ -64,7 +64,8 @@ class GlIssueScreen extends StatelessWidget {
                       padding: CommonStyle.padding,
                       child: Text.rich(
                         TextSpan(children: [
-                          WidgetSpan(child: Avatar(url: note.author!.avatarUrl)),
+                          WidgetSpan(
+                              child: Avatar(url: note.author!.avatarUrl)),
                           TextSpan(text: note.author!.name),
                           TextSpan(text: note.body),
                         ]),
diff --git a/lib/screens/gl_search.dart b/lib/screens/gl_search.dart
index b2323448..66e39bc4 100644
--- a/lib/screens/gl_search.dart
+++ b/lib/screens/gl_search.dart
@@ -26,7 +26,7 @@ class _GlSearchScreenState extends State<GlSearchScreen> {
 
   TextEditingController? _controller;
 
-  String get _keyword => _controller!.text?.trim() ?? '';
+  String get _keyword => _controller!.text.trim();
 
   @override
   void initState() {
diff --git a/lib/widgets/release_item.dart b/lib/widgets/release_item.dart
index f8b0b401..15bbb821 100644
--- a/lib/widgets/release_item.dart
+++ b/lib/widgets/release_item.dart
@@ -61,8 +61,8 @@ class ReleaseItem extends StatelessWidget {
                     color: theme.palette.secondaryText,
                     fontSize: 16,
                   ),
-                  child:
-                      Text(login! + " released " + timeago.format(publishedAt!)),
+                  child: Text(
+                      login! + " released " + timeago.format(publishedAt!)),
                 ),
               ],
             ),
diff --git a/lib/widgets/timeline_item.dart b/lib/widgets/timeline_item.dart
index 28ee2352..c389ace7 100644
--- a/lib/widgets/timeline_item.dart
+++ b/lib/widgets/timeline_item.dart
@@ -264,7 +264,8 @@ class TimelineItem extends StatelessWidget {
           textSpan: TextSpan(
             children: [
               TextSpan(
-                  text: ' transferred this issue from ' + p.fromRepository!.name)
+                  text:
+                      ' transferred this issue from ' + p.fromRepository!.name)
             ],
           ),
         );
@@ -331,7 +332,8 @@ class TimelineItem extends StatelessWidget {
         return TimelineEventItem(
           actor: p.actor!.login,
           textSpan: TextSpan(
-              text: ' deployed the pull request ' + p.pullRequest.headRef!.name),
+              text:
+                  ' deployed the pull request ' + p.pullRequest.headRef!.name),
         );
       case 'DeploymentEnvironmentChangedEvent':
         final p = node as GDeploymentEnvironmentChangedEventParts;