code_style: general cleanup (#1497)

.github/workflows/build.yml

@@ -31,7 +31,7 @@ jobs:
     container: ${{ matrix.container || '' }}
     steps:
       - name: Install common CLI tools
-        if: ${{ startsWith(matrix.runtime, 'linux-') }}
+        if: startsWith(matrix.runtime, 'linux-')
         run: |
           export DEBIAN_FRONTEND=noninteractive
           ln -fs /usr/share/zoneinfo/Etc/UTC /etc/localtime
@@ -45,7 +45,7 @@ jobs:
         with:
           dotnet-version: 9.0.x
       - name: Configure arm64 packages
-        if: ${{ matrix.runtime == 'linux-arm64' }}
+        if: matrix.runtime == 'linux-arm64'
         run: |
           sudo dpkg --add-architecture arm64
           echo 'deb [arch=arm64] http://ports.ubuntu.com/ubuntu-ports/ focal main restricted
@@ -55,7 +55,7 @@ jobs:
           sudo sed -i -e 's/^deb http/deb [arch=amd64] http/g' /etc/apt/sources.list
           sudo sed -i -e 's/^deb mirror/deb [arch=amd64] mirror/g' /etc/apt/sources.list
       - name: Install cross-compiling dependencies
-        if: ${{ matrix.runtime == 'linux-arm64' }}
+        if: matrix.runtime == 'linux-arm64'
         run: |
           sudo apt-get update
           sudo apt-get install -y llvm gcc-aarch64-linux-gnu
@@ -64,10 +64,10 @@ jobs:
       - name: Publish
         run: dotnet publish src/SourceGit.csproj -c Release -o publish -r ${{ matrix.runtime }}
       - name: Rename executable file
-        if: ${{ startsWith(matrix.runtime, 'linux-') }}
+        if: startsWith(matrix.runtime, 'linux-')
         run: mv publish/SourceGit publish/sourcegit
       - name: Tar artifact
-        if: ${{ startsWith(matrix.runtime, 'linux-') || startsWith(matrix.runtime, 'osx-') }}
+        if: startsWith(matrix.runtime, 'linux-') || startsWith(matrix.runtime, 'osx-')
         run: |
           tar -cvf "sourcegit.${{ matrix.runtime }}.tar" -C publish .
           rm -r publish/*

src/App.axaml.cs

@@ -148,23 +148,21 @@ namespace SourceGit
 
         public static void RaiseException(string context, string message)
         {
-            if (Current is App app && app._launcher != null)
+            if (Current is App { _launcher: not null } app)
                 app._launcher.DispatchNotification(context, message, true);
         }
 
         public static void SendNotification(string context, string message)
         {
-            if (Current is App app && app._launcher != null)
+            if (Current is App { _launcher: not null } app)
                 app._launcher.DispatchNotification(context, message, false);
         }
 
         public static void SetLocale(string localeKey)
         {
             var app = Current as App;
-            if (app == null)
-                return;
 
-            var targetLocale = app.Resources[localeKey] as ResourceDictionary;
+            var targetLocale = app?.Resources[localeKey] as ResourceDictionary;
             if (targetLocale == null || targetLocale == app._activeLocale)
                 return;
 
@@ -286,22 +284,14 @@ namespace SourceGit
 
         public static async void CopyText(string data)
         {
-            if (Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
-            {
-                if (desktop.MainWindow?.Clipboard is { } clipboard)
-                    await clipboard.SetTextAsync(data ?? "");
-            }
+            if (Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime { MainWindow.Clipboard: { } clipboard })
+                await clipboard.SetTextAsync(data ?? "");
         }
 
         public static async Task<string> GetClipboardTextAsync()
         {
-            if (Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
-            {
-                if (desktop.MainWindow?.Clipboard is { } clipboard)
-                {
-                    return await clipboard.GetTextAsync();
-                }
-            }
+            if (Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime { MainWindow.Clipboard: { } clipboard })
+                return await clipboard.GetTextAsync();
             return null;
         }
 
@@ -562,7 +552,7 @@ namespace SourceGit
             Models.AvatarManager.Instance.Start();
 
             string startupRepo = null;
-            if (desktop.Args != null && desktop.Args.Length == 1 && Directory.Exists(desktop.Args[0]))
+            if (desktop.Args is { Length: 1 } && Directory.Exists(desktop.Args[0]))
                 startupRepo = desktop.Args[0];
 
             var pref = ViewModels.Preferences.Instance;

src/Commands/Command.cs

@@ -43,7 +43,7 @@ namespace SourceGit.Commands
             proc.OutputDataReceived += (_, e) => HandleOutput(e.Data, errs);
             proc.ErrorDataReceived += (_, e) => HandleOutput(e.Data, errs);
 
-            var dummy = null as Process;
+            Process dummy = null;
             var dummyProcLock = new object();
             try
             {

src/Commands/QueryCommits.cs

@@ -132,9 +132,7 @@ namespace SourceGit.Commands
             if (shas.Length == 0)
                 return;
 
-            var set = new HashSet<string>();
-            foreach (var sha in shas)
-                set.Add(sha);
+            var set = new HashSet<string>(shas);
 
             foreach (var c in _commits)
             {

src/Commands/QueryRevisionFileNames.cs

@@ -18,10 +18,7 @@ namespace SourceGit.Commands
                 return [];
 
             var lines = rs.StdOut.Split('\0', System.StringSplitOptions.RemoveEmptyEntries);
-            var outs = new List<string>();
-            foreach (var line in lines)
-                outs.Add(line);
-            return outs;
+            return [.. lines];
         }
     }
 }

src/Commands/Worktree.cs

@@ -18,7 +18,7 @@ namespace SourceGit.Commands
 
             var rs = ReadToEnd();
             var worktrees = new List<Models.Worktree>();
-            var last = null as Models.Worktree;
+            Models.Worktree last = null;
             if (rs.IsSuccess)
             {
                 var lines = rs.StdOut.Split(['\r', '\n'], StringSplitOptions.RemoveEmptyEntries);

src/Models/AvatarManager.cs

@@ -55,7 +55,7 @@ namespace SourceGit.Models
             {
                 while (true)
                 {
-                    var email = null as string;
+                    string email = null;
 
                     lock (_synclock)
                     {
@@ -79,7 +79,7 @@ namespace SourceGit.Models
                         $"https://www.gravatar.com/avatar/{md5}?d=404";
 
                     var localFile = Path.Combine(_storePath, md5);
-                    var img = null as Bitmap;
+                    Bitmap img = null;
                     try
                     {
                         var client = new HttpClient() { Timeout = TimeSpan.FromSeconds(2) };
@@ -113,7 +113,7 @@ namespace SourceGit.Models
                         _requesting.Remove(email);
                     }
 
-                    Dispatcher.UIThread.InvokeAsync(() =>
+                    Dispatcher.UIThread.Post(() =>
                     {
                         _resources[email] = img;
                         NotifyResourceChanged(email, img);

src/Models/CommitGraph.cs

@@ -82,7 +82,7 @@ namespace SourceGit.Models
 
             foreach (var commit in commits)
             {
-                var major = null as PathHelper;
+                PathHelper major = null;
                 var isMerged = commit.IsMerged;
 
                 // Update current y offset

src/Models/CommitLink.cs

@@ -27,19 +27,19 @@ namespace SourceGit.Models
                         trimmedUrl = url.AsSpan(0, url.Length - 4);
 
                     if (url.StartsWith("https://github.com/", StringComparison.Ordinal))
-                        outs.Add(new($"Github ({trimmedUrl.Slice(19)})", $"{url}/commit/"));
+                        outs.Add(new($"Github ({trimmedUrl[19..]})", $"{url}/commit/"));
                     else if (url.StartsWith("https://gitlab.", StringComparison.Ordinal))
-                        outs.Add(new($"GitLab ({trimmedUrl.Slice(trimmedUrl.Slice(15).IndexOf('/') + 16)})", $"{url}/-/commit/"));
+                        outs.Add(new($"GitLab ({trimmedUrl[(trimmedUrl[15..].IndexOf('/') + 16)..]})", $"{url}/-/commit/"));
                     else if (url.StartsWith("https://gitee.com/", StringComparison.Ordinal))
-                        outs.Add(new($"Gitee ({trimmedUrl.Slice(18)})", $"{url}/commit/"));
+                        outs.Add(new($"Gitee ({trimmedUrl[18..]})", $"{url}/commit/"));
                     else if (url.StartsWith("https://bitbucket.org/", StringComparison.Ordinal))
-                        outs.Add(new($"BitBucket ({trimmedUrl.Slice(22)})", $"{url}/commits/"));
+                        outs.Add(new($"BitBucket ({trimmedUrl[22..]})", $"{url}/commits/"));
                     else if (url.StartsWith("https://codeberg.org/", StringComparison.Ordinal))
-                        outs.Add(new($"Codeberg ({trimmedUrl.Slice(21)})", $"{url}/commit/"));
+                        outs.Add(new($"Codeberg ({trimmedUrl[21..]})", $"{url}/commit/"));
                     else if (url.StartsWith("https://gitea.org/", StringComparison.Ordinal))
-                        outs.Add(new($"Gitea ({trimmedUrl.Slice(18)})", $"{url}/commit/"));
+                        outs.Add(new($"Gitea ({trimmedUrl[18..]})", $"{url}/commit/"));
                     else if (url.StartsWith("https://git.sr.ht/", StringComparison.Ordinal))
-                        outs.Add(new($"sourcehut ({trimmedUrl.Slice(18)})", $"{url}/commit/"));
+                        outs.Add(new($"sourcehut ({trimmedUrl[18..]})", $"{url}/commit/"));
                 }
             }
 

src/Models/DealWithChangesAfterStashing.cs

@@ -2,21 +2,15 @@
 
 namespace SourceGit.Models
 {
-    public class DealWithChangesAfterStashing
+    public class DealWithChangesAfterStashing(string label, string desc)
     {
-        public string Label { get; set; }
-        public string Desc { get; set; }
+        public string Label { get; set; } = label;
+        public string Desc { get; set; } = desc;
 
         public static readonly List<DealWithChangesAfterStashing> Supported = [
             new ("Discard", "All (or selected) changes will be discarded"),
             new ("Keep Index", "Staged changes are left intact"),
             new ("Keep All", "All (or selected) changes are left intact"),
         ];
-
-        public DealWithChangesAfterStashing(string label, string desc)
-        {
-            Label = label;
-            Desc = desc;
-        }
     }
 }

src/Models/DiffResult.cs

@@ -199,7 +199,7 @@ namespace SourceGit.Models
             writer.WriteLine($"+++ b/{change.Path}");
 
             // If last line of selection is a change. Find one more line.
-            var tail = null as string;
+            string tail = null;
             if (selection.EndLine < Lines.Count)
             {
                 var lastLine = Lines[selection.EndLine - 1];
@@ -323,7 +323,7 @@ namespace SourceGit.Models
             writer.WriteLine($"+++ b/{change.Path}");
 
             // If last line of selection is a change. Find one more line.
-            var tail = null as string;
+            string tail = null;
             if (selection.EndLine < Lines.Count)
             {
                 var lastLine = Lines[selection.EndLine - 1];

src/Models/ExternalMerger.cs

@@ -96,16 +96,9 @@ namespace SourceGit.Models
             {
                 return Exec.Split(';');
             }
-            else
-            {
-                var patterns = new List<string>();
-                var choices = Exec.Split(';', StringSplitOptions.RemoveEmptyEntries);
-                foreach (var c in choices)
-                {
-                    patterns.Add(Path.GetFileName(c));
-                }
-                return patterns.ToArray();
-            }
+
+            var choices = Exec.Split(';', StringSplitOptions.RemoveEmptyEntries);
+            return Array.ConvertAll(choices, Path.GetFileName);
         }
     }
 }

src/Models/TextInlineChange.cs

@@ -50,7 +50,7 @@ namespace SourceGit.Models
             var ret = new List<TextInlineChange>();
             var posOld = 0;
             var posNew = 0;
-            var last = null as TextInlineChange;
+            TextInlineChange last = null;
             do
             {
                 while (posOld < sizeOld && posNew < sizeNew && !chunksOld[posOld].Modified && !chunksNew[posNew].Modified)

src/Native/Windows.cs

@@ -257,7 +257,7 @@ namespace SourceGit.Native
         {
             // Schedule the DWM frame extension to run in the next render frame
             // to ensure proper timing with the window initialization sequence
-            Dispatcher.UIThread.InvokeAsync(() =>
+            Dispatcher.UIThread.Post(() =>
             {
                 var platformHandle = w.TryGetPlatformHandle();
                 if (platformHandle == null)

src/ViewModels/Blame.cs

@@ -34,7 +34,7 @@ namespace SourceGit.ViewModels
 
         public bool IsBinary
         {
-            get => _data != null && _data.IsBinary;
+            get => _data?.IsBinary ?? false;
         }
 
         public bool CanBack

src/ViewModels/BranchCompare.cs

@@ -49,7 +49,7 @@ namespace SourceGit.ViewModels
             {
                 if (SetProperty(ref _selectedChanges, value))
                 {
-                    if (value != null && value.Count == 1)
+                    if (value?.Count == 1)
                         DiffContext = new DiffContext(_repo, new Models.DiffOption(_based.Head, _to.Head, value[0]), _diffContext);
                     else
                         DiffContext = null;

src/ViewModels/BranchTreeNode.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using Avalonia;
+using AvaloniaEdit.Utils;
 using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace SourceGit.ViewModels
@@ -86,8 +87,7 @@ namespace SourceGit.ViewModels
 
             public void SetExpandedNodes(List<string> expanded)
             {
-                foreach (var node in expanded)
-                    _expanded.Add(node);
+                _expanded.AddRange(expanded);
             }
 
             public void Run(List<Models.Branch> branches, List<Models.Remote> remotes, bool bForceExpanded)
@@ -165,7 +165,7 @@ namespace SourceGit.ViewModels
                     return;
                 }
 
-                var lastFolder = null as BranchTreeNode;
+                BranchTreeNode lastFolder = null;
                 var start = 0;
 
                 while (sepIdx != -1)
@@ -250,8 +250,7 @@ namespace SourceGit.ViewModels
                     {
                         if (r.Backend is Models.Branch)
                             return r.TimeToSort == l.TimeToSort ? Models.NumericSort.Compare(l.Name, r.Name) : r.TimeToSort.CompareTo(l.TimeToSort);
-                        else
-                            return 1;
+                        return 1;
                     }
 
                     if (r.Backend is Models.Branch)

src/ViewModels/CheckoutAndFastForward.cs

@@ -49,7 +49,7 @@ namespace SourceGit.ViewModels
             var updateSubmodules = IsRecurseSubmoduleVisible && RecurseSubmodules;
             return Task.Run(() =>
             {
-                var succ = false;
+                bool succ;
                 var needPopStash = false;
 
                 if (!_repo.ConfirmCheckoutBranch())

src/ViewModels/Clone.cs

@@ -151,7 +151,7 @@ namespace SourceGit.ViewModels
                 {
                     var node = Preferences.Instance.FindOrAddNodeByRepositoryPath(path, null, true);
                     var launcher = App.GetLauncher();
-                    var page = null as LauncherPage;
+                    LauncherPage page = null;
                     foreach (var one in launcher.Pages)
                     {
                         if (one.Node.Id == _pageId)

src/ViewModels/ConfigureWorkspace.cs

@@ -17,7 +17,7 @@ namespace SourceGit.ViewModels
             set
             {
                 if (SetProperty(ref _selected, value))
-                    CanDeleteSelected = value != null && !value.IsActive;
+                    CanDeleteSelected = value is { IsActive: false };
             }
         }
 

src/ViewModels/ConventionalCommitMessageBuilder.cs

@@ -72,10 +72,9 @@ namespace SourceGit.ViewModels
                 builder.Append(")");
             }
 
-            if (string.IsNullOrEmpty(_breakingChanges))
-                builder.Append(": ");
-            else
-                builder.Append("!: ");
+            if (!string.IsNullOrEmpty(_breakingChanges))
+                builder.Append("!");
+            builder.Append(": ");
 
             builder.Append(_description);
             builder.Append("\n\n");

src/ViewModels/CreateBranch.cs

@@ -112,10 +112,8 @@ namespace SourceGit.ViewModels
 
                 return ValidationResult.Success;
             }
-            else
-            {
-                return new ValidationResult("Missing runtime context to create branch!");
-            }
+
+            return new ValidationResult("Missing runtime context to create branch!");
         }
 
         public override Task<bool> Sure()
@@ -188,7 +186,7 @@ namespace SourceGit.ViewModels
                     if (succ && CheckoutAfterCreated)
                     {
                         var fake = new Models.Branch() { IsLocal = true, FullName = $"refs/heads/{fixedName}" };
-                        if (BasedOn is Models.Branch based && !based.IsLocal)
+                        if (BasedOn is Models.Branch { IsLocal: false } based)
                             fake.Upstream = based.FullName;
 
                         var folderEndIdx = fake.FullName.LastIndexOf('/');

src/ViewModels/DiffContext.cs

@@ -120,7 +120,7 @@ namespace SourceGit.ViewModels
 
                 _info = info;
 
-                var rs = null as object;
+                object rs = null;
                 if (latest.TextDiff != null)
                 {
                     var count = latest.TextDiff.Lines.Count;

src/ViewModels/ExecuteCustomAction.cs

@@ -207,14 +207,13 @@ namespace SourceGit.ViewModels
         {
             org = org.Replace("${REPO}", GetWorkdir());
 
-            if (Target is Models.Branch b)
-                return org.Replace("${BRANCH}", b.FriendlyName);
-            else if (Target is Models.Commit c)
-                return org.Replace("${SHA}", c.SHA);
-            else if (Target is Models.Tag t)
-                return org.Replace("${TAG}", t.Name);
-
-            return org;
+            return Target switch
+            {
+                Models.Branch b => org.Replace("${BRANCH}", b.FriendlyName),
+                Models.Commit c => org.Replace("${SHA}", c.SHA),
+                Models.Tag t => org.Replace("${TAG}", t.Name),
+                _ => org
+            };
         }
 
         private string GetWorkdir()

src/ViewModels/Histories.cs

@@ -261,7 +261,7 @@ namespace SourceGit.ViewModels
             if (commit.IsCurrentHead)
                 return;
 
-            var firstRemoteBranch = null as Models.Branch;
+            Models.Branch firstRemoteBranch = null;
             foreach (var d in commit.Decorators)
             {
                 if (d.Type == Models.DecoratorType.LocalBranchHead)
@@ -379,7 +379,7 @@ namespace SourceGit.ViewModels
                         return;
 
                     var options = new FolderPickerOpenOptions() { AllowMultiple = false };
-                    var log = null as CommandLog;
+                    CommandLog log = null;
                     try
                     {
                         var picker = await storageProvider.OpenFolderPickerAsync(options);
@@ -753,7 +753,7 @@ namespace SourceGit.ViewModels
                     return;
 
                 var options = new FolderPickerOpenOptions() { AllowMultiple = false };
-                var log = null as CommandLog;
+                CommandLog log = null;
                 try
                 {
                     var selected = await storageProvider.OpenFolderPickerAsync(options);

src/ViewModels/LFSLocks.cs

@@ -86,19 +86,11 @@ namespace SourceGit.ViewModels
         {
             var visible = new List<Models.LFSLock>();
 
-            if (!_showOnlyMyLocks)
+            foreach (var lfsLock in _cachedLocks)
             {
-                foreach (var lfsLock in _cachedLocks)
+                if (!_showOnlyMyLocks || lfsLock.User == _userName)
                     visible.Add(lfsLock);
             }
-            else
-            {
-                foreach (var lfsLock in _cachedLocks)
-                {
-                    if (lfsLock.User == _userName)
-                        visible.Add(lfsLock);
-                }
-            }
 
             VisibleLocks = visible;
         }

src/ViewModels/Launcher.cs

@@ -417,8 +417,7 @@ namespace SourceGit.ViewModels
                 }
             }
 
-            if (_activePage != null)
-                _activePage.Notifications.Add(notification);
+            _activePage?.Notifications.Add(notification);
         }
 
         public ContextMenu CreateContextForWorkspace()

src/ViewModels/Preferences.cs

@@ -584,13 +584,6 @@ namespace SourceGit.ViewModels
             }
         }
 
-        private void SortNodesRecursive(List<RepositoryNode> collection)
-        {
-            SortNodes(collection);
-            foreach (var node in collection)
-                SortNodesRecursive(node.SubNodes);
-        }
-
         private RepositoryNode FindNodeRecursive(string id, List<RepositoryNode> collection)
         {
             foreach (var node in collection)

src/ViewModels/Pull.cs

@@ -83,7 +83,7 @@ namespace SourceGit.ViewModels
             }
             else
             {
-                var autoSelectedRemote = null as Models.Remote;
+                Models.Remote autoSelectedRemote = null;
                 if (!string.IsNullOrEmpty(Current.Upstream))
                 {
                     var remoteNameEndIdx = Current.Upstream.IndexOf('/', 13);
@@ -96,7 +96,7 @@ namespace SourceGit.ViewModels
 
                 if (autoSelectedRemote == null)
                 {
-                    var remote = null as Models.Remote;
+                    Models.Remote remote = null;
                     if (!string.IsNullOrEmpty(_repo.Settings.DefaultRemote))
                         remote = _repo.Remotes.Find(x => x.Name == _repo.Settings.DefaultRemote);
                     _selectedRemote = remote ?? _repo.Remotes[0];

src/ViewModels/Push.cs

@@ -102,7 +102,7 @@ namespace SourceGit.ViewModels
 
             // Gather all local branches and find current branch.
             LocalBranches = new List<Models.Branch>();
-            var current = null as Models.Branch;
+            Models.Branch current = null;
             foreach (var branch in _repo.Branches)
             {
                 if (branch.IsLocal)
@@ -142,7 +142,7 @@ namespace SourceGit.ViewModels
             // Set default remote to the first if it has not been set.
             if (_selectedRemote == null)
             {
-                var remote = null as Models.Remote;
+                Models.Remote remote = null;
                 if (!string.IsNullOrEmpty(_repo.Settings.DefaultRemote))
                     remote = repo.Remotes.Find(x => x.Name == _repo.Settings.DefaultRemote);
 

src/ViewModels/RevisionCompare.cs

@@ -39,7 +39,7 @@ namespace SourceGit.ViewModels
             {
                 if (SetProperty(ref _selectedChanges, value))
                 {
-                    if (value != null && value.Count == 1)
+                    if (value?.Count == 1)
                     {
                         var option = new Models.DiffOption(GetSHA(_startPoint), GetSHA(_endPoint), value[0]);
                         DiffContext = new DiffContext(_repo, option, _diffContext);
@@ -85,12 +85,9 @@ namespace SourceGit.ViewModels
             _repo = null;
             _startPoint = null;
             _endPoint = null;
-            if (_changes != null)
-                _changes.Clear();
-            if (_visibleChanges != null)
-                _visibleChanges.Clear();
-            if (_selectedChanges != null)
-                _selectedChanges.Clear();
+            _changes?.Clear();
+            _visibleChanges?.Clear();
+            _selectedChanges?.Clear();
             _searchFilter = null;
             _diffContext = null;
         }

src/ViewModels/RevisionFileTreeNode.cs

@@ -18,7 +18,7 @@ namespace SourceGit.ViewModels
 
         public bool IsFolder
         {
-            get => Backend != null && Backend.Type == Models.ObjectType.Tree;
+            get => Backend?.Type == Models.ObjectType.Tree;
         }
 
         public bool IsExpanded

src/ViewModels/StashesPage.cs

@@ -67,8 +67,7 @@ namespace SourceGit.ViewModels
                                 untracked = new Commands.CompareRevisions(_repo.FullPath, Models.Commit.EmptyTreeSHA1, value.Parents[2]).Result();
                                 var needSort = changes.Count > 0 && untracked.Count > 0;
 
-                                foreach (var c in untracked)
-                                    changes.Add(c);
+                                changes.AddRange(untracked);
 
                                 if (needSort)
                                     changes.Sort((l, r) => Models.NumericSort.Compare(l.Path, r.Path));

src/ViewModels/WorkingCopy.cs

@@ -167,7 +167,7 @@ namespace SourceGit.ViewModels
                     }
                     else
                     {
-                        if (_selectedStaged != null && _selectedStaged.Count > 0)
+                        if (_selectedStaged?.Count > 0)
                             SelectedStaged = [];
 
                         if (value.Count == 1)
@@ -193,7 +193,7 @@ namespace SourceGit.ViewModels
                     }
                     else
                     {
-                        if (_selectedUnstaged != null && _selectedUnstaged.Count > 0)
+                        if (_selectedUnstaged?.Count > 0)
                             SelectedUnstaged = [];
 
                         if (value.Count == 1)
@@ -269,12 +269,12 @@ namespace SourceGit.ViewModels
 
             var lastSelectedUnstaged = new HashSet<string>();
             var lastSelectedStaged = new HashSet<string>();
-            if (_selectedUnstaged != null && _selectedUnstaged.Count > 0)
+            if (_selectedUnstaged?.Count > 0)
             {
                 foreach (var c in _selectedUnstaged)
                     lastSelectedUnstaged.Add(c.Path);
             }
-            else if (_selectedStaged != null && _selectedStaged.Count > 0)
+            else if (_selectedStaged?.Count > 0)
             {
                 foreach (var c in _selectedStaged)
                     lastSelectedStaged.Add(c.Path);
@@ -1203,7 +1203,7 @@ namespace SourceGit.ViewModels
 
             var menu = new ContextMenu();
 
-            var ai = null as MenuItem;
+            MenuItem ai = null;
             var services = _repo.GetPreferredOpenAIServices();
             if (services.Count > 0)
             {
@@ -1796,7 +1796,7 @@ namespace SourceGit.ViewModels
             else
             {
                 var pathSpecFile = Path.GetTempFileName();
-                using (var writer = new StreamWriter(pathSpecFile))
+                await using (var writer = new StreamWriter(pathSpecFile))
                 {
                     foreach (var c in changes)
                         await writer.WriteLineAsync(c.Path);
@@ -1833,7 +1833,7 @@ namespace SourceGit.ViewModels
             else
             {
                 var pathSpecFile = Path.GetTempFileName();
-                using (var writer = new StreamWriter(pathSpecFile))
+                await using (var writer = new StreamWriter(pathSpecFile))
                 {
                     foreach (var c in changes)
                     {

src/Views/AddWorktree.axaml.cs

@@ -25,7 +25,7 @@ namespace SourceGit.Views
                 if (selected.Count == 1)
                 {
                     var folder = selected[0];
-                    var folderPath = folder is { Path: { IsAbsoluteUri: true } path } ? path.LocalPath : folder?.Path.ToString();
+                    var folderPath = folder is { Path: { IsAbsoluteUri: true } path } ? path.LocalPath : folder.Path.ToString();
                     TxtLocation.Text = folderPath.TrimEnd('\\', '/');
                 }
             }

src/Views/Blame.axaml.cs

@@ -90,7 +90,7 @@ namespace SourceGit.Views
             {
                 var view = TextView;
                 var maxWidth = 0.0;
-                if (view != null && view.VisualLinesValid && _editor.BlameData != null)
+                if (view is { VisualLinesValid: true } && _editor.BlameData != null)
                 {
                     var typeface = view.CreateTypeface();
                     var calculated = new HashSet<string>();

src/Views/BranchTree.axaml.cs

@@ -401,7 +401,7 @@ namespace SourceGit.Views
             if (selected == null || selected.Count == 0)
                 return;
 
-            var prev = null as ViewModels.BranchTreeNode;
+            ViewModels.BranchTreeNode prev = null;
             foreach (var row in Rows)
             {
                 if (row.IsSelected)

src/Views/CaptionButtons.axaml.cs

@@ -42,8 +42,7 @@ namespace SourceGit.Views
         private void CloseWindow(object _, RoutedEventArgs e)
         {
             var window = this.FindAncestorOfType<Window>();
-            if (window != null)
-                window.Close();
+            window?.Close();
 
             e.Handled = true;
         }

src/Views/ChangeCollectionView.axaml.cs

@@ -379,9 +379,7 @@ namespace SourceGit.Views
                 }
                 else if (selected.Count > 0)
                 {
-                    var sets = new HashSet<Models.Change>();
-                    foreach (var c in selected)
-                        sets.Add(c);
+                    var sets = new HashSet<Models.Change>(selected);
 
                     var nodes = new List<ViewModels.ChangeTreeNode>();
                     foreach (var row in tree.Rows)
@@ -447,9 +445,7 @@ namespace SourceGit.Views
 
                 if (selected.Count > 0)
                 {
-                    var sets = new HashSet<Models.Change>();
-                    foreach (var c in selected)
-                        sets.Add(c);
+                    var sets = new HashSet<Models.Change>(selected);
 
                     var nodes = new List<ViewModels.ChangeTreeNode>();
                     foreach (var row in tree.Rows)

src/Views/ChromelessWindow.cs

@@ -70,7 +70,7 @@ namespace SourceGit.Views
 
         private void OnWindowBorderPointerPressed(object sender, PointerPressedEventArgs e)
         {
-            if (sender is Border border && border.Tag is WindowEdge edge && CanResize)
+            if (sender is Border { Tag: WindowEdge edge } && CanResize)
                 BeginResizeDrag(edge, e);
         }
     }

src/Views/CommitDetail.axaml.cs

@@ -12,7 +12,7 @@ namespace SourceGit.Views
 
         private void OnChangeDoubleTapped(object sender, TappedEventArgs e)
         {
-            if (DataContext is ViewModels.CommitDetail detail && sender is Grid grid && grid.DataContext is Models.Change change)
+            if (DataContext is ViewModels.CommitDetail detail && sender is Grid { DataContext: Models.Change change })
             {
                 detail.ActivePageIndex = 1;
                 detail.SelectedChanges = new() { change };
@@ -23,7 +23,7 @@ namespace SourceGit.Views
 
         private void OnChangeContextRequested(object sender, ContextRequestedEventArgs e)
         {
-            if (DataContext is ViewModels.CommitDetail detail && sender is Grid grid && grid.DataContext is Models.Change change)
+            if (DataContext is ViewModels.CommitDetail detail && sender is Grid { DataContext: Models.Change change } grid)
             {
                 var menu = detail.CreateChangeContextMenu(change);
                 menu?.Open(grid);

src/Views/CommitRefsPresenter.cs

@@ -179,7 +179,7 @@ namespace SourceGit.Views
                 return new Size(0, 0);
 
             var refs = commit.Decorators;
-            if (refs != null && refs.Count > 0)
+            if (refs?.Count > 0)
             {
                 var typeface = new Typeface(FontFamily);
                 var typefaceBold = new Typeface(FontFamily, FontStyle.Normal, FontWeight.Bold);

src/Views/ConfirmRestart.axaml.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Diagnostics;
 
 using Avalonia.Interactivity;
@@ -12,12 +11,6 @@ namespace SourceGit.Views
             InitializeComponent();
         }
 
-        private void CloseWindow(object _1, RoutedEventArgs _2)
-        {
-            Console.Out.WriteLine("No passphrase entered.");
-            App.Quit(-1);
-        }
-
         private void Restart(object _1, RoutedEventArgs _2)
         {
             var selfExecFile = Process.GetCurrentProcess().MainModule!.FileName;

src/Views/DiffView.axaml.cs

@@ -45,10 +45,8 @@ namespace SourceGit.Views
         private void OnUseFullTextDiffClicked(object sender, RoutedEventArgs e)
         {
             var textDiffView = this.FindDescendantOfType<TextDiffView>();
-            if (textDiffView == null)
-                return;
 
-            var presenter = textDiffView.FindDescendantOfType<ThemedTextDiffPresenter>();
+            var presenter = textDiffView?.FindDescendantOfType<ThemedTextDiffPresenter>();
             if (presenter == null)
                 return;
 

src/Views/ExecuteCustomAction.axaml.cs

@@ -35,10 +35,8 @@ namespace SourceGit.Views
                 return;
 
             var control = sender as Control;
-            if (control == null)
-                return;
 
-            var selector = control.DataContext as ViewModels.CustomActionControlPathSelector;
+            var selector = control?.DataContext as ViewModels.CustomActionControlPathSelector;
             if (selector == null)
                 return;
 

src/Views/FilterModeSwitchButton.axaml.cs

@@ -56,10 +56,8 @@ namespace SourceGit.Views
         private void OnChangeFilterModeButtonClicked(object sender, RoutedEventArgs e)
         {
             var repoView = this.FindAncestorOfType<Repository>();
-            if (repoView == null)
-                return;
 
-            var repo = repoView.DataContext as ViewModels.Repository;
+            var repo = repoView?.DataContext as ViewModels.Repository;
             if (repo == null)
                 return;
 

src/Views/Histories.axaml

@@ -47,10 +47,6 @@
                 ContextRequested="OnCommitListContextRequested"
                 DoubleTapped="OnCommitListDoubleTapped"
                 KeyDown="OnCommitListKeyDown">
-        <DataGrid.Resources>
-          <SolidColorBrush x:Key="DataGridGridLinesBrush" Color="{DynamicResource Color.Border0}" />
-        </DataGrid.Resources>
-        
         <DataGrid.Styles>
           <Style Selector="DataGridColumnHeader">
             <Setter Property="MinHeight" Value="24"/>
@@ -75,7 +71,7 @@
                                VerticalAlignment="Stretch"
                                Fill="{DynamicResource Brush.Border0}"
                                IsVisible="{TemplateBinding AreSeparatorsVisible}" />
-                  </Grid>                  
+                  </Grid>
                 </Border>
               </ControlTemplate>
             </Setter>
@@ -96,13 +92,13 @@
             </Setter>
           </Style>
         </DataGrid.Styles>
-        
+
         <DataGrid.Columns>
           <DataGridTemplateColumn Width="*" IsReadOnly="True">
             <DataGridTemplateColumn.Header>
               <TextBlock Classes="table_header" Text="{DynamicResource Text.Histories.Header.GraphAndSubject}" HorizontalAlignment="Center"/>
             </DataGridTemplateColumn.Header>
-            
+
             <DataGridTemplateColumn.CellTemplate>
               <DataTemplate DataType="m:Commit">
                 <Border Padding="{Binding Margin}" ClipToBounds="True" Background="Transparent">
@@ -159,7 +155,7 @@
             <DataGridTemplateColumn.Header>
               <TextBlock Classes="table_header" Text="{DynamicResource Text.Histories.Header.Author}" HorizontalAlignment="Center"/>
             </DataGridTemplateColumn.Header>
-            
+
             <DataGridTemplateColumn.CellTemplate>
               <DataTemplate DataType="m:Commit">
                 <Grid ColumnDefinitions="20,*" Background="Transparent">
@@ -188,7 +184,7 @@
             <DataGridTemplateColumn.Header>
               <TextBlock Classes="table_header" Text="{DynamicResource Text.Histories.Header.SHA}" HorizontalAlignment="Center"/>
             </DataGridTemplateColumn.Header>
-            
+
             <DataGridTemplateColumn.CellTemplate>
               <DataTemplate DataType="m:Commit">
                 <Border Padding="8,0,0,0" Background="Transparent" ClipToBounds="True">

src/Views/Histories.axaml.cs

@@ -161,11 +161,9 @@ namespace SourceGit.Views
             double startY = 0;
             foreach (var child in rowsPresenter.Children)
             {
-                var row = child as DataGridRow;
-                if (row.IsVisible)
+                if (child is DataGridRow { IsVisible: true } row)
                 {
-                    if (rowHeight != row.Bounds.Height)
-                        rowHeight = row.Bounds.Height;
+                    rowHeight = row.Bounds.Height;
 
                     if (row.Bounds.Top <= 0 && row.Bounds.Top > -rowHeight)
                     {
@@ -237,10 +235,8 @@ namespace SourceGit.Views
                 if (e.Key == Key.B)
                 {
                     var repoView = this.FindAncestorOfType<Repository>();
-                    if (repoView == null)
-                        return;
 
-                    var repo = repoView.DataContext as ViewModels.Repository;
+                    var repo = repoView?.DataContext as ViewModels.Repository;
                     if (repo == null || !repo.CanCreatePopup())
                         return;
 
@@ -260,7 +256,7 @@ namespace SourceGit.Views
             if (DataContext is ViewModels.Histories histories &&
                 CommitListContainer.SelectedItems is { Count: 1 } &&
                 sender is DataGrid grid &&
-                e.Source != grid)
+                !Equals(e.Source, grid))
             {
                 if (e.Source is CommitRefsPresenter crp)
                 {

src/Views/InteractiveRebase.axaml.cs

@@ -87,7 +87,7 @@ namespace SourceGit.Views
 
         private void OnRowHeaderPointerPressed(object sender, PointerPressedEventArgs e)
         {
-            if (sender is Border border && border.DataContext is ViewModels.InteractiveRebaseItem item)
+            if (sender is Border { DataContext: ViewModels.InteractiveRebaseItem item })
             {
                 var data = new DataObject();
                 data.Set("InteractiveRebaseItem", item);

src/Views/RepositoryConfigure.axaml

@@ -499,7 +499,7 @@
                     </StackPanel>
                   </Button>
                   <TextBlock Margin="0,2,0,0" TextWrapping="Wrap" Text="{DynamicResource Text.Configure.CustomAction.InputControls.Tip}" Foreground="{DynamicResource Brush.FG2}"/>
-                  
+
                   <CheckBox Margin="0,8,0,0" Content="{DynamicResource Text.Configure.CustomAction.WaitForExit}" IsChecked="{Binding WaitForExit, Mode=TwoWay}"/>
                 </StackPanel>
               </DataTemplate>

src/Views/RepositoryToolbar.axaml.cs

@@ -118,8 +118,7 @@ namespace SourceGit.Views
 
         private void StartBisect(object sender, RoutedEventArgs e)
         {
-            if (DataContext is ViewModels.Repository { IsBisectCommandRunning: false } repo &&
-                repo.InProgressContext == null &&
+            if (DataContext is ViewModels.Repository { IsBisectCommandRunning: false, InProgressContext: null } repo &&
                 repo.CanCreatePopup())
             {
                 if (repo.LocalChangesCount > 0)

src/Views/RevisionFileTreeView.axaml.cs

@@ -216,7 +216,7 @@ namespace SourceGit.Views
             if (node.IsExpanded)
             {
                 var subtree = GetChildrenOfTreeNode(node);
-                if (subtree != null && subtree.Count > 0)
+                if (subtree?.Count > 0)
                 {
                     var subrows = new List<ViewModels.RevisionFileTreeNode>();
                     MakeRows(subrows, subtree, depth + 1);
@@ -320,10 +320,8 @@ namespace SourceGit.Views
                 return node.Children;
 
             var vm = DataContext as ViewModels.CommitDetail;
-            if (vm == null)
-                return null;
 
-            var objects = vm.GetRevisionFilesUnderFolder(node.Backend.Path + "/");
+            var objects = vm?.GetRevisionFilesUnderFolder(node.Backend.Path + "/");
             if (objects == null || objects.Count == 0)
                 return null;
 

src/Views/StashChanges.axaml

@@ -32,7 +32,7 @@
           </DataTemplate>
         </ComboBox.ItemTemplate>
       </ComboBox>
-      
+
       <TextBlock Grid.Row="1" Grid.Column="0"
                  HorizontalAlignment="Right" VerticalAlignment="Top"
                  Margin="0,8,8,0"
@@ -54,7 +54,7 @@
                  Margin="0,2,4,4"
                  Text="{DynamicResource Text.PopupEnterKeyTip}"
                  TextWrapping="Wrap"
-                 Foreground="{DynamicResource Brush.FG2}"/>     
+                 Foreground="{DynamicResource Brush.FG2}"/>
 
       <CheckBox Grid.Row="3" Grid.Column="1"
                 Height="32"

src/Views/StashSubjectPresenter.cs

@@ -67,7 +67,7 @@ namespace SourceGit.Views
             var foreground = Foreground;
             var x = 0.0;
             var h = Bounds.Height;
-            var prefix = null as FormattedText;
+            FormattedText prefix = null;
 
             var match = REG_KEYWORD_ON().Match(subject);
             if (match.Success)

src/Views/SubmodulesView.axaml.cs

@@ -164,7 +164,7 @@ namespace SourceGit.Views
         {
             if (sender is Control control && DataContext is ViewModels.Repository repo)
             {
-                if (control.DataContext is ViewModels.SubmoduleTreeNode node && node.Module != null)
+                if (control.DataContext is ViewModels.SubmoduleTreeNode { Module: not null } node)
                 {
                     var menu = repo.CreateContextMenuForSubmodule(node.Module);
                     menu?.Open(control);

src/Views/TagsView.axaml.cs

@@ -205,7 +205,7 @@ namespace SourceGit.Views
         private void OnSelectionChanged(object sender, SelectionChangedEventArgs _)
         {
             var selected = (sender as ListBox)?.SelectedItem;
-            var selectedTag = null as Models.Tag;
+            Models.Tag selectedTag = null;
             if (selected is ViewModels.TagTreeNode node)
                 selectedTag = node.Tag;
             else if (selected is Models.Tag tag)

src/Views/TextDiffView.axaml.cs

@@ -101,7 +101,7 @@ namespace SourceGit.Views
 
                 var lines = presenter.GetLines();
                 var view = TextView;
-                if (view != null && view.VisualLinesValid)
+                if (view?.VisualLinesValid ?? false)
                 {
                     var typeface = view.CreateTypeface();
                     foreach (var line in view.VisualLines)
@@ -175,7 +175,7 @@ namespace SourceGit.Views
 
                 var lines = presenter.GetLines();
                 var view = TextView;
-                if (view != null && view.VisualLinesValid)
+                if (view?.VisualLinesValid ?? false)
                 {
                     var typeface = view.CreateTypeface();
                     foreach (var line in view.VisualLines)
@@ -189,7 +189,7 @@ namespace SourceGit.Views
 
                         var info = lines[index - 1];
                         var y = line.GetTextLineVisualYPosition(line.TextLines[0], VisualYPosition.LineMiddle) - view.VerticalOffset;
-                        var indicator = null as FormattedText;
+                        FormattedText indicator = null;
                         if (info.Type == Models.TextDiffLineType.Added)
                         {
                             indicator = new FormattedText(
@@ -545,14 +545,11 @@ namespace SourceGit.Views
         public virtual void GotoFirstChange()
         {
             var blockNavigation = BlockNavigation;
-            if (blockNavigation != null)
+            var prev = blockNavigation?.GotoFirst();
+            if (prev != null)
             {
-                var prev = blockNavigation.GotoFirst();
-                if (prev != null)
-                {
-                    TextArea.Caret.Line = prev.Start;
-                    ScrollToLine(prev.Start);
-                }
+                TextArea.Caret.Line = prev.Start;
+                ScrollToLine(prev.Start);
             }
         }
 
@@ -657,14 +654,11 @@ namespace SourceGit.Views
         public virtual void GotoLastChange()
         {
             var blockNavigation = BlockNavigation;
-            if (blockNavigation != null)
+            var next = blockNavigation?.GotoLast();
+            if (next != null)
             {
-                var next = blockNavigation.GotoLast();
-                if (next != null)
-                {
-                    TextArea.Caret.Line = next.Start;
-                    ScrollToLine(next.Start);
-                }
+                TextArea.Caret.Line = next.Start;
+                ScrollToLine(next.Start);
             }
         }
 
@@ -1830,10 +1824,8 @@ namespace SourceGit.Views
                 return;
 
             var diff = DataContext as Models.TextDiff;
-            if (diff == null)
-                return;
 
-            var change = diff.Option.WorkingCopyChange;
+            var change = diff?.Option.WorkingCopyChange;
             if (change == null)
                 return;
 
@@ -1842,10 +1834,8 @@ namespace SourceGit.Views
                 return;
 
             var repoView = this.FindAncestorOfType<Repository>();
-            if (repoView == null)
-                return;
 
-            var repo = repoView.DataContext as ViewModels.Repository;
+            var repo = repoView?.DataContext as ViewModels.Repository;
             if (repo == null)
                 return;
 
@@ -1888,10 +1878,8 @@ namespace SourceGit.Views
                 return;
 
             var diff = DataContext as Models.TextDiff;
-            if (diff == null)
-                return;
 
-            var change = diff.Option.WorkingCopyChange;
+            var change = diff?.Option.WorkingCopyChange;
             if (change == null)
                 return;
 
@@ -1900,10 +1888,8 @@ namespace SourceGit.Views
                 return;
 
             var repoView = this.FindAncestorOfType<Repository>();
-            if (repoView == null)
-                return;
 
-            var repo = repoView.DataContext as ViewModels.Repository;
+            var repo = repoView?.DataContext as ViewModels.Repository;
             if (repo == null)
                 return;
 
@@ -1942,10 +1928,8 @@ namespace SourceGit.Views
                 return;
 
             var diff = DataContext as Models.TextDiff;
-            if (diff == null)
-                return;
 
-            var change = diff.Option.WorkingCopyChange;
+            var change = diff?.Option.WorkingCopyChange;
             if (change == null)
                 return;
 
@@ -1954,10 +1938,8 @@ namespace SourceGit.Views
                 return;
 
             var repoView = this.FindAncestorOfType<Repository>();
-            if (repoView == null)
-                return;
 
-            var repo = repoView.DataContext as ViewModels.Repository;
+            var repo = repoView?.DataContext as ViewModels.Repository;
             if (repo == null)
                 return;
 

src/Views/Welcome.axaml.cs

@@ -208,10 +208,8 @@ namespace SourceGit.Views
             if (e.Data.Contains("MovedRepositoryTreeNode") || e.Data.Contains(DataFormats.Files))
             {
                 var grid = sender as Grid;
-                if (grid == null)
-                    return;
 
-                var to = grid.DataContext as ViewModels.RepositoryNode;
+                var to = grid?.DataContext as ViewModels.RepositoryNode;
                 if (to == null)
                     return;