code_review: PR #480

* remove `string.IsNullOrEmpty(OS.ShellOrTerminal)` checking from detail backend since it has been checked by `Native.OS.OpenTerminal`
* remove `ViewModels.Preference.IsTerminalConfigured` because it is only used by itself (Unlike `IsGitConfigured`).
* add `Native.OS.TestShellOrTerminal` and use it instead of setting `Preference.ShellOrTerminal` directly, because we have binded a callback that will save preference into file when its property changed. It may cause lag in some enviroments if we saving preference into file too frequently (see PR #436).
* run `dotnet format`

src/Native/Linux.cs

@@ -27,9 +27,7 @@ namespace SourceGit.Native
         public string FindTerminal(Models.ShellOrTerminal shell)
         {
             if (string.IsNullOrEmpty(shell.Exec))
-            {
                 return string.Empty;
-            }
 
             var pathVariable = Environment.GetEnvironmentVariable("PATH") ?? string.Empty;
             var pathes = pathVariable.Split(Path.PathSeparator, StringSplitOptions.RemoveEmptyEntries);
@@ -76,23 +74,18 @@ namespace SourceGit.Native
 
         public void OpenTerminal(string workdir)
         {
-            if (string.IsNullOrEmpty(OS.ShellOrTerminal))
-            {
-                App.RaiseException(workdir, $"Terminal is not specified! Please confirm that the correct shell/terminal has been configured.");
-                return;
-            }
-
             var startInfo = new ProcessStartInfo();
             var home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
             startInfo.WorkingDirectory = string.IsNullOrEmpty(workdir) ? home : workdir;
             startInfo.FileName = OS.ShellOrTerminal;
+
             try
             {
                 Process.Start(startInfo);
             }
             catch (Exception e)
             {
-                App.RaiseException(workdir, e.Message);
+                App.RaiseException(workdir, $"Failed to start '{OS.ShellOrTerminal}'. Reason: {e.Message}");
             }
         }
 

src/Native/OS.cs

@@ -74,12 +74,17 @@ namespace SourceGit.Native
             return _backend.FindGitExecutable();
         }
 
-        public static void SetShellOrTerminal(Models.ShellOrTerminal shellOrTerminal)
+        public static bool TestShellOrTerminal(Models.ShellOrTerminal shell)
         {
-            if (shellOrTerminal == null)
+            return !string.IsNullOrEmpty(_backend.FindTerminal(shell));
+        }
+
+        public static void SetShellOrTerminal(Models.ShellOrTerminal shell)
+        {
+            if (shell == null)
                 ShellOrTerminal = string.Empty;
             else
-                ShellOrTerminal = _backend.FindTerminal(shellOrTerminal);
+                ShellOrTerminal = _backend.FindTerminal(shell);
         }
 
         public static void OpenInFileManager(string path, bool select = false)

src/Native/Windows.cs

@@ -158,7 +158,7 @@ namespace SourceGit.Native
 
         public void OpenTerminal(string workdir)
         {
-            if (string.IsNullOrEmpty(OS.ShellOrTerminal) || !File.Exists(OS.ShellOrTerminal))
+            if (!File.Exists(OS.ShellOrTerminal))
             {
                 App.RaiseException(workdir, $"Terminal is not specified! Please confirm that the correct shell/terminal has been configured.");
                 return;

src/ViewModels/Preference.cs

@@ -18,44 +18,15 @@ namespace SourceGit.ViewModels
                 if (_instance == null)
                 {
                     _isLoading = true;
-
+                    _instance = Load();
-                    var path = Path.Combine(Native.OS.DataDir, "preference.json");
-                    if (!File.Exists(path))
-                    {
-                        _instance = new Preference();
-                    }
-                    else
-                    {
-                        try
-                        {
-                            _instance = JsonSerializer.Deserialize(File.ReadAllText(path), JsonCodeGen.Default.Preference);
-                        }
-                        catch
-                        {
-                            _instance = new Preference();
-                        }
-                    }
                     _isLoading = false;
                 }
 
                 if (!_instance.IsGitConfigured())
                     _instance.GitInstallPath = Native.OS.FindGitExecutable();
 
-                if (!_instance.IsTerminalConfigured())
+                if (_instance._shellOrTerminal == -1)
-                {
+                    _instance.AutoSelectShellOrTerminal();
-                    for (var i = 0; i < Models.ShellOrTerminal.Supported.Count; i++)
-                    {
-                        _instance.ShellOrTerminal = i;
-                        if (string.IsNullOrEmpty(_instance.ShellOrTerminalPath))
-                        {
-                            _instance.ShellOrTerminal = -1;
-                        }
-                        else
-                        {
-                            break;
-                        }
-                    }
-                }
 
                 if (_instance.Workspaces.Count == 0)
                     _instance.Workspaces.Add(new Workspace() { Name = "Default", Color = 4278221015 });
@@ -396,11 +367,6 @@ namespace SourceGit.ViewModels
             return !string.IsNullOrEmpty(path) && File.Exists(path);
         }
 
-        public bool IsTerminalConfigured()
-        {
-            return ShellOrTerminal != -1;
-        }
-
         public bool ShouldCheck4UpdateOnStartup()
         {
             if (!_check4UpdatesOnStartup)
@@ -519,6 +485,35 @@ namespace SourceGit.ViewModels
             File.WriteAllText(file, data);
         }
 
+        private static Preference Load()
+        {
+            var path = Path.Combine(Native.OS.DataDir, "preference.json");
+            if (!File.Exists(path))
+                return new Preference();
+
+            try
+            {
+                return JsonSerializer.Deserialize(File.ReadAllText(path), JsonCodeGen.Default.Preference);
+            }
+            catch
+            {
+                return new Preference();
+            }
+        }
+
+        private void AutoSelectShellOrTerminal()
+        {
+            for (int i = 0; i < Models.ShellOrTerminal.Supported.Count; i++)
+            {
+                var shell = Models.ShellOrTerminal.Supported[i];
+                if (Native.OS.TestShellOrTerminal(shell))
+                {
+                    ShellOrTerminal = i;
+                    break;
+                }
+            }
+        }
+
         private RepositoryNode FindNodeRecursive(string id, List<RepositoryNode> collection)
         {
             foreach (var node in collection)
@@ -557,7 +552,7 @@ namespace SourceGit.ViewModels
                 return true;
             }
 
-            foreach (RepositoryNode one in collection)
+            foreach (var one in collection)
             {
                 if (RemoveNodeRecursive(node, one.SubNodes))
                     return true;

src/Views/ImageDiffView.axaml.cs

@@ -1,17 +1,7 @@
-using System;
-
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Input;
-using Avalonia.Media;
-using Avalonia.Media.Imaging;
 
 namespace SourceGit.Views
 {
-    
-
-    
-
     public partial class ImageDiffView : UserControl
     {
         public ImageDiffView()