fix(launch): reject option-like and missing paths, resolve them absolute and drop the folder-missing page

YKanBan/Assets/Locales/Resources.resx

@@ -265,12 +265,6 @@
   <data name="Error_Argument_Usage" xml:space="preserve">
     <value>Usage: ykanban &lt;path&gt;</value>
   </data>
-  <data name="Error_DirectoryMissing_Title" xml:space="preserve">
-    <value>Folder not found</value>
-  </data>
-  <data name="Error_DirectoryMissing_Message" xml:space="preserve">
-    <value>The folder does not exist: {0}</value>
-  </data>
   <data name="Error_NotInitialized_Title" xml:space="preserve">
     <value>No workspace here</value>
   </data>

YKanBan/Assets/Locales/Resources.zh-Hans.resx

@@ -265,12 +265,6 @@
   <data name="Error_Argument_Usage" xml:space="preserve">
     <value>用法：ykanban &lt;路径&gt;</value>
   </data>
-  <data name="Error_DirectoryMissing_Title" xml:space="preserve">
-    <value>目录不存在</value>
-  </data>
-  <data name="Error_DirectoryMissing_Message" xml:space="preserve">
-    <value>目录不存在：{0}</value>
-  </data>
   <data name="Error_NotInitialized_Title" xml:space="preserve">
     <value>尚未初始化</value>
   </data>

YKanBan/Launching/LaunchArguments.cs

@@ -4,9 +4,11 @@ namespace YKanBan.Launching;
 
 /// <summary>
 /// Parses raw command-line arguments. The only accepted form is a single,
-/// non-blank workspace path (<c>ykanban &lt;path&gt;</c>); zero arguments,
-/// more than one argument, or a blank argument is rejected as an argument
-/// error. The path itself is not checked for existence here.
+/// non-blank, existing workspace folder (<c>ykanban &lt;path&gt;</c>); zero
+/// arguments, more than one argument, a blank argument, an argument starting
+/// with <c>-</c> (any option form, <c>--help</c> included), a malformed path or
+/// a path that is not an existing folder is rejected as an argument error. A
+/// relative path is resolved against the process's current directory.
 /// </summary>
 public static class LaunchArguments {
     /// <summary>
@@ -14,15 +16,28 @@ public static class LaunchArguments {
     /// <c>ykanban &lt;path&gt;</c> contract.
     /// </summary>
     /// <param name="arguments">The raw arguments, excluding the executable name.</param>
-    /// <param name="folderPath">The parsed workspace path on success, otherwise <see langword="null"/>.</param>
-    /// <returns><see langword="true"/> when exactly one non-blank path was supplied.</returns>
+    /// <param name="folderPath">The absolute, existing workspace folder on success, otherwise <see langword="null"/>.</param>
+    /// <returns><see langword="true"/> when exactly one usable path was supplied.</returns>
     public static bool TryParse(IReadOnlyList<string> arguments, [NotNullWhen(true)] out string? folderPath) {
-        if (arguments.Count == 1 && !string.IsNullOrWhiteSpace(arguments[0])) {
-            folderPath = arguments[0];
-            return true;
+        folderPath = null;
+        if (arguments.Count != 1 || string.IsNullOrWhiteSpace(arguments[0]) || arguments[0].StartsWith('-')) {
+            return false;
         }
 
-        folderPath = null;
-        return false;
+        string fullPath;
+        try {
+            fullPath = Path.GetFullPath(arguments[0]);
+        } catch (Exception exception) when (exception is ArgumentException or NotSupportedException or PathTooLongException) {
+            // A path the OS cannot even represent is a bad argument, not a missing folder.
+            return false;
+        }
+
+        // Existence is checked here so every caller gets an already validated folder.
+        if (!Directory.Exists(fullPath)) {
+            return false;
+        }
+
+        folderPath = fullPath;
+        return true;
     }
 }

YKanBan/ViewModels/ErrorPages/DirectoryMissingPageViewModel.cs

@@ -1,29 +0,0 @@
-using System.Globalization;
-
-namespace YKanBan.ViewModels.ErrorPages;
-
-/// <summary>
-/// The full-window page shown when the folder passed on the command line does
-/// not exist. It has no operations.
-/// </summary>
-public sealed class DirectoryMissingPageViewModel : ViewModelBase {
-    /// <summary>
-    /// Initializes the page for a missing folder.
-    /// </summary>
-    /// <param name="folderPath">The folder path that does not exist.</param>
-    public DirectoryMissingPageViewModel(string folderPath) {
-        FolderPath = folderPath;
-        Message = string.Format(
-            Resources.Culture ?? CultureInfo.CurrentCulture, Resources.Error_DirectoryMissing_Message, folderPath);
-    }
-
-    /// <summary>
-    /// Gets the folder path that does not exist.
-    /// </summary>
-    public string FolderPath { get; }
-
-    /// <summary>
-    /// Gets the localized explanatory message.
-    /// </summary>
-    public string Message { get; }
-}

YKanBan/ViewModels/MainWindowViewModel.cs

@@ -69,11 +69,6 @@ public sealed partial class MainWindowViewModel : ViewModelBase {
             return;
         }
 
-        if (!Directory.Exists(folderPath)) {
-            Content = new DirectoryMissingPageViewModel(folderPath);
-            return;
-        }
-
         try {
             OpenWorkspace(folderPath);
         } catch (WorkspaceNotInitializedException) {

YKanBan/Views/ErrorPages/DirectoryMissingPageView.axaml

@@ -1,18 +0,0 @@
-<UserControl xmlns="https://github.com/avaloniaui"
-             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             xmlns:vm="using:YKanBan.ViewModels.ErrorPages"
-             xmlns:lang="using:YKanBan"
-             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-             mc:Ignorable="d" d:DesignWidth="1000" d:DesignHeight="640"
-             x:Class="YKanBan.Views.ErrorPages.DirectoryMissingPageView"
-             x:DataType="vm:DirectoryMissingPageViewModel">
-
-    <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="12"
-                MaxWidth="560" Margin="32">
-        <TextBlock Text="{x:Static lang:Resources.Error_DirectoryMissing_Title}"
-                   FontSize="20" FontWeight="SemiBold" HorizontalAlignment="Center"/>
-        <TextBlock Text="{Binding Message}"
-                   TextWrapping="Wrap" HorizontalAlignment="Center" TextAlignment="Center"/>
-    </StackPanel>
-</UserControl>

YKanBan/Views/ErrorPages/DirectoryMissingPageView.axaml.cs

@@ -1,9 +0,0 @@
-using Avalonia.Controls;
-
-namespace YKanBan.Views.ErrorPages;
-
-public partial class DirectoryMissingPageView : UserControl {
-    public DirectoryMissingPageView() {
-        InitializeComponent();
-    }
-}