Fixes #5561 - Make TuiConfigurationBuilder flat-key binding trim/AOT-safe

Terminal.Gui/Configuration/Settings/TuiConfigurationBuilder.cs

@@ -1,4 +1,3 @@
-using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using Microsoft.Extensions.Configuration;
@@ -168,7 +167,7 @@ public void ApplyToStaticFacades ()
 
     [UnconditionalSuppressMessage ("Trimming", "IL2026", Justification = "Settings POCOs are simple types preserved by DynamicDependency in ConfigPropertyHostTypes.")]
     [UnconditionalSuppressMessage ("AOT", "IL3050", Justification = "Settings POCOs are simple types; no generic instantiation needed at runtime.")]
-    private static void BindSection<T> (IConfiguration config, string sectionName, Action<T> apply) where T : new ()
+    private static void BindSection<[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicProperties)] T> (IConfiguration config, string sectionName, Action<T> apply) where T : new ()
     {
         T settings = new ();
         IConfigurationSection section = config.GetSection (sectionName);
@@ -206,10 +205,10 @@ private static void BindThemeScalar (IConfiguration config)
 
     /// <summary>
     ///     Binds flat dotted keys (e.g. <c>Driver.Force16Colors</c>) from the configuration root to the
-    ///     corresponding properties on the settings POCO.
+    ///     corresponding properties on the settings POCO. <typeparamref name="T"/>'s public properties are
+    ///     preserved for trimming via the <see cref="DynamicallyAccessedMembersAttribute"/> on the type parameter.
     /// </summary>
-    [UnconditionalSuppressMessage ("Trimming", "IL2026", Justification = "Settings POCOs are simple types preserved by DynamicDependency in ConfigPropertyHostTypes.")]
-    private static void BindFlatDottedKeys<T> (IConfiguration config, string sectionName, T settings)
+    private static void BindFlatDottedKeys<[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicProperties)] T> (IConfiguration config, string sectionName, T settings)
     {
         string prefix = sectionName + ".";
 
@@ -244,8 +243,12 @@ private static void BindFlatDottedKeys<T> (IConfiguration config, string section
     }
 
     /// <summary>
-    ///     Converts a configuration string value to the target property type, using a fast path for the
-    ///     common scalar types and falling back to a <see cref="TypeConverter"/>.
+    ///     Converts a configuration string value to the target property type. Only the scalar types used by the
+    ///     settings POCOs are supported, so this path is trim/AOT-safe — it deliberately avoids
+    ///     <c>TypeDescriptor.GetConverter</c> (which is <see cref="RequiresUnreferencedCodeAttribute"/> /
+    ///     <see cref="RequiresDynamicCodeAttribute"/> and breaks NativeAOT/trimmed consumers). New non-scalar
+    ///     settings property types must be added here explicitly. Unsupported types return <see langword="null"/>
+    ///     and are skipped by <see cref="BindFlatDottedKeys{T}"/>.
     /// </summary>
     private static object? ConvertValue (string value, Type targetType)
     {
@@ -269,16 +272,14 @@ private static void BindFlatDottedKeys<T> (IConfiguration config, string section
             return value.Length > 0 ? new Rune (value [0]) : new Rune ('+');
         }
 
-        if (targetType.IsEnum)
+        if (targetType == typeof (Key))
         {
-            return Enum.Parse (targetType, value);
+            return Key.TryParse (value, out Key key) ? key : null;
         }
 
-        TypeConverter converter = TypeDescriptor.GetConverter (targetType);
-
-        if (converter.CanConvertFrom (typeof (string)))
+        if (targetType.IsEnum)
         {
-            return converter.ConvertFromInvariantString (value);
+            return Enum.Parse (targetType, value);
         }
 
         return null;

Tests/UnitTestsParallelizable/Configuration/MecDottedKeyTests.cs

@@ -4,6 +4,7 @@
 using System.Text;
 using Microsoft.Extensions.Configuration;
 using Terminal.Gui.Configuration;
+using Terminal.Gui.Input;
 
 namespace ConfigurationTests;
 
@@ -154,4 +155,28 @@ public void ApplyToStaticFacades_StillBindsNestedSectionFormat ()
             DriverSettings.Defaults = original;
         }
     }
+
+    /// <summary>
+    ///     Verifies issue #5561 fix: a flat dotted <see cref="Key"/> key (<c>PopoverMenu.DefaultKey</c>) binds via
+    ///     the AOT-safe <see cref="Key"/> fast path — i.e. without the trim-unsafe <c>TypeDescriptor.GetConverter</c>
+    ///     fallback that was removed.
+    /// </summary>
+    [Fact]
+    public void ApplyToStaticFacades_BindsFlatDottedKeyTypedProperty ()
+    {
+        PopoverMenuSettings original = PopoverMenuSettings.Defaults;
+
+        try
+        {
+            TuiConfigurationBuilder builder = new ();
+            builder.RuntimeConfig = """{ "PopoverMenu.DefaultKey": "Ctrl+P" }""";
+            builder.ApplyToStaticFacades ();
+
+            Assert.Equal (Key.P.WithCtrl, PopoverMenuSettings.Defaults.DefaultKey);
+        }
+        finally
+        {
+            PopoverMenuSettings.Defaults = original;
+        }
+    }
 }