Make source generators culture invariant

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.Execute.cs

@@ -4,6 +4,7 @@
 
 using System.Collections.Immutable;
 using System.ComponentModel;
+using System.Globalization;
 using System.Linq;
 using CommunityToolkit.Mvvm.SourceGenerators.ComponentModel.Models;
 using CommunityToolkit.Mvvm.SourceGenerators.Diagnostics;
@@ -756,7 +757,7 @@ public static string GetGeneratedPropertyName(IFieldSymbol fieldSymbol)
                 propertyName = propertyName.TrimStart('_');
             }
 
-            return $"{char.ToUpper(propertyName[0])}{propertyName.Substring(1)}";
+            return $"{char.ToUpper(propertyName[0], CultureInfo.InvariantCulture)}{propertyName.Substring(1)}";
         }
     }
 }

CommunityToolkit.Mvvm.SourceGenerators/Input/ICommandGenerator.Execute.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
 using System.Linq;
 using CommunityToolkit.Mvvm.SourceGenerators.Diagnostics;
 using CommunityToolkit.Mvvm.SourceGenerators.Extensions;
@@ -358,7 +359,7 @@ public static (string FieldName, string PropertyName) GetGeneratedFieldAndProper
 
             propertyName += "Command";
 
-            string fieldName = $"{char.ToLower(propertyName[0])}{propertyName.Substring(1)}";
+            string fieldName = $"{char.ToLower(propertyName[0], CultureInfo.InvariantCulture)}{propertyName.Substring(1)}";
 
             return (fieldName, propertyName);
         }

tests/CommunityToolkit.Mvvm.UnitTests/Test_ICommandAttribute.cs

@@ -462,6 +462,16 @@ public async Task Test_ICommandAttribute_TaskOfTReturns()
         Assert.AreEqual("Hello world", await (Task<string>)greetWithParamAndCommandTask);
     }
 
+    // See https://github.com/CommunityToolkit/dotnet/issues/230
+    [TestMethod]
+    public void Test_ICommandAttribute_CultureAwareCommandName()
+    {
+        ModelWithCultureAwareCommandName model = new();
+
+        // This just needs to ensure it compiles, really
+        model.InitializeCommand.Execute(null);
+    }
+
     #region Region
     public class Region
     {
@@ -787,4 +797,13 @@ private async Task<string> GreetWithParamAndTokenAsync(object _, CancellationTok
             return "Hello world";
         }
     }
+
+    partial class ModelWithCultureAwareCommandName
+    {
+        // This starts with "I" to ensure it's converted to lowercase using invariant culture
+        [ICommand]
+        private void Initialize()
+        {
+        }
+    }
 }

tests/CommunityToolkit.Mvvm.UnitTests/Test_ObservablePropertyAttribute.cs

@@ -591,6 +591,23 @@ public void Test_ObservableProperty_WithBaseViewModelWithObservableObjectAttribu
         CollectionAssert.AreEqual(new[] { nameof(model.MyProperty), nameof(model.OtherProperty) }, propertyNames);
     }
 
+    // See https://github.com/CommunityToolkit/dotnet/issues/230
+    [TestMethod]
+    public void Test_ObservableProperty_ModelWithCultureAwarePropertyName()
+    {
+        ModelWithCultureAwarePropertyName model = new();
+
+        List<string?> propertyNames = new();
+
+        model.PropertyChanged += (s, e) => propertyNames.Add(e.PropertyName);
+
+        model.InputFolder = 42;
+
+        Assert.AreEqual(model.InputFolder, 42);
+
+        CollectionAssert.AreEqual(new[] { nameof(model.InputFolder) }, propertyNames);
+    }
+
     public abstract partial class BaseViewModel : ObservableObject
     {
         public string? Content { get; set; }
@@ -965,4 +982,13 @@ partial class ModelWithMultipleGenericParameters<T, U> : ObservableObject, IValu
         [ObservableProperty]
         private List<T>? list;
     }
+
+    [ObservableObject]
+    partial class ModelWithCultureAwarePropertyName
+    {
+        // This starts with "i" as it's one of the characters that can change when converted to uppercase.
+        // For instance, when using the Turkish language pack, this would become "İnputFolder" if done wrong.
+        [ObservableProperty]
+        private int _inputFolder;
+    }
 }