Feature Add OutputScheduler to ReactiveCommand

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2023-2025 ReactiveUI
+Copyright (c) ReactiveUI 2023-2025
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -16,6 +16,8 @@ ReactiveUI Source Generators automatically generate ReactiveUI objects to stream
 - `[ObservableAsProperty(PropertyName = "ReadOnlyPropertyName")]`
 - `[ReactiveCommand]`
 - `[ReactiveCommand(CanExecute = nameof(IObservableBoolName))]` with CanExecute
+- `[ReactiveCommand(OutputScheduler = "RxApp.MainThreadScheduler")]` using a ReactiveUI Scheduler
+- `[ReactiveCommand(OutputScheduler = nameof(_isheduler))]` using a Scheduler defined in the class
 - `[ReactiveCommand][property: AttributeToAddToCommand]` with Attribute passthrough
 - `[IViewFor(nameof(ViewModelName))]`
 - `[RoutedControlHost("YourNameSpace.CustomControl")]`
@@ -411,6 +413,30 @@ public partial class MyReactiveClass
 }
 ```
 
+### Usage ReactiveCommand with ReactiveUI OutputScheduler
+```csharp
+using ReactiveUI.SourceGenerators;
+
+public partial class MyReactiveClass
+{
+    [ReactiveCommand(OutputScheduler = "RxApp.MainThreadScheduler")]
+    private void Execute() { }
+}
+```
+
+### Usage ReactiveCommand with custom OutputScheduler
+```csharp
+using ReactiveUI.SourceGenerators;
+
+public partial class MyReactiveClass
+{
+    private IScheduler _customScheduler = new TestScheduler();
+
+    [ReactiveCommand(OutputScheduler = nameof(_customScheduler))]
+    private void Execute() { }
+}
+```
+
 ## Usage IViewFor `[IViewFor(nameof(ViewModelName))]`
 
 ### IViewFor usage

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveAsyncCommand#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -25,6 +25,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveAsyncCommandWithParameter#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -25,6 +25,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveCommand#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -25,6 +25,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveCommandWithNestedClasses#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -25,6 +25,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveCommandWithOutputScheduler#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -0,0 +1,38 @@
+//HintName: ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.cs
+// Copyright (c) 2025 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System;
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// ReativeCommandAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
+internal sealed class ReactiveCommandAttribute : Attribute
+{
+    /// <summary>
+    /// Gets the can execute method or property.
+    /// </summary>
+    /// <value>
+    /// The name of the CanExecute Observable of bool.
+    /// </value>
+    public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/REACTIVECMD/ReactiveCMDGeneratorTests.FromReactiveCommandWithParameter#ReactiveUI.SourceGenerators.ReactiveCommandAttribute.g.verified.cs

@@ -25,6 +25,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/UnitTests/ReactiveCMDGeneratorTests.cs

@@ -134,6 +134,32 @@ private async Task Test3(string baseString)
         return TestHelper.TestPass(sourceCode);
     }
 
+    /// <summary>
+    /// Froms the reactive command with output scheduler.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Fact]
+    public Task FromReactiveCommandWithOutputScheduler()
+    {
+        // Arrange: Setup the source code that matches the generator input expectations.
+        const string sourceCode = """
+                using System;
+                using ReactiveUI;
+                using ReactiveUI.SourceGenerators;
+                using System.Reactive.Linq;
+                using System.Threading.Tasks;
+                namespace TestNs;
+                public partial class TestVM : ReactiveObject
+                {
+                    [ReactiveCommand(OutputScheduler = "RxApp.MainThreadScheduler")]
+                    private int Test1() => 10;
+                }
+            """;
+
+        // Act: Initialize the helper and run the generator. Assert: Verify the generated code.
+        return TestHelper.TestPass(sourceCode);
+    }
+
     /// <summary>
     /// Froms the reactive command with nested classes.
     /// </summary>

src/ReactiveUI.SourceGenerators.Execute/Program.cs

@@ -13,5 +13,5 @@ public static class Program
     /// <summary>
     /// Defines the entry point of the application.
     /// </summary>
-    public static void Main() => _ = TestViewModel.Instance;
+    public static void Main() => Application.Run(new TestViewWinForms());
 }

src/ReactiveUI.SourceGenerators.Execute/TestViewModel.cs

@@ -5,6 +5,7 @@
 
 using System.Diagnostics.CodeAnalysis;
 using System.Reactive;
+using System.Reactive.Concurrency;
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
@@ -28,6 +29,8 @@ public partial class TestViewModel : ReactiveObject, IActivatableViewModel, IDis
     private readonly Subject<double?> _testSubject = new();
     private readonly Subject<double> _testNonNullSubject = new();
 
+    private IScheduler _scheduler = RxApp.MainThreadScheduler;
+
     [property: JsonInclude]
     [DataMember]
     [ObservableAsProperty]
@@ -74,6 +77,8 @@ public TestViewModel()
         {
             Console.Out.WriteLine("Activated");
             _test11PropertyHelper = this.WhenAnyValue(x => x.Test12Property).ToProperty(this, x => x.Test11Property, out _).DisposeWith(disposables);
+            GetDataCommand.Do(_ => Console.Out.WriteLine("GetDataCommand Executed")).Subscribe().DisposeWith(disposables);
+            GetDataCommand.Execute().Subscribe().DisposeWith(disposables);
         });
 
         Console.Out.WriteLine("MyReadOnlyProperty before init");
@@ -362,6 +367,10 @@ protected virtual void Dispose(bool disposing)
     [ReactiveCommand]
     private async Task<Point> Test10Async(int size, CancellationToken ct) => await Task.FromResult(new Point(size, size));
 
-    [ReactiveCommand(CanExecute = nameof(_observable))]
+    [ReactiveCommand(CanExecute = nameof(_observable), OutputScheduler = nameof(_scheduler))]
     private void TestPrivateCanExecute() => Console.Out.WriteLine("TestPrivateCanExecute");
+
+    [ReactiveCommand]
+    private Task<System.Collections.IEnumerable> GetData(CancellationToken ct) =>
+        Task.FromResult<System.Collections.IEnumerable>(Array.Empty<System.Collections.IEnumerable>());
 }

src/ReactiveUI.SourceGenerators.Execute/TestViewWinForms.cs

@@ -21,6 +21,7 @@ public TestViewWinForms()
         {
             InitializeComponent();
             ViewModel = TestViewModel.Instance;
+            ViewModel.Activator.Activate();
         }
     }
 }

src/ReactiveUI.SourceGenerators/AttributeDefinitions.cs

@@ -82,6 +82,12 @@ internal sealed class ReactiveObjectAttribute : Attribute;
 
     public const string ReactiveCommandAttributeType = "ReactiveUI.SourceGenerators.ReactiveCommandAttribute";
 
+    /// <summary>
+    /// Gets the reactive command attribute.
+    /// </summary>
+    /// <value>
+    /// The reactive command attribute.
+    /// </value>
     public static string ReactiveCommandAttribute => $$"""
 // Copyright (c) {{DateTime.Now.Year}} .NET Foundation and Contributors. All rights reserved.
 // Licensed to the .NET Foundation under one or more agreements.
@@ -110,6 +116,14 @@ internal sealed class ReactiveCommandAttribute : Attribute
     /// The name of the CanExecute Observable of bool.
     /// </value>
     public string? CanExecute { get; init; }
+
+    /// <summary>
+    /// Gets the output scheduler.
+    /// </summary>
+    /// <value>
+    /// The output scheduler.
+    /// </value>
+    public string? OutputScheduler { get; init; }
 }
 #nullable restore
 #pragma warning restore

src/ReactiveUI.SourceGenerators/Core/Extensions/ITypeSymbolExtensions.cs

@@ -172,6 +172,23 @@ public static bool IsObservableReturnType(this ITypeSymbol? typeSymbol)
         return false;
     }
 
+    public static bool IsIShedulerType(this ITypeSymbol? typeSymbol)
+    {
+        var nameFormat = SymbolDisplayFormat.FullyQualifiedFormat;
+        do
+        {
+            var typeName = typeSymbol?.ToDisplayString(nameFormat);
+            if (typeName == "global::System.Reactive.Concurrency.IScheduler")
+            {
+                return true;
+            }
+
+            typeSymbol = typeSymbol?.BaseType;
+        }
+        while (typeSymbol != null);
+        return false;
+    }
+
     public static bool IsObservableBoolType(this ITypeSymbol? typeSymbol)
     {
         var nameFormat = SymbolDisplayFormat.FullyQualifiedFormat;

src/ReactiveUI.SourceGenerators/ReactiveCommand/Models/CommandInfo.cs

@@ -18,6 +18,7 @@ internal record CommandInfo(
     bool IsObservable,
     string? CanExecuteObservableName,
     CanExecuteTypeInfo? CanExecuteTypeInfo,
+    string? OutputScheduler,
     EquatableArray<string> ForwardedPropertyAttributes)
 {
     private const string UnitTypeName = "global::System.Reactive.Unit";