Fix for OAPH nullability for reference types

src/ReactiveUI.SourceGenerator.Tests/OAPH/OAPFromObservableGeneratorTests.FromObservablePropertiesWithAttributeNullableRef#ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute.g.verified.cs

@@ -0,0 +1,38 @@
+//HintName: ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute.g.cs
+// Copyright (c) 2024 .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>
+/// ObservableAsPropertyAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
+internal sealed class ObservableAsPropertyAttribute : Attribute
+{
+    /// <summary>
+    /// Gets the name of the property.
+    /// </summary>
+    /// <value>
+    /// The name of the property.
+    /// </value>
+    public string? PropertyName { get; init; }
+
+    /// <summary>
+    /// Gets the Readonly state of the OAPH property.
+    /// </summary>
+    /// <value>
+    /// The is read only of the OAPH property.
+    /// </value>
+    public bool ReadOnly { get; init; } = true;
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/OAPH/OAPFromObservableGeneratorTests.FromObservablePropertiesWithAttributeNullableRef#TestVM.ObservableAsPropertyFromObservable.g.verified.cs

@@ -0,0 +1,34 @@
+//HintName: TestVM.ObservableAsPropertyFromObservable.g.cs
+// <auto-generated/>
+using ReactiveUI;
+
+#pragma warning disable
+#nullable enable
+
+namespace TestNs
+{
+    /// <summary>
+    /// Partial class for the TestVM which contains ReactiveUI Reactive property initialization.
+    /// </summary>
+    public partial class TestVM
+    {
+        /// <inheritdoc cref="Test7Property"/>
+        private object? _test7Property;
+
+        /// <inheritdoc cref="_test7PropertyHelper"/>
+        private ReactiveUI.ObservableAsPropertyHelper<object?>? _test7PropertyHelper;
+
+        /// <inheritdoc cref="_test7Property"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        [global::System.Text.Json.Serialization.JsonIncludeAttribute()]
+        public object? Test7Property { get => _test7Property = (_test7PropertyHelper == null ? _test7Property : _test7PropertyHelper.Value); }
+
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        protected void InitializeOAPH()
+        {
+            _test7PropertyHelper = Test7!.ToProperty(this, nameof(Test7Property));
+        }
+    }
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/OAPH/OAPFromObservableGeneratorTests.FromObservablePropertiesWithAttributeRef#ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute.g.verified.cs

@@ -0,0 +1,38 @@
+//HintName: ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute.g.cs
+// Copyright (c) 2024 .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>
+/// ObservableAsPropertyAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property | AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
+internal sealed class ObservableAsPropertyAttribute : Attribute
+{
+    /// <summary>
+    /// Gets the name of the property.
+    /// </summary>
+    /// <value>
+    /// The name of the property.
+    /// </value>
+    public string? PropertyName { get; init; }
+
+    /// <summary>
+    /// Gets the Readonly state of the OAPH property.
+    /// </summary>
+    /// <value>
+    /// The is read only of the OAPH property.
+    /// </value>
+    public bool ReadOnly { get; init; } = true;
+}
+#nullable restore
+#pragma warning restore

src/ReactiveUI.SourceGenerator.Tests/OAPH/OAPFromObservableGeneratorTests.FromObservablePropertiesWithAttributeRef#TestVM.ObservableAsPropertyFromObservable.g.verified.cs

@@ -0,0 +1,34 @@
+//HintName: TestVM.ObservableAsPropertyFromObservable.g.cs
+// <auto-generated/>
+using ReactiveUI;
+
+#pragma warning disable
+#nullable enable
+
+namespace TestNs
+{
+    /// <summary>
+    /// Partial class for the TestVM which contains ReactiveUI Reactive property initialization.
+    /// </summary>
+    public partial class TestVM
+    {
+        /// <inheritdoc cref="Test6Property"/>
+        private object _test6Property;
+
+        /// <inheritdoc cref="_test6PropertyHelper"/>
+        private ReactiveUI.ObservableAsPropertyHelper<object>? _test6PropertyHelper;
+
+        /// <inheritdoc cref="_test6Property"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        [global::System.Text.Json.Serialization.JsonIncludeAttribute()]
+        public object Test6Property { get => _test6Property = _test6PropertyHelper?.Value ?? _test6Property; }
+
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        protected void InitializeOAPH()
+        {
+            _test6PropertyHelper = Test6!.ToProperty(this, nameof(Test6Property));
+        }
+    }
+}
+#nullable restore
+#pragma warning restore

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

@@ -169,5 +169,73 @@ public partial class TestVM : ReactiveObject
         return VerifyGenerator(driver);
     }
 
+    /// <summary>
+    /// Tests that the source generator correctly generates observable properties.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Fact]
+    public Task FromObservablePropertiesWithAttributeRef()
+    {
+        // Arrange: Setup the source code that matches the generator input expectations.
+        const string sourceCode = """
+                using System;
+                using System.Runtime.Serialization;
+                using System.Text.Json.Serialization;
+                using ReactiveUI;
+                using ReactiveUI.SourceGenerators;
+                using System.Reactive.Linq;
+
+                namespace TestNs;
+
+                public partial class TestVM : ReactiveObject
+                {
+                    [ObservableAsProperty(PropertyName = "MyNamedProperty")]
+                    [property: JsonInclude]
+                    [DataMember]
+                    public IObservable<object> Test6 => Observable.Return(new object());
+                }
+            """;
+
+        // Act: Initialize the helper and run the generator.
+        var driver = TestHelper.TestPass(sourceCode);
+
+        // Assert: Verify the generated code.
+        return VerifyGenerator(driver);
+    }
+
+    /// <summary>
+    /// Tests that the source generator correctly generates observable properties.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Fact]
+    public Task FromObservablePropertiesWithAttributeNullableRef()
+    {
+        // Arrange: Setup the source code that matches the generator input expectations.
+        const string sourceCode = """
+                using System;
+                using System.Runtime.Serialization;
+                using System.Text.Json.Serialization;
+                using ReactiveUI;
+                using ReactiveUI.SourceGenerators;
+                using System.Reactive.Linq;
+
+                namespace TestNs;
+
+                public partial class TestVM : ReactiveObject
+                {
+                    [ObservableAsProperty(PropertyName = "MyNamedProperty")]
+                    [property: JsonInclude]
+                    [DataMember]
+                    public IObservable<object?> Test7 => Observable.Return(new object());
+                }
+            """;
+
+        // Act: Initialize the helper and run the generator.
+        var driver = TestHelper.TestPass(sourceCode);
+
+        // Assert: Verify the generated code.
+        return VerifyGenerator(driver);
+    }
+
     private SettingsTask VerifyGenerator(GeneratorDriver driver) => Verify(driver).UseDirectory(TestHelper.VerifiedFilePath()).ScrubLinesContaining("[global::System.CodeDom.Compiler.GeneratedCode(\"");
 }

src/ReactiveUI.SourceGenerators.Execute.Nested1/Class1.cs

@@ -0,0 +1,18 @@
+// Copyright (c) 2024 .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 ReactiveUI;
+using ReactiveUI.SourceGenerators;
+
+namespace SGReactiveUI.SourceGenerators.Execute.Nested1;
+
+/// <summary>
+/// Class1.
+/// </summary>
+public partial class Class1 : ReactiveObject
+{
+    [Reactive]
+    private string? _property1;
+}

src/ReactiveUI.SourceGenerators.Execute.Nested1/ReactiveUI.SourceGenerators.Execute.Nested1.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators\ReactiveUI.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="ReactiveUI" />
+  </ItemGroup>
+
+</Project>

src/ReactiveUI.SourceGenerators.Execute.Nested2/Class1.cs

@@ -0,0 +1,18 @@
+// Copyright (c) 2024 .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 ReactiveUI;
+using ReactiveUI.SourceGenerators;
+
+namespace SGReactiveUI.SourceGenerators.Execute.Nested2;
+
+/// <summary>
+/// Class1.
+/// </summary>
+public partial class Class1 : ReactiveObject
+{
+    [Reactive]
+    private string? _property1;
+}

src/ReactiveUI.SourceGenerators.Execute.Nested2/ReactiveUI.SourceGenerators.Execute.Nested2.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators\ReactiveUI.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators.Execute.Nested1\ReactiveUI.SourceGenerators.Execute.Nested1.csproj" />
+  </ItemGroup>
+
+</Project>

src/ReactiveUI.SourceGenerators.Execute.Nested3/Class1.cs

@@ -0,0 +1,18 @@
+// Copyright (c) 2024 .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 ReactiveUI;
+using ReactiveUI.SourceGenerators;
+
+namespace SGReactiveUI.SourceGenerators.Execute.Nested3;
+
+/// <summary>
+/// Class1.
+/// </summary>
+public partial class Class1 : ReactiveObject
+{
+    [Reactive]
+    private string? _property1;
+}

src/ReactiveUI.SourceGenerators.Execute.Nested3/ReactiveUI.SourceGenerators.Execute.Nested3.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <LangVersion>12.0</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators\ReactiveUI.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators.Execute.Nested2\ReactiveUI.SourceGenerators.Execute.Nested2.csproj" />
+  </ItemGroup>
+
+</Project>

src/ReactiveUI.SourceGenerators.Execute/TestViewModel.cs

@@ -84,6 +84,11 @@ public TestViewModel()
         _observableAsPropertyTest2Property = 11223344;
         Console.Out.WriteLine(ObservableAsPropertyTest2Property);
         Console.Out.WriteLine(_observableAsPropertyTest2Property);
+
+        _referenceTypeObservableProperty = default!;
+        ReferenceTypeObservable = Observable.Return(new object());
+        NullableReferenceTypeObservable = Observable.Return(new object());
+
         InitializeOAPH();
 
         Console.Out.WriteLine(Test1Command);
@@ -239,6 +244,12 @@ public TestViewModel()
     /// </summary>
     public ViewModelActivator Activator { get; } = new();
 
+    [ObservableAsProperty]
+    private IObservable<object> ReferenceTypeObservable { get; }
+
+    [ObservableAsProperty]
+    private IObservable<object?> NullableReferenceTypeObservable { get; }
+
     /// <summary>
     /// Gets observables as property test.
     /// </summary>