Fix for Memory Leak

#659

samples/Directory.build.props

@@ -2,7 +2,6 @@
   <PropertyGroup>
     <Nullable>enable</Nullable>
     <AvaloniaVersion>11.0.10</AvaloniaVersion>
-    <CodeAnalysisRuleSet>$(MSBuildThisFileDirectory)..\src\analyzers.ruleset</CodeAnalysisRuleSet>
     <WarningsAsErrors>CS8600;CS8602;CS8603;CS8604;CS8605;CS8606;CS8607;CS8608;CS8609;CS8610;CS8611;CS8612;CS8613;CS8614;CS8615;CS8616;CS8617;CS8618;CS8619;CS8620;CS8621;CS8622;CS8623;CS8624;CS8625</WarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>

src/Directory.build.props

@@ -1,48 +1,52 @@
-<Project>  
-  <PropertyGroup>
-    <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
-    <Product>ReactiveUI.Validations ($(TargetFramework))</Product>
-    <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <PackageProjectUrl>https://github.com/reactiveui/ReactiveUI.Validation/</PackageProjectUrl>
-    <PackageIconUrl>https://github.com/reactiveui/ReactiveUI.Validation/blob/master/media/logo.png?raw=true</PackageIconUrl>
-    <Authors>.NET Foundation and Contributors</Authors>
-    <Description>Validations library for ReactiveUI.</Description>
-    <Owners>xpaulbettsx;ghuntley</Owners>
-    <PackageTags>reactiveui;validation library;reactive programming;xamarin forms;netcore;portable;xamarin;xamarin ios;xamarin mac;android;monodroid;uwp;net45</PackageTags>
-    <PackageReleaseNotes>https://github.com/reactiveui/reactiveui.validation/releases</PackageReleaseNotes>
-    <RepositoryUrl>https://github.com/reactiveui/reactiveui.validation</RepositoryUrl>
-    <RepositoryType>git</RepositoryType>
-    <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <IsTestProject>$(MSBuildProjectName.Contains('Tests'))</IsTestProject>
-    <DebugType>Embedded</DebugType>
-    <!-- Optional: Publish the repository URL in the built .nupkg (in the NuSpec <Repository> element) -->
-    <PublishRepositoryUrl>true</PublishRepositoryUrl>
-    <!-- Optional: Embed source files that are not tracked by the source control manager in the PDB -->
-    <EmbedUntrackedSources>true</EmbedUntrackedSources>
-    <!-- Optional: Include PDB in the built .nupkg -->
-    <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
-    <CodeAnalysisRuleSet>$(MSBuildThisFileDirectory)analyzers.ruleset</CodeAnalysisRuleSet>
-    <WarningsAsErrors>CS8600;CS8602;CS8603;CS8604;CS8605;CS8606;CS8607;CS8608;CS8609;CS8610;CS8611;CS8612;CS8613;CS8614;CS8615;CS8616;CS8617;CS8618;CS8619;CS8620;CS8621;CS8622;CS8623;CS8624;CS8625</WarningsAsErrors>
-    <LangVersion>preview</LangVersion>
-    <EnableNETAnalyzers>True</EnableNETAnalyzers>
-    <AnalysisLevel>latest</AnalysisLevel>
-  </PropertyGroup>
+<Project>
+	<PropertyGroup>
+		<Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
+		<Product>ReactiveUI.Validations ($(TargetFramework))</Product>
+		<PackageLicenseExpression>MIT</PackageLicenseExpression>
+		<PackageProjectUrl>https://github.com/reactiveui/ReactiveUI.Validation/</PackageProjectUrl>
+		<PackageIconUrl>https://github.com/reactiveui/ReactiveUI.Validation/blob/master/media/logo.png?raw=true</PackageIconUrl>
+		<Authors>.NET Foundation and Contributors</Authors>
+		<Description>Validations library for ReactiveUI.</Description>
+		<Owners>xanaisbettsx;ghuntley</Owners>
+		<PackageTags>reactiveui;validation library;reactive programming;netcore;netstandard;netframework</PackageTags>
+		<PackageIcon>logo.png</PackageIcon>
+		<PackageReadmeFile>README.md</PackageReadmeFile>
+		<PackageReleaseNotes>https://github.com/reactiveui/reactiveui.validation/releases</PackageReleaseNotes>
+		<RepositoryUrl>https://github.com/reactiveui/reactiveui.validation</RepositoryUrl>
+		<RepositoryType>git</RepositoryType>
+		<GenerateDocumentationFile>true</GenerateDocumentationFile>
+		<IsTestProject>$(MSBuildProjectName.Contains('Tests'))</IsTestProject>
+		<DebugType>Embedded</DebugType>
+		<!-- Optional: Publish the repository URL in the built .nupkg (in the NuSpec <Repository> element) -->
+		<PublishRepositoryUrl>true</PublishRepositoryUrl>
+		<!-- Optional: Embed source files that are not tracked by the source control manager in the PDB -->
+		<EmbedUntrackedSources>true</EmbedUntrackedSources>
+		<!-- Optional: Include PDB in the built .nupkg -->
+		<AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
+		<WarningsAsErrors>CS8600;CS8602;CS8603;CS8604;CS8605;CS8606;CS8607;CS8608;CS8609;CS8610;CS8611;CS8612;CS8613;CS8614;CS8615;CS8616;CS8617;CS8618;CS8619;CS8620;CS8621;CS8622;CS8623;CS8624;CS8625</WarningsAsErrors>
+		<LangVersion>preview</LangVersion>
+		<EnableNETAnalyzers>True</EnableNETAnalyzers>
+		<AnalysisLevel>latest</AnalysisLevel>
+		<NoWarn>$(NoWarn);IDE1006</NoWarn>
+	</PropertyGroup>
 
-  <ItemGroup>
-    <None Include="$(MSBuildThisFileDirectory)..\LICENSE" Pack="true" PackagePath="LICENSE" />
-  </ItemGroup>
+	<ItemGroup>
+		<None Include="$(MSBuildThisFileDirectory)..\media\logo.png" Pack="true" PackagePath="\" />
+		<None Include="$(MSBuildThisFileDirectory)..\LICENSE" Pack="true" PackagePath="LICENSE" />
+		<None Include="$(MSBuildThisFileDirectory)..\README.md" Pack="true" PackagePath="\" />
+	</ItemGroup>
 
-  <ItemGroup Condition="'$(IsTestProject)' != 'true'">
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" /> 
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.6.133" PrivateAssets="all" />
-    <PackageReference Include="stylecop.analyzers" Version="1.2.0-beta.556" PrivateAssets="all" />
-    <PackageReference Include="Roslynator.Analyzers" Version="4.12.2" PrivateAssets="All" />
-  </ItemGroup>
-  <ItemGroup>
-    <AdditionalFiles Include="$(MSBuildThisFileDirectory)stylecop.json" Link="stylecop.json" />
-  </ItemGroup>
+	<ItemGroup Condition="'$(IsTestProject)' != 'true'">
+		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
+	</ItemGroup>
+	<ItemGroup>
+		<PackageReference Include="Nerdbank.GitVersioning" Version="3.6.133" PrivateAssets="all" />
+		<PackageReference Include="stylecop.analyzers" Version="1.2.0-beta.556" PrivateAssets="all" />
+		<PackageReference Include="Roslynator.Analyzers" Version="4.12.2" PrivateAssets="All" />
+	</ItemGroup>
+	<ItemGroup>
+		<AdditionalFiles Include="$(MSBuildThisFileDirectory)stylecop.json" Link="stylecop.json" />
+	</ItemGroup>
+
+</Project>
 
- </Project>
-

src/ReactiveUI.Validation.Tests/MemoryLeakTests.cs

@@ -37,28 +37,20 @@ public void Instance_Released_IsGarbageCollected()
         new Action(
             () =>
             {
-                var sut = new TestClassMemory();
+                var memTest = new TestClassMemory();
 
-                reference = new WeakReference(sut, true);
-                sut.Dispose();
+                reference = new WeakReference(memTest, true);
+                memTest.Dispose();
             })();
 
-        // Sut should have gone out of scope about now, so the garbage collector can clean it up
+        // memTest should have gone out of scope about now, so the garbage collector can clean it up
         dotMemory.Check(
             memory => memory.GetObjects(
                 where => where.Type.Is<TestClassMemory>()).ObjectsCount.Should().Be(0, "it is out of scope"));
 
         GC.Collect();
         GC.WaitForPendingFinalizers();
 
-        if (reference.Target is TestClassMemory sut)
-        {
-            // ReactiveObject does not inherit from IDisposable, so we need to check ValidationContext
-            sut.ValidationContext.Should().BeNull("it is garbage collected");
-        }
-        else
-        {
-            reference.Target.Should().BeNull("it is garbage collected");
-        }
+        reference.Target.Should().BeNull("it is garbage collected");
     }
 }

src/ReactiveUI.Validation.Tests/Models/TestClassMemory.cs

@@ -31,7 +31,7 @@ public TestClassMemory()
             .DisposeWith(_disposable);
 
         // commenting out the following statement makes the test green
-        ValidationContext.ValidationStatusChange
+        ValidationContext?.ValidationStatusChange
             .Subscribe(/* you do something here, but this does not matter for now. */)
             .DisposeWith(_disposable);
     }

src/ReactiveUI.Validation.Tests/ValidationContextTests.cs

@@ -125,14 +125,15 @@ public void IsValidShouldNotifyOfValidityChange()
         viewModel.ValidationContext.Add(nameValidation);
 
         var latestValidity = false;
-        viewModel.IsValid().Subscribe(isValid => latestValidity = isValid);
+        var d = viewModel.IsValid().Subscribe(isValid => latestValidity = isValid);
         Assert.False(latestValidity);
 
         viewModel.Name = "Jonathan";
         Assert.True(latestValidity);
 
         viewModel.Name = string.Empty;
         Assert.False(latestValidity);
+        d.Dispose();
     }
 
     /// <summary>
@@ -220,4 +221,4 @@ public void ShouldClearAttachedValidationRulesForTheGivenProperty()
         Assert.NotEmpty(viewModel.ValidationContext.Text);
         Assert.Equal(name2ErrorMessage, viewModel.ValidationContext.Text.ToSingleLine());
     }
-}
+}

src/ReactiveUI.Validation/Contexts/ValidationContext.cs

@@ -6,7 +6,6 @@
 using System;
 using System.Buffers;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reactive.Concurrency;
 using System.Reactive.Disposables;
@@ -31,15 +30,17 @@ namespace ReactiveUI.Validation.Contexts;
 /// </remarks>
 public class ValidationContext : ReactiveObject, IValidationContext
 {
+    private static readonly CompositeDisposable _collectionDisposables = [];
+    private readonly CompositeDisposable _disposables = [];
+
     private readonly ReplaySubject<IValidationState> _validationStatusChange = new(1);
     private readonly ReplaySubject<bool> _validSubject = new(1);
 
-    private readonly IConnectableObservable<bool> _validationConnectable;
+    private readonly IObservable<bool> _validationObservable;
     private readonly ObservableAsPropertyHelper<IValidationText> _validationText;
     private readonly ObservableAsPropertyHelper<bool> _isValid;
 
-    private readonly CompositeDisposable _disposables = [];
-    private SourceList<IValidationComponent> _validationSource = new();
+    private readonly SourceList<IValidationComponent> _validationSource = new();
     private bool _isActive;
 
     /// <summary>
@@ -52,15 +53,15 @@ public ValidationContext(IScheduler? scheduler = null)
         var changeSets = _validationSource.Connect().ObserveOn(scheduler);
         Validations = changeSets.AsObservableList();
 
-        _validationConnectable = changeSets
+        _validationObservable = changeSets
             .StartWithEmpty()
             .AutoRefreshOnObservable(x => x.ValidationStatusChange)
             .QueryWhenChanged(static x =>
                 {
                     using ReadOnlyCollectionPooled<IValidationComponent> validationComponents = new(x);
+                    validationComponents.DisposeWith(_collectionDisposables);
                     return validationComponents.Count is 0 || validationComponents.All(v => v.IsValid);
-                })
-            .Multicast(_validSubject);
+                });
 
         _isValid = _validSubject
             .StartWith(true)
@@ -95,7 +96,7 @@ public IObservable<bool> Valid
     /// <summary>
     /// Gets get the list of validations.
     /// </summary>
-    public IObservableList<IValidationComponent> Validations { get; private set; }
+    public IObservableList<IValidationComponent> Validations { get; }
 
     /// <inheritdoc/>
     public bool IsValid
@@ -183,11 +184,9 @@ protected virtual void Dispose(bool disposing)
             _validationStatusChange.Dispose();
             _validSubject.Dispose();
             _validationSource.Clear();
-            Validations.Dispose();
             _validationSource.Dispose();
-
-            Validations = null!;
-            _validationSource = null!;
+            Validations.Dispose();
+            _collectionDisposables.Dispose();
         }
     }
 
@@ -199,7 +198,7 @@ private void Activate()
         }
 
         _isActive = true;
-        _disposables.Add(_validationConnectable.Connect());
+        _disposables.Add(_validationObservable.Subscribe(_validSubject));
     }
 
     /// <summary>

src/ReactiveUI.Validation/Helpers/ReactiveValidationObject.cs

@@ -27,9 +27,9 @@ namespace ReactiveUI.Validation.Helpers;
 /// </summary>
 public abstract class ReactiveValidationObject : ReactiveObject, IValidatableViewModel, INotifyDataErrorInfo, IDisposable
 {
-    private CompositeDisposable _disposables = [];
-    private IValidationTextFormatter<string> _formatter;
-    private HashSet<string> _mentionedPropertyNames = [];
+    private readonly CompositeDisposable _disposables = [];
+    private readonly IValidationTextFormatter<string> _formatter;
+    private readonly HashSet<string> _mentionedPropertyNames = [];
     private bool _hasErrors;
 
     /// <summary>
@@ -77,7 +77,7 @@ public bool HasErrors
     }
 
     /// <inheritdoc />
-    public IValidationContext ValidationContext { get; private set; }
+    public IValidationContext ValidationContext { get; }
 
     /// <summary>
     /// Returns a collection of error messages, required by the INotifyDataErrorInfo interface.
@@ -121,11 +121,8 @@ protected virtual void Dispose(bool disposing)
         if (!_disposables.IsDisposed && disposing)
         {
             _disposables.Dispose();
+            ValidationContext.Dispose();
             _mentionedPropertyNames.Clear();
-            _formatter = null!;
-            _mentionedPropertyNames = null!;
-            _disposables = null!;
-            ValidationContext = null!;
         }
     }