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Merge pull request #1081 from CommunityToolkit/user/sergiopedri/handle-canexecute-overrides
Handle 'CanExecute' with method overrides
2 parents 95043f5 + 7d4d6ec commit 2388b9a

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-2
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5 files changed

+224
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lines changed

‎src/CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.projitems‎

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@@ -74,6 +74,7 @@
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\GeneratorAttributeSyntaxContextWithOptions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\IncrementalGeneratorInitializationContextExtensions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\IncrementalValuesProviderExtensions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\IMethodSymbolExtensions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\MethodDeclarationSyntaxExtensions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\SymbolInfoExtensions.cs" />
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<Compile Include="$(MSBuildThisFileDirectory)Extensions\ISymbolExtensions.cs" />

‎src/CommunityToolkit.Mvvm.SourceGenerators/Extensions/IMethodSymbolExtensions.cs‎

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@@ -0,0 +1,78 @@
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// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT license.
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// See the LICENSE file in the project root for more information.
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using System.Collections.Immutable;
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using System.Linq;
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using Microsoft.CodeAnalysis;
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namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
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/// <summary>
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/// Extension methods for the <see cref="IMethodSymbol"/> type.
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/// </summary>
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internal static class IMethodSymbolExtensions
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{
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/// <summary>
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/// Checks whether all input symbols are <see cref="IMethodSymbol"/>-s in the same override hierarchy.
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/// </summary>
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/// <param name="symbols">The input <see cref="ISymbol"/> set to check.</param>
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/// <returns>Whether all input symbols are <see cref="IMethodSymbol"/>-s in the same override hierarchy.</returns>
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public static bool AreAllInSameOverriddenMethodHierarchy(this ImmutableArray<ISymbol> symbols)
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{
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IMethodSymbol? baseSymbol = null;
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// Look for the base method
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foreach (ISymbol currentSymbol in symbols)
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{
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// If any input symbol is not a method, we can stop right away
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if (currentSymbol is not IMethodSymbol methodSymbol)
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{
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return false;
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}
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if (methodSymbol.IsVirtual)
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{
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// If we already found a base method, all methods can't possibly be in the same hierarchy
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if (baseSymbol is not null)
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{
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return false;
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}
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baseSymbol = methodSymbol;
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}
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}
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// If we didn't find any, stop here
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if (baseSymbol is null)
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{
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return false;
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}
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// Verify all methods are in the same tree
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foreach (ISymbol currentSymbol in symbols)
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{
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IMethodSymbol methodSymbol = (IMethodSymbol)currentSymbol;
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// Ignore the base method
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if (SymbolEqualityComparer.Default.Equals(methodSymbol, baseSymbol))
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{
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continue;
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}
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// If the current method isn't an override, then fail
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if (methodSymbol.OverriddenMethod is not { } overriddenMethod)
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{
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return false;
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}
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// The current method must be overriding another one in the set
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if (!symbols.Any(symbol => SymbolEqualityComparer.Default.Equals(symbol, overriddenMethod)))
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{
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return false;
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}
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}
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return true;
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}
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}

‎src/CommunityToolkit.Mvvm.SourceGenerators/Input/RelayCommandGenerator.Execute.cs‎

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@@ -810,8 +810,10 @@ private static bool TryGetCanExecuteExpressionType(
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diagnostics.Add(InvalidCanExecuteMemberNameError, methodSymbol, memberName, methodSymbol.ContainingType);
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}
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else if (canExecuteSymbols.Length > 1)
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else if (canExecuteSymbols.Length > 1 && !canExecuteSymbols.AreAllInSameOverriddenMethodHierarchy())
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{
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// We specifically allow targeting methods which are overridden: they'll be more than one,
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// but it doesn't matter since you'd only ever call "one", being the most derived one.
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diagnostics.Add(MultipleCanExecuteMemberNameMatchesError, methodSymbol, memberName, methodSymbol.ContainingType);
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}
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else if (TryGetCanExecuteExpressionFromSymbol(canExecuteSymbols[0], commandTypeArguments, out canExecuteExpressionType))

‎tests/CommunityToolkit.Mvvm.SourceGenerators.UnitTests/Test_SourceGeneratorsCodegen.cs‎

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@@ -2060,6 +2060,60 @@ partial class MyViewModel
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VerifyGenerateSources(source, new[] { new RelayCommandGenerator() }, ("MyViewModel.Test.g.cs", result));
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}
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[TestMethod]
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public void RelayCommandWithOverriddenCanExecute_TargetsOverriddenMethod()
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{
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string source = """
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using CommunityToolkit.Mvvm.ComponentModel;
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using CommunityToolkit.Mvvm.Input;
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namespace MyApp;
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public partial class BaseViewModel : ObservableObject
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{
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protected virtual bool CanDoStuff()
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{
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return false;
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}
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}
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public partial class SampleViewModel : BaseViewModel
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{
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[RelayCommand(CanExecute = nameof(CanDoStuff)]
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private void DoStuff()
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{
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}
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protected override bool CanDoStuff()
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{
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return true;
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}
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}
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""";
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string result = """
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// <auto-generated/>
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#pragma warning disable
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#nullable enable
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namespace MyApp
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{
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/// <inheritdoc/>
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partial class SampleViewModel
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{
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/// <summary>The backing field for <see cref="DoStuffCommand"/>.</summary>
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[global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator", <ASSEMBLY_VERSION>)]
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private global::CommunityToolkit.Mvvm.Input.RelayCommand? doStuffCommand;
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/// <summary>Gets an <see cref="global::CommunityToolkit.Mvvm.Input.IRelayCommand"/> instance wrapping <see cref="DoStuff"/>.</summary>
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[global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator", <ASSEMBLY_VERSION>)]
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[global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
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public global::CommunityToolkit.Mvvm.Input.IRelayCommand DoStuffCommand => doStuffCommand ??= new global::CommunityToolkit.Mvvm.Input.RelayCommand(new global::System.Action(DoStuff), CanDoStuff);
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}
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}
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""";
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VerifyGenerateSources(source, new[] { new RelayCommandGenerator() }, ("MyApp.SampleViewModel.DoStuff.g.cs", result));
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}
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[TestMethod]
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public void ObservableProperty_AnnotatedFieldHasValueIdentifier()
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{

‎tests/CommunityToolkit.Mvvm.SourceGenerators.UnitTests/Test_SourceGeneratorsDiagnostics.cs‎

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@@ -2259,6 +2259,80 @@ await CSharpAnalyzerWithLanguageVersionTest<WinRTRelayCommandIsNotGeneratedBinda
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editorconfig: [("_MvvmToolkitIsUsingWindowsRuntimePack", true)]);
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}
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[TestMethod]
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public void RelayCommandWithOverriddenCanExecute_DoesNotWarn()
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{
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const string source = """
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using CommunityToolkit.Mvvm.ComponentModel;
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using CommunityToolkit.Mvvm.Input;
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namespace MyApp
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{
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public partial class BaseViewModel : ObservableObject
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{
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protected virtual bool CanDoStuff()
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{
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return false;
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}
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}
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public partial class SampleViewModel : BaseViewModel
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{
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[RelayCommand(CanExecute = nameof(CanDoStuff))]
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private void DoStuff()
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{
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}
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protected override bool CanDoStuff()
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{
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return true;
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}
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}
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}
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""";
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VerifyGeneratedDiagnostics<RelayCommandGenerator>(source, LanguageVersion.CSharp12);
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}
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[TestMethod]
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public void RelayCommandWithOverriddenCanExecute_WithOneMethodNotInTheSameHierarchy_Warns()
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{
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const string source = """
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using CommunityToolkit.Mvvm.ComponentModel;
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using CommunityToolkit.Mvvm.Input;
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namespace MyApp
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{
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public partial class BaseViewModel : ObservableObject
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{
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protected virtual bool CanDoStuff()
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{
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return false;
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}
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protected bool CanDoStuff(string x)
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{
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}
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}
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public partial class SampleViewModel : BaseViewModel
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{
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[RelayCommand(CanExecute = nameof(CanDoStuff)]
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private void DoStuff()
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{
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}
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private override bool CanDoStuff()
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{
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return true;
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}
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}
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}
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""";
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VerifyGeneratedDiagnostics<RelayCommandGenerator>(source, "MVVMTK0010");
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}
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[TestMethod]
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public async Task WinRTClassUsingNotifyPropertyChangedAttributesAnalyzer_NotTargetingWindows_DoesNotWarn()
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{
@@ -2451,10 +2525,23 @@ internal static async Task VerifyAnalyzerDiagnosticsAndSuccessfulGeneration<TAna
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/// <param name="diagnosticsIds">The diagnostic ids to expect for the input source code.</param>
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internal static void VerifyGeneratedDiagnostics<TGenerator>(string source, params string[] diagnosticsIds)
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where TGenerator : class, IIncrementalGenerator, new()
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{
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VerifyGeneratedDiagnostics<TGenerator>(source, LanguageVersion.CSharp8, diagnosticsIds);
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}
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/// <summary>
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/// Verifies the output of a source generator.
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/// </summary>
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/// <typeparam name="TGenerator">The generator type to use.</typeparam>
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/// <param name="source">The input source to process.</param>
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/// <param name="languageVersion">The language version to use to parse code and run tests.</param>
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/// <param name="diagnosticsIds">The diagnostic ids to expect for the input source code.</param>
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internal static void VerifyGeneratedDiagnostics<TGenerator>(string source, LanguageVersion languageVersion, params string[] diagnosticsIds)
2540+
where TGenerator : class, IIncrementalGenerator, new()
24542541
{
24552542
IIncrementalGenerator generator = new TGenerator();
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2457-
VerifyGeneratedDiagnostics(CSharpSyntaxTree.ParseText(source, CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)), new[] { generator }, diagnosticsIds, []);
2544+
VerifyGeneratedDiagnostics(CSharpSyntaxTree.ParseText(source, CSharpParseOptions.Default.WithLanguageVersion(languageVersion)), new[] { generator }, diagnosticsIds, []);
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}
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/// <summary>

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