Add an option to detect overloads with optional parameters (#771)

docs/Rules/MA0032.md

@@ -16,6 +16,22 @@ class Test
 }
 ````
 
+## Configuration
+
+````
+MA0032.allowOverloadsWithOptionalParameters = false
+````
+
+````c#
+Foo.Bar(); // report when MA0032.allowOverloadsWithOptionalParameters is true
+
+class Foo
+{
+    public static void Bar() => throw null;
+    public static void Bar(CancellationToken cancellationToken, bool dummy = false) => throw null;
+}
+````
+
 ## Additional resources
 
 - [Enforcing asynchronous code good practices using a Roslyn analyzer](https://www.meziantou.net/enforcing-asynchronous-code-good-practices-using-a-roslyn-analyzer.htm)

docs/Rules/MA0040.md

@@ -18,6 +18,22 @@ class Test
 
 This rule only reports a diagnostic when a `CancellationToken` is available in the scope. [MA0032](MA0032.md) detects the same cases, but reports them even if applying a fix would require you to change the calling method's signature.
 
+## Configuration
+
+````
+MA0032.allowOverloadsWithOptionalParameters = false
+````
+
+````c#
+Foo.Bar(); // report when MA0032.allowOverloadsWithOptionalParameters is true
+
+class Foo
+{
+    public static void Bar() => throw null;
+    public static void Bar(CancellationToken cancellationToken, bool dummy = false) => throw null;
+}
+````
+
 ## Additional resources
 
 - [Enforcing asynchronous code good practices using a Roslyn analyzer](https://www.meziantou.net/enforcing-asynchronous-code-good-practices-using-a-roslyn-analyzer.htm)

src/Meziantou.Analyzer/Internals/OverloadFinder.cs

@@ -22,40 +22,43 @@ public bool HasOverloadWithAdditionalParameterOfType(
         if (currentOperation.SemanticModel is null)
             return false;
 
-        return FindOverloadWithAdditionalParameterOfType(methodSymbol, syntaxNode: currentOperation.Syntax, includeObsoleteMethods: false, additionalParameterTypes) is not null;
+        return FindOverloadWithAdditionalParameterOfType(methodSymbol, syntaxNode: currentOperation.Syntax, includeObsoleteMethods: false, allowOptionalParameters: false, additionalParameterTypes) is not null;
     }
 
     private IMethodSymbol? FindOverloadWithAdditionalParameterOfType(
         IMethodSymbol methodSymbol,
         params ITypeSymbol[] additionalParameterTypes)
     {
-        return FindOverloadWithAdditionalParameterOfType(methodSymbol, includeObsoleteMethods: false, additionalParameterTypes);
+        return FindOverloadWithAdditionalParameterOfType(methodSymbol, includeObsoleteMethods: false, allowOptionalParameters: false, additionalParameterTypes);
     }
 
     public IMethodSymbol? FindOverloadWithAdditionalParameterOfType(
         IMethodSymbol methodSymbol,
         bool includeObsoleteMethods,
+        bool allowOptionalParameters,
         params ITypeSymbol[] additionalParameterTypes)
     {
-        return FindOverloadWithAdditionalParameterOfType(methodSymbol, syntaxNode: null, includeObsoleteMethods, additionalParameterTypes);
+        return FindOverloadWithAdditionalParameterOfType(methodSymbol, syntaxNode: null, includeObsoleteMethods, allowOptionalParameters, additionalParameterTypes);
     }
 
     public IMethodSymbol? FindOverloadWithAdditionalParameterOfType(
         IMethodSymbol methodSymbol,
         IOperation operation,
         bool includeObsoleteMethods,
+        bool allowOptionalParameters,
         params ITypeSymbol[] additionalParameterTypes)
     {
         if (operation.SemanticModel is null)
             return null;
 
-        return FindOverloadWithAdditionalParameterOfType(methodSymbol, operation.Syntax, includeObsoleteMethods, additionalParameterTypes);
+        return FindOverloadWithAdditionalParameterOfType(methodSymbol, operation.Syntax, includeObsoleteMethods, allowOptionalParameters, additionalParameterTypes);
     }
 
     public IMethodSymbol? FindOverloadWithAdditionalParameterOfType(
         IMethodSymbol methodSymbol,
         SyntaxNode? syntaxNode,
         bool includeObsoleteMethods,
+        bool allowOptionalParameters,
         params ITypeSymbol[] additionalParameterTypes)
     {
         if (additionalParameterTypes is null)
@@ -83,20 +86,20 @@ public bool HasOverloadWithAdditionalParameterOfType(
                 if (!includeObsoleteMethods && IsObsolete(method))
                     continue;
 
-                if (HasSimilarParameters(methodSymbol, method, additionalParameterTypes))
+                if (HasSimilarParameters(methodSymbol, method, allowOptionalParameters, additionalParameterTypes))
                     return method;
             }
         }
 
         return null;
     }
 
-    public static bool HasSimilarParameters(IMethodSymbol method, IMethodSymbol otherMethod, params ITypeSymbol[] additionalParameterTypes)
+    public static bool HasSimilarParameters(IMethodSymbol method, IMethodSymbol otherMethod, bool allowOptionalParameters, params ITypeSymbol[] additionalParameterTypes)
     {
         if (method.IsEqualTo(otherMethod))
             return false;
 
-        if (otherMethod.Parameters.Length - method.Parameters.Length != additionalParameterTypes.Length)
+        if (!allowOptionalParameters && otherMethod.Parameters.Length - method.Parameters.Length != additionalParameterTypes.Length)
             return false;
 
         // Most of the time, an overload has the same order for the parameters
@@ -139,6 +142,7 @@ public static bool HasSimilarParameters(IMethodSymbol method, IMethodSymbol othe
         }
 
         // Slower search, allows to find overload with different parameter order
+        // Also, handle allow optional parameters
         {
             var otherMethodParameters = otherMethod.Parameters;
 
@@ -166,7 +170,16 @@ public static bool HasSimilarParameters(IMethodSymbol method, IMethodSymbol othe
                 }
             }
 
-            return otherMethodParameters.Length == 0;
+            if (otherMethodParameters.Length == 0)
+                return true;
+
+            if (allowOptionalParameters)
+            {
+                if (otherMethodParameters.All(p => p.IsOptional))
+                    return true;
+            }
+
+            return false;
         }
     }
 

src/Meziantou.Analyzer/Rules/DoNotUseBlockingCallInAsyncContextAnalyzer.cs

@@ -299,10 +299,10 @@ private bool IsPotentialMember(IInvocationOperation operation, IMethodSymbol met
                 if (methodSymbol.HasAttribute(ObsoleteAttributeSymbol))
                     return false;
 
-                if (OverloadFinder.HasSimilarParameters(method, methodSymbol))
+                if (OverloadFinder.HasSimilarParameters(method, methodSymbol, allowOptionalParameters: false))
                     return true;
 
-                if (CancellationTokenSymbol is not null && OverloadFinder.HasSimilarParameters(method, methodSymbol, CancellationTokenSymbol))
+                if (CancellationTokenSymbol is not null && OverloadFinder.HasSimilarParameters(method, methodSymbol, allowOptionalParameters: false, CancellationTokenSymbol))
                     return true;
             }
 

src/Meziantou.Analyzer/Rules/UseAnOverloadThatHasCancellationTokenAnalyzer.cs

@@ -8,6 +8,7 @@
 using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading;
+using Meziantou.Analyzer.Configurations;
 using Meziantou.Analyzer.Internals;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -105,7 +106,7 @@ private bool HasExplicitCancellationTokenArgument(IInvocationOperation operation
 
         private sealed record AdditionalParameterInfo(int ParameterIndex, string? Name, bool HasEnumeratorCancellationAttribute);
 
-        private bool HasAnOverloadWithCancellationToken(IInvocationOperation operation, [NotNullWhen(true)] out AdditionalParameterInfo? parameterInfo)
+        private bool HasAnOverloadWithCancellationToken(OperationAnalysisContext context, IInvocationOperation operation, [NotNullWhen(true)] out AdditionalParameterInfo? parameterInfo)
         {
             parameterInfo = default;
             var method = operation.TargetMethod;
@@ -115,7 +116,8 @@ private bool HasAnOverloadWithCancellationToken(IInvocationOperation operation,
             if (IsArgumentImplicitlyDeclared(operation, CancellationTokenSymbol, out parameterInfo))
                 return true;
 
-            var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, operation, includeObsoleteMethods: false, CancellationTokenSymbol);
+            var allowOptionalParameters = context.Options.GetConfigurationValue(operation, "MA0032.allowOverloadsWithOptionalParameters", defaultValue: false);
+            var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, operation, includeObsoleteMethods: false, allowOptionalParameters, CancellationTokenSymbol);
             if (overload is not null)
             {
                 for (var i = 0; i < overload.Parameters.Length; i++)
@@ -163,7 +165,7 @@ public void AnalyzeInvocation(OperationAnalysisContext context)
             if (HasExplicitCancellationTokenArgument(operation))
                 return;
 
-            if (!HasAnOverloadWithCancellationToken(operation, out var parameterInfo))
+            if (!HasAnOverloadWithCancellationToken(context, operation, out var parameterInfo))
                 return;
 
             var availableCancellationTokens = FindCancellationTokens(operation, context.CancellationToken);
@@ -208,7 +210,7 @@ public void AnalyzeLoop(OperationAnalysisContext context)
                     return;
 
                 // Already handled by AnalyzeInvocation
-                if (HasAnOverloadWithCancellationToken(invocation, out _))
+                if (HasAnOverloadWithCancellationToken(context, invocation, out _))
                     return;
 
                 collection = invocation.GetChildOperations().FirstOrDefault();

src/Meziantou.Analyzer/Rules/UseIFormatProviderAnalyzer.cs

@@ -79,7 +79,7 @@ public void AnalyzeInvocation(OperationAnalysisContext context)
                     return;
                 }
 
-                var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, operation, includeObsoleteMethods: false, _cultureSensitiveContext.FormatProviderSymbol);
+                var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, operation, includeObsoleteMethods: false, allowOptionalParameters: false, _cultureSensitiveContext.FormatProviderSymbol);
                 if (overload is not null)
                 {
                     context.ReportDiagnostic(Rule, operation, operation.TargetMethod.Name, _cultureSensitiveContext.FormatProviderSymbol.ToDisplayString());
@@ -106,7 +106,7 @@ public void AnalyzeInvocation(OperationAnalysisContext context)
 
             if (_cultureSensitiveContext.CultureInfoSymbol is not null && !operation.HasArgumentOfType(_cultureSensitiveContext.CultureInfoSymbol))
             {
-                var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, includeObsoleteMethods: false, _cultureSensitiveContext.CultureInfoSymbol);
+                var overload = _overloadFinder.FindOverloadWithAdditionalParameterOfType(operation.TargetMethod, includeObsoleteMethods: false, allowOptionalParameters: false, _cultureSensitiveContext.CultureInfoSymbol);
                 if (overload is not null)
                 {
                     context.ReportDiagnostic(Rule, operation, operation.TargetMethod.Name, _cultureSensitiveContext.CultureInfoSymbol.ToDisplayString());

tests/Meziantou.Analyzer.Test/Rules/UseAnOverloadThatHasCancellationTokenAnalyzerTests.cs

@@ -1187,4 +1187,45 @@ await CreateProjectBuilder()
               .ShouldFixCodeWith(Fix)
               .ValidateAsync();
     }
+
+    [Fact]
+    public async Task SuggestOverloadWithOptionalParameters_AllowOptionalParameters_True()
+    {
+        await CreateProjectBuilder()
+              .WithSourceCode("""
+                using System.Threading;
+                using System.Threading.Tasks;
+
+                [|Sample.Repro()|];
+
+                class Sample
+                {
+                    public static void Repro() => throw null;
+                    public static void Repro(CancellationToken cancellationToken, bool dummy = false) => throw null;
+                }
+                """)
+              .AddAnalyzerConfiguration("MA0032.allowOverloadsWithOptionalParameters", "true")
+              .WithOutputKind(Microsoft.CodeAnalysis.OutputKind.ConsoleApplication)
+              .ValidateAsync();
+    }
+
+    [Fact]
+    public async Task SuggestOverloadWithOptionalParameters_AllowOptionalParameters_False()
+    {
+        await CreateProjectBuilder()
+              .WithSourceCode("""
+                using System.Threading;
+                using System.Threading.Tasks;
+
+                Sample.Repro();
+
+                class Sample
+                {
+                    public static void Repro() => throw null;
+                    public static void Repro(CancellationToken cancellationToken, bool dummy = false) => throw null;
+                }
+                """)
+              .WithOutputKind(Microsoft.CodeAnalysis.OutputKind.ConsoleApplication)
+              .ValidateAsync();
+    }
 }