Fix false-positive for MA0106 when capturing a parameter inside the l…

…ambda
meziantou · Dec 18, 2023 · 241bedc · 241bedc
1 parent 186ea1c
commit 241bedc
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 3 deletions.
diff --git a/src/Meziantou.Analyzer/Rules/AvoidClosureWhenUsingConcurrentDictionaryAnalyzer.cs b/src/Meziantou.Analyzer/Rules/AvoidClosureWhenUsingConcurrentDictionaryAnalyzer.cs
@@ -184,8 +184,9 @@ private static void DetectClosure(OperationAnalysisContext context, IOperation a
             var dataFlow = semanticModel.AnalyzeDataFlow(syntax);
             if (dataFlow.CapturedInside.Length > 0)
             {
+                // A parameter can be captured inside (by another lambda)
                 var parameters = GetParameters(argumentOperation);
-                if (dataFlow.Captured.Any(s => !parameters.Contains(s, SymbolEqualityComparer.Default)))
+                if (dataFlow.CapturedInside.Any(s => !parameters.Contains(s, SymbolEqualityComparer.Default)))
                 {
                     context.ReportDiagnostic(RuleFactoryArg, argumentOperation, string.Join(", ", dataFlow.Captured.Select(symbol => symbol.Name)));
                 }

diff --git a/src/Meziantou.Analyzer/Rules/EqualityShouldBeCorrectlyImplementedAnalyzerCommon.cs b/src/Meziantou.Analyzer/Rules/EqualityShouldBeCorrectlyImplementedAnalyzerCommon.cs
@@ -1,5 +1,4 @@
-using System;
-using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis;
 
 namespace Meziantou.Analyzer.Rules;
 

diff --git a/...st/Rules/ConcurrentDictionaryMustPreventClosureWhenAccessingTheKeyAnalyzerTests_MA0106.cs b/...st/Rules/ConcurrentDictionaryMustPreventClosureWhenAccessingTheKeyAnalyzerTests_MA0106.cs
@@ -119,4 +119,28 @@ await CreateProjectBuilder()
             .WithSourceCode(SourceCode)
             .ValidateAsync();
     }
+
+    [Fact]
+    public async Task GetOrAdd_NoClosure()
+    {
+        const string SourceCode = """
+            using System;
+            using System.Collections.Concurrent;
+            using System.Linq;
+
+            var dict = new ConcurrentDictionary<string, Type>();
+            dict.GetOrAdd("", static layout2 =>
+            {
+                var types = System.Array.Empty<string>().Where(t => t == layout2);
+                throw null!;
+            });
+
+            var dummy = new object();
+            var f = new System.Func<bool>(() => dummy != null);
+            """;
+        await CreateProjectBuilder()
+            .WithOutputKind(Microsoft.CodeAnalysis.OutputKind.ConsoleApplication)
+            .WithSourceCode(SourceCode)
+            .ValidateAsync();
+    }
 }