Fix S3237: Rule should not throw NullReferenceException when using ex…

…pression body accessor (#1022)
SonarSource · Dec 18, 2017 · a9477c7 · a9477c7
1 parent f2f5f17
commit a9477c7
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Showing 2 changed files with 15 additions and 3 deletions.
diff --git a/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/UseValueParameter.cs b/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/UseValueParameter.cs
@@ -19,7 +19,6 @@
  */
 
 using System.Collections.Immutable;
-using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -53,13 +52,14 @@ protected sealed override void Initialize(SonarAnalysisContext context)
 
                     var accessorDeclaration = cbc.CodeBlock as AccessorDeclarationSyntax;
                     if (accessorDeclaration == null ||
-                        accessorDeclaration.IsKind(SyntaxKind.GetAccessorDeclaration))
+                        accessorDeclaration.IsKind(SyntaxKind.GetAccessorDeclaration) ||
+                        accessorDeclaration.Body == null)
                     {
                         return;
                     }
 
                     if (accessorDeclaration.Body.Statements.Count == 1 &&
-                        accessorDeclaration.Body.Statements.Single() is ThrowStatementSyntax)
+                        accessorDeclaration.Body.Statements[0] is ThrowStatementSyntax)
                     {
                         return;
                     }

diff --git a/sonaranalyzer-dotnet/src/Tests/SonarAnalyzer.UnitTest/TestCases/UseValueParameter.cs b/sonaranalyzer-dotnet/src/Tests/SonarAnalyzer.UnitTest/TestCases/UseValueParameter.cs
@@ -115,4 +115,16 @@ public override event EventHandler Bar
             remove { } // Noncompliant
         }
     }
+
+    class Program
+    {
+
+        private string id;
+
+        public string Id
+        {
+            get => null;
+            set => id = 10; // Compliant (should not be, see https://github.com/SonarSource/sonar-csharp/issues/1021)
+        }
+    }
 }