Fix S3358 FP: Nested ternary operator is in a lambda

analyzers/src/SonarAnalyzer.CSharp/Rules/DoNotNestTernaryOperators.cs

@@ -33,20 +33,21 @@ public sealed class DoNotNestTernaryOperators : DoNotNestTernaryOperatorsBase
     {
         private const string MessageFormat = "Extract this nested ternary operation into an independent statement.";
 
-        private static readonly DiagnosticDescriptor rule =
-            DescriptorFactory.Create(DiagnosticId, MessageFormat);
-        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(rule);
+        private static readonly DiagnosticDescriptor Rule = DescriptorFactory.Create(DiagnosticId, MessageFormat);
 
-        protected override void Initialize(SonarAnalysisContext context)
-        {
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(Rule);
+
+        protected override void Initialize(SonarAnalysisContext context) =>
             context.RegisterSyntaxNodeActionInNonGenerated(c =>
                 {
-                    if (c.Node.Ancestors().OfType<ConditionalExpressionSyntax>().Any())
+                    if (c.Node.Ancestors()
+                        .TakeWhile(x => !x.IsAnyKind(SyntaxKind.ParenthesizedLambdaExpression, SyntaxKind.SimpleLambdaExpression))
+                        .OfType<ConditionalExpressionSyntax>()
+                        .Any())
                     {
-                        c.ReportIssue(Diagnostic.Create(rule, c.Node.GetLocation()));
+                        c.ReportIssue(Diagnostic.Create(Rule, c.Node.GetLocation()));
                     }
                 },
                 SyntaxKind.ConditionalExpression);
-        }
     }
 }

analyzers/src/SonarAnalyzer.VisualBasic/Rules/DoNotNestTernaryOperators.cs

@@ -32,21 +32,24 @@ namespace SonarAnalyzer.Rules.VisualBasic
     public sealed class DoNotNestTernaryOperators : DoNotNestTernaryOperatorsBase
     {
         private const string MessageFormat = "Extract this nested If operator into independent If...Then...Else statements.";
-        private static readonly DiagnosticDescriptor rule =
-            DescriptorFactory.Create(DiagnosticId, MessageFormat);
-        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(rule);
+        private static readonly DiagnosticDescriptor Rule = DescriptorFactory.Create(DiagnosticId, MessageFormat);
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
 
-        protected override void Initialize(SonarAnalysisContext context)
-        {
-            context.RegisterSyntaxNodeActionInNonGenerated(
-                c =>
+        protected override void Initialize(SonarAnalysisContext context) =>
+            context.RegisterSyntaxNodeActionInNonGenerated(c =>
                 {
-                    if (c.Node.Ancestors().OfType<TernaryConditionalExpressionSyntax>().Any())
+                    if (c.Node.Ancestors()
+                        .TakeWhile(x => !x.IsAnyKind(
+                            SyntaxKind.MultiLineFunctionLambdaExpression,
+                            SyntaxKind.SingleLineFunctionLambdaExpression,
+                            SyntaxKind.MultiLineSubLambdaExpression,
+                            SyntaxKind.SingleLineSubLambdaExpression))
+                        .OfType<TernaryConditionalExpressionSyntax>()
+                        .Any())
                     {
-                        c.ReportIssue(Diagnostic.Create(rule, c.Node.GetLocation()));
+                        c.ReportIssue(Diagnostic.Create(Rule, c.Node.GetLocation()));
                     }
                 },
                 SyntaxKind.TernaryConditionalExpression);
-        }
     }
 }

analyzers/tests/SonarAnalyzer.UnitTest/Rules/DoNotNestTernaryOperatorsTest.cs

@@ -26,14 +26,15 @@ namespace SonarAnalyzer.UnitTest.Rules
     [TestClass]
     public class DoNotNestTernaryOperatorsTest
     {
+        private readonly VerifierBuilder verifierCS = new VerifierBuilder<CS.DoNotNestTernaryOperators>();
+        private readonly VerifierBuilder verifierVB = new VerifierBuilder<VB.DoNotNestTernaryOperators>();
+
         [TestMethod]
         public void DoNotNestTernaryOperators_CS() =>
-            OldVerifier.VerifyAnalyzer(@"TestCases\DoNotNestTernaryOperators.cs",
-                new CS.DoNotNestTernaryOperators());
+            verifierCS.AddPaths("DoNotNestTernaryOperators.cs").Verify();
 
         [TestMethod]
         public void DoNotNestTernaryOperators_VB() =>
-            OldVerifier.VerifyAnalyzer(@"TestCases\DoNotNestTernaryOperators.vb",
-                new VB.DoNotNestTernaryOperators());
+            verifierVB.AddPaths("DoNotNestTernaryOperators.vb").Verify();
     }
 }

analyzers/tests/SonarAnalyzer.UnitTest/TestCases/DoNotNestTernaryOperators.cs

@@ -24,6 +24,14 @@ public bool FooImpl(bool isMale, bool isMarried)
                 ? "Mrs. "
                 : "Miss ";
 
+            var lambda1 = true // Compliant. Nested in Lambda is valid
+                ? new Func<string>(() => true ? "a" : "b")
+                : new Func<string>(() => true ? "c" : "d");
+
+            var lambda2 = true
+                ? new Func<string, string>(s => true ? "a" : "b")
+                : new Func<string, string>(s => true ? "c" : "d");
+
             return false;
         }
     }

analyzers/tests/SonarAnalyzer.UnitTest/TestCases/DoNotNestTernaryOperators.vb

@@ -19,6 +19,25 @@ Namespace Tests.TestCases
             Dim x3 = If(isMale, "Mr. ",
                 If(isMarried, "Mrs. ", "Miss "))
 '               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Noncompliant
+
+            Dim x4 = If(isMale, Function() "Mr.", Function() If(isMarried, "Mrs.", "Miss")) ' Compliant. Ternary expressions in lambdas are not considered nested.
+            Dim x5 = If(isMale, Sub() PrintGreeting("Mr."),  Sub() PrintGreeting(If(isMarried, "Mrs.", "Miss")))
+            Dim x6 = If(isMale, Function()
+                                    Return "Mr."
+                                End Function,
+                                Function()
+                                    Return If(isMarried, "Mrs.", "Miss")
+                                End Function)
+            Dim x7 = If(isMale, Sub()
+                                    PrintGreeting("Mr.")
+                                End Sub,
+                                Sub()
+                                    PrintGreeting(If(isMarried, "Mrs.", "Miss"))
+                                End Sub)
+
         End Function
+
+        Private Sub PrintGreeting(greeting As String)
+        End Sub
     End Class
 End Namespace