use null propagation and mark as warning in editorconfig (#5383)

Author: SimonCropp

src/Analyzers/MSTest.Analyzers.CodeFixes/AvoidExpectedExceptionAttributeFixer.cs

@@ -59,12 +59,8 @@ public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
         }
 
         IMethodSymbol? methodSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration, context.CancellationToken);
-        if (methodSymbol is null)
-        {
-            return;
-        }
 
-        AttributeData? attribute = methodSymbol.GetAttributes().FirstOrDefault(
+        AttributeData? attribute = methodSymbol?.GetAttributes().FirstOrDefault(
             attr => SymbolEqualityComparer.Default.Equals(attr.AttributeClass, expectedExceptionAttributeSymbol));
 
         if (attribute?.ApplicationSyntaxReference is not { } syntaxRef)

src/Analyzers/MSTest.Analyzers.CodeFixes/PreferConstructorOverTestInitializeFixer.cs

@@ -43,13 +43,9 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         TextSpan diagnosticSpan = diagnostic.Location.SourceSpan;
 
         SyntaxToken syntaxToken = root.FindToken(diagnosticSpan.Start);
-        if (syntaxToken.Parent is null)
-        {
-            return;
-        }
 
         // Find the method declaration identified by the diagnostic.
-        MethodDeclarationSyntax? methodDeclaration = syntaxToken.Parent.AncestorsAndSelf().OfType<MethodDeclarationSyntax>().FirstOrDefault();
+        MethodDeclarationSyntax? methodDeclaration = syntaxToken.Parent?.AncestorsAndSelf().OfType<MethodDeclarationSyntax>().FirstOrDefault();
         if (methodDeclaration == null)
         {
             return;

src/Analyzers/MSTest.Analyzers.CodeFixes/PreferDisposeOverTestCleanupFixer.cs

@@ -44,13 +44,9 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         TextSpan diagnosticSpan = diagnostic.Location.SourceSpan;
 
         SyntaxToken syntaxToken = root.FindToken(diagnosticSpan.Start);
-        if (syntaxToken.Parent is null)
-        {
-            return;
-        }
 
         // Find the TestCleanup method declaration identified by the diagnostic.
-        MethodDeclarationSyntax? testCleanupMethod = syntaxToken.Parent.AncestorsAndSelf().OfType<MethodDeclarationSyntax>().FirstOrDefault();
+        MethodDeclarationSyntax? testCleanupMethod = syntaxToken.Parent?.AncestorsAndSelf().OfType<MethodDeclarationSyntax>().FirstOrDefault();
         if (testCleanupMethod == null ||
             !IsTestCleanupMethodValid(testCleanupMethod) ||
             testCleanupMethod.Parent is not TypeDeclarationSyntax containingType)

src/Analyzers/MSTest.Analyzers.CodeFixes/PreferTestInitializeOverConstructorFixer.cs

@@ -43,13 +43,9 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         TextSpan diagnosticSpan = diagnostic.Location.SourceSpan;
 
         SyntaxToken syntaxToken = root.FindToken(diagnosticSpan.Start);
-        if (syntaxToken.Parent is null)
-        {
-            return;
-        }
 
         // Find the constructor declaration identified by the diagnostic.
-        ConstructorDeclarationSyntax? constructorDeclaration = syntaxToken.Parent.AncestorsAndSelf().OfType<ConstructorDeclarationSyntax>().FirstOrDefault();
+        ConstructorDeclarationSyntax? constructorDeclaration = syntaxToken.Parent?.AncestorsAndSelf().OfType<ConstructorDeclarationSyntax>().FirstOrDefault();
         if (constructorDeclaration == null)
         {
             return;

src/Platform/Microsoft.Testing.Platform/ServerMode/JsonRpc/PassiveNode.cs

@@ -102,12 +102,9 @@ public async Task SendAttachmentsAsync(TestsAttachments testsAttachments, Cancel
 
     public void Dispose()
     {
-        if (_messageHandler != null)
+        if (_messageHandler is IDisposable disposable)
         {
-            if (_messageHandler is IDisposable disposable)
-            {
-                disposable.Dispose();
-            }
+            disposable.Dispose();
         }
     }
 }