Fix warnings.

Author: JohanLarsson

AspNetCoreAnalyzers/.editorconfig

@@ -6,3 +6,6 @@ dotnet_diagnostic.SA0001.severity = none
 dotnet_diagnostic.SA1401.severity = none
 # SA1633: The file header is missing or not located at the top of the file.
 dotnet_diagnostic.SA1633.severity = none
+
+# RS2008: Enable analyzer release tracking
+dotnet_diagnostic.RS2008.severity = none

AspNetCoreAnalyzers/Analyzers/AttributeAnalyzer.cs

@@ -337,7 +337,8 @@ bool HasWrongType(IParameterSymbol parameterSymbol, out Replacement<TypeSyntax>
                 {
                     // https://docs.microsoft.com/en-us/aspnet/core/fundamentals/routing?view=aspnetcore-2.2#route-constraint-reference
                     if (TryGetType(constraint.Span, out var type) &&
-                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out var parameter))
+                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out var parameter) &&
+                        parameter is { Type: { } })
                     {
                         newType = new Replacement<TypeSyntax>(
                             parameter.Type,
@@ -351,7 +352,8 @@ bool HasWrongType(IParameterSymbol parameterSymbol, out Replacement<TypeSyntax>
                     if (constraint.Span.Equals("?", StringComparison.Ordinal) &&
                         parameterSymbol.Type.IsValueType &&
                         parameterSymbol.Type.OriginalDefinition.SpecialType != SpecialType.System_Nullable_T &&
-                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out parameter))
+                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out parameter) &&
+                        parameter is { Type: { } })
                     {
                         newType = new Replacement<TypeSyntax>(
                             parameter.Type,
@@ -368,7 +370,8 @@ bool HasWrongType(IParameterSymbol parameterSymbol, out Replacement<TypeSyntax>
                         parameterSymbol.Type.OriginalDefinition.SpecialType == SpecialType.System_Nullable_T &&
                         parameterSymbol.Type is INamedTypeSymbol namedType &&
                         namedType.TypeArguments.TrySingle(out var typeArg) &&
-                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out var parameter))
+                        parameterSymbol.TrySingleDeclaration(context.CancellationToken, out var parameter) &&
+                        parameter is { Type: { } })
                     {
                         newType = new Replacement<TypeSyntax>(
                             parameter.Type,

AspNetCoreAnalyzers/CodeFixes/ParameterTypeFix.cs

@@ -23,7 +23,8 @@ protected override async Task RegisterCodeFixesAsync(DocumentEditorCodeFixContex
 
             foreach (var diagnostic in context.Diagnostics)
             {
-                if (syntaxRoot.TryFindNodeOrAncestor(diagnostic, out TypeSyntax? typeSyntax) &&
+                if (syntaxRoot is { } &&
+                    syntaxRoot.TryFindNodeOrAncestor(diagnostic, out TypeSyntax? typeSyntax) &&
                     diagnostic.Properties.TryGetValue(nameof(TypeSyntax), out var typeName))
                 {
                     context.RegisterCodeFix(

AspNetCoreAnalyzers/CodeFixes/RenameParameterFix.cs

@@ -28,7 +28,9 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                                              .ConfigureAwait(false);
             foreach (var diagnostic in context.Diagnostics)
             {
-                if (syntaxRoot.TryFindNodeOrAncestor(diagnostic, out ParameterSyntax? parameterSyntax) &&
+                if (syntaxRoot is { } &&
+                    syntaxRoot.TryFindNodeOrAncestor(diagnostic, out ParameterSyntax? parameterSyntax) &&
+                    semanticModel is { } &&
                     semanticModel.TryGetSymbol(parameterSyntax, context.CancellationToken, out var parameter) &&
                     diagnostic.Properties.TryGetValue(nameof(NameSyntax), out var name))
                 {

AspNetCoreAnalyzers/CodeFixes/RenameTypeFix.cs

@@ -28,7 +28,9 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                                              .ConfigureAwait(false);
             foreach (var diagnostic in context.Diagnostics)
             {
-                if (syntaxRoot.TryFindNodeOrAncestor(diagnostic, out ClassDeclarationSyntax? classDeclarationSyntax) &&
+                if (syntaxRoot is { } &&
+                    syntaxRoot.TryFindNodeOrAncestor(diagnostic, out ClassDeclarationSyntax? classDeclarationSyntax) &&
+                    semanticModel is { } &&
                     semanticModel.TryGetSymbol(classDeclarationSyntax, context.CancellationToken, out var parameter) &&
                     diagnostic.Properties.TryGetValue(nameof(NameSyntax), out var name))
                 {

AspNetCoreAnalyzers/CodeFixes/TemplateTextFix.cs

@@ -31,7 +31,8 @@ protected override async Task RegisterCodeFixesAsync(DocumentEditorCodeFixContex
 
             foreach (var diagnostic in context.Diagnostics)
             {
-                if (syntaxRoot.TryFindNodeOrAncestor<LiteralExpressionSyntax>(diagnostic, out var literal) &&
+                if (syntaxRoot is { } &&
+                    syntaxRoot.TryFindNodeOrAncestor<LiteralExpressionSyntax>(diagnostic, out var literal) &&
                     diagnostic.Properties.TryGetValue(nameof(UrlTemplate), out var text))
                 {
                     context.RegisterCodeFix(