Code Fixers should use correct InvocationExpression

Author: inyutin-maxim

System.IO.Abstractions.Analyzers.Tests/TestData/CodeFix/DirectoryCodeFix/AfterFix.txt

@@ -15,7 +15,7 @@ namespace SomeNameSpace
 		{
 			const string filePath = "C:\\temp";
 
-			_fileSystem.Directory.Exists(filePath);
+			new ConfigurationBuilder().SetBasePath(_fileSystem.Directory.GetCurrentDirectory());
 		}
 	}
 }

System.IO.Abstractions.Analyzers.Tests/TestData/CodeFix/DirectoryCodeFix/BeforeFix.txt

@@ -15,7 +15,7 @@ namespace SomeNameSpace
 		{
 			const string filePath = "C:\\temp";
 
-			Directory.Exists(filePath);
+			new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory());
 		}
 	}
 }

System.IO.Abstractions.Analyzers/Analyzers/BaseFileSystemNodeAnalyzer.cs

@@ -46,8 +46,10 @@ protected override void AnalyzeCompilation(CompilationStartAnalysisContext compi
 
 		private bool IsTypesEquals(TypeSyntax type) => type.NormalizeWhitespace().ToFullString() == GetFileSystemType().Name;
 
-		private bool IsStaticInvocationStartWith(InvocationExpressionSyntax invocation) => invocation.Expression.NormalizeWhitespace()
-			.ToFullString()
-			.StartsWith(GetFileSystemType().Name + ".", StringComparison.CurrentCultureIgnoreCase);
+		private bool IsStaticInvocationStartWith(InvocationExpressionSyntax invocation) =>
+			invocation.IsKind(SyntaxKind.InvocationExpression)
+			&& invocation.Expression.NormalizeWhitespace()
+				.ToFullString()
+				.StartsWith(GetFileSystemType().Name + ".", StringComparison.CurrentCultureIgnoreCase);
 	}
 }

System.IO.Abstractions.Analyzers/CodeFixes/BaseInvokeCodeFix.cs

@@ -22,14 +22,16 @@ public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
 		{
 			var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
 
-			if (root.FindNode(context.Span).Ancestors().OfType<ClassDeclarationSyntax>().Any(RoslynClassFileSystem.HasFileSystemField))
-			{
-				var invocation = root.FindNode(context.Span).FirstAncestorOrSelf<InvocationExpressionSyntax>();
+			var classDeclaration = root.FindNode(context.Span).FirstAncestorOrSelf<ClassDeclarationSyntax>();
 
-				var @class = root.FindNode(context.Span)
-					.FirstAncestorOrSelf<ClassDeclarationSyntax>();
+			if (RoslynClassFileSystem.HasFileSystemField(classDeclaration))
+			{
+				var invocation = root.FindNode(context.Span)
+					.DescendantNodesAndSelf()
+					.OfType<InvocationExpressionSyntax>()
+					.FirstOrDefault();
 
-				var field = RoslynClassFileSystem.GetFileSystemFieldFromClass(@class);
+				var field = RoslynClassFileSystem.GetFileSystemFieldFromClass(classDeclaration);
 
 				context.RegisterCodeFix(new FileSystemInvokeCodeAction(Title,
 						context.Document,