GraphQLTools

GraphQLTools is a Visual Studio 2022 extension designed to provide GraphQL support for the StringSyntaxAttribute feature introduced in .NET 7.

Currently, there is no native support for GraphQL formatting and syntax highlighting, so that's where GraphQLTools comes in. By decorating your string parameters or members with [StringSyntax("GraphQL")] you can incorporate GraphQL syntax highlighting and checking into your C# code.

Features and limitations

GraphQLTools enhances the coding experience by classifying various components of GraphQL documents using distinct syntax highlighting for

• Punctuators
• Contextual keywords (like query, fragment, on)
• Operation names
• Fragment names
• Variable names
• Directive names
• Type names
• Field names
• Aliased field names
• Argument names
• Object field names
• Strings
• Numbers
• Enums
• Comments

At this time, only executable definitions (operations and fragments) are supported by the parser, whereas type system definitions and extensions are not. In addition to syntax highlighting, the extension helps identify syntax errors with diagnostic error messages displayed in tooltips upon mouse hover.

Like in the native feature, regular, verbatim, and raw string literals are supported, while interpolated strings are not.

It's worth noting that the StringSyntax attribute allows flexibility in the casing of the syntax parameter within the attribute's constructor. For example, both [StringSyntax("GraphQL")] and [StringSyntax("graphql")] are valid.