Argument validation on Directives is inconsistent

[olbrich]

Describe the bug

When defining a directive, if one sets validations for the arguments, unexpected things happen.

For example...

module Directives
  class Feature < GraphQL::Schema::Directive
    description "Directs the executor to run this only based on the state of a server-side feature flag."

    argument :if, String, required: false, validates: { format: /\d+/,  }, description: "Include the element if the feature flag is enabled."
    argument :unless, String, required: false, validates: { format: /\d+/,  }, description: "Include the element if the feature flag is disabled."
    
    # validates required: { one_of: %i[if unless] }  # Doesn't work at all

    ...
end

With an argument definition like this we would expect a validation failure when invoked like @feature(if: "flag") because the validation checks for numbers instead of strings (this is a contrived validation, BTW).

What actually happens is that the include? method is called with a GraphQL::ExecutionError as the second argument (which should be a GraphQL::Execution::Interpreter::Arguments of the directive).

I also observe that it is not possible to add a validates requires: { one_of: %i[if unless] } for a directive, that just fails.

Versions

    graphql-enterprise (1.4.0)
      graphql (>= 2.0.18)
      graphql-pro (>= 1.24.0)
    graphql-pro (1.27.4)
      graphql (>= 1.7.5)

Rails 7.2.2.1

Expected behavior

• I'd expect an argument validation error to be raised back to the executor and generate an appropriate error message.
• Use of validates ... should work as documented for directive arguments as well.

[rmosolgo]

Hey, sorry for the trouble with this. Directive arguments have definitely not gotten a lot of attention 😅 . I agree it should work the way you describe here. I'll take a look soon and follow up here!