queryField.go

import "github.com/vektah/gqlparser/ast"

var viewerField = &gateway.QueryField{
    Name: "viewer",
    Type: ast.NamedType("User", &ast.Position{}),
    // this function must return the ID of the object that the field resolves to
    Resolver: func(ctx context.Context, args map[string]interface{}) (string, error) {
        // for now just return the value in context
        return ctx.Value("user-id").(string), nil
    },
}