Example of GraphQL::Pro pundit_integration with node field

pundit_example.rb

require "bundler/inline"

gemfile do
  gem "pundit", "2.1.0"
  gem "graphql", "1.12.5"
  source "https://gems.graphql.pro" do
    gem "graphql-pro", "1.17.6"
  end
end

class Schema < GraphQL::Schema
  class BaseObject < GraphQL::Schema::Object
    include GraphQL::Pro::PunditIntegration::ObjectIntegration
  end

  class UserPolicy
    def initialize(user, object)
      @user = user
      @object = object
    end

    # A user object can only be viewed if the current user
    # _is_ that same user
    def view?
      @user == @object[:handle]
    end
  end

  class User < BaseObject
    implements GraphQL::Types::Relay::Node
    field :handle, String, null: false
    pundit_role :view
    # Since I'm using `Hash`es to represent users,
    # I have to manually identify the `UserPolicy`.
    pundit_policy_class UserPolicy
  end

  class Query < BaseObject
    pundit_role nil
    add_field(GraphQL::Types::Relay::NodeField)
  end

  query(Query)
  orphan_types(User)

  # The `id` _is_ the handle, it's not really an ID
  def self.object_from_id(id, ctx)
    { handle: id, id: id }
  end
  
  # There's only one type in this schema, so assume everything is a User
  def self.resolve_type(type, obj, ctx)
    User
  end
end

query_str = "{ node(id: \"matz\") { ... on User { handle } } }"

# No `current_user`, unauthorized:
pp Schema.execute(query_str).to_h
# {"data"=>{"node"=>nil}}

# Mismatched `current_user`, unauthorized:
pp Schema.execute(query_str, context: { current_user: "dhh" }).to_h
# {"data"=>{"node"=>nil}}

# Matching `current_user`, authorized:
pp Schema.execute(query_str, context: { current_user: "matz" }).to_h
# {"data"=>{"node"=>{"handle"=>"matz"}}}