Conventions for setting up a GraphQL Server on Rails - CreateCommentMutator

create_comment_mutator.rb

# app/queries/create_comment_mutator.rb
class CreateCommentMutator < ApplicationQuery
  property :post_id
  property :comment, validates: { length: { minimum: 1, maximum: 500 } }

  validate :post_belongs_to_team

  def post_belongs_to_team
    return if post.present?

    errors[:base] << 'Could not find a post in your team with that ID'
  end

  def create_comment
    Posts::CreateCommentService.new(post).create(current_user, comment)
  end

  def authorized?
    current_user.present?
  end

  private

  def post
    current_user.team.posts.find_by(id: post_id)
  end
end