hashid.rb

# frozen_string_literal: true

module Types
  class Hashid < GraphQL::Schema::Scalar
    graphql_name "UID"
    default_scalar true
    description "Unique identifer"

    def self.coerce_input(value, _ctx)
      HashidHelper.decode(value)
    rescue StandardError
      raise GraphQL::CoercionError, "#{value.inspect} is not a valid UID"
    end

    def self.coerce_result(value, _ctx)
      HashidHelper.encode(value)
    end
  end
end

hashid_helper.rb

# frozen_string_literal: true

require "hashids"

module HashidHelper
  class << self
    delegate :encode, to: :hashid

    def decode(value)
      hashid.decode(value).first
    end

    private

    def hashid
      @hashid ||= Hashids.new(
        ENV["HASHID_SALT"] || "",
        ENV["HASHID_MIN_LENGTH"] || 10
      )
    end
  end
end