validates model when uses function mongo insert_many

game.rb

# model Game

class Game
  include Mongoid::Document
  include Mongoid::Timestamps

  attr_accessor :skip_uniqueness_validations
  attr_readonly :skip_uniqueness_validations

  field :game_name, type: String
  field :game_id, type: String

  belongs_to :user, class_name: 'User', required: false
  # skip validation of uniqueness to model User
  validates_presence_of :user, unless: :skip_uniqueness_validations
  validates_presence_of :user_id

  validates :game_name, presence: true, allow_nil: true
  validates :game_id, presence: true

  # How method "valid?" makes a query find to Mongo to check if field is unique,
  # this validations must be skipped for that not make requests to Mongo.
  validates_uniqueness_of :game_id, unless: :skip_uniqueness_validations
  validates_uniqueness_of :game_name, unless: :skip_uniqueness_validations
end

InsertManyWithValidations.rb

class InsertManyWithValidations
  user = User.first

  games = [
    { game_id: '1', name: 'Halo' },
    { game_id: '2', name: 'GoW' },
    { game_id: '2', name: 'KF' },
  ]

  games = games.map do |game|
    game_model = Game.new(
      user_id: user.id,
      game_id: game[:game_id],
      game_name: game[:name],
      skip_uniqueness_validations: true # no validates uniqueness (improves performance)
    )
    game_model.set_created_at # add created_at and updated_at

    # method "valid?" will run all validations, except uniqueness
    raise ModelInvalidError unless game_model.valid?

    game_hash = HashWithIndifferentAccess[game_model.attributes]
    game_hash.symbolize_keys.except(:_id)
  end

  Game.collection.insert_many(games)
  
rescue ServiceInvalidError => e
  puts e.message
  puts e.backtrace[0..5]
  # run rollback
end

class ModelInvalidError < StandardError; end