ruby factory_girlで自定义策略を作る提示参考：http：//qiita.com/kitaro_tn/items/6200cbabbbea0c1ac168

Posted 2021-05-16

module FactoryGirl
  module Strategy
    class Stub
      @@next_id = 1000

      def association(runner)
        runner.run(:build_stubbed)
      end

      def result(evaluation)
        evaluation.object.tap do |instance|
          stub_database_interaction_on_result(instance)
          clear_changed_attributes_on_result(instance)
          evaluation.notify(:after_stub, instance)
        end
      end

      private
      ... # 省略
end

FactoryGirl.define do

  factory :user do
    name      'Bob'
    age       31
    height    172
    weight    64

    before(:stub_custom) do |user, evaluation|
      user.bmi = (user.weight / ((user.height / 100.0) ** 2)).round(1)

    end

    before(:build_custom) do |user, evaluation|
      user.bmi = (user.weight / ((user.height / 100.0) ** 2)).round(1)

    end

  end
end

# 作成したStrategyを使用することにより、id, delete_flag, created_at, updated_atを自動挿入したインスタンスを返す
user = FactoryGirl.stub_custom(:user)

# 各フィールドに抜けのないインスタンスが10生成される
users = FactoryGirl.stub_custom_list(:user, 10)

require 'activerecord-import'

users = FactoryGirl.stub_custom_list(:user, 10)

User.import users

module FactoryGirl
  class FactoryRunner
    def initialize(name, strategy, traits_and_overrides)
      @name     = name
      @strategy = strategy

      @overrides = traits_and_overrides.extract_options!
      @traits    = traits_and_overrides
    end

    def run(runner_strategy = @strategy, &block)
      factory = FactoryGirl.factory_by_name(@name)

      factory.compile

      if @traits.any?
        factory = factory.with_traits(@traits)
      end

      instrumentation_payload = {
        name: @name,
        strategy: runner_strategy,
        traits: @traits,
        overrides: @overrides,
        factory: factory
      }

      ActiveSupport::Notifications.instrument('factory_girl.run_factory', instrumentation_payload) do
        factory.run(runner_strategy, @overrides, &block)
      end
    end
  end
end

class CustomStub < FactoryGirl::Strategy::Stub

  def association(runner)
    runner.run(:build_stubbed)
  end

  def result(evaluation)
    evaluation.object.tap do |instance|
      evaluation.notify(:before_stub_custom, instance)
      stub_database_interaction_on_result(instance)
      evaluation.notify(:after_stub_custom, instance)
    end
  end

end

# ここで実際に作成したクラスを登録する
FactoryGirl.register_strategy(:stub_custom, CustomStub)
FactoryGirl.register_callback(:before_stub_custom)
FactoryGirl.register_callback(:after_stub_custom)

module FactoryGirl
  module Strategy
    class Create
      def association(runner)
        runner.run
      end

      def result(evaluation)
        evaluation.object.tap do |instance|
          evaluation.notify(:after_build, instance)
          evaluation.notify(:before_create, instance)
          evaluation.create(instance)
          evaluation.notify(:after_create, instance)
        end
      end
    end
  end
end

module FactoryGirl
  module Strategy
    class Build
      def association(runner)
        runner.run
      end

      def result(evaluation)
        evaluation.object.tap do |instance|
          evaluation.notify(:after_build, instance)
        end
      end
    end
  end
end