Enema of the state

bad_state.rb

# frozen_string_literal: true
module Hodor
  class MainService

    def initialize(
      foo_klass: Foo
      bar_service: Hodor::BarService.new,
      baz_service: Hodor::BazService.new,
      qux_service: Hodor::QuxService.new
      )
     
      @foo_klass = foo_klass

      #initialize dependencies
      @bar_service = bar_service
      @baz_service = baz_service
      @qux_service = qux_service
    end

    def call(foo_id, status_name)
      @foo = foo_klass.find(foo_id)
      @foo_status = foo.statuses.where(name: status_name)

      #call each dependent service

      # This service updates all bar records with foo_status to have a different status
      @bar_service.(foo_id, foo_status)
      
      # This service erases foo_status from bar's history (join records)
      @baz_service.(foo_id, foo_status)
      
      # This service erases foo_status from foo (destroys statuses that were associated with foo)
      @qux_service.(foo_id, foo_status)

      # publish changes to foo
      foo
    end
  end
end

base_state_test.rb

module Hodor 
  class MainServiceTest 
    
    test 'it should call' do 
      sut = MainService.new(foo_klass: fake, bar_service: FakeService)
      result = sut.call(1)
      assert_result
    end
    
  end 
end