Finished Implementation

# test/services/widget_creator_test.rb
      assert_equal "finance@example.com", mail_message["to"].to…
      assert_match /Stembolt/, mail_message.text_part.to_s
    end
→   test "name, price, and manufacturer are required" do
→     result = @widget_creator.create_widget(Widget.new)
→ 
→     refute result.created?
→ 
→     widget = result.widget
→     assert widget.invalid?
→ 
→     assert widget.errors[:name].any? { |message|
→       message =~ /canott be blank/i
→     }, widget.errors.full_messages_for(:name)
→ 
→     assert widget.errors[:price_cents].any? { |message|
→       message =~ /is not a number/i
→     }, widget.errors.full_messages_for(:price_cents)
→ 
→     assert widget.errors[:manufacturer].any? { |message|
→       message =~ /must exist/i
→     }, widget.errors.full_messages_for(:manufacturer)
→ 
→   end
→ 
→   test "price cannot be 0" do
→     result = @widget_creator.create_widget(Widget.new(
→       name: "Stembolt",
→       price_cents: 0,
→       manufacturer_id: @manufacturer.id
→     ))
→ 
→     refute result.created?
→ 
→     assert result.widget.errors[:price_cents].any? { |message|
→       message =~ /greater than 0/i
→     }, result.widget.errors.full_messages_for(:price_cents)
→ 
→   end
→ 
→   test "price cannot be more than 10,000" do
→     result = @widget_creator.create_widget(Widget.new(
→       name: "Stembolt",
→       price_cents: 10_000_01,
→       manufacturer_id: @manufacturer.id
→     ))
→ 
→     refute result.created?
→ 
→     assert result.widget.errors[:price_cents].any? { |message|
→       message =~ /less than or equal to 1000000/i
→     }, result.widget.errors.full_messages_for(:price_cents)
→ 
→   end
→ 
→   test "legacy manufacturers cannot have a price under $100" do
→     legacy_manufacturer = FactoryBot.create(:manufacturer,
→       created_at: DateTime.new(2010,1,1) - 1.day)
→ 
→     result = @widget_creator.create_widget(Widget.new(
→       name: "Stembolt",
→       price_cents: 99_00,
→       manufacturer_id: legacy_manufacturer.id
→     ))
→ 
→     refute result.created?
→ 
→     assert result.widget.errors[:price_cents].any? { |message|
→       message =~ /< \$100.*legacy/i
→     }, result.widget.errors.full_messages_for(:price_cents)
→   end
→   test "email admin staff for widgets on new manufacturers " do
→     new_manufacturer = FactoryBot.create(:manufacturer,
→       name: "Cyberdyne Systems",
→       created_at: 59.days.ago)
→ 
→     result = @widget_creator.create_widget(Widget.new(
→       name: "Stembolt",
→       price_cents: 99_00,
→       manufacturer_id: new_manufacturer.id
→     ))
→ 
→     assert result.created?
→ 
→     assert_equal 1, ActionMailer::Base.deliveries.size
→     mail_message = ActionMailer::Base.deliveries.first
→     assert_equal "admin@example.com", mail_message["to"].to_s
→     assert_match /Stembolt/, mail_message.text_part.to_s
→     assert_match /Cyberdyne Systems/, mail_message.text_part.to_s
→   end
  end

# app/services/widget_creator.rb
      widget.widget_status =
        WidgetStatus.find_by!(name: "Fresh")
      widget.save
→     if widget.invalid?
→       return Result.new(created: false, widget: widget)
→     end
      if widget.price_cents > 7_500_00
        FinanceMailer.high_priced_widget(widget).deliver_now
      end

# app/mailers/admin_mailer.rb
class AdminMailer < ApplicationMailer
  def new_widget_from_new_manufacturer(widget)
    @widget = widget
    mail to: "admin@example.com"
  end
end