Rails：如何测试 state_machine？

Question

请帮帮我。我很困惑。我知道如何编写模型的状态驱动行为，但我不知道我应该在规范中写什么...

我的model.rb文件看起来

class Ratification < ActiveRecord::Base
  belongs_to :user

  attr_protected :status_events

  state_machine :status, :initial => :boss do
    state :boss
    state :owner
    state :declarant
    state :done

    event :approve do
      transition :boss => :owner, :owner => :done
    end

    event :divert do
      transition [:boss, :owner] => :declarant
    end

    event :repeat do
      transition :declarant => :boss
    end

  end
end

我使用state_machine gem。

请告诉我课程。

Answer 1

这个问题很老，但我有同样的问题。以state_machine gem 为例：

class Vehicle
  state_machine :state, :initial => :parked do
    event :park do
      transition [:idling, :first_gear] => :parked
    end

    event :ignite do
      transition :stalled => same, :parked => :idling
    end

    event :idle do
      transition :first_gear => :idling
    end

    event :shift_up do
      transition :idling => :first_gear, :first_gear => :second_gear, :second_gear => :third_gear
    end

    event :shift_down do
      transition :third_gear => :second_gear, :second_gear => :first_gear
    end
  end
end

我的解决方案是：

describe Vehicle do

  before :each do
    @vehicle = Factory(:vehicle)
  end

  describe 'states' do
    describe ':parked' do
      it 'should be an initial state' do
        # Check for @vehicle.parked? to be true
        @vehicle.should be_parked
      end

      it 'should change to :idling on :ignite' do
        @vehicle.ignite!
        @vehicle.should be_idling
      end

      ['shift_up!', 'shift_down!'].each do |action|
        it "should raise an error for #{action}" do
          lambda {@job_offer.send(action)}.should raise_error
        end
      end
    end
  end
end

我正在使用：

• 红宝石 (1.9.3)
• 导轨 (3.1.3)
• rspec (2.8.0.rc1)
• factory_girl (2.3.2)
• state_machine (1.1.0)

Answer 2

state_machine_rspec gem 包含许多用于编写简明规范的辅助方法。

 describe Ratification do
   it { should have_states :boss, :declarant, :done, :owner }
   it { should handle_events :approve, when: :boss }
   it { should handle_events :approve, when: :owner }
   it { should handle_events :divert, when: :boss }
   it { should handle_events :divert, when: :owner }
   it { should handle_events :repeat, when: :declarant }
   it { should reject_events :approve, :divert, :repeat, when: :done }
   it { should reject_events :approve, :divert, :repeat, when: :done }
 end

这些 RSpec 匹配器将协助处理高级别的 state_machine 规范。从这里开始，需要为can_approve?、can_divert? 和can_repeat? 的业务案例编写规范。

Answer 3

我写了一个 RSpec 自定义匹配器。它允许以优雅而简单的方式测试状态流：check it out

Answer 4

不幸的是，我认为您需要对每个状态进行测试 -> 状态转换，这可能感觉像是代码重复。

describe Ratification do
  it "should initialize to :boss" do
    r = Ratification.new
    r.boss?.should == true
  end

  it "should move from :boss to :owner to :done as it's approved" do
    r = Ratification.new
    r.boss?.should == true
    r.approve
    r.owner?.should == true
    r.approve
    r.done?.should == true
  end

  # ...
end

幸运的是，我认为这通常适合集成测试。例如，支付系统的一个极其简单的状态机是：

class Bill < ActiveRecord::Base
  belongs_to :account

  attr_protected :status_events

  state_machine :status, :initial => :unpaid do
    state :unpaid
    state :paid

    event :mark_as_paid do
      transition :unpaid => :paid
    end
  end
end

您可能仍然需要进行上述单元测试，但您可能还会进行集成测试，例如：

describe Account do
  it "should mark the most recent bill as paid" do
    @account.recent_bill.unpaid?.should == true
    @account.process_creditcard(@credit_card)
    @account.recent_bill.paid?.should == true
  end
end

这是一个很大的放弃，但希望这是有道理的。我也不太习惯 RSpec，所以希望我没有在那里犯太多错误。如果有更优雅的测试方法，我还没有找到。