ruby-on-rails – Rspec,shoulda,validate_uniqueness_of具有范

describe Productlimit do

  before(:each) do 
    @productlimit = Factory.create(:productlimit,:user => Factory.create(:user))
  end

  subject { @productlimit }

  ...

  it { should validate_uniqueness_of(:price_cents).scoped_to(:direction_down,:currency,:market_id,:user_id) }
  ...
end

但我得到以下混乱的错误：

1) Productlimit 
     Failure/Error: it { should validate_uniqueness_of(:price_cents).scoped_to(:direction_down,:user_id) }
       Expected errors to include "has already been taken" when price_cents is set to 9530,got errors: ["direction_down has already been taken (false)"]

你可以帮我吗？我不明白为什么这不工作,因为错误信息似乎是正确的？

编辑：

在其他情况下也会发生这种情况：

# product_spec.rb
...
it { should validate_numericality_of(:price).with_message("price_cents must be greater than 0 (0)") }  

# rake spec:models
Failure/Error: it { should validate_numericality_of(:price).with_message("price_cents must be greater than 0 (0)") }
   Expected errors to include "price_cents must be greater than 0 (0)" when price is set to "abcd",got errors: ["price_cents must be greater than 0 (0)"]