从 FactoryGirl create 获取未定义的方法“to_sym”

Question

我有一个简单的规范：

describe Setting do
  subject { create(:setting) }
  it { should be_valid }
end

与工厂：

FactoryGirl.define do
  factory :setting do
    key "some_key"
    value "The appropriate value"
  end 
end

当我运行规范时：

rake spec SPEC=spec/models/setting_spec.rb 

我收到以下错误：

1) Setting should be valid                                                                                              
 Failure/Error: it { should be_valid }
 NoMethodError:
   undefined method `to_sym' for nil:NilClass
 # ./spec/models/setting_spec.rb:6:in `block (2 levels) in <top (required)>'

我尝试使用 let(:setting) 代替主题行并得到同样的错误。

按 cmets 编辑：

错误是指it { should be_valid }这一行

型号是：

class Setting < ActiveRecord::Base
  attr_accessor :key, :value
  validates_uniqueness_of :key
end

这是踪迹：

 # /var/lib/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/validations/uniqueness.rb:26:in `validate_each'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validator.rb:153:in `block in validate'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validator.rb:150:in `each'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validator.rb:150:in `validate'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:310:in `_callback_before_1986'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:407:in `_run__3464288744618424855__validate__1974049388273351148__callbacks'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:405:in `__run_callback'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:385:in `_run_validate_callbacks'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:81:in `run_callbacks'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validations.rb:228:in `run_validations!'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validations/callbacks.rb:53:in `block in run_validations!'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:403:in `_run__3464288744618424855__validation__1974049388273351148__callbacks'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:405:in `__run_callback'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:385:in `_run_validation_callbacks'
 # /var/lib/gems/1.9.1/gems/activesupport-3.2.16/lib/active_support/callbacks.rb:81:in `run_callbacks'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validations/callbacks.rb:53:in `run_validations!'
 # /var/lib/gems/1.9.1/gems/activemodel-3.2.16/lib/active_model/validations.rb:195:in `valid?'
 # /var/lib/gems/1.9.1/gems/activerecord-3.2.16/lib/active_record/validations.rb:69:in `valid?'
 # /var/lib/gems/1.9.1/gems/rspec-expectations-2.14.5/lib/rspec/expectations/handler.rb:24:in `handle_matcher'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/memoized_helpers.rb:68:in `should'
 # ./spec/models/setting_spec.rb:6:in `block (2 levels) in <top (required)>'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example.rb:114:in `instance_eval'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example.rb:114:in `block in run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example.rb:254:in `with_around_each_hooks'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example.rb:111:in `run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example_group.rb:390:in `block in run_examples'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example_group.rb:386:in `map'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example_group.rb:386:in `run_examples'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/example_group.rb:371:in `run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:28:in `block (2 levels) in run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:28:in `map'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:28:in `block in run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/reporter.rb:58:in `report'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:25:in `run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:77:in `rescue in run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:73:in `run'
 # /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:17:in `block in autorun'

spec_helper.rb：http://pastebin.com/6fzDXnux

Answer 1

此错误的直接原因是该类派生自 ActiveRecord::Base，而 ActiveRecord 无法确定主键（AR 需要用于验证唯一性）。这很可能是因为您没有运行迁移来创建 settings 表，或者您在没有主键的情况下创建了 settings 表。

违规行（基于提供的回溯）：

relation = relation.and(table[finder_class.primary_key.to_sym].not_eq(record.send(:id))) if record.persisted?

请注意，to_sym 正在被 finder_class.primary_key 调用。

Answer 2

您也可以通过在模型中添加以下行来解决相同问题。

self.primary_key = 'id'

例如

Class Person
  self.primary_key = 'id'

end