ruby-on-rails – 由于模型中的外键,FactoryGirl炸毁了规格

我有一个模型Foo,它将state_code作为外键. States表是(或多或少)静态表,用于保存50个州的代码和名称,以及其他美国邮政编码(例如波多黎各的“PR”).我选择使用state_code作为状态的主键和Foo上的外键,而不是像state_id那样.它对人类更好,并简化了我想调用状态代码的视图逻辑. (编辑 – 只是为了澄清：我并不是说从视图中调用代码来访问模型;我的意思是将状态显示为@ foo.state_code似乎比@ foo.state.state_code更简单.)

Foo与模特Bar也有很多关系.两个模型规范都传递了有效工厂的规范,但出于某种原因,当运行构建Bar实例的功能规范时,由于与state_code相关的外键问题,测试会爆炸

我得到了所有模型的模型规格,包括有效工厂的测试.但是,每当我尝试为’Bar’创建测试对象时,我都会遇到麻烦.使用构建会炸毁Foo中state_code的外键错误(尽管事实上Foo工厂明确指定了一个确认在状态中作为state_code存在的值).对Bar对象使用build_stubbed似乎不会持久保存该对象.

型号：

# models/foo.rb
class Foo < ActiveRecord
  belongs_to :state,foreign_key: 'state_code',primary_key: 'state_code'
  has_many :bars
  validates :state_code,presence: true,length: { is: 2 }

  # other code omitted...
end

# models/state.rb
class State < ActiveRecord
  self.primary_key = 'state_code'
  has_many :foos,foreign_key: 'state_code'
  validates :state_code,uniqueness: true,length: { is: 2 } 

  # other code omitted...
end

# models/bar.rb
class Bar < ActiveRecord
  belongs_to :foo

  # other code omitted
end

下面的工厂为我的Foo和Bar模型传递绿色,所以从模型的角度看工厂似乎很好：

# spec/factores/foo_bar_factory.rb
require 'faker'
require 'date'

FactoryGirl.define do
  factory :foo do
    name { Faker::Company.name }
    city { Faker::Address.city }
    website { Faker::Internet.url }
    state_code { 'AZ' } # Set code for Arizona b/c doesn't matter which state
  end

  factory :bar do
    name { Faker::Name.name }
    website_url { Faker::Internet.url }
    # other columns omitted
    association :foo
  end
end

……基本规格是：

# spec/models/foo_spec.rb
require 'rails_helper'

describe Foo,type: :model do
  let(:foo) { build(:foo) }

  it "has a valid factory" do
    expect(foo).to be_valid
  end

  # code omitted...
end

# spec/models/bar_spec.rb
require 'rails_helper'

describe Bar,type: :model do
  let(:bar) { build_stubbed(:bar) } # have to build_stubbed - build causes error

  it "has a valid factory" do
    expect(bar).to be_valid
  end
end

该规范通过,没有任何问题.但是如果我使用build(：bar)代替build而不是build_stubbed,我在外键上会出错：

1) Bar has a valid factory
     Failure/Error: let(:bar) { build(:bar) }
ActiveRecord::InvalidForeignKey:
       PG::ForeignKeyViolation: ERROR:  insert or update on table "bars" violates foreign key constraint "fk_rails_3dd3a7c4c3"
       DETAIL:  Key (state_code)=(AZ) is not present in table "states".

代码’AZ’肯定在状态表中,所以我不清楚它失败的原因.

在一个功能规范中,我试图创建持久存储在数据库中的bar实例,因此我可以测试它们是否在#index,#show和#edit actions中正确显示.但是我似乎无法让它正常工作.功能规范失败：
#spec / features / bar_pages_spec.rb
需要’rails_helper’

feature "Bar pages" do
  context "when signed in as admin" do
    let!(:bar_1) { build_stubbed(:bar) }
    let!(:bar_2) { build_stubbed(:bar) }
    let!(:bar_3) { build_stubbed(:bar) }

  # code omitted...

   scenario "clicking manage bar link shows all bars" do
     visit root_path
     click_link "Manage bars"
     save_and_open_page

     expect(page).to have_css("tr td a",text: bar_1.name)
     expect(page).to have_css("tr td a",text: bar_2.name)
     expect(page).to have_css("tr td a",text: bar_3.name)
   end
 end

此规范失败,并显示一条指示无匹配的消息.使用save_and_open_page不会在视图中显示预期的项目. (我有一个包含开发数据的工作页面,所以我知道逻辑实际上按预期工作). The thoughtbot post on build_stubbed表示它应该持久化对象：

It makes objects look look like they’ve been persisted,creates
associations with the build_stubbed strategy (whereas build still uses
create),and stubs out a handful of methods that interact with the
database and raises if you call them.

…但在我的规范中它似乎没有这样做.尝试在此规范中使用build代替build_stubbed会产生上述相同的外键错误.

我真的被困在这里了.模型似乎有有效的工厂并通过所有规格.但是功能规范要么炸毁外键关系,要么似乎不会在视图之间保留build_stubbed对象.感觉就像一团糟,但我找不到正确的方法来解决它.我在实践中有实际的,工作的观点,做我期望的 – 但我希望测试覆盖率有效.

UPDATE

我回去并更新了所有的模型代码,以删除state_code的自然键.我遵循了@Max的所有建议. Foo表现在使用state_id作为状态的外键;我按照推荐等方式复制了app / models / concerns / belongs_to_state.rb的代码.

更新了schema.rb：

create_table "foos",force: :cascade do |t|
  # columns omitted
  t.integer  "state_id"
end

create_table "states",force: :cascade do |t|
  t.string   "code",null: false
  t.string   "name"
end

add_foreign_key "foos","states"

模型规格通过,我的一些简单的功能规格通过.我现在意识到只有在创建了多个Foo对象时才会出现问题.发生这种情况时,由于列上的唯一性约束,第二个对象失败：代码

Failure/Error: let!(:foo_2) { create(:foo) }
     ActiveRecord::RecordInvalid:
       Validation failed: Code has already been taken

我试图在工厂中直接设置：state_id列：foo以避免调用：state工厂.例如.

# in factory for foo:
state_id { 1 }

# generates following error on run:
Failure/Error: let!(:foo_1) { create(:foo) }
     ActiveRecord::InvalidForeignKey:
       PG::ForeignKeyViolation: ERROR:  insert or update on table "foos" violates foreign key constraint "fk_rails_5f3d3f12c3"
       DETAIL:  Key (state_id)=(1) is not present in table "states".

显然,state_id不在状态中,因为它在状态上是id,在foos中是state_id.另一种方法：

# in factory for foo:
state { 1 }    # alternately w/ same error ->  state 1

ActiveRecord::AssociationTypeMismatch:
   State(#70175500844280) expected,got Fixnum(#70175483679340)

要么：

# in factory for foo:
state { State.first }

ActiveRecord::RecordInvalid:
   Validation failed: State can't be blank

我真正想做的就是创建一个Foo对象的实例,让它包含与states表中某个状态的关系.我不期望对状态表做很多改变 – 它实际上只是一个参考.

我不需要创建一个新状态.我只需要使用states表中的：id列中的66个值之一填充Foo对象上的外键state_id.从概念上讲,工厂：foo理想情况下只需为：state_id选择1到66之间的整数值.它在控制台中工作：

irb(main):001:0> s = Foo.new(name: "Test",state_id: 1)
=> #<Foo id: nil,name: "Test",city: nil,created_at: nil,updated_at: nil,zip_code: nil,state_id: 1>
irb(main):002:0> s.valid?
  State Load (0.6ms)  SELECT  "states".* FROM "states" WHERE "states"."id" = $1 LIMIT 1  [["id",1]]
  State Exists (0.8ms)  SELECT  1 AS one FROM "states" WHERE ("states"."code" = 'AL' AND "states"."id" != 1) LIMIT 1
=> true

我现在唯一可以看到的方法是摆脱状态中的代码列的唯一性约束.或者 – 删除foos和状态之间的外键约束,并让Rails强制执行该关系.

对不起,大量的帖子……

create_table "countries",force: :cascade do |t|
    t.string   "code",null: false # ISO 3166-1 alpha-2 or alpha-3
    t.datetime "created_at",null: false
    t.datetime "updated_at",null: false
end

add_index "countries",["code"],name: "index_countries_on_code"

create_table "states",force: :cascade do |t|
    t.integer  "country_id"
    t.string   "code",null: false
    t.string   "name",null: false
    t.datetime "created_at",null: false
end

add_index "states",name: "index_states_on_code"
add_index "states",["country_id","code"],name: "index_states_on_country_id_and_code"
add_index "states",["country_id"],name: "index_states_on_country_id"

class State < ActiveRecord::Base
  # Only the State model should be validating its attributes.
  # You have a major violation of concerns.
  validates_uniqueness_of :state_code
  validates_length_of :state_code,is: 2
end

# app/models/concerns/belongs_to_state.rb
module BelongsToState

  extend ActiveSupport::Concern

  included do
    belongs_to :state
    validates :state,presence: true
    validates_associated :state # will not let you save a Foo or Bar if the state is invalid.
  end

  def state_code
    state.state_code
  end

  def state_code= code
    self.assign_attributes(state: State.find_by!(state_code: code))
  end
end

class Foo < ActiveRecord::Base
  include BelongsToState
end

class Bar < ActiveRecord::Base
  include BelongsToState
end

# spec/factories/foos.rb
require 'faker'
FactoryGirl.define do
  factory :foo do
    name { Faker::Company.name }
    city { Faker::Address.city }
    website { Faker::Internet.url }
    state
  end
end

# spec/factories/states.rb
FactoryGirl.define do
  factory :state do
    state_code "AZ"
    name "Arizona"
  end
end

require 'rails_helper'

RSpec.describe Foo,type: :model do

  let(:foo) { build(:foo) }
  it { should validate_presence_of :state }

  it 'validates the associated state' do
    foo.state.state_code = 'XYZ'
    foo.valid?
    expect(foo.errors).to have_key :state
  end

  describe '#state_code' do
    it 'returns the state code' do
      expect(foo.state_code).to eq 'AZ'
    end
  end

  describe '#state_code=' do
    let!(:vt) { State.create(state_code: 'VT') }
    it 'allows you to set the state with a string' do
      foo.state_code = 'VT'
      expect(foo.state).to eq vt
    end
  end
end

# spec/models/state_spec.rb
require 'rails_helper'

RSpec.describe State,type: :model do
  it { should validate_length_of(:state_code).is_equal_to(2) }
  it { should validate_uniqueness_of(:state_code) }
end

feature "Bar management" do
  context "as an Admin" do
    let!(:bars){ 3.times.map { create(:bar) } }

    background do
      visit root_path
      click_link "Manage bars"
    end

    scenario "I should see all the bars on the management page" do
      # just testing a sampling is usually good enough
      expect(page).to have_link bars.first.name 
      expect(page).to have_link bars.last.name 
    end  

    scenario "I should be able to edit a Bar" do
      click_link bars.first.name
      fill_in('Name',with: 'Moe′s tavern')
      # ...
    end  
  end
end