我无法使用 FactoryGirl.create 创建对象，验证失败 用户已被占用

Question

我正在尝试使用 gem FactoryGirl 创建一个平衡对象，但是当我打开 Rails 控制台并编写命令 FactoryGirl.create(:balance) 时出现错误。

我在我的模型之间创建关联 has_one 和 belongs_to，此外还为外部字段中的唯一键添加验证，这些是我的模型。

余额

class Balance < ActiveRecord::Base
  #association macros
  belongs_to :user
  belongs_to :wallet

  #validation macros
  validates :user_id, presence: true, uniqueness: true
  validates :wallet_id, presence: true, uniqueness: true
end

钱包

class Wallet < ActiveRecord::Base
  #association macros
  belongs_to :user
  belongs_to :wallet_type
  has_one :bank_account, dependent: :destroy
  has_one :debit_card, dependent: :destroy
  has_one :credit_card, dependent: :destroy
  has_one :balance, dependent: :destroy

  #validation macros
  validates :user_id, presence: true
  validates :wallet_type_id, presence: true

end

用户

class User < ActiveRecord::Base
  #association macros  
  ...
  has_one :salt
  has_one :balance

end

工厂平衡

FactoryGirl.define do
  factory :balance do
    user
    wallet
    amount 2000
  end
end

我的平衡测试

RSpec.describe @Balance, type: :model do

  describe "Balance" do

    before(:each) do
      @user = FactoryGirl.create(:user)
      @wallet = FactoryGirl.create(:wallet)
      @balance = FactoryGirl.create(:balance, user_id: @user[:id], wallet_id: @wallet[:id])
    end

    it "when is valid" do
      expect(@balance).to be_valid
    end

    it "when is presence user_id" do
      expect(@balance).to validate_presence_of :user_id
    end

    it "when is presence wallet_id" do
      expect(@balance).to validate_presence_of :wallet_id
    end

    pending "when is uniqueness user_id" do
      expect(@balance).to validate_uniqueness_of :user_id
    end

    pending "when is uniqueness wallet_id" do
      expect(@balance).to validate_uniqueness_of :wallet_id
    end

    it "when is belongs_to :user" do
      should belong_to(:user)
    end

    it "when is belongs_to :wallet" do
      should belong_to(:wallet)
    end

  end

end

当我创建余额对象FactoryGirl.create(:balance) 时，出现以下错误。

ActiveRecord::RecordInvalid: Validation failed: User has already been taken
    from .../lib/active_record/validations.rb:79:in `raise_record_invalid'
    from .../lib/active_record/validations.rb:43:in `save!'
    from .../lib/active_record/attribute_methods/dirty.rb:29:in `save!'
    from .../lib/active_record/transactions.rb:291:in `block in save!'
    from .../lib/active_record/transactions.rb:351:in `block in with_transaction_returning_status'
    from .../lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
    from .../lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
    from .../lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
    from .../lib/active_record/transactions.rb:220:in `transaction'
    from .../lib/active_record/transactions.rb:348:in `with_transaction_returning_status'
    from .../lib/active_record/transactions.rb:291:in `save!'
    from .../lib/factory_girl/configuration.rb:14:in `block in initialize'
    from .../lib/factory_girl/evaluation.rb:15:in `[]'
    from .../lib/factory_girl/evaluation.rb:15:in `create'
    from .../lib/factory_girl/strategy/create.rb:12:in `block in result'
    from .../lib/factory_girl/strategy/create.rb:9:in `tap'
    from .../lib/factory_girl/strategy/create.rb:9:in `result'
    from .../lib/factory_girl/factory.rb:42:in `run'
    from .../lib/factory_girl/factory_runner.rb:23:in `block in run'
    from .../lib/active_support/notifications.rb:166:in `instrument'
    from .../lib/factory_girl/factory_runner.rb:22:in `run'
    from .../lib/factory_girl/strategy_syntax_method_registrar.rb:20:in `block in define_singular_strategy_method'
    from (irb):1
    from .../lib/rails/commands/console.rb:110:in `start'
    from .../lib/rails/commands/console.rb:9:in `start'
    from .../lib/rails/commands/commands_tasks.rb:68:in `console'
    from .../lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from ..lib/rails/commands.rb:17:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'irb(main):002:0> a= FactoryGirl.create(:balance)

Answer 1

问题

您在运行测试时看到此错误：

ActiveRecord::RecordInvalid: Validation failed: User has already been taken

因为您在之前的任何测试运行中都创建了该用户。所以，它得到了验证错误。

解决方案

您可以使用database_cleaner gem，这将确保您运行测试的测试数据库处于干净状态。

您可以通过将其添加到您的 Gemfile 来安装 gem：

group :test do
  gem 'database_cleaner'
end

然后，运行：

bundle install

之后，在您的spec_helper.rb 中配置database_cleaner：

RSpec.configure do |config|
  config.before(:suite) do
    DatabaseCleaner.strategy = :transaction
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end
end

此配置将确保上次测试运行的数据在每个规范之后都会被截断。而且，每次运行新规范时，都是针对干净的数据库进行的。

您可以从 gem 的 documentation 页面查看如何使用 RSpec 配置 database_cleaner。