Rails Shoulda Matcher - 测试模块化模型的问题答案

【问题标题】：Rails Shoulda Matcher - Issue with testing Modularized ModelRails Shoulda Matcher - 测试模块化模型的问题
【发布时间】：2018-01-21 16:44:08
【问题描述】：

我正在使用 RSpec 和 Shoulda-Matchers 来测试我的模型。

我知道如何测试模型是否是这样的

class Headquarter < ApplicationRecord
  has_many :branches
end

class Branch < ApplicationRecord
  belongs_to :headquarter
end

我可以像这样写一个 shoulda-matcher：

RSpec.describe Headquarter, type: :model do
  it { should have_many(branches)}
end

RSpec.describe Branch, type: :model do
  it { should belong_to(:headquarter)}
end

我的问题

但是当我使用模块化模型时会出现问题，例如Company::Headquarter和Company::Branch

我尝试使用此代码：

RSpec.describe Company::Headquarter, type: :model do
  it { should have_many(:company_branches)}
end

但它给了我一个错误，似乎它没有将模型识别为模块化。

Failure/Error: it { should have_many(:company_branches)}
   Expected Company::Headquarter to have a has_many association called company_branches (Company::Branch does not have a headquarter_id foreign key.)

当我期待 company_headquarter_id时，请注意错误中的headquarter_id。这就是它无法识别 ID 的原因。

【问题讨论】：

标签： ruby-on-rails rspec

【解决方案1】：

戳代码文档后，发现两个有用的sn-p：

对于自定义类名

  # ##### class_name
  #
  # Use `class_name` to test usage of the `:class_name` option. This
  # asserts that the model you're referring to actually exists.
  #
  #     class Person < ActiveRecord::Base
  #       has_many :hopes, class_name: 'Dream'
  #     end
  #
  #     # RSpec
  #     RSpec.describe Person, type: :model do
  #       it { should have_many(:hopes).class_name('Dream') }
  #     end
  #
  #     # Minitest (Shoulda)
  #     class PersonTest < ActiveSupport::TestCase
  #       should have_many(:hopes).class_name('Dream')
  #     end

对于自定义外键：

  # ##### with_foreign_key
  #
  # Use `with_foreign_key` to test usage of the `:foreign_key` option.
  #
  #     class Person < ActiveRecord::Base
  #       has_many :worries, foreign_key: 'worrier_id'
  #     end
  #
  #     # RSpec
  #     RSpec.describe Person, type: :model do
  #       it { should have_many(:worries).with_foreign_key('worrier_id') }
  #     end
  #
  #     # Minitest (Shoulda)
  #     class PersonTest < ActiveSupport::TestCase
  #       should have_many(:worries).with_foreign_key('worrier_id')
  #     end

如何解决

型号

如果您有上述型号：

Company::Headquarter，添加foreign_key标签

class Company::Headquarter < ApplicationRecord
  has_many :company_branches, :class_name => 'Company::Branch', foreign_key: 'company_headquarter_id'

end

Company::Branch

class Company::Branch < ApplicationRecord
  belongs_to :company_headquarter, :class_name => 'Company::Headquarter'
end

对于 RSpec

headquarter_spec.rb，注意 class_name 和 with_foreign_key 函数。

RSpec.describe Company::Headquarter, type: :model do
  it { should have_many(:company_branches).class_name('Company::Branch').with_foreign_key('company_headquarter_id')}
end

来源：Shoulda-Matchers, association matcher Documentation

【讨论】：