关注所包含的测试 belongs_to答案

【问题标题】：Test belongs_to included by concern关注所包含的测试 belongs_to
【发布时间】：2016-10-21 13:12:27
【问题描述】：

我有模特

class Survey < ActiveRecord::Base
  include Respondable
end

在 DB surveys 表中有下一个字段：

responses_saved_date
responses_saved_by_type
responses_saved_by_id

和模块

module Respondable
  extend ActiveSupport::Concern

  included do
    belongs_to :responses_saved_by,    :polymorphic => :true
  end

  def update_saved_settings!(person=nil)
    self.responses_saved_date = Time.now
    self.responses_saved_by   = person
    self.save
  end
end

根据这篇博文https://semaphoreci.com/community/tutorials/testing-mixins-in-isolation-with-minitest-and-rspec，我尝试为负责任的关注编写单元测试，以隔离测试它

这是我的 rspec：

describe Respondable do
  class DummySurvey < ActiveRecord::Base
    include Respondable
  end

  subject { DummySurvey.new }

  it { should belong_to(:responses_saved_by) }

  it 'saves the settings with user' do
    subject.update_saved_settings!(user)

    subject.responses_saved_date.should_not be_nil
    subject.responses_saved_by.should eq user
  end

  it 'saves the settings without user' do
    subject.update_saved_settings!

    subject.responses_saved_date.should_not be_nil
    subject.responses_saved_by.should be_nil
  end
end

当我运行测试时，我收到下一个错误：

Failure/Error: subject { DummySurvey.new }
ActiveRecord::StatementInvalid:
    PG::UndefinedTable: ERROR:  relation "dummy_survey" does not exist
    LINE 5: WHERE a.attrelid = '"dummy_survey"'...
                                 ^
    : SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                         pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
                    FROM pg_attribute a LEFT JOIN pg_attrdef d
                      ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                   WHERE a.attrelid = '"dummy_survey"'::regclass
                     AND a.attnum > 0 AND NOT a.attisdropped
                   ORDER BY a.attnum

【问题讨论】：

标签： ruby-on-rails ruby testing rspec activesupport-concern

【解决方案1】：

我想如果你写

class DummySurvey < Survey

而不是

class DummySurvey < ActiveRecord::Base

你应该是金色的。当您定义一个继承自 ActiveRecord::Base 的类时，期望您的数据库具有正确的表和列（通过迁移设置，并由 Rails 命名约定确定）。

Rails 应该在测试运行后重置测试数据库，因此使用与实际应用相同的模型类是可行的。

【讨论】：

【解决方案2】：

也许一些单独测试它的方法是：

describe Respondable do
  class DummySurvey
    attr_accessor :responses_saved_date, :responses_saved_by
    def save
      @saved = true
    end

    def persisted?
      @saved
    end

    def self.belongs_to(association, options = {})
      @associations ||= {}
      @associations[association] = OpenStruct.new(active_record: true, macro: :belongs_to,
        options: options, foreign_key: options[:foreign_key] || "#{association}_id")
    end

    def self.reflect_on_association(association)
      @associations ||= {}
      @associations[association]
    end

    def self.column_names
      ['responses_saved_by_type', 'responses_saved_by_id']
    end

    include Respondable
  end

  subject { DummySurvey.new }
  let(:user) { Object.new }

  it { should belong_to(:responses_saved_by) }

  it 'saves the settings with user' do
    subject.update_saved_settings!(user)

    subject.responses_saved_date.should_not be_nil
    subject.responses_saved_by.should eq user
    subject.should be_persisted
  end

  it 'saves the settings without user' do
    subject.update_saved_settings!

    subject.responses_saved_date.should_not be_nil
    subject.responses_saved_by.should be_nil
    subject.should be_persisted
  end
end

或者，您可以在测试中为类DummySurvey 创建数据库表或设置现有表的table_name：

class DummySurvey < ActiveRecord::Base
  self.table_name = 'surveys'
  include Respondable
end

【讨论】：