RSpec 中的虚拟 ActiveRecord 模型

Question

我有一个模块可以向 ActiveRecord 添加一些功能。为了测试这个模型，我想在 RSpec 中创建一个虚拟模型，这样我就可以独立于我的生产模型：

describe MyModule do
  before do
    ActiveRecord::Base.connection.create_table :articles, force: true do |t|
      t.string(:name)
    end
  end

  after do
    ActiveRecord::Base.connection.drop_table(:articles, if_exists: true)
  end

  class Article < ApplicationRecord
    belongs_to :author
  end

  class Author < ApplicationRecord
    has_many :articles
  end

  it "does some stuff" do
    ...
  end
end

问题是，Rubocop 抱怨RSpec/LeakyConstantDeclaration并建议将固定类提取到let：

  let(:article_class) do
    Class.new(ApplicationRecord) do
      has_many :comments
    end
  end
  let(:author_class) do
    Class.new(ApplicationRecord) do
      has_many :articles
    end
  end

  before do
    stub_const("Article", article_class)
    stub_const("Author", author_class)
  end

当我运行单个测试时，这非常有效。但是，当我运行多个测试时，它们会失败，因为缺少文章和/或作者。过去的测试似乎会影响其他测试。

ActiveRecord 似乎不能很好地处理这种模型定义。所以我想知道是否有更好的方法在RSpec中定义虚拟模型？

Answer 1

您可以提取共享上下文

RSpec.shared_context 'with test tables  and models' do 
  before do
    ActiveRecord::Base.connection.create_table :articles, force: true do |t|
      t.string(:name)
    end

    stub_const("Article", article_class)
    stub_const("Author", author_class)
  end

  after do
    ActiveRecord::Base.connection.drop_table(:articles, if_exists: true)
  end

  let(:article_class) do
    Class.new(ApplicationRecord) do
      has_many :comments
    end
  end

  let(:author_class) do
    Class.new(ApplicationRecord) do
      has_many :articles
    end
  end

并将其包含在每个需要它的测试中。

describe MyModule do
  include_context 'with test tables  and models' 

  # your examples here
end