ruby-on-rails - 在 RSpec 中引用类名

Question

将常量或带引号的字符串传递给类名的 rspec 有什么区别吗？

常数:

require 'spec_helper'

describe Match do
end

引用:

require 'spec_helper'

describe "Match" do
end

Answer 1

describe 的第一个参数是该示例组的描述。但是，根据 https://www.relishapp.com/rspec/rspec-core/v/3-0/docs/subject/implicitly-defined-subject :

If the first argument to the outermost example group is a class, an instance of that class is exposed to each example via the subject method.

它还添加了:

While the examples below demonstrate how subject can be used as a user-facing concept, we recommend that you reserve it for support of custom matchers and/or extension libraries that hide its use from examples.

行为规则比上面暗示的要复杂一点，但是，至少从 RSpec 2.99 开始是这样。例如，非类参数仍然通过 subject 方法公开，但最里面的示例组优先。此外，关于实例化类的规则将适用，即使它不是最外层的示例组。

以下传递示例说明了更多情况:

# simple case for class
describe Object do
  specify {subject.should be_an_instance_of(Object)}
end

# simple case for non-class
describe "String" do
  specify {subject.should be_eql("String")}
end

# nested non-class arguments; inner takes precedence
describe "Outer String" do
  describe "String" do
    specify {subject.should be_eql("String")}
  end
end

# nested class arguments; outer takes precedence
describe Object do
  describe Module do
    specify {subject.should be_an_instance_of(Object)}
  end
end

# class inside non-class; class takes precedence
describe "String" do
  describe Object do
    specify {subject.should be_an_instance_of(Object)}
  end
end

# class inside explicit subject; explicit subject takes precedence
describe "Outer string" do
  subject {"String"}
  describe Object do
    specify {subject.should be_eql("String")}
  end
end

# class outside explicit subject; explicit subject takes precedence
describe Object do
  subject {"String"}
  describe Module do
    specify {subject.should be_eql("String")}
  end
end