Ruby on rails 如何覆盖从RSpec内部验证引用的常量

我的模型有这样的自定义验证

class User
  # skip before

  MAX_FILE_SIZE = 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end

context "MAX_FILE_SIZE is default" do
  it do
    # test something
  end
end
context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
  end
  it do
    # test something
  end
end

context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
    load "user.rb"
  end
  it do
    # test something
  end
end

class User
  # skip before

  MAX_FILE_SIZE ||= 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end  

我想通过重写规范中的

MAX\u FILE\u SIZE

来测试

MAX\u FILE\u SIZE

。所以，我这样写

class User
  # skip before

  MAX_FILE_SIZE = 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end

context "MAX_FILE_SIZE is default" do
  it do
    # test something
  end
end
context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
  end
  it do
    # test something
  end
end

context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
    load "user.rb"
  end
  it do
    # test something
  end
end

class User
  # skip before

  MAX_FILE_SIZE ||= 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end  

第一次测试通过了。但是，由于未更改最大文件大小，第二次测试失败

---

你能告诉我为什么吗？以及如何解决这种情况。

文档中说，在示例运行后，常量值会重置

您是否尝试在示例中删除常量

context "MAX_FILE_SIZE is 1byte" do
  it do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
    # test something
  end
end

---

我找到了原因

由于

config/environments/test.rb

中的

config.cache\u classes=true，我的自定义验证器只创建了一次。更改的常量值对验证器的实例无效

我不知道最好的解决办法

下面的不是一个好的解决方案

在
config/environments/test.rb
中设置
config.cache\u classes=false
在设置常量值存根后重新加载模型类，如下所示

class User
  # skip before

  MAX_FILE_SIZE = 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end

context "MAX_FILE_SIZE is default" do
  it do
    # test something
  end
end
context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
  end
  it do
    # test something
  end
end

context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
    load "user.rb"
  end
  it do
    # test something
  end
end

class User
  # skip before

  MAX_FILE_SIZE ||= 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end  


模型类中禁止更改常量值，如下所示

class User
  # skip before

  MAX_FILE_SIZE = 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end

context "MAX_FILE_SIZE is default" do
  it do
    # test something
  end
end
context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
  end
  it do
    # test something
  end
end

context "MAX_FILE_SIZE is 1byte" do
  before do
    stub_const "User::MAX_FILE_SIZE", 1.bytes.to_i
    load "user.rb"
  end
  it do
    # test something
  end
end

class User
  # skip before

  MAX_FILE_SIZE ||= 10.megabytes.to_i
  validates :file, size: { max: MAX_FILE_SIZE }

  # skip after
end  


谢谢上述案件将获得通过。实际上，我的规范是rspec rails的请求规范。这个常数似乎改变了。但是，第二个例子失败了。