ruby-on-rails - Rspec raise_error 不适用于自定义错误

Question

我有一个自定义错误类 ApiError :

class ApiError < StandardError
  attr_reader :message, :code, :details, :raw_json
  def initialize(json)
    @message  = json["message"]
    @code     = json["code"]
    @raw_json = json

    super json.to_s
  end
end

所以我试着写了几个规范来测试它，但没有一个通过。
第一:

it 'raises an error' do
  expect { raise ApiError, "Some error"}.to raise_error ApiError.new("Some error")
end

它失败了:

Failure/Error: expect { raise ApiError, "Some error"}.to raise_error ApiError, "Some error"

       expected ApiError with "Some error", got #<ApiError: Some error> with backtrace:
         # ./spec/models/...:39:in `block (4 levels) in <top (required)>'
         # ./spec/models/...:39:in `block (3 levels) in <top (required)>'

还有一个让我很惊讶的选择:

it 'raises an error 2' do
  expect { raise ApiError, "Some error"}.to raise_error ApiError, "Some error"
end

它失败了:

Failure/Error: expect { raise ApiError, "Some error"}.to raise_error ApiError.new("Some error")

       expected #<ApiError: Some error>, got #<ApiError: Some error> with backtrace:
         # ./spec/models/...:43:in `block (4 levels) in <top (required)>'
         # ./spec/models...:43:in `block (3 levels) in <top (required)>'

所以呢？在消息中，它们看起来相当平等。任何人都可以知道是什么问题吗？还有，写 ApiError, "123" 有什么区别？和 ApiError.new("123")在规范文件中？

==========更新==========

用设置 message 注释掉一个字符串ApiError 类中的属性，以防它不覆盖默认值没有帮助

class ApiError < StandardError
  attr_reader :message, :code, :details, :raw_json
  def initialize(json)
    # @message  = json["message"]
    @code     = json["code"]
    @raw_json = json

    super json.to_s
  end
end

Answer 1

message是 StandardError 的一个属性.您正在覆盖它和 message是 nil在您的异常对象中。重命名您的属性，它应该通过

class ApiError < StandardError
  attr_reader :api_error_message, :code, :details, :raw_json
  def initialize(json)
    @api_error_message  = json["message"]
    @code     = json["code"]
    @raw_json = json

    super json.to_s
  end
end

it 'raises an error' do
  expect { raise ApiError, "Some error"}.to raise_error ApiError, "Some error"
end

更新:

如果需要设置message至 json["message"]

  class ApiError < StandardError
    attr_reader :code, :details, :raw_json
    def initialize(json)
      @code     = json["code"]
      @raw_json = json

      super json["message"]
    end
  end

  it 'raises an error' do
    expect { raise ApiError, {"message" => "Some error"}}.to raise_error(ApiError, "Some error")
  end