2.5 --> 2.6: backwards incompatible change in MalformedCSVError#new

[Spakman]

In Ruby 2.5, CSV::MalformedCSVError simply inherited from RuntimeError. In 2.6, it defines its own #new, taking 2 arguments (as opposed to the single argument of RuntimeError).

Code explicitly raising new errors of this class outside of the CSV library implementation itself breaks since it doesn't include the second argument (a line number).

Is making the line number optional something you'd entertain?

[kou]

Could you show codes that creating CSV::MalformedCSVError?

[Mifrill]

@kou just this:

    def raise_malformed_csv_error
      raise CSV::MalformedCSVError
    end

with 2.6 ruby it's raised this:

     Failure/Error: raise CSV::MalformedCSVError
     
     ArgumentError:
       wrong number of arguments (given 0, expected 2)

because of this:
36e1cb2

csv/lib/csv.rb

Lines 212 to 219 in 36e1cb2

	class MalformedCSVError < RuntimeError
	attr_reader :line_number
	alias_method :lineno, :line_number
	def initialize(message, line_number)
	@line_number = line_number
	super("#{message} in line #{line_number}.")
	end
	end

For Ruby 2.5 code was without required arguments:

  # The error thrown when the parser encounters illegal CSV formatting.
  class MalformedCSVError < RuntimeError; end

  #

https://bugs.ruby-lang.org/issues/16133

[kou]

Thanks.
One more question. Why do you want to raise CSV::MalformedCSVError manually?

[Mifrill]

@kou well, in our specific case, we have a logic with check of valid headers

...
raise_malformed_csv_error unless valid_headers?
...

    def raise_malformed_csv_error
      raise CSV::MalformedCSVError
    end

    def valid_headers?
      has_required_columns? && has_only_supported_columns?
    end

So, I'm thinking about this error like a any error of CSV parsing, like a it's an explicit error, which was inherited from RuntimeError.

[kou]

Thanks.
It seems that it's an application specific error and it's not a general CSV error. So you should use your own error class instead of reusing CSV::MalformedCSVError.

[Mifrill]

@kou okay, thanks, I will take note and we will discuss it with colleagues. We've just got this error while ruby update. Now we'got how to resolve it. Thank you

[kou]

OK. I close this.