From: Justin Collins <justincollins@...>
Date: 2013-06-12T05:17:31+09:00
Subject: Re: How would I refactor these four `unless` statements?

On 06/11/2013 12:38 PM, Rafal C. wrote:
> Let's say I have the following four `unless` statements in a row. At
> first I thought about using `if` and `elsif` statements and negate the
> condition but I'm not sure which way is suitable/readable/good-practice.
>
>    unless @params.include?(:js_code) || @params.include?(:code_url)
>      raise BadParameters, 'You must include at least one...'
>    end
>    unless @params.include?(:compilation_level)
>      raise BadParameters, 'The :compilation_level...'
>    end
>    unless @params.include?(:output_format)
>      raise BadParameters, 'The :output_format...'
>    end
>    unless @params.include?(:output_info)
>      raise BadParameters, 'The :output_info...'
>    end
>
> Thanks in advance!
>

For the conditions that are really similar, you could do something like:

   missing_keys = [:compilation_level, :output_format, :output_info] - 
@params.keys

   unless missing_keys.empty?
     raise BadParameters, "Missing keys: #{missing_keys.inspect}"
   end


-Justin