style is the only thing.

a.rb

# shitty 


   attributes[:name] = options[:name] unless options[:name].blank?
    attributes[:first_name] = options[:first_name] unless options[:first_name].blank?
    attributes[:last_name] = options[:last_name] unless options[:last_name].blank?
    attributes[:linkedin_id] = options[:linkedin_id] unless options[:linkedin_id].blank?
    attributes[:company] = options[:company] unless options[:company].blank?
    attributes[:company_id] = options[:company_id] unless options[:company_id].blank?
    attributes[:linkedin_picture_url] = options[:linkedin_picture_url] unless options[:linkedin_picture_url].blank?



# shitty, but i can read it...

    attributes[:name]                 = options[:name]                 unless options[:name].blank?
    attributes[:first_name]           = options[:first_name]           unless options[:first_name].blank?
    attributes[:last_name]            = options[:last_name]            unless options[:last_name].blank?
    attributes[:linkedin_id]          = options[:linkedin_id]          unless options[:linkedin_id].blank?
    attributes[:company]              = options[:company]              unless options[:company].blank?
    attributes[:company_id]           = options[:company_id]           unless options[:company_id].blank?
    attributes[:linkedin_picture_url] = options[:linkedin_picture_url] unless options[:linkedin_picture_url].blank?



# at least it's DRY, but fuck it's hard to read... 

   [:name, :first_name, :last_name, :linkedin_id, :company, :company_id, :linkedin_picture_url].each do |key|
     attributes[key] = options[key] unless options[key].blank?
   end



# minimum required to be good 
#
# * the variable name makes the intention clear
# * the list isn't jammed onto one line hiding typos and confounding quick editing
# * it's primed for configuration (whitelist is an option)
# * stack errors come from *one line*
# * it separates the logic of listing what to whitelist and how to extract a key from options
# * reading a commit diff is actually possible (thanks @drbrain)
#


    whitelist = [ 
      :name,
      :first_name, 
      :last_name,
      :linkedin_id,
      :company,
      :company_id,
      :linkedin_picture_url
    ]
    
    whitelist.each do |key|
      attributes[key] = options[key] unless options[key].blank?
    end

Well, for Hash at least, the Ruby Spec project codifies the "hanging comma":

https://github.com/rubyspec/rubyspec/blob/master/language/hash_spec.rb#L48

And similar specs for a hanging comma at the end of an argument list for send:

https://github.com/rubyspec/rubyspec/blob/master/language/versions/send_1.9.rb

I don't see anything equivalent for Array unfortunately. However, there does seem to be support in the grammar parse.y for it:

(excerpted from four locations in the file)

primary     : literal
        | tLBRACK aref_args ']'
            {
            /*%%%*/
            if ($2 == 0) {
                $$ = NEW_ZARRAY(); /* zero length array*/
            }
            else {
                $$ = $2;
            }
            /*%
            $$ = dispatch1(array, escape_Qundef($2));
            %*/
            }
aref_args   : none
        | args trailer
            {
            $$ = $1;
            }
        | args ',' assocs trailer
            {
            /*%%%*/
            $$ = arg_append($1, NEW_HASH($3));
            /*%
            $$ = arg_add_assocs($1, $3);
            %*/
            }
        | assocs trailer
            {
            /*%%%*/
            $$ = NEW_LIST(NEW_HASH($1));
            /*%
            $$ = arg_add_assocs(arg_new(), $1);
            %*/
            }
        ;

trailer     : /* none */
        | '\n'
        | ','
        ;