Rails 4.2, arel 6: wrong number of arguments for #accept

[slothbear]

Thanks for search_cop! I was using attr_searchable before, and I've been upgrading my app. I just started a new Rails 4.2 project and did the most basic search_cop installation.

class Bug < ActiveRecord::Base
  include SearchCop
  search_scope :search do
    attributes :title
  end
end

When I try a search, I get the following error:

Bug.search("cimon")
ArgumentError: wrong number of arguments (1 for 2)
    from /Users/adam/.rvm/gems/ruby-2.1.2/gems/arel-6.0.0.beta2/lib/arel/visitors/reduce.rb:6:in `accept'

I don't know this area very well, but it looks like arel 6 added a second argument to the #accept method:
rails/arel@a6a7c75
which search_cop uses in query_builder:
https://github.com/mrkamel/search_cop/blob/master/lib/search_cop/query_builder.rb#L12

I tried downgrading arel to lower version, but it said arel 6 is required for rails 4.2.

[mrkamel]

Hi, thx for the report. I'll dig into this.

[slothbear]

I forgot to mention – I included fairly few details in my report because it seemed easily reproducible. If you don't find it so, I'm happy to provide more.

[mrkamel]

Sure, no problem. It's indeed rather obvious, but not as simple as adding the missing param. Arel now seems to favor #compile over #accept. That alone would not be an issue, but Arel 6 seems to include many API specific changes, especially this commit in Arel, which IMO focuses on performance tweaks, breaks a lot in SearchCop: rails/arel@93d7213 which will force us to now wrap every String with Arel::Nodes.build_quoted before handing it out to Arel. Otherwise we'll get exceptions telling us that plain strings are unsupported. Thus, i'm thinking about dropping Arel. SearchCop already has a lot of code to handle specific Arel versions, just take a look into https://github.com/mrkamel/search_cop/blob/master/lib/search_cop/arel/visitors.rb - and generating the SQL by ourselves would not be that hard.

[mrkamel]

Hi, as you probably noticed, i created a branch 'drop_arel' which replaces Arel with a custom visitors. I'll merge it into master, probably today or tomorrow and bump a new gem version. In the meantime, you're very welcome to try it out:

gem 'search_cop', :git => 'https://github.com/mrkamel/search_cop.git', :branch => 'drop_arel'

[slothbear]

Looks good. I'm not going to get to it for the next couple of days, but I'll definitely try things this week. Thanks for the quick fix.

[mrkamel]

In the meantime, this has been merged into master.