Enumerize messes up Arel "LIKE" queries

[zor-el]

This is quite a nasty issue because of its rather broad impact. It disrupts the operation of other gems that rely on Arel, most notably the Ransack gem where any "contains"-type search on an enumerized field gives the wrong results.

Enumerize version: 2.1.2

Reproduce:

class User < ApplicationRecord
  extend Enumerize
  enumerize :role, in: [:user, :a_admin, :b_admin], predicates: true
end

t = User.arel_table
puts User.where(t[:role].matches '%admin%').to_sql

Outcome:

SELECT "users".* FROM "users" WHERE ("users"."role" LIKE NULL) -- LIKE NULL ?!?

Expected outcome (this is produced w/o the enumerize line):

SELECT "users".* FROM "users" WHERE ("users"."role" LIKE "%admin%")

[nashby]

Hey @zor-el! Thanks for reporting this issue! I've created a PR fixing this issue. Could you please it out? #305

[zor-el]

Hey there! The fix works for me! Eagerly awaiting the merge, better yet, the bugfix release so I can bundle it with my project as usual. Great work!

[zor-el]

I figured I'd close the issue once the fix is merged.

[zor-el]

@nashby, after looking at the fix again, I think serialize now always returns the passed value. Let me elaborate.

The fix was done in the Enumerize::ActiveRecord::Type#serialize, which now has the code:

def serialize(value)
  v = @attr.find_value(value)
  (v && v.value) || value
end

After expanding @attr.find_value (and imagining there was an attr_reader for value_hash), it is equivalent to:

def serialize(value)
  v = @attr.value_hash[value.to_s] unless value.nil?
  (v && v.value) || value
end

AFAICT, value_hash[s].value == s for any s in value_hash.keys. Which means the return value is value.to_s if that is found in the value_hash, or value if it is not.

Hence, we can just as well go for the simpler and faster implementation:

def serialize(value)
  value.to_s
end

What do you think?

[nashby]

@zor-el hm, don't think it always returns passed value. Why do you think so? We even have test that checks it https://github.com/brainspec/enumerize/blob/master/test/activerecord_test.rb#L513

And no, we can't use value.to_s since we need to support custom values like enumerize :role, in: {:user => 1, :admin => 2}

[zor-el]

Uh, okay, turns out my AFAICT missed that use case. The way that I've been always using it (enumerize :foo, in: [:bar, :baz]) it would have.

[nashby]

@zor-el no worries! Thanks for looking into it! ❤️

[zor-el]

@nashby, but when I think about it, isn't serialize supposed to transform into the database representation of the value? And isn't the database representation of an enumized attribiute always a string? And wouldn't that be the key also in a case like enumerize :foo, in: { bar: 1, baz: 2 }?

Otherwise, if serialize('bar') would return 1, then 1 would be stored in the database instead of 'bar', which IMO wouldn't be correct.

Just asking. I'm not at all sure. I've been doing Rails for quite some time now, but there are so many corners I haven't explored yet in depth... :o