Rails/FindEach should ignore queries with lock

[artplan1]

Is your feature request related to a problem? Please describe.

find_each doesn't play well with lock in query.

example: https://dev.betterdoc.org/tools/2019/04/05/use-pessimistic-locking-to-make-long-running-tasks-in-rails-free-of-race-conditions.html

Describe the solution you'd like

add lock to IGNORED_METHODS https://github.com/rubocop-hq/rubocop-rails/blob/master/lib/rubocop/cop/rails/find_each.rb#L25

Describe alternatives you've considered

allow to configure ignored_methods for this cop

[koic]

Oddly, it doesn't reproduce on the master branch testing. Can you provide a display for rubocop -V?

[artplan1]

sorry, I probably didn't explain it well

in our case rubocop-rails proposes to change User.lock.each to User.lock.find_each that leads to unexpected results.
this issue is explained here as well: https://dev.betterdoc.org/tools/2019/04/05/use-pessimistic-locking-to-make-long-running-tasks-in-rails-free-of-race-conditions.html

just in case

rubocop -V                 
1.4.0 (using Parser 2.7.2.0, rubocop-ast 1.1.1, running on ruby 2.7.2 x86_64-darwin19)
  - rubocop-performance 1.9.0
  - rubocop-rails 2.8.1