Some methods to detect whether an Enumberable object contains a constrained number of elements that match a given condition

A second reason to create this gem is to explore various other services -- see the status list below.


  • Version: Gem Version
  • Travis CI: Build Status
  • Code Climate: Code Climate


Add this line to your application's Gemfile:

gem 'limit_detectors'

And then execute:

$ bundle

Or install it yourself as:

$ gem install limit_detectors


In your code you can require 'limit_detectors' then define you classes (or use built-in classes like Array, Hash or other enumerable objects), extend these objects with LimitDetectors (or include the module in your class) and then call at_most? (or àt_least?') on your object.

For example:

$pry -I lib -r limit_detectors
[1] pry(main)> a = [1, 2, 3, 4, 5]
=> [1, 2, 3, 4, 5]
[2] pry(main)> a.extend LimitDetectors
=> [1, 2, 3, 4, 5]
[3] pry(main)> a.at_most?(4){|e| e.odd?}
=> true # There are indeed no more than 4 odd numbers in the array
[4] pry(main)> a.at_most?(1){|e| e.even?}
=> false # In fact there are two even numbers in the array


Please note the current version of 0.0.something, which means the future releases may not be compatible with the current version.

This gem is tested with these Ruby versions (MRI, unless JRuby):

  • 2.5.8
  • 2.6.6
  • 2.7.1

as well as a current version of JRuby.


  1. Fork it ([my-github-username]/limit_detectors/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Reporting a bug

Please, provide answers to the following questions, when submitting a bug report:

  1. What's actually happening? What the observed behaviour?
  2. What's the expectation, i.e. what should have happened?
  3. Why did you expect this behaviour?

If you provide an RSpec check that demonstrates the bug, would give extra good karma, especially in case of a minimal check, something that just demonstrates the bug without any (or much) overhead.