Rspec custom matchers for Rails query counter

• Prevent N+1 problem

Add this line to your application's Gemfile:

gem 'rspec-query-limit'

And then execute:

$ bundle

Support for rspec versions 2 and 3

Add to your spec/spec_helper.rb

require 'rspec/query_limit'

And then you can use matchers

describe UserEmails do
  describe '#primary_emails' do
    users = User.all
    expect { UserEmails.primary_emails(users) }.to query_limit_eq(2)
  end
end

Numbers of queries must be equal

query_limit_eq(number)

Stackoverflow

1. Fork it
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