Grouping Rspec Tests

grouping_rspec_test

#!/usr/bin/env ruby
require 'optparse'

options = { group: 0, total_groups: 0, pattern: 'spec/**/*_spec.rb' }
OptionParser.new do |opts|
  opts.banner = "Usage: bin/rspec [options]"
  opts.on('-t', '--total-groups NUMBER', 'Total number of rspec groups') do |t|
    options[:total_groups] = t.to_i
  end
  opts.on('-g', '--group NUMBER', 'Execute group number out of total groups') do |g|
    options[:group] = g.to_i
  end
  opts.on('-p' '--pattern spec/**/*_spec.rb', 'The pattern used to find the rspec files') do |p|
    options[:pattern] = p
  end
  opts.on('-r' '--rspec-options', 'Options that you want to pass to rspec') do |r|
  end
end.parse!
if options[:group].to_i <= 0
  puts 'group has to be greater than zero'
  exit
end
if options[:group] > options[:total_groups]
  puts 'group has to be less than or equal to total groups'
  exit
end
groups = Array.new(options[:total_groups]) { { total: 0, tests: [] } }
files = Dir[options[:pattern]].sort { |a, z| File.stat(a).size <=> File.stat(z).size }
index = 0
while files.size > 0
  groups[index][:tests] << files.pop
  groups[index][:total] += 1
  index += 1
  index = 0 if index >= groups.size
end
group = groups[options[:group] - 1]
puts group
if group[:total].zero?
  puts "There are no tests for group #{options[:group]}"
  exit 0
end
puts "Executing rspec: #{group[:total]} in group #{options[:group]} of #{options[:total_groups]}"
if system("bin/bundle exec rspec #{group[:tests].join(' ')} -f progress --color --tty")
  exit 0
else
  exit 1
end

Usage of this script.

grouping_rspec_test --total-groups 5 --group 1
grouping_rspec_test --total-groups 5 --group 2
grouping_rspec_test --total-groups 5 --group 3
grouping_rspec_test --total-groups 5 --group 4
grouping_rspec_test --total-groups 5 --group 5

The script takes into account also the size of test files and tries to keep the total groups of each RSpec test file equal. This helps with not having one group taking much longer than the rest as the work should be more distributed. This script is not a recommended replacement to some of the other parallel tools out there however it is nice if you just need something quick and dirty to get the job done.