Rake tasks to run specs in parallel, to use multiple CPUs and speedup test runtime.

Setup

script/plugin install git://github.com/grosser/parallel_specs.git

Add <%= ENV['TEST_ENV_NUMBER'] %> to the database name for the test environment in config/database.yml,
it is '' for process 1, and '2' for process 2.

test:
  adapter: mysql
  database: xxx_test<%= ENV['TEST_ENV_NUMBER'] %>
  username: root

For each environment, create the databases

mysql -u root -> create database xxx_test2;

Run like hell :D

rake spec:parallel:prepare[2] #db:reset for each database

rake spec:parallel[1] --> 86 seconds
rake spec:parallel    --> 47 seconds (default = 2)
rake spec:parallel[4] --> 26 seconds
...

Example output

2 processes for 210 specs, ~ 105 specs per process
... test output ...
Took 29.925333 seconds

TIPS

• ./script/generate rspec if you are running rspec from gems (this plugin uses script/spec which may fail if rspec files are outdated)
• with zsh this would be rake "spec:parallel:prepare[3]"

TODO

• find out how many CPUs the user has here
• grab the 'xxx examples ..' line and display them after all tests have finished

Authors

inspired by pivotal labs

Contributors

• Joakim Kolsjö -- joakim.kolsjo<$at$>gmail.com

Michael Grosser
grosser.michael@gmail.com
Hereby placed under public domain, do what you want, just do not hold me accountable...