Split a big test file into multiple chunks and run them in parallel

Install

gem install parallel_split_test

Usage

1: prepare your databases

To use 1 database per test-process, add this to your config/database.yml

test:
  database: yourproject_test<%= ENV['TEST_ENV_NUMBER'] %>

• TEST_ENV_NUMBER is '' for the first process and 2 for the 2nd, it reuses your normal test database
• Optionally install parallel_tests to get database helper tasks like rake parallel:prepare

2: find a slow/big test file

# spec/xxx_spec.rb
require "spec_helper"

describe "X" do
  it {sleep 5}
  it {sleep 5}
  it {sleep 5}
end

3: run

parallel_split_test spec/xxx_spec.rb [regular test options]

Output

parallel_split_test spec/xx_spec.rb

Running examples in 2 processes
.

Finished in 5 seconds
1 example, 0 failures
..

Finished in 1 seconds
2 examples, 0 failures

Summary:
1 example, 0 failures
2 examples, 0 failures
Took 10.06 seconds with 2 processes

TIPS

• use -o/--out to get unified/clean output from all processes
• set number of processes to use with PARALLEL_SPLIT_TEST_PROCESSES environment variable
• unify JUnit output for rspec

TODO

• Cucumber support
• Test::Unit / Minitest support

Authors

Contributors

• bootstraponline

Michael Grosser
michael@grosser.it
License: MIT