parallel_testsとは

マルチコアCPUで並列実行するテスト用のGem

parallel_testsを導入する

インストール

Gemfile編集

Terminal

vi Gemfile

# Gemfile
gem 'parallel_tests'

database.yml編集

並列実行の為にデータベースを複数用意します
その為にはdatabase.ymlのdatabase属性の末尾に変数を追加する必要がある

Terminal

vi config/database.yml

# config/database.yml
test:
  database: hogehoge_db
  ⬇️
  database: hogehoge_db<%= ENV['TEST_ENV_NUMBER'] %>

gem install

Terminal

# gem install parallel_tests

copy gem to docker container directory

この辺りはDocker composeの構成によります（特定のディレクトリにGemを配置している場合は各構成に合わせてコピーペースト

Terminal

$ cp ../.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/cache/parallel_tests-2.28.0.gem vendor/cache/

セットアップ

docker-build (need gem install)

Terminal

$ docker-compose build

docker up

Terminal

$ docker-compose up

parallel database create (setup) Development環境

Terminal

# rails parallel:create
warning: parser/current is loading parser/ruby24, which recognizes
warning: 2.4.0-compliant syntax, but you are running 2.4.1.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
warning: parser/current is loading parser/ruby24, which recognizes
warning: 2.4.0-compliant syntax, but you are running 2.4.1.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
Database 'hoge_test_user_01' already exists
Database 'hoge_test_user_02' already exists
Database 'hoge_test_user_01' already exists
Database 'hoge_test_user_02' already exists
Database 'hoge_test_user_012' already exists
Created database 'hoge_test_masterENV'
[turntable] *** executing to database: hoge_test_user_01
[turntable] *** executing to database: hoge_test_user_02
[turntable] *** executing to database: hoge_test_user_01
[turntable] *** executing to database: hoge_test_user_02
Database 'hoge_test_user_022' already exists
Created database 'hoge_test_masterENV2'
[turntable] *** executing to database: hoge_test_user_012
Created database 'hoge_test_user_012'
[turntable] *** executing to database: hoge_test_user_022
Created database 'hoge_test_user_022'
[turntable] *** executing to database: hoge_test_user_012
[turntable] *** executing to database: hoge_test_user_022

# rails parallel:create RAILS_ENV=test
・・・

Terminal

# rails parallel:prepare
warning: parser/current is loading parser/ruby24, which recognizes
warning: 2.4.0-compliant syntax, but you are running 2.4.1.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
warning: parser/current is loading parser/ruby24, which recognizes
warning: 2.4.0-compliant syntax, but you are running 2.4.1.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
[turntable] *** executing to database: hoge_test_user_012
[turntable] *** executing to database: hoge_test_user_022
[turntable] *** executing to database: hoge_test_user_012
[turntable] *** executing to database: hoge_test_user_022
[turntable] *** executing to database: hoge_test_user_01
[turntable] *** executing to database: hoge_test_user_02
[turntable] *** executing to database: hoge_test_user_01
[turntable] *** executing to database: hoge_test_user_02

# rails parallel:prepare RAILS_ENV=test
・・・

db setup

Terminal

# rails parallel:rails[db:setup] 使えない模様・・・
👇
# rails parallel:rake[db:setup]
# rails parallel:rake[db:egg]

parallel_testsを導入した結果

rspec 検証

Terminal

# time rails parallel:spec

結果

parallel前

real    15m24.627s
user    6m37.260s
sys     1m43.660s

parallel後

real    6m41.693s
user    4m42.820s
sys     2m13.030s

注釈

rspecをparallel_testsを使って高速化する