Tips for Job Interviews as a Junior Software Developer Sep 27, 2020
As coding bootcamps such as Coder Academy and General Assembly churn out more and more software developers, and as more and more people…
Please also see this blog post on tweaking your ruby GC settings.
I use and love DatabaseCleaner, although historically I had never paid too much attention on the performance of its varies cleaning strategies - I’d always used truncation.
We use Postgres, and after digging around and finding out the difference between DELETE and TRUNCATE, I ended up improving our test suite speed by about 30-40% simply by tweaking the cleaning strategies.
RSpec.configure do |config|
config.before :suite do
DatabaseCleaner.clean_with :truncation
DatabaseCleaner.strategy = :transaction
end
config.before do
if example.metadata[:js] || example.metadata[:type] == :feature
DatabaseCleaner.strategy = :deletion
else
DatabaseCleaner.strategy = :transaction
DatabaseCleaner.start
end
end
config.after do
DatabaseCleaner.clean
end
endEssentially, we want to truncate the DB only once before the whole suite runs to ensure a clean slate DB, then we only want to use deletion on Capybara tests, everything else should just use transaction which is the fastest strategy.
Now, as a bonus, I have just discovered @amatsuda’s DatabaseRewinder which is a lightweight alternative that supports only ActiveRecord. It offers comparable performance with a much similar API.
RSpec.configure do |config|
config.before :suite do
DatabaseRewinder.clean_all
end
config.after do
DatabaseRewinder.clean
end
endBy the way, we also use parallel_tests to scale our test suite to multiple processes, even on Travis CI and Wercker.
Hooray to faster tests! :)