Tagged: tdd

Fix slow rspec on macOS – 10x speedup

For some reason rspec was running horribly slow on my macOS laptop, with a simple test suite taking over 30 seconds to run. This made TDD almost unbearable:


>rspec spec/features
...
Finished in 27.29 seconds (files took 33.71 seconds to load)
8 examples, 2 failures

After some googling, the recommended approach is to compile spring binstubs for rspec. For good hygiene, we’ll use bundler to do this, and use guard so we can leave a terminal window open on a second monitor and see test results automatically after saving code changes.


# edit /Gemfile
group :development do
gem 'guard'
gem 'guard-rspec'
gem 'spring'
gem 'spring-commands-rspec'
gem 'spring-watcher-listen'
end

>bundle install --path vendor/bundle --without=production --binstubs # install gems into vendor/bundle
>echo 'vendor/bundle' >> .gitignore # don't track installed gemfiles

Now replace the bundler rails binstubs with updated rails gem versions and insert spring:


>bundle exec rails app:update:bin # now regenerate standard rails binstubs
>bin/rails app:update:bin # norly plox use teh rail binstubs
>bundle exec spring binstub --all # use spring versions of binstubs
>bundle exec guard init # create guard config file /Guardfile

Note: bin/rails can get overwritten by bundler and stop accepting commands eg “bin/rails server” will show the default output of “rails” instead of launching the server. This can be fixed by running “bundle binstubs railties” then updating the binstubs again as per the instructions above.

Running “bundle config –delete bin” will stop bundler from blatting bin/rails but this also means you will need to manually generate binstubs using eg “bundle binstubs cucumber”.

Note also that bundler pulls in config from $APP/.bundle/config and ~/.bundle.config, so disabling binstubs in your app folder can be overridden by your home directory config.


# edit /Guardfile
guard :rspec, cmd: “bundle exec bin/rspec”, failed_mode: :keep do

>bundle exec guard


Finished in 1.72 seconds (files took 3.17 seconds to load)
5 examples, 2 failures

From 33 seconds to 3 seconds. Nice!

Note: now instead of using “bundle exec” rails or rake, use bin/$GEMNAME eg “bin/rails console”. The spring server running in the background will respond much faster than booting rails each time.