Low-Latency Development

An overview of 15 utilities that make it faster and easier to develop Rails applications.

Transcript

1. Low-Latency Development Photo by Mike Boening: https://flic.kr/p/AYGcEi
2. Low-Latency Development Shorten the feedback loop while you are: 1. Writing code 2. Running code
3. Part 1: Writing code
4. Guard The Codebase Photo by Thomas Quine: https://flic.kr/p/sq4KeJ
5. Setting up Guard 1. Add a guard plugin to the Gemfile 2. Run `guard init PLUGIN_NAME` 3. Customize the Guardfile as needed 4. Run `bundle exec guard` when starting development
6. group :guard do
 gem 'guard-bundler', require: false
 gem 'guard-jshintrb', require: false
 gem 'guard-rails', require: false
 gem 'guard-rubocop', require: false
 gem 'guard-rspec', require: false
 gem 'guard-scss-lint', require: false
 gem 'guard-spring', require: false
 gem 'terminal-notifier', require: false
 gem 'terminal-notifier-guard', require: false
 end Gemfile
7. Guard Bundler guard :bundler do
 watch('Gemfile')
 end https://github.com/guard/guard-bundler Guardfile
8. Guard JShintRB guard :jshintrb do
 watch(%r{^app/assets/javascripts/.+.js})
 watch(%r{^spec/javascripts/.+.js})
 end https://github.com/thegarage/guard-jshintrb Guardfile
9. Guard Rails guard 'rails' do
 watch('Gemfile.lock')
 watch(%r{^(config|lib)/.*})
 end https://github.com/ranmocy/guard-rails Guardfile
10. Guard Rubocop guard :rubocop, all_on_start: false, cli: ['--format', 'clang', '--rails', '--config', './.hound.yml' ] do
 watch(%r{.+\.rb$})
 watch(%r{(?:.+/)?\.hound\.yml$}) { |m| File.dirname(m[0]) }
 end https://github.com/yujinakayama/guard-rubocop Guardfile
11. group :development do
 gem 'spring-commands-rspec'
 end guard :rspec, cmd: 'bundle exec bin/rspec' do
 …
 end Guard RSpec https://github.com/guard/guard-rspec Gemfile Guardfile
12. Guard SCSS Lint guard :scsslint, all_on_start: false do
 watch(%r{.+\.scss$})
 end https://github.com/chrislopresto/guard-scss-lint Guardfile
13. Guard Spring guard 'spring', bundler: true do
 watch('Gemfile.lock')
 watch(%r{^config/})
 watch(%r{^spec/(support|factories)/})
 watch(%r{^spec/factory.rb})
 end https://github.com/mknapik/guard-spring Guardfile
14. Guard Notifications notification :terminal_notifier, subtitle: 'Example Application' https://github.com/Springest/terminal-notifier-guard Guardfile
15. Guard Pitfalls • Guard plugins are usually written by third parties. Not all libraries have guard integration; some plugins are out of date. • Notification proxying is fussy with tmux & tmate • File system event detection is platform-specific • Running multiple plugins at once increases the maintenance burden e.g. spring & rspec.
16. Part 2: Running code
17. REPL FTW Photo by Thomas Quine: https://flic.kr/p/7MEW5
18. http://pryrepl.org/ $ pry
 [1] pry(main)> Terminal
19. Better Errors https://github.com/charliesome/better_errors Gemfile gem 'better_errors', group: :development
20. group :development, :test do
 gem 'byebug'
 gem 'pry-byebug'
 end Byebug https://github.com/deivid-rodriguez/byebug Gemfile byebug Insert into code at desired breakpoint
21. Rails Console http://guides.rubyonrails.org/command_line.html#rails-console $ ./bin/rails console
 Running via Spring preloader in process 11166
 Loading development environment (Rails 4.2.5)
 [1] pry(main)> Terminal Gemfile gem 'pry-rails', group: :development
22. REPL Pitfalls • UNSAFE for production • Can be an excuse to ignore logs & logging • Extra work to attach to a remote or detached process e.g. spring
23. Low-Latency Development Get the information you need quickly.