Fasterer will suggest some speed improvements which you can check in detail at the fast-ruby repo.
Please note that you shouldn't follow the suggestions blindly. Using a while loop instead of a each_with_index probably shouldn't be considered if you're doing a regular Rails project, but maybe if you're doing something very speed dependent such as Rack or if you're building your own framework, you might consider this speed increase.
gem install fasterer
Run it from the root of your project:
app/models/post.rb:57 Array#select.first is slower than Array#detect. app/models/post.rb:61 Array#select.first is slower than Array#detect. db/seeds/cities.rb:15 Hash#keys.each is slower than Hash#each_key. db/seeds/cities.rb:33 Hash#keys.each is slower than Hash#each_key. test/options_test.rb:84 Hash#merge! with one argument is slower than Hash#. test/module_test.rb:272 Don't rescue NoMethodError, rather check with respond_to?. spec/cache/mem_cache_store_spec.rb:161 Use tr instead of gsub when grepping plain strings.
Configuration is done through the .fasterer.yml file. This can placed in the root of your project, or any ancestor folder.
- Turn off speed suggestions
- Blacklist files or complete folder paths
speedups: rescue_vs_respond_to: true module_eval: true shuffle_first_vs_sample: true for_loop_vs_each: true each_with_index_vs_while: false map_flatten_vs_flat_map: true reverse_each_vs_reverse_each: true select_first_vs_detect: true sort_vs_sort_by: true fetch_with_argument_vs_block: true keys_each_vs_each_key: true hash_merge_bang_vs_hash_brackets: true block_vs_symbol_to_proc: true proc_call_vs_yield: true gsub_vs_tr: true select_last_vs_reverse_detect: true getter_vs_attr_reader: true setter_vs_attr_writer: true exclude_paths: - 'vendor/**/*.rb' - 'db/schema.rb'
These 3rd-party integrations enable you to run
as part of a larger framework.
This integration allows to use
fastereras either a pre-commit hook or within CI. It uses the https://pre-commit.com/ framework for managing and maintaining multi-language pre-commit hooks.
Github-action for running fasterer via reviewdog. Reviewdog provides a way to post review comments in pull requests.
- find vs bsearch
- Array#count vs Array#size
- Enumerable#each + push vs Enumerable#map
- Hash#merge vs Hash#merge!
- String#casecmp vs String#downcase + ==
- String concatenation
- String#match vs String#start_with?/String#end_with?
- String#gsub vs String#sub
- Fork it ( https://github.com/DamirSvrtan/fasterer/fork )
- Create your feature branch (
git checkout -b my-new-feature)
- Commit your changes (
git commit -am 'Add some feature')
- Push to the branch (
git push origin my-new-feature)
- Create a new Pull Request