README.md
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# Fasterer
Make your Rubies go faster with this command line tool highly inspired by [fast-ruby](https://github.com/JuanitoFatas/fast-ruby) and [Sferik's talk at Baruco Conf](https://speakerdeck.com/sferik/writing-fast-ruby).
Fasterer will suggest some speed improvements which you can check in detail at the [fast-ruby repo](https://github.com/JuanitoFatas/fast-ruby).
**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.
## Installation
```shell
gem install fasterer
```
## Usage
Run it from the root of your project:
```shell
fasterer
```
## Example output
```
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
Configuration is done through the **.fasterer.yml** file. This can placed in the root of your
project, or any ancestor folder.
Options:
* Turn off speed suggestions
* Blacklist files or complete folder paths
Example:
```yaml
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'
```
## Integrations
These 3rd-party integrations enable you to run `fasterer` automatically
as part of a larger framework.
* https://github.com/jumanjihouse/pre-commit-hooks
This integration allows to use `fasterer` as 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.
* https://github.com/prontolabs/pronto-fasterer
Pronto runner for Fasterer, speed improvements suggester.
[Pronto](https://github.com/mmozuras/pronto) also integrates via
[danger-pronto](https://github.com/RestlessThinker/danger-pronto) into the
[danger](https://github.com/danger/danger) framework for pull requests
on Github, Gitlab, and BitBucket.
* https://github.com/vk26/action-fasterer
Github-action for running fasterer via [reviewdog](https://github.com/reviewdog/reviewdog). Reviewdog provides a way to post review comments in pull requests.
## Speedups TODO:
4. find vs bsearch
5. Array#count vs Array#size
7. Enumerable#each + push vs Enumerable#map
17. Hash#merge vs Hash#merge!
20. String#casecmp vs String#downcase + ==
21. String concatenation
22. String#match vs String#start_with?/String#end_with?
23. String#gsub vs String#sub
## Contributing
1. Fork it ( https://github.com/DamirSvrtan/fasterer/fork )
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create a new Pull Request