Codeshift
A Ruby codemod CLI to transform your source code using AST(Abstract Syntax Trees) and the parser gem. It is typically used on Ruby codebase like RAILS applications and other stuff.
Installation
$ gem install codeshift
Usage
This tool requires a transform.rb
file which contains the transform logic to be
applied on the source files in a folder.
$ codeshift -t [TRANSFORM FILE] [PATHS]
To apply the transform logic on your app/models
files
$ codeshift -t transform.rb app/models
For example if you want to reverse the local variable names and method names in your code you will be doing something like this:
Create a new Ruby file with the tranformation logic to be applied on the AST of the source code. For writing transforms you can make use of Ruby AST Explorer and cybertron
transform.rb
# Your Transform Class should always extend from
# Parser:: TreeRewriter
class Transform < Parser::TreeRewriter
def on_lvasgn(node)
# Reverse the variable names
replace(node.loc.name, node.children[0].to_s.reverse)
end
def on_def(node)
replace(node.loc.name, node.children[0].to_s.reverse)
end
end
If your source code looks like below in a folder called ~/Desktop/test/ruby
sample.rb
tips = ["hello", "world"]
def print_tips
tips.each { |key, value| print "Tip #{key}: #{value}" }
end
Then use the transform against your source code
$ codeshift -t transform.rb ~/Desktop/test/ruby
Then your source will be transformed something like:
sample.rb
spit = ["hello", "world"]
def spit_tnirp
tips.each { |key, value| print "Tip #{key}: #{value}" }
end
Options
Usage: codeshift -t
- --version Print version number
- -t, --transform=TRANSFORM path to the transform file. Can be either a local path or url (default: ./transform.rb)
- -h, --help Prints this help
transform-file
The transform file could be a local file or a remote url. For example you can use a remote transform like below:
$ codeshift -t https://gist.githubusercontent.com/[user]/.../transform.rb ~/Desktop/test/ruby
path
The path could be a list of directories or files separated by space.
$ codeshift -t transform.rb ~/app/legacy/ruby ~/app/old
$ codeshift -t transform.rb ~/code/legacy/app/models/account.rb ~/old/app/models/customer.rb
Related tools
Development
After checking out the repo, run bin/setup
to install dependencies. Then, run rake spec
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/rajasegar/codeshift. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.
Code of Conduct
Everyone interacting in the Codeshift project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.