= churn

A Project to give the churn file, class, and method for a project for a given checkin
Over time the tool adds up the history of chruns to give the number of times a file, class, or method is changing during the life of a project.
Churn for files is immediate, but classes and methods requires buildings up a history using churn between revisions. The history is stored in ./tmp

Currently has full Git, Mercurial (hg), and Bazaar (bzr) support, and partial SVN support (supports only file level churn currently)

Authors:
* danmayer
* ajwalters 
* cldwalker
* absurdhero

Execute with:
    rake churn #after adding require 'lib/tasks/churn_tasks' to projects rakefile
    churn
    
== Example Output
  **********************************************************************
  * Revision Changes 
  **********************************************************************
  Files: 
  +-------------------------------+
  | file                          |
  +-------------------------------+
  | Rakefile                      |
  | lib/churn/churn_calculator.rb |
  +-------------------------------+
   
  Classes: 
  +-------------------------------+-----------------+
  | file                          | klass           |
  +-------------------------------+-----------------+
  | lib/churn/churn_calculator.rb | ChurnCalculator |
  +-------------------------------+-----------------+
   
  Methods: 
  +-------------------------------+-----------------+-------------------------------+
  | file                          | klass           | method                        |
  +-------------------------------+-----------------+-------------------------------+
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#filters       |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#display_array |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#to_s          |
  +-------------------------------+-----------------+-------------------------------+
 
  **********************************************************************
  * Project Churn 
  **********************************************************************
  Files: 
  +------------------------------------+---------------+
  | file_path                          | times_changed |
  +------------------------------------+---------------+
  | lib/churn/churn_calculator.rb      | 14            |
  | README.rdoc                        | 7             |
  | lib/tasks/churn_tasks.rb           | 6             |
  | Rakefile                           | 6             |
  | lib/churn/git_analyzer.rb          | 4             |
  | VERSION                            | 4             |
  | test/test_helper.rb                | 4             |
  | test/unit/churn_calculator_test.rb | 3             |
  | test/churn_test.rb                 | 3             |
  +------------------------------------+---------------+ 
   
  Classes: 
  +-------------------------------+-----------------+---------------+
  | file                          | klass           | times_changed |
  +-------------------------------+-----------------+---------------+
  | lib/churn/churn_calculator.rb | ChurnCalculator | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | 1             |
  +-------------------------------+-----------------+---------------+
   
  Methods: 
  +-------------------------------+-----------------+-----------------------------------------+---------------+
  | file                          | klass           | method                                  | times_changed |
  +-------------------------------+-----------------+-----------------------------------------+---------------+
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#to_s                    | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#display_array           | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#calculate_revision_data | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#filters                 | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#initialize              | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#filters                 | 1             |
  | lib/churn/churn_calculator.rb | ChurnCalculator | ChurnCalculator#to_s                    | 1             |
  +-------------------------------+-----------------+-----------------------------------------+---------------+


TODO:
* SVN only supports file, add full SVN support 
* support bazaar, cvs, and darcs 
* make storage directory configurable instead of using tmp
* allow passing in directories to churn, directories to ignore
* add a filter that allows for other files besides. *.rb
* ignore files pattern, so you can ignore things like vendor/, lib/, or docs/
* finish adding better documenation using YARD
* better man page formatting from README (switch to markdown?)
* rake task for building manpage (currently manually run  ronn -b1 README.rdoc)
* bug that reports '/dev/null' as a file during revision changes
* don't output methods and classes on a commit that has none detected (css and view only commits, etc)

Executable Usage:
* 'gem install churn'
* go to project root run 'churn'

Rake Usage:
* 'gem install churn'
* on any project you want to use churn, add "require 'churn'" to your rake file
* run 'rake churn' to view the current output, file churn history is immediate, class and method churn builds up a history as it is run on each revision
* temporary files with class / method churn history are stored in /tmp, to clear churn history delete them

== Note on Patches/Pull Requests
 
* Fork the project.
* Make your feature addition or bug fix.
* Add tests for it. This is important so I don't break it in a
  future version unintentionally.
* Commit, do not mess with rakefile, version, or history.
  (if you want to have your own version, that is fine but
   bump version in a commit by itself I can ignore when I pull)
* Send me a pull request. Bonus points for topic branches.

== Copyright

Copyright (c) 2010 Dan Mayer. See LICENSE for details.