cobradeps

cobradeps

Prints and exports the dependencies within component-based Ruby/Rails applications (#cbra)

Installation

Add this line to your application's Gemfile:

gem 'cobradeps'

And then execute:

$ bundle

Or install it yourself as:

$ gem install cobradeps

Dependencies

You need Graphviz to generate the graph.png

OS X

If you're using OS X and homebrew, you just need to:

brew install graphviz

Other Operating Systems

For more information about installation on other operating systems, just check Graphviz Download Page

Usage

cobradeps [OPTION] [application path]

Component-based Ruby/Rails dependency grapher.

Options are...
    -t, --text                       DEFAULT Outputs a textual representation of the dependencies
    -g, --graph                      Outputs graph.png to the current directory
    -d, --dot                        Outputs graph.dot to the current directory

    -h, -H, --help                   Display this help message.

Example

There are sample #cobra folder structures in spec/examples. Here is the graph generated for the letters app structure:

Using path "..." do blocks

The preferred method of referencing #cbra dependencies is via the path block syntax supported by bundler(http://teotti.com/gemfiles-hierarchy-in-ruby-on-rails-component-based-architecture/):

path "../" do
  gem "B"
  gem "C"
  gem "D"
  gem "E1"
  gem "E2"
  gem "F"
end

Note, that you only need to add direct dependencies when using the block syntax (and not transitive dependencies as discussed below).

#cobra extension to Gemfile

The :path option used for #cobras is typically a relative path. Because of that all gems and apps transitively including a gem need to state the relative path to every gem with a path relatuive to their root. For an app, this is the reason why it is unclear which gems it really directly depends on. That's why all dependencies of apps are omitted from the output graph.

To include direct dependencies of an application, add an additional option to the gem line from the Gemfile like so:

gem "B", path: "../B", group: :direct
gem "C", path: "../C"
gem "D", path: "../D"
gem "E1", path: "../E1"
gem "E2", path: "../E2"
gem "F", path: "../F"

Why do I need to add group: :direct?? In the first release, cobradeps was checking for direct: true, until some time ago this year, the extraneous option direct: worked, but then a check was added to not allow extra options and the feature has been broken ever since. (as stated by @shageman on his merge commit).

So the hack to allow cobradeps check for direct dependency was use one of the possible options that bundler allows on Gemfile, and as group is used to group gems, normally only used with common values (:production, :development and :test) what makes possible for cobradeps checks for group: :direct

This is the Gemfile of app A from the letters example of which you see the graph above.

##TODOs

• support windows folders (searching for a couple slashes)
• support windows: don't shell out to find gemspecs and gemfiles
• info if no gem file found for gem
• warn if gem has name different than folder
• warn if same gem name is found with path and without
• error if there are multiple gem specs
• error if there is not gem file in root

License

Copyright (c) 2014 Stephan Hagemann, [e-mail], @shageman

Released under the MIT license. See LICENSE file for details.