Busted

Disclaimers

• Requires MRI Ruby 2.1.0dev at trunk

--

Find code that busts the Ruby 2.1+ cache.

• Report when code invalidates Ruby's internal cache
• Uses RubyVM.stat

Usage

Any Cache

Busted.cache? do
  class Beer
  end
end
#=> true

Busted.run do
  class Pizza
  end
end
#=> {:invalidations=>{:method=>0, :constant=>1}}

Method Cache

Busted.method_cache? do
  def beer
  end
end
#=> true

Busted.method_cache_invalidations do
  def pizza
  end
end
#=> 3

Constant Cache

Busted.constant_cache? do
  STOUT = "stout"
end
#=> true

Busted.constant_cache_invalidations do
  CHEESE = "cheese"
end
#=> 1

No Cache Busted

Busted.cache? do
  beer = "beer"
end
#=> false

Busted.run do
  pizza = "pizza"
end
#=> {:invalidations=>{:method=>0, :constant=>0}}

Advanced Usage

Busted can report method cache invalidation locations via dtrace. The running process must have root privileges, and dtrace must be installed.

trace.rb

require "busted"
require "pp"

report = Busted.run(trace: true) do
  def cookie; end
end
pp report

$ whoami
simeon

$ id simeon
uid=501(simeon) gid=20(staff) groups=20(staff),80(admin)

# simeon is an admin; sudo does not require a password
$ sudo grep admin /etc/sudoers
%admin  ALL=(ALL) NOPASSWD: ALL

$ sudo dtrace -V
dtrace: Sun D 1.6.2

# No need to sudo
# Busted runs dtrace in a child process with root privileges
$ ruby trace.rb
{:invalidations=>{:method=>1, :constant=>0},
 :traces=>
  {:method=>[{:class=>"global", :sourcefile=>"trace.rb", :lineno=>"5"}]}}

Busted includes an example dtrace probe for use on the command line or an application. See the probe for usage.

Installation

Requires MRI Ruby 2.1.0dev

Add this line to your application's Gemfile:

gem "busted"

And then execute:

$ bundle

Or install it yourself as:

$ gem install busted

Contributing

Check out this guide if you'd like to contribute.

License

This project is licensed under the MIT License.

Standing On The Shoulders Of Giants

A big thank you to Charlie Somerville and Aman Gupta for helping flesh out RubyVM.stat and committing it to Ruby core!