Ruby Object Tracker

An easy way to track Ruby objects. Logs class and instance method calls with arguments, file name, line number and execution time. Helpful for debugging and learning the language.

Requirements

Ruby 2+

Installation

Add this line to your application's Gemfile:

gem 'object_tracker', '~> 2.1'

Usage

class Person
  extend ObjectTracker

  def greet(name)
    "ello, #{name}!"
  end
end

Track a single method:

Person.track_all! :greet

Or track all methods (such as to_s, object_id, respond_to?, etc):

Person.track_all!

Or track an instance:

obj = Person.new.extend ObjectTracker
obj.track_all!

Or track an object without extending the class:

ObjectTracker.(Person)
ObjectTracker.(Person, :greet)
ObjectTracker.(Person, except: :respond_to?)
ObjectTracker.(me = Person.new)

Hook methods

Pass a proc (or anything that responds to #call) to the :before or :after options and they will be called before and after the method call, respectively. This allows you to do things like track the number of methods calls.

method_calls = Hash.new 0
slow_methods = Set.new []
hooks = [
  before: ->(context, name, args) { method_calls[name] += 1 },
  after: ->(context, name, args, duration) { slow_methods << name if duration > 0.05 }
]
ObjectTracker.(Person, *hooks)

Logging

ObjectTracker uses the default Ruby logger with a default DEBUG level

Silence logging

ObjectTracker.logger.level = Logger::ERROR

[Example] ActiveRecord Tracking

Tracking an ActiveRecord 3.2 model

ObjectTracker.(u = User.first).audits;nil
#=>   User Load (0.3ms)  SELECT `users`.* FROM `users` LIMIT 1
#=> [2017-04-13T21:45:48.827952]  INFO -- ObjectTracker: following #<User:0x007f838d8cf560>
#=> [2017-04-13T21:45:48.828223] DEBUG -- ObjectTracker: User#class [RUBY CORE] (0.00000)
#=> [2017-04-13T21:45:48.838797] DEBUG -- ObjectTracker: User#association with [audits] [lib/active_record/associations.rb:155] (0.01073)
#=> [2017-04-13T21:45:48.838853] DEBUG -- ObjectTracker: User#audits [lib/active_record/associations/builder/association.rb:43] (0.01082)

Troubleshooting

Having problems? Maybe a specific method is throwing some obscure error? Try ignoring that method, so we can get back on track!

Person.track_all! except: :bad_method

Contributing

Fork it
Run tests with rake (just kidding, there are no tests)
Boot a console with bin/console
Make sure things still work
Make changes and submit a PR to https://github.com/ridiculous/object_tracker

License

MIT

ridiculous / object_tracker