At

At is a small library that allows you to access instance variables on an object as if they were attr_accessors for testing purposes.

Basically, at directly translates this:

value = object.instance_eval { @instance_variable }
object.instance_eval { @instance_variable = "#{value}!" }

into this:

value = object.at.instance_variable
object.at.instance_variable = "#{value}!"

Install

Bundler: `gem 'at'`

RubyGems: `gem install at`

Usage

If I want to test the output of the full_name method in my User class below, I would normally have three options for testing all possible outcomes; initialize a User object for each test case, initialize one User object and use instance_eval to set the instance variables individually, or create attr_accessors for each instance variable I would like to test. In Rspec, I can use assigns to test the value of the instance variable, but I can't get the value of the instance variable.

At solves these problems.

require 'at'

class User
  def initialize(first_name=nil, last_name=nil)
    @first_name, @last_name = first_name, last_name
  end

  def full_name
    [@first_name, @last_name].compact.join(" ")
  end
end

describe User, '#full_name' do
  it 'should output the full name correctly' do
    subject.at.first_name = 'John'
    subject.at.last_name = 'Doe'

    subject.full_name.should == 'John Doe'
  end
end

Check out the specs for a better usage example.

Contributing

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
Fork the project
Start a feature/bugfix branch
Commit and push until you are happy with your contribution
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright

The MIT License (MIT) - See LICENSE for further details.

At