Capataz

Provides Ruby code execution control by defining rules for syntax and runtime behavior.

Installation

Add this line to your application's Gemfile:

gem 'capataz'

And then execute:

$ bundle

Or install it yourself as:

$ gem install capataz

Usage

Take for example the following Ruby code:

class A
  attr_reader :value, :secret_value
  def initialize
    @value = rand(10)
    @secret_value = rand(value)
  end
end

class B < A; end

So you can configure your code syntax and runtime rules

Capataz.config do

  deny_declarations_of :module, :class

  deny_invoke_of :constantize

  allowed_constants A

  deny_for A, :secret_value
  
  maximum_iterations 100
  
  maximum_invocations_of '+': 5
end

And then you can control your Ruby code execution by evaluating it with Capataz

Capataz.eval <<-RUBY
class C
end
RUBY #ERROR: can not define classes

Capataz.eval <<-RUBY
B.new
RUBY #ERROR: Illegal access to constant B 

Capataz.eval <<-RUBY
'B'.constantize.new
RUBY #ERROR: invoking method constantize is not allowed

Capataz.eval <<-RUBY
A.new.value
RUBY # 5 (a random value)

Capataz.eval <<-RUBY
A.new.secret_value
RUBY #ERROR: undefined method secret_value for #<A:0x000000022e7960>

Capataz.eval <<-RUBY
s = 0
100.times { s += 1 }
s
RUBY # 100

Capataz.eval <<-RUBY
s = 0
101.times { s += 1 }
s
RUBY #ERROR: Maximum allowed iterations exceeded (101)

Capataz.eval <<-RUBY
s = 0
10.times { 10.times { s += 1 } }
s
RUBY # 100

Capataz.eval <<-RUBY
s = 0
11.times { 10.times { s += 1 } }
s
RUBY #ERROR: Maximum allowed iterations exceeded (101)

Capataz.eval <<-RUBY
s = 0
5.times { s = s + 1 }
s
RUBY # 5

Capataz.eval <<-RUBY
s = 0
6.times { s = s + 1 }
s
RUBY #ERROR: Maximum allowed invocations for '+' exceeded (6)

Capataz.eval <<-RUBY
[1,2,3,4,5,6].inject(&:+)
RUBY # 21 (the + operator is invoked 5 times to summ 6 numbers)

Capataz.eval <<-RUBY
[1,2,3,4,5,6,7].inject(&:+)
RUBY #ERROR: Maximum allowed invocations for '+' exceeded (6)

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it ( https://github.com/macarci/capataz/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request