fault_injection.rb

Overview

What is it?

A ‘fault injection’ tool for ruby.

What is a ‘fault injection’? What is it used for?

Fault injection is one of testing techniques. It makes easier to test your application’s error handling behavior or to improve the coverage of your tests.

See http://en.wikipedia.org/wiki/Fault_injection for more details.

Can I use it in my application code?

No. It is for your testing code.

Can I use it everywhere in my test code?

You should not. It is for some limited situation that rarely happen or difficult to set up (ex. IOError). If you can make ‘evil situation’ easily, that’s better ;)

Installing

sudo gem install faultinjection

Sample codes

# sample.rb
class Foo
  def foo
    puts "I love injection"
  end

  def bar
    10 / 2  # this is line 7
  end
end

# test.rb
require 'fault_injection'
include FaultInjection

inject "Foo#foo > Kernel#puts", IOError, "IO error"

f = Foo.new
f.foo #=> IOError

inject "sample.rb:7",ZeroDivisionError

f.bar #=> ZeroDivisionError

License

This code is free to use under the terms of the MIT license.

Contact

The SVN repository is available at http://faultinjection.rubyforge.org/svn/ for anonymous access.

Comments are welcome. Feel free to Send an email to keisukefukuda.spam@gmail.com

(Please remove ”.spam” from the address for anti-spam, and include ‘ruby’ or ‘fault_injection’ in the title)

Keisuke Fukuda, 11th January 2008
Theme extended from Paul Battley