Zonebie

Zonebie prevents bugs in code that deals with timezones by randomly assigning a zone on every run.

Requirements

MRI (1.8.7, 1.9.2, 1.9.3)
JRuby (1.6)
Rubinius (1.2, 2.0)

And either of these gems which adds timezone support to Ruby:

activesupport >= 2.3 (Rails 2.3, 3.0, 3.1, 3.2)
tzinfo >= 0.3

Installation

If using Bundler (recommended), add to Gemfile:

gem 'zonebie'

Usage with Rails & ActiveSupport

ActiveSupport allows setting a global timezone that will be used for many date and time calculations throughout the application.

Zonebie can set this to a random timezone at the beginning of test runs. Specifically for ActiveSupport, it sets Time.zone.

Test::Unit & Minitest

Add to test/test_helper.rb:

Zonebie.set_random_timezone

RSpec

Add to spec/spec_helper.rb:

Zonebie.set_random_timezone

Cucumber

Add a file features/support/zonebie.rb with the following contents:

Zonebie.set_random_timezone

Usage with TZInfo

Zonebie can use the tzinfo gem, allowing it to work outside of ActiveSupport (Rails).

However, Zonebie.set_random_timezone does not work outside of ActiveSupport because there is not a concept of a global timezone setting. If you simply need a random timezone for some other part of your tests, Zonebie can help.

zone = TZInfo::Timezone.get(Zonebie.random_timezone)
puts zone.now

# Also works in Rails/ActiveSupport
zone = ActiveSupport::TimeZone[Zonebie.random_timezone]
puts zone.now

Reproducing Bugs

When Zonebie.set_random_timezone is called, Zonebie assigns a timezone and prints a message to STDOUT:

[Zonebie] Setting timezone to "Eastern Time (US & Canada)"

If you would rather that Zonebie not print out this information during your tests, put Zonebie in quiet mode before calling set_random_timezone:

Zonebie.quiet = true

To rerun tests with a specific timezone (e.g., to reproduce a bug that only seems present in one zone), set the TZ environment variable:

# Assuming tests run with simply `rake`
TZ="Eastern Time (US & Canada)" rake

For the Geographically Impaired

Zonebie can generate an ASCII map that shows where on the globe your tests are running.

Note that this makes a request to Google Maps, so it's likely not a good idea to run on each test run :)

                     .....   ......                                             
                    ..... ...........                       .                   
                .  . ..  ...........       .                  .                 
            .    .. ..  ...........                    .       ..               
            ..   .. .      ........                 .      .......              
   .....     .... .   ...   .......          ..      . . ...................    
............ ........  ...  ...    ..      ..... ...............................
  ...  ......... .    ..                 ..... ............................  .  
          ........... ... .           ..  .....................  ......         
            .............               ........ .. ...................         
            ...........               ..   .  ..... ............... .           
               ...   .               .............. ................            
                 ...                ............. ..     ..  ...   .            
                      .....           .. ..........               . .           
                      ..........           ......                       .       
                        .......            .....  .                 .....       
                        .....               ...                   .........     
                       ....                                             ..      
                       ..                                                       
                        .                                                       
                                                                                
                         .                                                      
                        ..                    .......... ...................    
           .     .... ....          ..........................................  
       ............... .         ............................................   
    ..................       .  .............................................   
     .....................     .............................................    
     .........................................................................  
     ...........................................................................

Enable the map by setting the :ascii_map option to true. Again, because it makes an HTTP request, you likely only want to enable it in certain circumstances (e.g., on a CI server or when you explicitly request it):

Zonebie.set_random_timezone(:ascii_map => ENV['CI'] || ENV['MAP'])

And run with:

MAP=1 rake

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Added some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request

highgroove/zonebie