FixtureScenariosBuilder

This plugin is an add-on to the FixtureScenarios plugin by Tom Preston-Werner. FixtureScenarios is required for this plugin to work.

FixtureScenarios Info: http://code.google.com/p/fixture-scenarios/ SVN : http://fixture-scenarios.googlecode.com/svn/trunk/fixture_scenarios

This plugin Info: http://errtheblog.com/post/7708 SVN : svn://errtheblog.com/svn/plugins/fixture_scenarios_builder Bugs: http://err.lighthouseapp.com/projects/466-plugins/tickets/new

== The Setup

You may, from time to time, wish to build your fixtures entirely in Ruby. Doing so has its advantages, such as automatically created join tables and default attributes. YAML files, however, bring with them some real nice features in Rails which are difficult to abandon: transactional fixtures, table_name(:key) helpers, and auto-clearing between tests. How does one get the best of both worlds?

== The Download

Using the +scenario+ method within <tt>scenarios.rb</tt> file, FixtureScenariosBuilder can create your YAML fixture scenarios automatically at run time from Ruby-created fixtures.

Create a <tt>scenarios.rb</tt> file and place it in the root "fixtures" directory:

[RAILS_ROOT] +-test/ +-fixtures/ +-scenarios.rb

Now build your scenarios in this file, wrapping scenarios in the +scenario+ method and providing it with the name of your scenario.
A brief example of a complete <tt>scenarios.rb</tt> file:

scenario :banned_users do %w( Tom Chris Kevin ).each_with_index do |user, index| User.create(:name => user, :banned => index.odd?) end end

Assuming +banned+ is a boolean field, this will create for us (when our tests are first run) the following:

[RAILS_ROOT] +-test/ +-fixtures/ +-banned_users/ +-users.yml

Our generated <tt>users.yml</tt> file will look something like this:

chris: name: Chris id: "2" banned: "1" updated_at: 2007-05-09 09:08:04 created_at: 2007-05-09 09:08:04 kevin: name: Kevin id: "3" banned: "0" updated_at: 2007-05-09 09:08:04 created_at: 2007-05-09 09:08:04 tom: name: Tom id: "1" banned: "0" updated_at: 2007-05-09 09:08:04 created_at: 2007-05-09 09:08:04

Notice how the keys correspond to the user names. FixtureScenariosBuilder will try, to an extent, to guess the name of your key. If it can't figure it out, keys will be the standard user_001, user_002, etc format.

Thanks to Paul Cantrell's handywork, custom key names are supported. Simply use the +name+ method:

scenario :foo do name "small_red_widget", Widget.create(:size => 'small', :color => 'red') name "big_blue_widget", Widget.create(:size => 'big', :color => 'blue') end

Another option is to assign your records to instance variables, then call +names_from_ivars+ at the conclusion of your +scenario+ block.

scenario :foo do @small_red_widget = Widget.create(:size => 'small', :color => 'red') @big_blue_widget = Widget.create(:size => 'big', :color => 'blue')

names_from_ivars! end

The above produces the following YAML:

small_red_widget: size: small color: red updated_at: 2007-12-27 10:09:05 created_at: 2007-12-27 10:09:05 big_blue_widget: size: big color: blue updated_at: 2007-12-27 10:19:23 created_at: 2007-12-27 10:19:23

On subsequent test runs this YAML file will not be needlessly re-created. YAML files will only be re-generated when the <tt>scenarios.rb</tt> file is modified.

If you for some reason need to force your scenarios to rebuild, pass in the REBUILD_FIXTURES environment variables:

$ rake test:units REBUILD_FIXTURES=true

Scenarios can also be nested using the familiar Rake-style dependency declaration.

scenario :users do %w( Tom Chris ).each do |user| User.create(:name => user) end end

scenario :banned_users => :users do User.create(:name => 'Kevin', :banned => true) end

== Rake

FixtureScenariosBuilder comes with one Rake task, `db:scenario:build' -- use it to attempt to build your scenarios on demand.

== Bugs!

Please report bugs here: http://err.lighthouseapp.com/projects/466-plugins/tickets

Chris Wanstrath => chris[at]ozmm[dot]org