filter_assertions plugin for Rails

This plugin extends the class ActionController::TestCase by adding assertions to test if before filters have been applied (via before_filter or append_before_filter) or skipped (via skip_before_filter).

These assertions are added for use in your functional tests:

• assert_before_filter: use this to test your before_filter or append_before_filter statements.
• assert_no_before_filter: use this to test your skip_before_filter statements.
• assert_forgery_protection: use this to test your protect_from_forgery statements.

Installation

script/plugin install git://github.com/pie4dan/filter_assertions.git

Examples

# Test if the before_filter :authenticate applies to all actions in the controller
assert_before_filter :authenticate

# Test if the filter only applies to actions 'index' and 'new'
assert_before_filter :authenticate, :only => [:index, :new]

# Test if the filter applies to all actions axcept 'index'
assert_before_filter :authenticate, :except => :index

The assert_no_before_filter assertion takes the same options and the assert_forgery_protection only takes the :except or :only options.

There are different ways to test for the same functionality:

# These two assertion are equivalent
assert_before_filter :authenticate, :except => :index
assert_no_before_filter :authenticate, :only => :index

How it works

The assertions of this plugin do not test for functionality of your before_filters. It looks for the specified filters in the controller's filter_chain and checks if the filters are applied or skipped for the specified actions.
That means you can even check for before_filters when you usually skip them in your functional tests.

Why would I want to test for before_filters like that?

It's usually a good idea to test your controllers including its before_filters and create different tests for when a before_filter applies and for when it doesn't.
But there might be cases when you can't do this easily. Maybe there's an external dependency a filter relies on - such as an external service or app for authentication for example. With this plugin, you could skip all before_filters for your tests and still be able to test if they would normally apply (deployed on a server for example).

However - as said before - this plugin does not test any functionality of the filters themselves. The assertions only check if the filters apply to all actions or a subset of actions of the controller you are testing.

TODO

Make this plugin work with Rails 3 (it has only been tested with Rails 2.3 so far).

Credits

This plugin is based on the idea and code described in this blog post by S M Sohan: Unit/Functional Test Rails ActionController filters following DRY.

Copyright (c) 2011 Daniel Pietzsch, released under the MIT license