The ELC Community Blog

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Testing Libraries

by josh on November 16, 2007

Another way to make Test::Unit act like RSpec

It's really frustrated to try and increase your test coverage in libraries and helpers when you have to instantiate a controller first. So - don't.

To get around this and at the same time make your testing infrastructure easier to manage, you can create a separate directories in your test directory for testing your helpers.

mkdir test/helpers

Create an application_helper_test.rb file in that dir and put the typical stuff in it:

require File.dirname(__FILE__) + '/../test_helper'

class ArticlesHelperTest < Test::Unit::TestCase

end

Now make sure the Articles Helper is included:

class ArticlesHelperTest < Test::Unit::TestCase
  include ArticlesHelper
end

Now you can test that your helper methods directly:

module ArticlesHelper
  def article_title_helper(article)
    "#{article.title} - #{article.created_at.strftime("%Y %B %d")}"
  end
end

   1  def test_article_title_helper
   2    assert_equal 'Title - 2007 August 6', article_title_helper(article)
   3  end

The same goes for any library. I would argue that if you need to include the library tests in your application, don't put the library in lib. app/lib is ideal for vendor libraries, not local ones.

You'll need to make sure you modify your RCov Task appropriately to include this directory.