Testing UploadColumn with Machinist and Ruby on Rails

In my current Ruby on Rails project, I’m learning about Notahat’s machinist testing framework to build object graphs on which to write unit tests. Its a nice improvement on fixtures; using an object-orientated, programmatic approach to creating test data.

In the pursuit of 100% code coverage, I hit on a problem when trying to test UploadColumn, which was being used for handling images on a Product class. Normally in a Test::Unit class, I could invoke the fixture_file_upload method to simulate the multi-part form upload of an image, but in machinist I couldn’t do that. After finding next to nothing in the way of documentation for testing Upload column, I did some rummaging around in the gem and found the solution.

At the top of your blueprints file, include UploadColumn:

include UploadColumn

Then, in your blueprint, you can use the UploadedImage class to represent your uploaded image:

Product.blueprint do
 title
 description
 image { UploadedFile.upload(File.new(RAILS_ROOT + '/test/fixtures/label.png')) }
end

I hope that helps somebody…

Tags: machinist testing uploadcolumn, Rails, Ruby, Ruby On Rails

This entry was posted on October 6, 2009 at October 6, 2009 and is filed under Ruby On Rails, Testing. You can follow any responses to this entry through the RSS 2.0 feed.