Some good articles about testing in Ruby on Rails applications:
Integration Tests at clarkware.com
Rails Integration Testing
Integration test file uploads - This didn't actually work for me, but YMMV.
multipart_post - This one did work for me for uploading files in Integration tests, and integration_test_file_upload.rb is the file you install in RAILS_HOME/lib
Integration Testing by Jamis Buck, excellent article.
