Problem
You would like to test the carrierwave imageuploader with a cucumber test, but you would also like to use a generic step that can be used with different classes and different image file column names.

Solution
Use the following and perhaps put it a file named features/common_steps.rb

Then /^the url for the column "([^"]*)" of model "([^"]*)" should be "([^"]*)"$/ do |col,mdl,url|
  # First get tne class name from the mdl argument by using the Kernel.const_get method
  m = Kernel.const_get(mdl).first
  # And then use the send with the column name (col) to call the model's field,
  # the url method of ImageUploader to get the full path
  # and basename to get only the file name
  File.basename(m.send(col).url).should == url
end