Can I override task :environment in test_helper.rb to test rake tasks?

Question

I have a series of rake tasks in a Rakefile which I'd like to test as part of my specs etc. Each task is defined in the form:

task :do_somthing => :environment do
  # Do something with the database here
end

Where the :environment task sets up an ActiveRecord/DataMapper database connection and classes. I'm not using this as part of Rails but I have a series of tests which I like to run as part of BDD.

This snippet illustrates how I'm trying to test the rake tasks.

def setup
  @rake = Rake::Application.new
  Rake.application = @rake
  load File.dirname(__FILE__) + '/../../tasks/do_something.rake'
end

should "import data" do
  @rake["do_something"].invoke
  assert something_in_the_database
end

So my request for help - is it possible to over-ride the :environment task in my test_helper.rb file so I my rake testing interacts with the my test database, rather than production? I've tried redefining the task in the helper file, but this doesn't work.

Any help for a solution would be great, as I've been stuck on this for the past week.

Answer 1

My "solution" to a similar problem was to extract all the logic from my .rake files and create classes to perform the tasks, leaving just a one-line call in the rake file, which I felt confident in not testing too hard. The classes could then be tested pretty much normally.

I don't know how well this would stand up to a complex set of interdependent tasks that maintain some far-reaching state: probably not well, but then again that would most likely be an indication of some other design problem...

I'm curious to see if I've missed something better.

EDIT: There used to be a blog post here that (a) says the same thing and (b) says it better. Looks like he said it first, too.

Answer 2

I think you are looking for this line: require(File.join(RAILS_ROOT, 'config', 'environment')) it's exactly what you find in "task :environment" implementation

I use it to test my rake tasks using rspec