Question

How do I pass an error from my Module back to the rake task that called it?

My rake task looks like this:

require 'mymodule.rb'

task :queue => :environment do
  OPERATOR = Mymodule::Operator.new
  begin
    OPERATOR.initiate_call (1234567189)
  rescue StandardError => bang
    puts "Shit happened: #{ bang} "
  end   
end

And here is my module..

module Mymodule
  class Operator    
    def initiate_call (number)
      begin
        # make the call
      rescue StandardError => bang
        flash[:error] = "Error #{bang}"
        return
      end
    end    
  end
end

I also call this module from a controller so it would be nice to have an error handling solution that is more or less agnostic.

Running Rails 3. Any unrelated comments (i.e. suggestions) on my code structure are more than welcomed 🙂

Answer 1

Your Operator#initiate_call method traps StandardError exceptions so your rake task will never see them. I’d drop the rescue from initiate_call and let the caller deal with all the exception handling. Then, you’d have flash[:error] = "Error #{bang}" in your controller’s exception handler and the rake task would remain as-is.

The basic approach is to push the error handling up the call stack all the way to someone that can do something about it; initiate_call can’t really do anything useful with the exception so it shouldn’t try to handle it.