State :exit called when all transitions fail

When defining an aasm_state with an :exit option, the defined exit method is currently executed even if all transitions fail:


class Foo
  include AASM
  aasm_initial_state :open
  aasm_state :open,   :exit => :exit
  aasm_state :closed

  aasm_event :null do
    transitions :to => :closed, :from => [:open], :guard => :always_false
  end

  def always_false
    false
  end

  def exit
  end
end

foo = Foo.new
foo.null # => executes foo.exit, even though the guard fails.

This is highly unexpected behavior. The exit method should only be executed during a successful event transition.

Reported by Nathaniel Bibler · September 19th, 2008 @ 12:22 AM

Activity

Nathaniel Bibler
- Tag changed from bug to bug, patch
I've attached a patch which adds a spec to exercise this expectation, as well as a simple fix to pass it.
- 0001-State-exit-is-now-only-called-if-a-transition-actua.patch 1.48 KB
September 19th, 2008 @ 12:26 AM
Nathaniel Bibler
If it's any easier for you to check out, I've also got this modification on GitHub.

September 19th, 2008 @ 12:31 AM
rubyist
Thanks for the patch, Nathaniel, I'll check this out today.

-Scott

September 19th, 2008 @ 07:12 AM
Nathaniel Bibler
Technically, this patch may change the callback execution sequence in a way which is unexpected. While the specs do not test the order in which callbacks are executed, I imagine this may cause problems down the road.

The previous execution sequence:
1. OldState.exit
2. SuccessfulTransition.on_success
3. NewState.enter
With the above mentioned patch, the sequence is as follows:
1. SuccessfulTransition.on_success
2. OldState.exit
3. NewState.enter
I figured I'd mention it while I was thinking about it and it wasn't yet adopted. :-D
September 19th, 2008 @ 10:04 AM

Please Sign in or create a free account to add a new ticket.

With your very own profile, you can contribute to projects, track your activity, watch tickets, receive and update tickets through your email and much more.