bugfix: support reloading development environment in Rails #148

CHANGELOG.md

@@ -4,6 +4,10 @@
 
  * deprecated old aasm_* class methods (old-style DSL), in preparation for AASM v4.0.0
 
+## 3.3.3 (not yet released)
+
+ * bugfix: support reloading development environment in Rails (see [issue #148](https://github.com/aasm/aasm/issues/148))
+
 ## 3.3.2
 
  * bugfix: avoid conflicts with `failed` and `fired` event names (see [issue #157](https://github.com/aasm/aasm/issues/157)), thanks to [@MichaelXavier](https://github.com/MichaelXavier)

lib/aasm/state_machine.rb

@@ -28,7 +28,11 @@ module AASM
 
     def add_state(name, klass, options)
       set_initial_state(name, options)
-      @states << AASM::State.new(name, klass, options) unless @states.include?(name)
+
+      # allow reloading, extending or redefining a state
+      @states.delete(name) if @states.include?(name)
+
+      @states << AASM::State.new(name, klass, options)
     end
 
     private

spec/models/double_definer.rb

@@ -0,0 +1,21 @@
+class DoubleDefiner
+  include AASM
+
+  aasm do
+    state :started
+    state :finished
+
+    event :finish do
+      transitions :from => :started, :to => :finished
+    end
+
+    # simulating a reload
+    state :finished, :enter => :do_enter
+    event :finish do
+      transitions :from => :started, :to => :finished, :on_transition => :do_on_transition
+    end
+  end
+
+  def do_enter; end
+  def do_on_transition; end
+end

spec/unit/reloading_spec.rb

@@ -0,0 +1,15 @@
+require 'spec_helper'
+
+describe 'callbacks for the new DSL' do
+  let(:definer) { DoubleDefiner.new }
+
+  it "allows extending states" do
+    expect(definer).to receive(:do_enter)
+    definer.finish
+  end
+
+  it "allows extending events" do
+    expect(definer).to receive(:do_on_transition)
+    definer.finish
+  end
+end