[#25] Fixing bug: Duplicated models share state machine references

CHANGELOG.md

@@ -6,6 +6,7 @@ This project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html
 ## Unreleased
 
 ### Compatible changes
+- Fix bug where duplicated model instances referenced shared state machine state managers.
 
 ### Breaking changes
 

lib/rails_state_machine/model.rb

@@ -40,6 +40,10 @@ def state_machine_state_manager(state_attribute)
       @state_machine_state_managers[state_attribute] ||= StateManager.new(self, state_machine(state_attribute), state_attribute)
     end
 
+    def clear_state_machine_state_managers_cache
+      @state_machine_state_managers = nil
+    end
+
     def state_machine_state_managers
       self.state_machines.keys.collect do |state_attribute|
         state_machine_state_manager(state_attribute)

lib/rails_state_machine/state_machine.rb

@@ -120,6 +120,7 @@ def register_initial_state
       return unless initial_state_name
 
       @model.after_initialize do
+        clear_state_machine_state_managers_cache
         manager = state_machine_state_manager(state_attribute)
         if new_record? && !manager.state
           manager.state = initial_state_name

spec/rails_state_machine/state_machine_spec.rb

@@ -27,4 +27,19 @@
     end
   end
 
+  it 'does use different state machine objects for duplicated records' do
+    parcel = Parcel.create!(weight: 1)
+    parcel_dup = parcel.dup
+    parcel_dup.save!
+
+    expect(parcel_dup.may_pack?).to be true
+    expect(parcel.may_pack?).to be true
+
+    expect { parcel.pack_and_ship! }.to change { parcel.reload.state }.from('empty').to('shipped')
+      .and not_change { parcel_dup.reload.state }
+
+    expect(parcel_dup.may_pack?).to be true
+    expect(parcel.may_pack?).to be false
+  end
+
 end

spec/spec_helper.rb

@@ -5,6 +5,8 @@
 
 Dir["#{File.dirname(__FILE__)}/support/*.rb"].sort.each {|f| require f}
 
+RSpec::Matchers.define_negated_matcher :not_change, :change
+
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure
   config.example_status_persistence_file_path = '.rspec_status'