Add simple support for ActiveModel's StateMachine for ActiveRecord

1 files changed, 42 insertions, 0 deletions

diff --git a/activerecord/test/cases/state_machine_test.rb b/activerecord/test/cases/state_machine_test.rb
new file mode 100644
index 0000000000..5d13668bab
--- /dev/null
+++ b/activerecord/test/cases/state_machine_test.rb
@@ -0,0 +1,42 @@
+require 'cases/helper'
+require 'models/traffic_light'
+
+class StateMachineTest < ActiveRecord::TestCase
+  def setup
+    @light = TrafficLight.create!
+  end
+
+  test "states initial state" do
+    assert @light.off?
+    assert_equal :off, @light.current_state
+  end
+
+  test "transition to a valid state" do
+    @light.reset
+    assert @light.red?
+    assert_equal :red, @light.current_state
+
+    @light.green_on
+    assert @light.green?
+    assert_equal :green, @light.current_state
+  end
+
+  test "transition does not persist state" do
+    @light.reset
+    assert_equal :red, @light.current_state
+    @light.reload
+    assert_equal "off", @light.state
+  end
+
+  test "transition does persists state" do
+    @light.reset!
+    assert_equal :red, @light.current_state
+    @light.reload
+    assert_equal "red", @light.state
+  end
+
+  test "transition to an invalid state" do
+    assert_raise(ActiveModel::StateMachine::InvalidTransition) { @light.yellow_on }
+    assert_equal :off, @light.current_state
+  end
+end