Linting, Unit tests and naming updates based on PR

Fixed linting, updated unit tests and renamed event kwarg names.

mpf/devices/multiball.py

@@ -239,20 +239,20 @@ def _ball_drain_count_balls(self, balls, **kwargs):
 
         restart_grace_period_ms = self.config['restart_grace_period'].evaluate([])
 
-        if not self.machine.game or (self.machine.game.balls_in_play - balls < 1 and restart_grace_period_ms==0):
+        if not self.machine.game or (self.machine.game.balls_in_play - balls < 1 and restart_grace_period_ms == 0):
             self._multiball_end()
-        elif restart_grace_period_ms>0:
+        elif restart_grace_period_ms > 0:
             if self.machine.game.balls_in_play == 0:
-                self.delay.run_now(f"{self.name}_restart_grace_period")
+                self.delay.run_now("restart_grace_period")
             elif self.machine.game.balls_in_play - balls < 1:
-                self.machine.events.post(f"multiball_{self.name}_will_end", duration=restart_grace_period_ms)
+                self.machine.events.post(f"multiball_{self.name}_will_end", grace_period=restart_grace_period_ms)
                 '''event: multiball_(name)_will_end
                 desc: The multiball called (name) does not have multiple balls active, enabling grace period.
                 args:
-                    duration: duration of the restart grace period
+                    grace_period: restart duration grace period in ms
                 '''
 
-                self.delay.add(name=f"{self.name}_restart_grace_period",
+                self.delay.add(name="restart_grace_period",
                                ms=restart_grace_period_ms,
                                callback=self._multiball_end)
 
@@ -266,7 +266,6 @@ def _multiball_end(self):
         '''
         self.debug_log("Ball drained. MB ended.")
 
-
     @event_handler(5)
     def event_stop(self, **kwargs):
         """Event handler for stop event."""
@@ -304,10 +303,9 @@ def event_add_a_ball(self, **kwargs):
 
     def add_a_ball(self):
         """Add a ball if multiball has started."""
-
         # remove if it exists as multiball now has multiple balls
-        if self.delay.check(f"{self.name}_restart_grace_period"):
-            self.delay.remove(f"{self.name}_restart_grace_period")
+        if self.delay.check("restart_grace_period"):
+            self.delay.remove("restart_grace_period")
             self.machine.events.post(f"multiball_{self.name}_will_resume")
             '''event: multiball_(name)_will_resume
             desc: Multiball (name) has been resumed during end of multiball grace period.

mpf/tests/test_MultiBall.py

@@ -1235,20 +1235,20 @@ def testEndMultiballGracePeriodNoRestart(self):
         self.assertAvailableBallsOnPlayfield(1)
         self.mock_event("multiball_mb_grace_period_restart_will_end")
         self.mock_event("multiball_mb_grace_period_restart_ended")
+        self.mock_event("multiball_mb_grace_period_restart_will_resume")
 
         # start mb, default ball save, 5s restart grace period
         self.post_event("mb_grace_period_restart_start")
         self.advance_time_and_run(10)
         self.assertAvailableBallsOnPlayfield(2)
 
         self.drain_one_ball()
-        self.advance_time_and_run(5)
+        self.advance_time_and_run(10)
 
         self.assertEventCalled("multiball_mb_grace_period_restart_will_end", 1)
-        self.assertEventCalled("multiball_mb_grace_period_restart_ended", 0)
-
-        self.advance_time_and_run(5)
+        self.assertEventNotCalled("multiball_mb_grace_period_restart_will_resume")
         self.assertEventCalled("multiball_mb_grace_period_restart_ended", 1)
+        self.assertAvailableBallsOnPlayfield(1)
 
 
     def testEndMultiballGracePeriodAddABallRestart(self):
@@ -1268,12 +1268,18 @@ def testEndMultiballGracePeriodAddABallRestart(self):
         self.drain_one_ball()
         self.advance_time_and_run(3)
 
+        # we should now be in the grace period (set at 5 seconds)
         self.assertEventCalled("multiball_mb_grace_period_restart_will_end", 1)
-        self.assertEventCalled("multiball_mb_grace_period_restart_ended", 0)
+        self.assertEventNotCalled("multiball_mb_grace_period_restart_ended")
 
+        # trigger the add a ball during grace period
         self.post_event("add_ball")
-        self.assertEventCalled("multiball_mb_grace_period_restart_ended", 0)
+        self.advance_time_and_run()
+        self.assertEventNotCalled("multiball_mb_grace_period_restart_ended")
         self.assertEventCalled("multiball_mb_grace_period_restart_will_resume", 1)
-        self.advance_time_and_run(5)
+
+        # fast-forward time past the grace period and ensure multiball has resumed (i.e. with 2 balls)
+        self.advance_time_and_run(10)
         self.assertAvailableBallsOnPlayfield(2)
         self.assertEventCalled("ball_save_mb_grace_period_restart_timer_start")
+        self.assertEventNotCalled("multiball_mb_grace_period_restart_ended")