Add test cases for EventScheduler class

====  Tech Notes ====
- Add test cases
- Slight refactoring of EventScheduler class to make it easier to test

mycroft/skills/event_scheduler.py

@@ -51,11 +51,12 @@ class EventScheduler(Thread):
             Load json data with active events from json file.
         """
         if isfile(self.schedule_file):
+            json_data = {}
             with open(self.schedule_file) as f:
                 try:
                     json_data = json.load(f)
                 except Exception as e:
-                    LOG.error(e)
+                    LOG.error(e.message)
             current_time = time.time()
             for key in json_data:
                 event_list = json_data[key]
@@ -97,31 +98,34 @@ class EventScheduler(Thread):
 
     def run(self):
         while self.isRunning:
-            # Remove events
-            self.remove_events()
-            # Fetch newly scheduled events
-            self.fetch_new_events()
-            # Update events
-            self.update_events()
-
-            # Check all events
-            for event in self.events:
-                current_time = time.time()
-                e = self.events[event]
-                # Get scheduled times that has passed
-                passed = [(t, r, d) for (t, r, d) in e if t <= current_time]
-                # and remaining times that we're still waiting for
-                remaining = [(t, r, d) for t, r, d in e if t > current_time]
-                # Trigger registered methods
-                for sched_time, repeat, data in passed:
-                    self.emitter.emit(Message(event, data))
-                    # if this is a repeated event add a new trigger time
-                    if repeat:
-                        remaining.append((sched_time + repeat, repeat, data))
-                # update list of events
-                self.events[event] = remaining
+            self.check_state()
             time.sleep(0.5)
 
+    def check_state(self):
+        # Remove events
+        self.remove_events()
+        # Fetch newly scheduled events
+        self.fetch_new_events()
+        # Update events
+        self.update_events()
+
+        # Check all events
+        for event in self.events:
+            current_time = time.time()
+            e = self.events[event]
+            # Get scheduled times that has passed
+            passed = [(t, r, d) for (t, r, d) in e if t <= current_time]
+            # and remaining times that we're still waiting for
+            remaining = [(t, r, d) for t, r, d in e if t > current_time]
+            # Trigger registered methods
+            for sched_time, repeat, data in passed:
+                self.emitter.emit(Message(event, data))
+                # if this is a repeated event add a new trigger time
+                if repeat:
+                    remaining.append((sched_time + repeat, repeat, data))
+            # update list of events
+            self.events[event] = remaining
+
     def schedule_event(self, event, sched_time, repeat=None, data=None):
         """ Send event to thread using thread safe queue. """
         data = data or {}

test/unittests/skills/test_event_scheduler.py

@@ -0,0 +1,70 @@
+import unittest
+import mock
+import time
+
+from mycroft.skills.event_scheduler import EventScheduler
+
+"""
+    Test cases regarding the event scheduler.
+"""
+
+
+class TestEventScheduler(unittest.TestCase):
+    @mock.patch('threading.Thread')
+    @mock.patch('json.dump')
+    @mock.patch('mycroft.skills.event_scheduler.open')
+    def test_create(self, mock_open, mock_json_dump, mock_thread):
+        """
+            Test creating and shutting down event_scheduler.
+        """
+        mock_open.return_value = mock.MagicMock(spec=file)
+        emitter = mock.MagicMock()
+        es = EventScheduler(emitter)
+        es.shutdown()
+        self.assertEquals(mock_json_dump.call_args[0][0], {})
+
+    @mock.patch('threading.Thread')
+    @mock.patch('json.dump')
+    @mock.patch('mycroft.skills.event_scheduler.open')
+    def test_add_remove(self, mock_open, mock_json_dump, mock_thread):
+        """
+            Test add an event and then remove it.
+        """
+        # Thread start is mocked so will not actually run the thread loop
+        mock_open.return_value = mock.MagicMock(spec=file)
+        emitter = mock.MagicMock()
+        es = EventScheduler(emitter)
+
+        es.schedule_event('test', 90000000000, None)
+        es.schedule_event('test-2', 90000000000, None)
+
+        es.check_state()  # run one cycle
+        self.assertTrue('test' in es.events)
+        self.assertTrue('test-2' in es.events)
+
+        es.remove_event('test')
+        es.check_state()  # run one cycle
+        self.assertTrue('test' not in es.events)
+        self.assertTrue('test-2' in es.events)
+        es.shutdown()
+
+    @mock.patch('threading.Thread')
+    @mock.patch('json.load')
+    @mock.patch('json.dump')
+    @mock.patch('mycroft.skills.event_scheduler.open')
+    def test_save(self, mock_open, mock_dump, mock_load, mock_thread):
+        """
+            Test save functionality.
+        """
+        mock_open.return_value = mock.MagicMock(spec=file)
+        emitter = mock.MagicMock()
+        es = EventScheduler(emitter)
+
+        es.schedule_event('test', 900000000000, None)
+        es.schedule_event('test-repeat', 910000000000, 60)
+        es.check_state()
+
+        es.shutdown()
+
+        self.assertEquals(mock_dump.call_args[0][0],
+                          {'test': [(900000000000, None, {})]})