known devices yaml robustness (#2523)

homeassistant/components/device_tracker/__init__.py

@@ -377,12 +377,16 @@ def load_config(path, hass, consider_home, home_range):
     """Load devices from YAML configuration file."""
     if not os.path.isfile(path):
         return []
-    return [
-        Device(hass, consider_home, home_range, device.get('track', False),
-               str(dev_id).lower(), str(device.get('mac')).upper(),
-               device.get('name'), device.get('picture'),
-               device.get(CONF_AWAY_HIDE, DEFAULT_AWAY_HIDE))
-        for dev_id, device in load_yaml_config_file(path).items()]
+    try:
+        return [
+            Device(hass, consider_home, home_range, device.get('track', False),
+                   str(dev_id).lower(), str(device.get('mac')).upper(),
+                   device.get('name'), device.get('picture'),
+                   device.get(CONF_AWAY_HIDE, DEFAULT_AWAY_HIDE))
+            for dev_id, device in load_yaml_config_file(path).items()]
+    except HomeAssistantError:
+        # When YAML file could not be loaded/did not contain a dict
+        return []
 
 
 def setup_scanner_platform(hass, config, scanner, see_device):

tests/components/device_tracker/test_init.py

@@ -4,6 +4,7 @@ import unittest
 from unittest.mock import patch
 from datetime import datetime, timedelta
 import os
+import tempfile
 
 from homeassistant.loader import get_component
 import homeassistant.util.dt as dt_util
@@ -45,6 +46,18 @@ class TestComponentsDeviceTracker(unittest.TestCase):
 
         self.assertFalse(device_tracker.is_on(self.hass, entity_id))
 
+    def test_reading_broken_yaml_config(self):
+        """Test when known devices contains invalid data."""
+        with tempfile.NamedTemporaryFile() as fp:
+            # file is empty
+            assert device_tracker.load_config(fp.name, None, False, 0) == []
+
+            fp.write('100'.encode('utf-8'))
+            fp.flush()
+
+            # file contains a non-dict format
+            assert device_tracker.load_config(fp.name, None, False, 0) == []
+
     def test_reading_yaml_config(self):
         """Test the rendering of the YAML configuration."""
         dev_id = 'test'