Fix webostv select source (#11227)

* Fix reuse of variable name

This should fix #11224.

* Add tests for LgWebOSDevice.select_source

homeassistant/components/media_player/webostv.py

@@ -322,17 +322,17 @@ class LgWebOSDevice(MediaPlayerDevice):
 
     def select_source(self, source):
         """Select input source."""
-        source = self._source_list.get(source)
-        if source is None:
+        source_dict = self._source_list.get(source)
+        if source_dict is None:
             _LOGGER.warning("Source %s not found for %s", source, self.name)
             return
-        self._current_source_id = self._source_list[source]['id']
-        if source.get('title'):
-            self._current_source = self._source_list[source]['title']
-            self._client.launch_app(self._source_list[source]['id'])
-        elif source.get('label'):
-            self._current_source = self._source_list[source]['label']
-            self._client.set_input(self._source_list[source]['id'])
+        self._current_source_id = source_dict['id']
+        if source_dict.get('title'):
+            self._current_source = source_dict['title']
+            self._client.launch_app(source_dict['id'])
+        elif source_dict.get('label'):
+            self._current_source = source_dict['label']
+            self._client.set_input(source_dict['id'])
 
     def media_play(self):
         """Send play command."""

tests/components/media_player/test_webostv.py

@@ -0,0 +1,60 @@
+"""The tests for the LG webOS media player platform."""
+import unittest
+from unittest import mock
+
+from homeassistant.components.media_player import webostv
+
+
+class FakeLgWebOSDevice(webostv.LgWebOSDevice):
+    """A fake device without the client setup required for the real one."""
+
+    def __init__(self, *args, **kwargs):
+        """Initialise parameters needed for tests with fake values."""
+        self._source_list = {}
+        self._client = mock.MagicMock()
+        self._name = 'fake_device'
+        self._current_source = None
+
+
+class TestLgWebOSDevice(unittest.TestCase):
+    """Test the LgWebOSDevice class."""
+
+    def setUp(self):
+        """Configure a fake device for each test."""
+        self.device = FakeLgWebOSDevice()
+
+    def test_select_source_with_empty_source_list(self):
+        """Ensure we don't call client methods when we don't have sources."""
+        self.device.select_source('nonexistent')
+        assert 0 == self.device._client.launch_app.call_count
+        assert 0 == self.device._client.set_input.call_count
+
+    def test_select_source_with_titled_entry(self):
+        """Test that a titled source is treated as an app."""
+        self.device._source_list = {
+            'existent': {
+                'id': 'existent_id',
+                'title': 'existent_title',
+            },
+        }
+
+        self.device.select_source('existent')
+
+        assert 'existent_title' == self.device._current_source
+        assert [mock.call('existent_id')] == (
+            self.device._client.launch_app.call_args_list)
+
+    def test_select_source_with_labelled_entry(self):
+        """Test that a labelled source is treated as an input source."""
+        self.device._source_list = {
+            'existent': {
+                'id': 'existent_id',
+                'label': 'existent_label',
+            },
+        }
+
+        self.device.select_source('existent')
+
+        assert 'existent_label' == self.device._current_source
+        assert [mock.call('existent_id')] == (
+            self.device._client.set_input.call_args_list)