From ad62591f434a750fa4edee40292ba6e698cc497a Mon Sep 17 00:00:00 2001
From: pavoni <mail@gregdowling.com>
Date: Fri, 22 Jan 2016 16:30:02 +0000
Subject: [PATCH] Change error state to be 'error' rather than 'unknown', trace
 error.

---
 homeassistant/components/sensor/template.py | 8 +++++---
 tests/components/sensor/test_template.py    | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/homeassistant/components/sensor/template.py b/homeassistant/components/sensor/template.py
index eeb764e70a5..a75d0a3e656 100644
--- a/homeassistant/components/sensor/template.py
+++ b/homeassistant/components/sensor/template.py
@@ -12,7 +12,6 @@ import logging
 from homeassistant.helpers.entity import Entity
 from homeassistant.core import EVENT_STATE_CHANGED
 from homeassistant.const import (
-    STATE_UNKNOWN,
     ATTR_FRIENDLY_NAME,
     CONF_VALUE_TEMPLATE,
     ATTR_UNIT_OF_MEASUREMENT)
@@ -24,6 +23,8 @@ _LOGGER = logging.getLogger(__name__)
 
 CONF_SENSORS = 'sensors'
 
+STATE_ERROR = 'error'
+
 
 # pylint: disable=unused-argument
 def setup_platform(hass, config, add_devices, discovery_info=None):
@@ -107,5 +108,6 @@ class SensorTemplate(Entity):
     def update(self):
         try:
             self._state = template.render(self.hass, self._template)
-        except TemplateError:
-            self._state = STATE_UNKNOWN
+        except TemplateError as ex:
+            self._state = STATE_ERROR
+            _LOGGER.error(ex)
diff --git a/tests/components/sensor/test_template.py b/tests/components/sensor/test_template.py
index b4f6ab41c97..513117a8a9e 100644
--- a/tests/components/sensor/test_template.py
+++ b/tests/components/sensor/test_template.py
@@ -60,4 +60,4 @@ class TestTemplateSensor:
         self.hass.states.set('sensor.test_state', 'Works')
         self.hass.pool.block_till_done()
         state = self.hass.states.get('sensor.test_template_sensor')
-        assert state.state == 'unknown'
+        assert state.state == 'error'