From acbf45d5f89bb083595c810152746b3f24792268 Mon Sep 17 00:00:00 2001
From: Egor Tsinko <etsinko@gmail.com>
Date: Thu, 26 Oct 2017 23:57:31 -0600
Subject: [PATCH] added platform discovery code back into device_tracker
 (#10169)

---
 .../components/device_tracker/__init__.py      |  9 ++++++++-
 tests/components/device_tracker/test_init.py   | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/homeassistant/components/device_tracker/__init__.py b/homeassistant/components/device_tracker/__init__.py
index 9a6dffc6101..05131a039cd 100644
--- a/homeassistant/components/device_tracker/__init__.py
+++ b/homeassistant/components/device_tracker/__init__.py
@@ -21,7 +21,7 @@ from homeassistant.components import group, zone
 from homeassistant.config import load_yaml_config_file, async_log_exception
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
-from homeassistant.helpers import config_per_platform
+from homeassistant.helpers import config_per_platform, discovery
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.event import async_track_time_interval
 from homeassistant.helpers.restore_state import async_get_last_state
@@ -175,6 +175,13 @@ def async_setup(hass: HomeAssistantType, config: ConfigType):
 
     tracker.async_setup_group()
 
+    @asyncio.coroutine
+    def async_platform_discovered(platform, info):
+        """Load a platform."""
+        yield from async_setup_platform(platform, {}, disc_info=info)
+
+    discovery.async_listen_platform(hass, DOMAIN, async_platform_discovered)
+
     # Clean up stale devices
     async_track_utc_time_change(
         hass, tracker.async_update_stale, second=range(0, 60, 5))
diff --git a/tests/components/device_tracker/test_init.py b/tests/components/device_tracker/test_init.py
index ecdbe0085ee..a8531e2aa69 100644
--- a/tests/components/device_tracker/test_init.py
+++ b/tests/components/device_tracker/test_init.py
@@ -11,6 +11,7 @@ import os
 from homeassistant.components import zone
 from homeassistant.core import callback, State
 from homeassistant.setup import setup_component
+from homeassistant.helpers import discovery
 from homeassistant.loader import get_component
 from homeassistant.util.async import run_coroutine_threadsafe
 import homeassistant.util.dt as dt_util
@@ -310,6 +311,23 @@ class TestComponentsDeviceTracker(unittest.TestCase):
                 'No http request for macvendor made!'
         self.assertEqual(tracker.devices['b827eb000000'].vendor, vendor_string)
 
+    @patch(
+        'homeassistant.components.device_tracker.DeviceTracker.see')
+    @patch(
+        'homeassistant.components.device_tracker.demo.setup_scanner',
+        autospec=True)
+    def test_discover_platform(self, mock_demo_setup_scanner, mock_see):
+        """Test discovery of device_tracker demo platform."""
+        assert device_tracker.DOMAIN not in self.hass.config.components
+        discovery.load_platform(
+            self.hass, device_tracker.DOMAIN, 'demo', {'test_key': 'test_val'},
+            {})
+        self.hass.block_till_done()
+        assert device_tracker.DOMAIN in self.hass.config.components
+        assert mock_demo_setup_scanner.called
+        assert mock_demo_setup_scanner.call_args[0] == (
+            self.hass, {}, mock_see, {'test_key': 'test_val'})
+
     def test_update_stale(self):
         """Test stalled update."""
         scanner = get_component('device_tracker.test').SCANNER