Add tests for forecast.io (#2227)

* Add tests for forecast.io

* Fix linting items and don't call a platform a component

requirements_test.txt

@@ -7,3 +7,4 @@ pytest-timeout>=1.0.0
 pytest-capturelog>=0.7
 betamax==0.7.0
 pydocstyle>=1.0.0
+httpretty==0.8.14

tests/components/test_forecast.py

@@ -0,0 +1,77 @@
+"""The tests for the forecast.io platform."""
+import json
+import re
+import os
+import unittest
+from unittest.mock import MagicMock, patch
+
+import forecastio
+import httpretty
+import pytest
+from requests.exceptions import HTTPError
+
+from homeassistant.components.sensor import forecast
+from homeassistant import core as ha
+
+
+class TestForecastSetup(unittest.TestCase):
+    """Test the forecast.io platform."""
+
+    def setUp(self):
+        """Initialize values for this testcase class."""
+        self.hass = ha.HomeAssistant()
+        self.key = 'foo'
+        self.config = {
+            'api_key': 'foo',
+            'monitored_conditions': ['summary', 'icon']
+        }
+        self.lat = 37.8267
+        self.lon = -122.423
+        self.hass.config.latitude = self.lat
+        self.hass.config.longitude = self.lon
+
+    def test_setup_no_latitude(self):
+        """Test that the component is not loaded without required config."""
+        self.hass.config.latitude = None
+        self.assertFalse(forecast.setup_platform(self.hass, {}, MagicMock()))
+
+    @patch('forecastio.api.get_forecast')
+    def test_setup_bad_api_key(self, mock_get_forecast):
+        """Test for handling a bad API key."""
+        # The forecast API wrapper that we use raises an HTTP error
+        # when you try to use a bad (or no) API key.
+        url = 'https://api.forecast.io/forecast/{}/{},{}?units=auto'.format(
+            self.key, str(self.lat), str(self.lon)
+        )
+        msg = '400 Client Error: Bad Request for url: {}'.format(url)
+        mock_get_forecast.side_effect = HTTPError(msg,)
+
+        with pytest.raises(HTTPError):
+            forecast.setup_platform(self.hass, self.config, MagicMock())
+
+    @httpretty.activate
+    @patch('forecastio.api.get_forecast', wraps=forecastio.api.get_forecast)
+    def test_setup(self, mock_get_forecast):
+        """Test for successfully setting up the forecast.io platform."""
+        def load_fixture_from_json():
+            cwd = os.path.dirname(__file__)
+            fixture_path = os.path.join(cwd, '..', 'fixtures', 'forecast.json')
+            with open(fixture_path) as file:
+                content = json.load(file)
+            return json.dumps(content)
+
+        # Mock out any calls to the actual API and
+        # return the fixture json instead
+        uri = 'api.forecast.io\/forecast\/(\w+)\/(-?\d+\.?\d*),(-?\d+\.?\d*)'
+        httpretty.register_uri(
+            httpretty.GET,
+            re.compile(uri),
+            body=load_fixture_from_json(),
+        )
+        # The following will raise an error if the regex for the mock was
+        # incorrect and we actually try to go out to the internet.
+        httpretty.HTTPretty.allow_net_connect = False
+
+        forecast.setup_platform(self.hass, self.config, MagicMock())
+        self.assertTrue(mock_get_forecast.called)
+        self.assertEqual(mock_get_forecast.call_count, 2)