From ef132e4583c3d6df9557769db9b9d921ffcfcfef Mon Sep 17 00:00:00 2001
From: Paulus Schoutsen <paulus.schoutsen@mycase.com>
Date: Fri, 29 Jan 2016 18:44:21 -0800
Subject: [PATCH] Add tests for color util

---
 homeassistant/util/color.py | 13 +++++++------
 tests/util/test_color.py    | 17 +++++++++++++++++
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/homeassistant/util/color.py b/homeassistant/util/color.py
index a88fa16896bc..e5b11f2afeb1 100644
--- a/homeassistant/util/color.py
+++ b/homeassistant/util/color.py
@@ -47,6 +47,7 @@ def color_RGB_to_xy(R, G, B):
 
 # taken from
 # https://github.com/benknight/hue-python-rgb-converter/blob/master/rgb_cie.py
+# Copyright (c) 2014 Benjamin Knight / MIT License.
 # pylint: disable=bad-builtin
 def color_xy_brightness_to_RGB(vX, vY, brightness):
     '''
@@ -57,12 +58,12 @@ def color_xy_brightness_to_RGB(vX, vY, brightness):
         return (0, 0, 0)
 
     Y = brightness
-    if vY != 0:
-        X = (Y / vY) * vX
-        Z = (Y / vY) * (1 - vX - vY)
-    else:
-        X = 0
-        Z = 0
+
+    if vY == 0:
+        vY += 0.00000000001
+
+    X = (Y / vY) * vX
+    Z = (Y / vY) * (1 - vX - vY)
 
     # Convert to RGB using Wide RGB D65 conversion.
     r = X * 1.612 - Y * 0.203 - Z * 0.302
diff --git a/tests/util/test_color.py b/tests/util/test_color.py
index 6b0d169f5165..4b4a70ebe9c6 100644
--- a/tests/util/test_color.py
+++ b/tests/util/test_color.py
@@ -20,3 +20,20 @@ class TestColorUtil(unittest.TestCase):
 
         self.assertEqual((0.6400744994567747, 0.3299705106316933),
                          color_util.color_RGB_to_xy(255, 0, 0))
+
+    def test_color_xy_brightness_to_RGB(self):
+        """ Test color_RGB_to_xy. """
+        self.assertEqual((0, 0, 0),
+                         color_util.color_xy_brightness_to_RGB(1, 1, 0))
+
+        self.assertEqual((255, 235, 214),
+                         color_util.color_xy_brightness_to_RGB(.35, .35, 255))
+
+        self.assertEqual((255, 0, 45),
+                         color_util.color_xy_brightness_to_RGB(1, 0, 255))
+
+        self.assertEqual((0, 255, 0),
+                         color_util.color_xy_brightness_to_RGB(0, 1, 255))
+
+        self.assertEqual((0, 83, 255),
+                         color_util.color_xy_brightness_to_RGB(0, 0, 255))