From 8adab0ec0dd46813335b857e4e92b08c53b65cc1 Mon Sep 17 00:00:00 2001
From: Hugo <hugovk@users.noreply.github.com>
Date: Tue, 19 Dec 2017 17:12:58 +0200
Subject: [PATCH] Noise effect: take five pixels, assert not all same

---
 Tests/helper.py     | 14 ++++++++++----
 Tests/test_image.py | 25 ++++++++++---------------
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/Tests/helper.py b/Tests/helper.py
index 117c5da54..e5e08e15d 100644
--- a/Tests/helper.py
+++ b/Tests/helper.py
@@ -100,7 +100,7 @@ class PillowTestCase(unittest.TestCase):
                     logger.error("Url for test images: %s" %url)
                 except:
                     pass
-                    
+
             self.fail(msg or "got different content")
 
     def assert_image_similar(self, a, b, epsilon, msg=None):
@@ -161,6 +161,12 @@ class PillowTestCase(unittest.TestCase):
                 self.assertTrue(found)
         return result
 
+    def assert_all_same(self, items, msg=None):
+        self.assertTrue(items.count(items[0]) == len(items), msg)
+
+    def assert_not_all_same(self, items, msg=None):
+        self.assertFalse(items.count(items[0]) == len(items), msg)
+
     def skipKnownBadTest(self, msg=None, platform=None,
                          travis=None, interpreter=None):
         # Skip if platform/travis matches, and
@@ -206,7 +212,7 @@ class PillowLeakTestCase(PillowTestCase):
     # requires unix/osx
     iterations = 100 # count
     mem_limit = 512 # k
-    
+
     def _get_mem_usage(self):
         """
         Gets the RUSAGE memory usage, returns in K. Encapsulates the difference
@@ -214,7 +220,7 @@ class PillowLeakTestCase(PillowTestCase):
 
         :returns; memory usage in kilobytes
         """
-        
+
         from resource import getpagesize, getrusage, RUSAGE_SELF
         mem = getrusage(RUSAGE_SELF).ru_maxrss
         if sys.platform == 'darwin':
@@ -225,7 +231,7 @@ class PillowLeakTestCase(PillowTestCase):
             # linux
             # man 2 getrusage
             #        ru_maxrss (since Linux 2.6.32)
-            #  This is the maximum resident set size used (in  kilobytes). 
+            #  This is the maximum resident set size used (in  kilobytes).
             return mem # Kb
 
     def _test_leak(self, core):
diff --git a/Tests/test_image.py b/Tests/test_image.py
index 875e925a8..6f6d1983e 100644
--- a/Tests/test_image.py
+++ b/Tests/test_image.py
@@ -348,24 +348,19 @@ class TestImage(PillowTestCase):
         # Arrange
         size = (100, 100)
         sigma = 128
-        # To reduce chance of randomly having the same value twice
-        attempts = 5
 
         # Act
-        while attempts > 0:
-            im = Image.effect_noise(size, sigma)
+        im = Image.effect_noise(size, sigma)
 
-            # Assert
-            self.assertEqual(im.size, (100, 100))
-            self.assertEqual(im.mode, "L")
-            p0 = im.getpixel((0, 0))
-            p1 = im.getpixel((0, 1))
-            if p0 == p1:
-                # Let's roll again
-                attempts -= 1
-            else:
-                break
-        self.assertNotEqual(p0, p1)
+        # Assert
+        self.assertEqual(im.size, (100, 100))
+        self.assertEqual(im.mode, "L")
+        p0 = im.getpixel((0, 0))
+        p1 = im.getpixel((0, 1))
+        p2 = im.getpixel((0, 2))
+        p3 = im.getpixel((0, 3))
+        p4 = im.getpixel((0, 4))
+        self.assert_not_all_same([p0, p1, p2, p3, p4])
 
     def test_effect_spread(self):
         # Arrange