tests for features

Tests/test_features.py

@@ -2,19 +2,50 @@ from helper import unittest, PillowTestCase
 
 from PIL import features
 
+try:
+    from PIL import _webp
+    HAVE_WEBP = True
+except:
+    HAVE_WEBP = False
+    
 
 class TestFeatures(PillowTestCase):
 
-    def test_check_features(self):
+    def test_check(self):
+        # Check the correctness of the convenience function
+        for module in features.modules:
+            self.assertEqual(features.check_module(module),
+                             features.check(module))
+        for codec in features.codecs:
+            self.assertEqual(features.check_codec(codec),
+                             features.check(codec))
+        for feature in features.features:
+            self.assertEqual(features.check_feature(feature),
+                             features.check(feature))
+
+    @unittest.skipUnless(HAVE_WEBP, True)
+    def check_webp_transparency(self):
+        self.assertEqual(features.check('transp_webp'),
+                         not _webp.WebPDecoderBuggyAlpha())
+        self.assertEqual(features.check('transp_webp'),
+                         _webp.HAVE_TRANSPARENCY)
+
+    @unittest.skipUnless(HAVE_WEBP, True)
+    def check_webp_mux(self):
+        self.assertEqual(features.check('webp_mux'),
+                         _webp.HAVE_WEBPMUX)
+    
+    def test_check_modules(self):
         for feature in features.modules:
-            self.assertIn(
-                features.check_module(feature), [True, False, None])
+            self.assertIn(features.check_module(feature), [True, False])
         for feature in features.codecs:
             self.assertIn(features.check_codec(feature), [True, False])
 
-    def test_supported_features(self):
+    def test_supported_modules(self):
         self.assertIsInstance(features.get_supported_modules(), list)
         self.assertIsInstance(features.get_supported_codecs(), list)
+        self.assertIsInstance(features.get_supported_features(), list)
+        self.assertIsInstance(features.get_supported(), list)
 
     def test_unsupported_codec(self):
         # Arrange