bpo-19610: setup() now raises TypeError for invalid types (GH-4519)

The Distribution class now explicitly raises an
exception when 'classifiers', 'keywords' and
'platforms' fields are not specified as a list.

dist.py

@@ -1188,12 +1188,38 @@ class DistributionMetadata:
     def get_keywords(self):
         return self.keywords or []
 
+    def set_keywords(self, value):
+        # If 'keywords' is a string, it will be converted to a list
+        # by Distribution.finalize_options(). To maintain backwards
+        # compatibility, do not raise an exception if 'keywords' is
+        # a string.
+        if not isinstance(value, (list, str)):
+            msg = "'keywords' should be a 'list', not %r"
+            raise TypeError(msg % type(value).__name__)
+        self.keywords = value
+
     def get_platforms(self):
         return self.platforms or ["UNKNOWN"]
 
+    def set_platforms(self, value):
+        # If 'platforms' is a string, it will be converted to a list
+        # by Distribution.finalize_options(). To maintain backwards
+        # compatibility, do not raise an exception if 'platforms' is
+        # a string.
+        if not isinstance(value, (list, str)):
+            msg = "'platforms' should be a 'list', not %r"
+            raise TypeError(msg % type(value).__name__)
+        self.platforms = value
+
     def get_classifiers(self):
         return self.classifiers or []
 
+    def set_classifiers(self, value):
+        if not isinstance(value, list):
+            msg = "'classifiers' should be a 'list', not %r"
+            raise TypeError(msg % type(value).__name__)
+        self.classifiers = value
+
     def get_download_url(self):
         return self.download_url or "UNKNOWN"
 

tests/test_dist.py

@@ -195,6 +195,13 @@ class DistributionTestCase(support.LoggingSilencer,
         self.assertEqual(dist.metadata.platforms, ['one', 'two'])
         self.assertEqual(dist.metadata.keywords, ['one', 'two'])
 
+        attrs = {'keywords': 'foo bar',
+                 'platforms': 'foo bar'}
+        dist = Distribution(attrs=attrs)
+        dist.finalize_options()
+        self.assertEqual(dist.metadata.platforms, ['foo bar'])
+        self.assertEqual(dist.metadata.keywords, ['foo bar'])
+
     def test_get_command_packages(self):
         dist = Distribution()
         self.assertEqual(dist.command_packages, None)
@@ -338,9 +345,46 @@ class MetadataTestCase(support.TempdirManager, support.EnvironGuard,
         attrs = {'name': 'Boa', 'version': '3.0',
                  'classifiers': ['Programming Language :: Python :: 3']}
         dist = Distribution(attrs)
+        self.assertEqual(dist.get_classifiers(),
+                         ['Programming Language :: Python :: 3'])
         meta = self.format_metadata(dist)
         self.assertIn('Metadata-Version: 1.1', meta)
 
+    def test_classifier_invalid_type(self):
+        attrs = {'name': 'Boa', 'version': '3.0',
+                 'classifiers': ('Programming Language :: Python :: 3',)}
+        msg = "'classifiers' should be a 'list', not 'tuple'"
+        with self.assertRaises(TypeError, msg=msg):
+            Distribution(attrs)
+
+    def test_keywords(self):
+        attrs = {'name': 'Monty', 'version': '1.0',
+                 'keywords': ['spam', 'eggs', 'life of brian']}
+        dist = Distribution(attrs)
+        self.assertEqual(dist.get_keywords(),
+                         ['spam', 'eggs', 'life of brian'])
+
+    def test_keywords_invalid_type(self):
+        attrs = {'name': 'Monty', 'version': '1.0',
+                 'keywords': ('spam', 'eggs', 'life of brian')}
+        msg = "'keywords' should be a 'list', not 'tuple'"
+        with self.assertRaises(TypeError, msg=msg):
+            Distribution(attrs)
+
+    def test_platforms(self):
+        attrs = {'name': 'Monty', 'version': '1.0',
+                 'platforms': ['GNU/Linux', 'Some Evil Platform']}
+        dist = Distribution(attrs)
+        self.assertEqual(dist.get_platforms(),
+                         ['GNU/Linux', 'Some Evil Platform'])
+
+    def test_platforms_invalid_types(self):
+        attrs = {'name': 'Monty', 'version': '1.0',
+                 'platforms': ('GNU/Linux', 'Some Evil Platform')}
+        msg = "'platforms' should be a 'list', not 'tuple'"
+        with self.assertRaises(TypeError, msg=msg):
+            Distribution(attrs)
+
     def test_download_url(self):
         attrs = {'name': 'Boa', 'version': '3.0',
                  'download_url': 'http://example.org/boa'}