From 2e3155e2fe387cba93a6bd6a5e4a6d06a49c6a98 Mon Sep 17 00:00:00 2001
From: Brett Cannon <bcannon@gmail.com>
Date: Mon, 20 Jul 2009 03:22:43 +0000
Subject: [PATCH] Merged revisions 74107 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r74107 | brett.cannon | 2009-07-19 20:19:18 -0700 (Sun, 19 Jul 2009) | 8 lines

  Importlib's documentation said that importlib.abc.PyLoader inherited from
  importlib.abc.ResourceLoader, when in fact it did not. Fixed the ABC to inherit
  as documented.

  This does in introduce an backwards-incompatiblity as the code in PyLoader
  already required the single method ResourceLoader defined as an abstract
  method.
........
---
 Lib/importlib/abc.py           |  2 +-
 Lib/importlib/test/test_abc.py | 75 +++++++++++++++++++++++++++-------
 Misc/NEWS                      |  4 ++
 3 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index b2bdb02c926..7b89d0b4c93 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -76,7 +76,7 @@ InspectLoader.register(machinery.BuiltinImporter)
 InspectLoader.register(machinery.FrozenImporter)
 
 
-class PyLoader(_bootstrap.PyLoader, InspectLoader):
+class PyLoader(_bootstrap.PyLoader, ResourceLoader, InspectLoader):
 
     """Abstract base class to assist in loading source code by requiring only
     back-end storage methods to be implemented.
diff --git a/Lib/importlib/test/test_abc.py b/Lib/importlib/test/test_abc.py
index a54adb9f5a9..6e09534d8c3 100644
--- a/Lib/importlib/test/test_abc.py
+++ b/Lib/importlib/test/test_abc.py
@@ -1,30 +1,77 @@
 from importlib import abc
 from importlib import machinery
+import inspect
 import unittest
 
 
-class SubclassTests(unittest.TestCase):
+class InheritanceTests:
 
-    """Test that the various classes in importlib are subclasses of the
-    expected ABCS."""
+    """Test that the specified class is a subclass/superclass of the expected
+    classes."""
 
-    def verify(self, ABC, *classes):
-        """Verify the classes are subclasses of the ABC."""
-        for cls in classes:
-            self.assert_(issubclass(cls, ABC))
+    subclasses = []
+    superclasses = []
 
-    def test_Finder(self):
-        self.verify(abc.Finder, machinery.BuiltinImporter,
-                    machinery.FrozenImporter, machinery.PathFinder)
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        assert self.subclasses or self.superclasses, self.__class__
+        self.__test = getattr(abc, self.__class__.__name__)
 
-    def test_Loader(self):
-        self.verify(abc.Loader, machinery.BuiltinImporter,
-                    machinery.FrozenImporter)
+    def test_subclasses(self):
+        # Test that the expected subclasses inherit.
+        for subclass in self.subclasses:
+            self.assertTrue(issubclass(subclass, self.__test),
+                "{0} is not a subclass of {1}".format(subclass, self.__test))
+
+    def test_superclasses(self):
+        # Test that the class inherits from the expected superclasses.
+        for superclass in self.superclasses:
+            self.assertTrue(issubclass(self.__test, superclass),
+               "{0} is not a superclass of {1}".format(superclass, self.__test))
+
+
+class Finder(InheritanceTests, unittest.TestCase):
+
+    subclasses = [machinery.BuiltinImporter, machinery.FrozenImporter,
+                    machinery.PathFinder]
+
+
+class Loader(InheritanceTests, unittest.TestCase):
+
+    subclasses = [abc.PyLoader]
+
+
+class ResourceLoader(InheritanceTests, unittest.TestCase):
+
+    superclasses = [abc.Loader]
+
+
+class InspectLoader(InheritanceTests, unittest.TestCase):
+
+    superclasses = [abc.Loader]
+    subclasses = [abc.PyLoader, machinery.BuiltinImporter,
+                    machinery.FrozenImporter]
+
+
+class PyLoader(InheritanceTests, unittest.TestCase):
+
+    superclasses = [abc.Loader, abc.ResourceLoader, abc.InspectLoader]
+
+
+class PyPycLoader(InheritanceTests, unittest.TestCase):
+
+    superclasses = [abc.PyLoader]
 
 
 def test_main():
     from test.support import run_unittest
-    run_unittest(SubclassTests)
+    classes = []
+    for class_ in globals().values():
+        if (inspect.isclass(class_) and
+                issubclass(class_, unittest.TestCase) and
+                issubclass(class_, InheritanceTests)):
+            classes.append(class_)
+    run_unittest(*classes)
 
 
 if __name__ == '__main__':
diff --git a/Misc/NEWS b/Misc/NEWS
index 6aed9597d2b..76ead6f754d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -37,6 +37,10 @@ C-API
 Library
 -------
 
+- importlib.abc.PyLoader did not inherit from importlib.abc.ResourceLoader like
+  the documentation said it did even though the code in PyLoader relied on the
+  abstract method required by ResourceLoader.
+
 - Issue #6431: Make Fraction type return NotImplemented when it doesn't
   know how to handle a comparison without loss of precision.  Also add
   correct handling of infinities and nans for comparisons with float.