bpo-46647: make sure test_functools works with and without _functoolsmodule

Author: sobolevn

Lib/test/test_functools.py

@@ -13,21 +13,20 @@
 import typing
 import unittest
 import unittest.mock
-import os
 import weakref
 import gc
 from weakref import proxy
 import contextlib
 
 from test.support import import_helper
 from test.support import threading_helper
-from test.support.script_helper import assert_python_ok
 
 import functools
 
 py_functools = import_helper.import_fresh_module('functools',
                                                  blocked=['_functools'])
-c_functools = import_helper.import_fresh_module('functools')
+c_functools = import_helper.import_fresh_module('functools',
+                                                fresh=['_functools'])
 
 decimal = import_helper.import_fresh_module('decimal', fresh=['_decimal'])
 
@@ -202,7 +201,10 @@ def test_repr(self):
         kwargs = {'a': object(), 'b': object()}
         kwargs_reprs = ['a={a!r}, b={b!r}'.format_map(kwargs),
                         'b={b!r}, a={a!r}'.format_map(kwargs)]
-        if self.partial in (c_functools.partial, py_functools.partial):
+        if self.partial in (
+            getattr(c_functools, 'partial', object()),
+            py_functools.partial,
+        ):
             name = 'functools.partial'
         else:
             name = self.partial.__name__
@@ -224,7 +226,10 @@ def test_repr(self):
                        for kwargs_repr in kwargs_reprs])
 
     def test_recursive_repr(self):
-        if self.partial in (c_functools.partial, py_functools.partial):
+        if self.partial in (
+            getattr(c_functools, 'partial', object()),
+            py_functools.partial,
+        ):
             name = 'functools.partial'
         else:
             name = self.partial.__name__
@@ -390,11 +395,13 @@ class TestPartialC(TestPartial, unittest.TestCase):
     if c_functools:
         partial = c_functools.partial
 
-    class AllowPickle:
-        def __enter__(self):
-            return self
-        def __exit__(self, type, value, tb):
-            return False
+        class AllowPickle:
+            def __init__(self):
+                self._cm = replaced_module("functools", c_functools)
+            def __enter__(self):
+                return self._cm.__enter__()
+            def __exit__(self, type, value, tb):
+                return self._cm.__exit__(type, value, tb)
 
     def test_attributes_unwritable(self):
         # attributes should not be writable
@@ -1857,9 +1864,10 @@ def test_staticmethod(x):
 def py_cached_func(x, y):
     return 3 * x + y
 
-@c_functools.lru_cache()
-def c_cached_func(x, y):
-    return 3 * x + y
+if c_functools:
+    @c_functools.lru_cache()
+    def c_cached_func(x, y):
+        return 3 * x + y
 
 
 class TestLRUPy(TestLRU, unittest.TestCase):
@@ -1876,18 +1884,20 @@ def cached_staticmeth(x, y):
         return 3 * x + y
 
 
+@unittest.skipUnless(c_functools, 'requires the C _functools module')
 class TestLRUC(TestLRU, unittest.TestCase):
-    module = c_functools
-    cached_func = c_cached_func,
+    if c_functools:
+        module = c_functools
+        cached_func = c_cached_func,
 
-    @module.lru_cache()
-    def cached_meth(self, x, y):
-        return 3 * x + y
+        @module.lru_cache()
+        def cached_meth(self, x, y):
+            return 3 * x + y
 
-    @staticmethod
-    @module.lru_cache()
-    def cached_staticmeth(x, y):
-        return 3 * x + y
+        @staticmethod
+        @module.lru_cache()
+        def cached_staticmeth(x, y):
+            return 3 * x + y
 
 
 class TestSingleDispatch(unittest.TestCase):