1 files changed, 119 insertions, 2 deletions
diff --git a/Cython/Tests/TestCythonUtils.py b/Cython/Tests/TestCythonUtils.py
index 2641900c0..402616101 100644
--- a/Cython/Tests/TestCythonUtils.py
+++ b/Cython/Tests/TestCythonUtils.py
@@ -1,11 +1,128 @@
 import unittest
 
-from ..Utils import build_hex_version
+from Cython.Utils import (
+    _CACHE_NAME_PATTERN, _build_cache_name, _find_cache_attributes,
+    build_hex_version, cached_method, clear_method_caches, try_finally_contextmanager)
+
+METHOD_NAME = "cached_next"
+CACHE_NAME = _build_cache_name(METHOD_NAME)
+NAMES = CACHE_NAME, METHOD_NAME
+
+class Cached(object):
+    @cached_method
+    def cached_next(self, x):
+        return next(x)
+
 
 class TestCythonUtils(unittest.TestCase):
     def test_build_hex_version(self):
         self.assertEqual('0x001D00A1', build_hex_version('0.29a1'))
-        self.assertEqual('0x001D00A1', build_hex_version('0.29a1'))
         self.assertEqual('0x001D03C4', build_hex_version('0.29.3rc4'))
         self.assertEqual('0x001D00F0', build_hex_version('0.29'))
         self.assertEqual('0x040000F0', build_hex_version('4.0'))
+
+    ############################## Cached Methods ##############################
+
+    def test_cache_method_name(self):
+        method_name = "foo"
+        cache_name = _build_cache_name(method_name)
+        match = _CACHE_NAME_PATTERN.match(cache_name)
+
+        self.assertIsNot(match, None)
+        self.assertEqual(match.group(1), method_name)
+
+    def test_requirements_for_Cached(self):
+        obj = Cached()
+
+        self.assertFalse(hasattr(obj, CACHE_NAME))
+        self.assertTrue(hasattr(obj, METHOD_NAME))
+        self.set_of_names_equal(obj, set())
+
+    def set_of_names_equal(self, obj, value):
+        self.assertEqual(set(_find_cache_attributes(obj)), value)
+
+    def test_find_cache_attributes(self):
+        obj = Cached()
+        method_name = "bar"
+        cache_name = _build_cache_name(method_name)
+
+        setattr(obj, CACHE_NAME, {})
+        setattr(obj, cache_name, {})
+
+        self.assertFalse(hasattr(obj, method_name))
+        self.set_of_names_equal(obj, {NAMES, (cache_name, method_name)})
+
+    def test_cached_method(self):
+        obj = Cached()
+        value = iter(range(3))  # iter for Py2
+        cache = {(value,): 0}
+
+        # cache args
+        self.assertEqual(obj.cached_next(value), 0)
+        self.set_of_names_equal(obj, {NAMES})
+        self.assertEqual(getattr(obj, CACHE_NAME), cache)
+
+        # use cache
+        self.assertEqual(obj.cached_next(value), 0)
+        self.set_of_names_equal(obj, {NAMES})
+        self.assertEqual(getattr(obj, CACHE_NAME), cache)
+
+    def test_clear_method_caches(self):
+        obj = Cached()
+        value = iter(range(3))  # iter for Py2
+        cache = {(value,): 1}
+
+        obj.cached_next(value)  # cache args
+
+        clear_method_caches(obj)
+        self.set_of_names_equal(obj, set())
+
+        self.assertEqual(obj.cached_next(value), 1)
+        self.set_of_names_equal(obj, {NAMES})
+        self.assertEqual(getattr(obj, CACHE_NAME), cache)
+
+    def test_clear_method_caches_with_missing_method(self):
+        obj = Cached()
+        method_name = "bar"
+        cache_name = _build_cache_name(method_name)
+        names = cache_name, method_name
+
+        setattr(obj, cache_name, object())
+
+        self.assertFalse(hasattr(obj, method_name))
+        self.set_of_names_equal(obj, {names})
+
+        clear_method_caches(obj)
+        self.set_of_names_equal(obj, {names})
+
+    def test_try_finally_contextmanager(self):
+        states = []
+        @try_finally_contextmanager
+        def gen(*args, **kwargs):
+            states.append("enter")
+            yield (args, kwargs)
+            states.append("exit")
+
+        with gen(1, 2, 3, x=4) as call_args:
+            assert states == ["enter"]
+            self.assertEqual(call_args, ((1, 2, 3), {'x': 4}))
+        assert states == ["enter", "exit"]
+
+        class MyException(RuntimeError):
+            pass
+
+        del states[:]
+        with self.assertRaises(MyException):
+            with gen(1, 2, y=4) as call_args:
+                assert states == ["enter"]
+                self.assertEqual(call_args, ((1, 2), {'y': 4}))
+                raise MyException("FAIL INSIDE")
+            assert states == ["enter", "exit"]
+
+        del states[:]
+        with self.assertRaises(StopIteration):
+            with gen(1, 2, y=4) as call_args:
+                assert states == ["enter"]
+                self.assertEqual(call_args, ((1, 2), {'y': 4}))
+                raise StopIteration("STOP")
+            assert states == ["enter", "exit"]