Restore tests until the code is actually removed.

Lib/test/test_contextlib.py

@@ -100,6 +100,128 @@ class ContextManagerTestCase(unittest.TestCase):
         self.assertEqual(baz.foo, 'bar')
         self.assertEqual(baz.__doc__, "Whee!")
 
+class NestedTestCase(unittest.TestCase):
+
+    # XXX This needs more work
+
+    def test_nested(self):
+        @contextmanager
+        def a():
+            yield 1
+        @contextmanager
+        def b():
+            yield 2
+        @contextmanager
+        def c():
+            yield 3
+        with nested(a(), b(), c()) as (x, y, z):
+            self.assertEqual(x, 1)
+            self.assertEqual(y, 2)
+            self.assertEqual(z, 3)
+
+    def test_nested_cleanup(self):
+        state = []
+        @contextmanager
+        def a():
+            state.append(1)
+            try:
+                yield 2
+            finally:
+                state.append(3)
+        @contextmanager
+        def b():
+            state.append(4)
+            try:
+                yield 5
+            finally:
+                state.append(6)
+        try:
+            with nested(a(), b()) as (x, y):
+                state.append(x)
+                state.append(y)
+                1/0
+        except ZeroDivisionError:
+            self.assertEqual(state, [1, 4, 2, 5, 6, 3])
+        else:
+            self.fail("Didn't raise ZeroDivisionError")
+
+    def test_nested_right_exception(self):
+        state = []
+        @contextmanager
+        def a():
+            yield 1
+        class b(object):
+            def __enter__(self):
+                return 2
+            def __exit__(self, *exc_info):
+                try:
+                    raise Exception()
+                except:
+                    pass
+        try:
+            with nested(a(), b()) as (x, y):
+                1/0
+        except ZeroDivisionError:
+            self.assertEqual((x, y), (1, 2))
+        except Exception:
+            self.fail("Reraised wrong exception")
+        else:
+            self.fail("Didn't raise ZeroDivisionError")
+
+    def test_nested_b_swallows(self):
+        @contextmanager
+        def a():
+            yield
+        @contextmanager
+        def b():
+            try:
+                yield
+            except:
+                # Swallow the exception
+                pass
+        try:
+            with nested(a(), b()):
+                1/0
+        except ZeroDivisionError:
+            self.fail("Didn't swallow ZeroDivisionError")
+
+    def test_nested_break(self):
+        @contextmanager
+        def a():
+            yield
+        state = 0
+        while True:
+            state += 1
+            with nested(a(), a()):
+                break
+            state += 10
+        self.assertEqual(state, 1)
+
+    def test_nested_continue(self):
+        @contextmanager
+        def a():
+            yield
+        state = 0
+        while state < 3:
+            state += 1
+            with nested(a(), a()):
+                continue
+            state += 10
+        self.assertEqual(state, 3)
+
+    def test_nested_return(self):
+        @contextmanager
+        def a():
+            try:
+                yield
+            except:
+                pass
+        def foo():
+            with nested(a(), a()):
+                return 1
+            return 10
+        self.assertEqual(foo(), 1)
+
 class ClosingTestCase(unittest.TestCase):
 
     # XXX This needs more work