bpo-36921: Deprecate @coroutine for sake of async def (GH-13346)

The second attempt. Now deprecate `@coroutine` only, keep `yield from fut` as is.


https://bugs.python.org/issue36921

Lib/test/test_asyncio/test_locks.py

@@ -44,10 +44,11 @@ class LockTests(test_utils.TestCase):
         self.assertTrue(repr(lock).endswith('[unlocked]>'))
         self.assertTrue(RGX_REPR.match(repr(lock)))
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                yield from lock
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    yield from lock
 
         self.loop.run_until_complete(acquire_lock())
         self.assertTrue(repr(lock).endswith('[locked]>'))
@@ -56,10 +57,11 @@ class LockTests(test_utils.TestCase):
     def test_lock(self):
         lock = asyncio.Lock(loop=self.loop)
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from lock)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from lock)
 
         res = self.loop.run_until_complete(acquire_lock())
 
@@ -79,17 +81,18 @@ class LockTests(test_utils.TestCase):
             asyncio.BoundedSemaphore(loop=loop),
         ]
 
-        @asyncio.coroutine
-        def test(lock):
-            yield from asyncio.sleep(0.01)
-            self.assertFalse(lock.locked())
-            with self.assertWarns(DeprecationWarning):
-                with (yield from lock) as _lock:
-                    self.assertIs(_lock, None)
-                    self.assertTrue(lock.locked())
-                    yield from asyncio.sleep(0.01)
-                    self.assertTrue(lock.locked())
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def test(lock):
+                yield from asyncio.sleep(0.01)
                 self.assertFalse(lock.locked())
+                with self.assertWarns(DeprecationWarning):
+                    with (yield from lock) as _lock:
+                        self.assertIs(_lock, None)
+                        self.assertTrue(lock.locked())
+                        yield from asyncio.sleep(0.01)
+                        self.assertTrue(lock.locked())
+                    self.assertFalse(lock.locked())
 
         for primitive in primitives:
             loop.run_until_complete(test(primitive))
@@ -290,10 +293,11 @@ class LockTests(test_utils.TestCase):
     def test_context_manager(self):
         lock = asyncio.Lock(loop=self.loop)
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from lock)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from lock)
 
         with self.loop.run_until_complete(acquire_lock()):
             self.assertTrue(lock.locked())
@@ -303,10 +307,11 @@ class LockTests(test_utils.TestCase):
     def test_context_manager_cant_reuse(self):
         lock = asyncio.Lock(loop=self.loop)
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from lock)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from lock)
 
         # This spells "yield from lock" outside a generator.
         cm = self.loop.run_until_complete(acquire_lock())
@@ -773,10 +778,11 @@ class ConditionTests(test_utils.TestCase):
     def test_context_manager(self):
         cond = asyncio.Condition(loop=self.loop)
 
-        @asyncio.coroutine
-        def acquire_cond():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from cond)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_cond():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from cond)
 
         with self.loop.run_until_complete(acquire_cond()):
             self.assertTrue(cond.locked())
@@ -869,10 +875,11 @@ class SemaphoreTests(test_utils.TestCase):
         sem = asyncio.Semaphore(loop=self.loop)
         self.assertEqual(1, sem._value)
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from sem)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from sem)
 
         res = self.loop.run_until_complete(acquire_lock())
 
@@ -1012,10 +1019,11 @@ class SemaphoreTests(test_utils.TestCase):
     def test_context_manager(self):
         sem = asyncio.Semaphore(2, loop=self.loop)
 
-        @asyncio.coroutine
-        def acquire_lock():
-            with self.assertWarns(DeprecationWarning):
-                return (yield from sem)
+        with self.assertWarns(DeprecationWarning):
+            @asyncio.coroutine
+            def acquire_lock():
+                with self.assertWarns(DeprecationWarning):
+                    return (yield from sem)
 
         with self.loop.run_until_complete(acquire_lock()):
             self.assertFalse(sem.locked())