Fix iscoroutinefunction() to support mock/proxy obejcts

Author: 1st1

asyncio/coroutines.py

@@ -238,13 +238,17 @@ def wrapper(*args, **kwds):
             w.__qualname__ = getattr(func, '__qualname__', None)
             return w
 
-    wrapper._is_coroutine = True  # For iscoroutinefunction().
+    wrapper._is_coroutine = _is_coroutine  # For iscoroutinefunction().
     return wrapper
 
 
+# A marker for iscoroutinefunction.
+_is_coroutine = object()
+
+
 def iscoroutinefunction(func):
     """Return True if func is a decorated coroutine function."""
-    return (getattr(func, '_is_coroutine', False) or
+    return (getattr(func, '_is_coroutine', None) is _is_coroutine or
             _inspect_iscoroutinefunction(func))
 
 

tests/test_tasks.py

@@ -1376,6 +1376,8 @@ def fn2():
             yield
         self.assertTrue(asyncio.iscoroutinefunction(fn2))
 
+        self.assertFalse(asyncio.iscoroutinefunction(mock.Mock()))
+
     def test_yield_vs_yield_from(self):
         fut = asyncio.Future(loop=self.loop)