Unpack partial in iscoroutinefunction (#894)

param/_utils.py

@@ -208,18 +208,16 @@ def full_groupby(l, key=lambda x: x):
 
 def iscoroutinefunction(function):
     """
-    Whether the function is an asynchronous coroutine function.
-    """
-    if not hasattr(inspect, 'iscoroutinefunction'):
-        return False
-    import asyncio
-    try:
-        return (
-            inspect.isasyncgenfunction(function) or
-            asyncio.iscoroutinefunction(function)
-        )
-    except AttributeError:
-        return False
+    Whether the function is an asynchronous generator or a coroutine.
+    """
+    # Partial unwrapping not required starting from Python 3.11.0
+    # See https://github.com/holoviz/param/pull/894#issuecomment-1867084447
+    while isinstance(function, functools.partial):
+        function = function.func
+    return (
+        inspect.isasyncgenfunction(function) or
+        inspect.iscoroutinefunction(function)
+    )
 
 
 def flatten(line):

tests/testutils.py

@@ -1,12 +1,14 @@
 import datetime as dt
 import os
 
+from functools import partial
+
 import param
 import pytest
 
 from param import guess_param_types, resolve_path
 from param.parameterized import bothmethod
-from param._utils import _is_mutable_container
+from param._utils import _is_mutable_container, iscoroutinefunction
 
 
 try:
@@ -393,3 +395,29 @@ class P(param.Parameterized):
 )
 def test__is_mutable_container(obj, ismutable):
     assert _is_mutable_container(obj) is ismutable
+
+
+async def coro():
+    return
+
+
+def test_iscoroutinefunction_coroutine():
+    assert iscoroutinefunction(coro)
+
+
+def test_iscoroutinefunction_partial_coroutine():
+    pcoro = partial(partial(coro))
+    assert iscoroutinefunction(pcoro)
+
+
+async def agen():
+    yield
+
+
+def test_iscoroutinefunction_asyncgen():
+    assert iscoroutinefunction(agen)
+
+
+def test_iscoroutinefunction_partial_asyncgen():
+    pagen = partial(partial(agen))
+    assert iscoroutinefunction(pagen)