Enhance markcoroutinefunction to support functools.partial

Author: chaope

Lib/inspect.py

@@ -317,6 +317,7 @@ def markcoroutinefunction(func):
     """
     if hasattr(func, '__func__'):
         func = func.__func__
+    func = functools._unwrap_partial(func)
     func._is_coroutine_marker = _is_coroutine_mark
     return func
 

Lib/test/test_inspect/test_inspect.py

@@ -334,6 +334,17 @@ def do_something_static():
         self.assertTrue(inspect.iscoroutinefunction(Cl3.do_something_classy))
         self.assertTrue(inspect.iscoroutinefunction(Cl3.do_something_static))
 
+        # Test markcoroutinefunction with functools.partial
+        async def _fn4():
+            pass
+
+        def fn4():
+            return _fn4()
+
+        partial_fn4 = functools.partial(fn4)
+        marked_partial_fn4 = inspect.markcoroutinefunction(partial_fn4)
+        self.assertTrue(inspect.iscoroutinefunction(marked_partial_fn4))
+
         self.assertFalse(
             inspect.iscoroutinefunction(unittest.mock.Mock()))
         self.assertTrue(

Misc/NEWS.d/next/Library/2025-12-10-02-31-08.gh-issue-142418.XLGNh3.rst

@@ -0,0 +1,2 @@
+Fix markcoroutinefunction by letting it set the coroutine function marker on
+underlying function correctly.