From ca901bb528037f190b080f7027f8d80c6ac9e8c8 Mon Sep 17 00:00:00 2001
From: Chris Billington <chrisjbillington@gmail.com>
Date: Fri, 16 Oct 2026 20:49:08 +1100
Subject: [PATCH] Don't override task factory's `eager_start` default

PR #748 introduced a regression by passing `eager_start=None` to the
task factory when not provided by the caller. On Python 3.14 this is
interpreted as `False`, overriding `asyncio.eager_task_factory`'s
default of `eager_start=True` and resulting in non-eager tasks. On
Python 3.13, it's a `TypeError` , since `eager_task_factory` and user
factories with the `(loop, coro, *, name=None, context=None)` signature
do not accept an `eager_start` argument at all.

Forward `eager_start` to the factory and to `Task` only when provided by
the caller. This matches the behaviour of `asyncio`'s loop.

Add tests for behaviour when `eager_start=False` and when not provided.
---
 tests/test_base.py | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 uvloop/loop.pyx    |  8 +++++--
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/tests/test_base.py b/tests/test_base.py
index b226a84f..b737fb64 100644
--- a/tests/test_base.py
+++ b/tests/test_base.py
@@ -641,6 +641,58 @@ async def main():
 
         self.loop.run_until_complete(main())
 
+    @unittest.skipUnless(
+        sys.version_info >= (3, 12),
+        "asyncio.eager_task_factory requires Python 3.12+",
+    )
+    def test_eager_task_factory(self):
+        async def coro():
+            return "eager"
+
+        async def main():
+            task = self.loop.create_task(coro())
+            self.assertTrue(task.done())
+            self.assertEqual(task.result(), "eager")
+
+            task = asyncio.create_task(coro())
+            self.assertTrue(task.done())
+            self.assertEqual(task.result(), "eager")
+
+            if sys.version_info >= (3, 14):
+                task = asyncio.create_task(coro(), eager_start=False)
+                self.assertFalse(task.done())
+                self.assertEqual(await task, "eager")
+
+        self.loop.set_task_factory(asyncio.eager_task_factory)
+        try:
+            self.loop.run_until_complete(main())
+        finally:
+            self.loop.set_task_factory(None)
+
+    @unittest.skipUnless(
+        sys.version_info >= (3, 11),
+        "asyncio.Task accepts a context argument on Python 3.11+",
+    )
+    def test_task_factory_without_eager_start_kwarg(self):
+        async def coro():
+            return "result"
+
+        def factory(loop, coro, *, name=None, context=None):
+            return asyncio.Task(coro, loop=loop, name=name, context=context)
+
+        async def main():
+            task = self.loop.create_task(coro())
+            self.assertEqual(await task, "result")
+
+            task = asyncio.create_task(coro())
+            self.assertEqual(await task, "result")
+
+        self.loop.set_task_factory(factory)
+        try:
+            self.loop.run_until_complete(main())
+        finally:
+            self.loop.set_task_factory(None)
+
     def test_shutdown_asyncgens_01(self):
         finalized = list()
 
diff --git a/uvloop/loop.pyx b/uvloop/loop.pyx
index 802cdb69..5b62fab7 100644
--- a/uvloop/loop.pyx
+++ b/uvloop/loop.pyx
@@ -1417,10 +1417,14 @@ cdef class Loop:
         """
         self._check_closed()
         if PY313:
+            kwargs = {}
+            if eager_start is not None:
+                kwargs['eager_start'] = eager_start
             if self._task_factory is None:
-                task = aio_Task(coro, loop=self, context=context, eager_start=eager_start)
+                task = aio_Task(coro, loop=self, context=context, **kwargs)
             else:
-                task = self._task_factory(self, coro, context=context, eager_start=eager_start)
+                task = self._task_factory(
+                    self, coro, context=context, **kwargs)
         elif PY311:
             if self._task_factory is None:
                 task = aio_Task(coro, loop=self, context=context)