fix(sync): wait for initialize before leaving __enter__ (#3168)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 16cb16dc-1986-42c7-90ce-9549b32cfccb

Author: Skn0tt

playwright/_impl/_connection.py

@@ -305,7 +305,6 @@ def __init__(
         self._dispatcher_fiber = dispatcher_fiber
         self._transport = transport
         self._transport.on_message = lambda msg: self.dispatch(msg)
-        self._waiting_for_object: Dict[str, Callable[[ChannelOwner], None]] = {}
         self._last_id = 0
         self._objects: Dict[str, ChannelOwner] = {}
         self._callbacks: Dict[int, ProtocolCallback] = {}
@@ -341,7 +340,16 @@ async def run(self) -> None:
         self._root_object = RootChannelOwner(self)
 
         async def init() -> None:
-            self.playwright_future.set_result(await self._root_object.initialize())
+            try:
+                result = await self._root_object.initialize()
+                if not self.playwright_future.done():
+                    self.playwright_future.set_result(result)
+            except Exception as exc:
+                # No re-raise: callers observe playwright_future; a task
+                # exception would log "never retrieved". Skip set_* if async
+                # __aenter__ already cancelled the future after a transport error.
+                if not self.playwright_future.done():
+                    self.playwright_future.set_exception(exc)
 
         await self._transport.connect()
         self._init_task = self._loop.create_task(init())
@@ -374,11 +382,6 @@ def cleanup(self, cause: str = None) -> None:
         self._callbacks.clear()
         self.emit("close")
 
-    def call_on_object_with_known_name(
-        self, guid: str, callback: Callable[[ChannelOwner], None]
-    ) -> None:
-        self._waiting_for_object[guid] = callback
-
     def set_is_tracing(self, is_tracing: bool) -> None:
         if is_tracing:
             self._tracing_count += 1
@@ -574,10 +577,7 @@ def _create_remote_object(
         self, parent: ChannelOwner, type: str, guid: str, initializer: Dict
     ) -> ChannelOwner:
         initializer = self._replace_guids_with_channels(initializer)
-        result = self._object_factory(parent, type, guid, initializer)
-        if guid in self._waiting_for_object:
-            self._waiting_for_object.pop(guid)(result)
-        return result
+        return self._object_factory(parent, type, guid, initializer)
 
     def _replace_channels_with_guids(
         self,

playwright/sync_api/_context_manager.py

@@ -13,15 +13,14 @@
 # limitations under the License.
 
 import asyncio
-from typing import TYPE_CHECKING, Any, Optional, cast
+from typing import TYPE_CHECKING, Any, Optional
 
 from greenlet import greenlet
 
-from playwright._impl._connection import ChannelOwner, Connection
+from playwright._impl._connection import Connection
 from playwright._impl._errors import Error
 from playwright._impl._greenlets import MainGreenlet
 from playwright._impl._object_factory import create_remote_object
-from playwright._impl._playwright import Playwright
 from playwright._impl._transport import PipeTransport
 from playwright.sync_api._generated import Playwright as SyncPlaywright
 
@@ -66,19 +65,19 @@ def greenlet_main() -> None:
 
         g_self = greenlet.getcurrent()
 
-        def callback_wrapper(channel_owner: ChannelOwner) -> None:
-            playwright_impl = cast(Playwright, channel_owner)
-            self._playwright = SyncPlaywright(playwright_impl)
-            g_self.switch()
-
-        # Switch control to the dispatcher, it'll fire an event and pass control to
-        # the calling greenlet.
-        self._connection.call_on_object_with_known_name("Playwright", callback_wrapper)
+        # Wait until initialize completes (not just Playwright __create__), matching async.
+        self._connection.playwright_future.add_done_callback(lambda _: g_self.switch())
         dispatcher_fiber.switch()
 
-        playwright = self._playwright
-        playwright.stop = self.__exit__  # type: ignore
-        return playwright
+        try:
+            self._playwright = SyncPlaywright(
+                self._connection.playwright_future.result()
+            )
+        except BaseException:
+            self.__exit__()
+            raise
+        self._playwright.stop = self.__exit__  # type: ignore
+        return self._playwright
 
     def start(self) -> SyncPlaywright:
         return self.__enter__()

tests/sync/test_context_manager.py

@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import subprocess
+import sys
+import textwrap
+from pathlib import Path
 from typing import Dict
 
 import pytest
@@ -34,3 +38,29 @@ def test_context_managers_not_hang(context: BrowserContext) -> None:
     with pytest.raises(Exception, match="Oops!"):
         with context.new_page():
             raise Exception("Oops!")
+
+
+def test_empty_sync_playwright_does_not_warn(tmp_path: Path) -> None:
+    # Regression test for https://github.com/microsoft/playwright-python/issues/3165.
+    # __enter__ must wait for initialize to finish; otherwise teardown races the
+    # in-flight init callback and prints asyncio warnings on an empty with-block.
+    script = tmp_path / "empty_sync_playwright.py"
+    script.write_text(
+        textwrap.dedent(
+            """
+            from playwright.sync_api import sync_playwright
+
+            with sync_playwright() as pw:
+                pass
+            """
+        )
+    )
+    result = subprocess.run(
+        [sys.executable, str(script)],
+        capture_output=True,
+        text=True,
+        timeout=30,
+    )
+    assert result.returncode == 0, result.stderr
+    assert "Future exception was never retrieved" not in result.stderr
+    assert "Task was destroyed but it is pending" not in result.stderr