fix(transport): handle connection error correctly (#650) (#651)

Author: x0day

playwright/_impl/_browser_type.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import asyncio
 from pathlib import Path
 from typing import Dict, List, Optional, Union, cast
 
@@ -179,11 +180,24 @@ async def connect(
             self._connection._object_factory,
             transport,
         )
+        await connection._transport.start()
         connection._is_sync = self._connection._is_sync
         connection._loop = self._connection._loop
         connection._loop.create_task(connection.run())
+        obj = asyncio.create_task(
+            connection.wait_for_object_with_known_name("Playwright")
+        )
+        done, pending = await asyncio.wait(
+            {
+                obj,
+                connection._transport.on_error_future,  # type: ignore
+            },
+            return_when=asyncio.FIRST_COMPLETED,
+        )
+        if not obj.done():
+            obj.cancel()
+        playwright = next(iter(done)).result()
         self._connection._child_ws_connections.append(connection)
-        playwright = await connection.wait_for_object_with_known_name("Playwright")
         pre_launched_browser = playwright._initializer.get("preLaunchedBrowser")
         assert pre_launched_browser
         browser = cast(Browser, from_channel(pre_launched_browser))

playwright/_impl/_transport.py

@@ -42,6 +42,7 @@ def _get_stderr_fileno() -> Optional[int]:
 
 class Transport(ABC):
     def __init__(self) -> None:
+        self.on_error_future: asyncio.Future
         self.on_message = lambda _: None
 
     @abstractmethod
@@ -55,9 +56,14 @@ def dispose(self) -> None:
     async def wait_until_stopped(self) -> None:
         pass
 
-    async def run(self) -> None:
+    async def start(self) -> None:
+        if not hasattr(self, "on_error_future"):
+            self.on_error_future = asyncio.Future()
         self._loop = asyncio.get_running_loop()
-        self.on_error_future: asyncio.Future = asyncio.Future()
+
+    @abstractmethod
+    async def run(self) -> None:
+        pass
 
     @abstractmethod
     def send(self, message: Dict) -> None:
@@ -93,17 +99,28 @@ async def wait_until_stopped(self) -> None:
         await self._proc.wait()
 
     async def run(self) -> None:
-        await super().run()
+        await self.start()
         self._stopped_future: asyncio.Future = asyncio.Future()
 
-        self._proc = proc = await asyncio.create_subprocess_exec(
-            str(self._driver_executable),
-            "run-driver",
-            stdin=asyncio.subprocess.PIPE,
-            stdout=asyncio.subprocess.PIPE,
-            stderr=_get_stderr_fileno(),
-            limit=32768,
-        )
+        try:
+            self._proc = proc = await asyncio.create_subprocess_exec(
+                str(self._driver_executable),
+                "run-driver",
+                stdin=asyncio.subprocess.PIPE,
+                stdout=asyncio.subprocess.PIPE,
+                stderr=_get_stderr_fileno(),
+                limit=32768,
+            )
+        except FileNotFoundError:
+            self.on_error_future.set_exception(
+                Error(
+                    "playwright's driver is not found, You can read the contributing guide "
+                    "for some guidance on how to get everything setup for working on the code "
+                    "https://github.com/microsoft/playwright-python/blob/master/CONTRIBUTING.md"
+                )
+            )
+            return
+
         assert proc.stdout
         assert proc.stdin
         self._output = proc.stdin
@@ -160,15 +177,22 @@ async def wait_until_stopped(self) -> None:
         await self._connection.wait_closed()
 
     async def run(self) -> None:
-        await super().run()
+        await self.start()
 
         options: Dict[str, Any] = {}
         if self.timeout is not None:
             options["close_timeout"] = self.timeout / 1000
             options["ping_timeout"] = self.timeout / 1000
+
         if self.headers is not None:
             options["extra_headers"] = self.headers
-        self._connection = await websockets.connect(self.ws_endpoint, **options)
+        try:
+            self._connection = await websockets.connect(self.ws_endpoint, **options)
+        except Exception as err:
+            self.on_error_future.set_exception(
+                Error(f"playwright's websocket endpoint connection error: {err}")
+            )
+            return
 
         while not self._stopped:
             try:

playwright/async_api/_context_manager.py

@@ -32,10 +32,22 @@ async def __aenter__(self) -> AsyncPlaywright:
         )
         loop = asyncio.get_running_loop()
         self._connection._loop = loop
+        obj = asyncio.create_task(
+            self._connection.wait_for_object_with_known_name("Playwright")
+        )
+        await self._connection._transport.start()
         loop.create_task(self._connection.run())
-        playwright = AsyncPlaywright(
-            await self._connection.wait_for_object_with_known_name("Playwright")
+        done, pending = await asyncio.wait(
+            {
+                obj,
+                self._connection._transport.on_error_future,  # type: ignore
+            },
+            return_when=asyncio.FIRST_COMPLETED,
         )
+        if not obj.done():
+            obj.cancel()
+        obj = next(iter(done)).result()
+        playwright = AsyncPlaywright(obj)  # type: ignore
         playwright.stop = self.__aexit__  # type: ignore
         return playwright
 

tests/async/test_browsertype_connect.py

@@ -182,3 +182,13 @@ async def test_prevent_getting_video_path(
         == "Path is not available when using browserType.connect(). Use save_as() to save a local copy."
     )
     remote_server.kill()
+
+
+async def test_connect_to_closed_server_without_hangs(
+    browser_type: BrowserType, launch_server
+):
+    remote_server = launch_server()
+    remote_server.kill()
+    with pytest.raises(Error) as exc:
+        await browser_type.connect(remote_server.ws_endpoint)
+    assert "playwright's websocket endpoint connection error" in exc.value.message

tests/sync/test_browsertype_connect.py

@@ -145,3 +145,13 @@ def test_browser_type_connect_should_forward_close_events_to_pages(
     assert events == ["page::close", "context::close", "browser::disconnected"]
     remote.kill()
     assert events == ["page::close", "context::close", "browser::disconnected"]
+
+
+def test_connect_to_closed_server_without_hangs(
+    browser_type: BrowserType, launch_server
+):
+    remote_server = launch_server()
+    remote_server.kill()
+    with pytest.raises(Error) as exc:
+        browser_type.connect(remote_server.ws_endpoint)
+    assert "playwright's websocket endpoint connection error" in exc.value.message