fix(exec-bridge): clean up subprocess on cancellation

codex_telegram_bridge/tests/test_exec_bridge.py

@@ -1,4 +1,7 @@
 import asyncio
+import os
+
+import pytest
 
 from codex_telegram_bridge.exec_bridge import extract_session_id, truncate_for_telegram
 
@@ -148,3 +151,54 @@ def test_new_final_message_forces_notification_when_too_long_to_edit() -> None:
     assert len(bot.send_calls) == 2
     assert bot.send_calls[0]["disable_notification"] is True
     assert bot.send_calls[1]["disable_notification"] is False
+
+
+def test_codex_runner_cancellation_terminates_subprocess(tmp_path, monkeypatch) -> None:
+    from codex_telegram_bridge.exec_bridge import CodexExecRunner
+
+    pid_file = tmp_path / "pid"
+    codex_path = tmp_path / "codex"
+    codex_path.write_text(
+        "#!/usr/bin/env python3\n"
+        "import os\n"
+        "import time\n"
+        "\n"
+        "pid_file = os.environ.get('CODEX_FAKE_PID_FILE')\n"
+        "if pid_file:\n"
+        "    with open(pid_file, 'w', encoding='utf-8') as f:\n"
+        "        f.write(str(os.getpid()))\n"
+        "        f.flush()\n"
+        "\n"
+        "time.sleep(60)\n",
+        encoding="utf-8",
+    )
+    codex_path.chmod(0o755)
+    monkeypatch.setenv("CODEX_FAKE_PID_FILE", str(pid_file))
+
+    runner = CodexExecRunner(codex_cmd=str(codex_path), workspace=None, extra_args=[])
+
+    async def run_and_cancel() -> None:
+        task = asyncio.create_task(runner.run("hello", session_id=None))
+
+        for _ in range(100):
+            if pid_file.exists():
+                break
+            await asyncio.sleep(0.01)
+        assert pid_file.exists()
+
+        pid = int(pid_file.read_text(encoding="utf-8").strip())
+
+        task.cancel()
+        with pytest.raises(asyncio.CancelledError):
+            await task
+
+        for _ in range(200):
+            try:
+                os.kill(pid, 0)
+            except ProcessLookupError:
+                return
+            await asyncio.sleep(0.01)
+
+        raise AssertionError("cancelled codex subprocess is still running")
+
+    asyncio.run(run_and_cancel())