refactor: migrate exec bridge to anyio and harden cancellation (#6)

tests/test_exec_runner.py

@@ -1,11 +1,13 @@
-import asyncio
+import anyio
+import pytest
 
-from takopi.exec_bridge import CodexExecRunner
+from takopi.exec_bridge import CodexExecRunner, EventCallback
 
 
-def test_run_serialized_serializes_same_session() -> None:
+@pytest.mark.anyio
+async def test_run_serialized_serializes_same_session() -> None:
     runner = CodexExecRunner(codex_cmd="codex", extra_args=[])
-    gate = asyncio.Event()
+    gate = anyio.Event()
     in_flight = 0
     max_in_flight = 0
 
@@ -19,13 +21,68 @@ def test_run_serialized_serializes_same_session() -> None:
 
     runner.run = run_stub  # type: ignore[assignment]
 
-    async def run_test() -> None:
-        t1 = asyncio.create_task(runner.run_serialized("a", "sid"))
-        t2 = asyncio.create_task(runner.run_serialized("b", "sid"))
-        await asyncio.sleep(0)
+    async with anyio.create_task_group() as tg:
+        tg.start_soon(runner.run_serialized, "a", "sid")
+        tg.start_soon(runner.run_serialized, "b", "sid")
+        await anyio.sleep(0)
         gate.set()
-        await asyncio.gather(t1, t2)
-
-    asyncio.run(run_test())
 
     assert max_in_flight == 1
+
+
+@pytest.mark.anyio
+async def test_run_serialized_allows_parallel_new_sessions() -> None:
+    runner = CodexExecRunner(codex_cmd="codex", extra_args=[])
+    gate = anyio.Event()
+    in_flight = 0
+    max_in_flight = 0
+
+    async def run_stub(*_args, **_kwargs):
+        nonlocal in_flight, max_in_flight
+        in_flight += 1
+        max_in_flight = max(max_in_flight, in_flight)
+        await gate.wait()
+        in_flight -= 1
+        return ("sid", "ok", True)
+
+    runner.run = run_stub  # type: ignore[assignment]
+
+    async with anyio.create_task_group() as tg:
+        tg.start_soon(runner.run_serialized, "a", None)
+        tg.start_soon(runner.run_serialized, "b", None)
+        with anyio.move_on_after(1):
+            while max_in_flight < 2:
+                await anyio.sleep(0)
+        gate.set()
+
+    assert max_in_flight == 2
+
+
+@pytest.mark.anyio
+async def test_new_session_holds_lock_for_resumes() -> None:
+    runner = CodexExecRunner(codex_cmd="codex", extra_args=[])
+    finish = anyio.Event()
+    resume_started = anyio.Event()
+
+    async def run_stub(
+        _prompt: str,
+        session_id: str | None,
+        on_event: EventCallback | None = None,
+    ) -> tuple[str, str, bool]:
+        if session_id is None:
+            if on_event:
+                await on_event({"type": "thread.started", "thread_id": "sid"})
+            await finish.wait()
+            return ("sid", "ok", True)
+        resume_started.set()
+        return ("sid", "ok", True)
+
+    runner.run = run_stub  # type: ignore[assignment]
+
+    async with anyio.create_task_group() as tg:
+        tg.start_soon(runner.run_serialized, "first", None)
+        await anyio.sleep(0)
+        tg.start_soon(runner.run_serialized, "resume", "sid")
+        await anyio.sleep(0)
+        assert not resume_started.is_set()
+        finish.set()