Initial release: iai-mcp v0.1.0

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: XNLLLLH <XNLLLLH@users.noreply.github.com>

tests/test_daemon_s4_first_iter_defer.py

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+"""Phase 07.6 W1 / tests for the startup grace before the first
+`_s4_offline_loop` iteration.
+
+Defends against the regression where a freshly-spawned daemon immediately
+runs the heavy S4 viability scan (sigma.compute_and_emit ->
+retrieve.build_runtime_graph -> runtime_graph_cache.save -> json.dumps),
+materialising a multi-GB intermediate Python string (CONTEXT.md D-01:
+py-spy 2026-04-29 PID 7959 RSS 7.6GB).
+
+Project async-test idiom (mandatory): sync `def test_X(...)` body wraps
+`asyncio.run(_async_body(...))`. The project does NOT depend on
+`pytest-asyncio`; `@pytest.mark.asyncio` markers silently pass without
+running. See tests/test_cpu_watchdog.py:12, tests/test_cascade_no_block.py:11
+for the canonical pattern. The plan template prescribed pytest-asyncio
+markers; this file deviates (Rule 1 — fake-GREEN avoidance) per project
+precedent.
+"""
+from __future__ import annotations
+
+import asyncio
+import time
+from types import SimpleNamespace
+
+
+# ---------------------------------------------------------------------------
+# helpers
+# ---------------------------------------------------------------------------
+
+def _fake_store():
+    """_s4_offline_loop only forwards `store` to s4.run_offline_pass and
+    write_event; both are stubbed in these tests, so a SimpleNamespace
+    placeholder is enough — never touches LanceDB.
+    """
+    return SimpleNamespace()
+
+
+# ---------------------------------------------------------------------------
+# Test 1: grace=0 fast-path — first iter runs within ≤100ms
+# ---------------------------------------------------------------------------
+
+def test_grace_zero_runs_first_iter_within_100ms(monkeypatch):
+    """D-06 (a): grace=0 => stubbed run_offline_pass invoked within ≤100ms."""
+    asyncio.run(_grace_zero_fast_path_body(monkeypatch))
+
+
+async def _grace_zero_fast_path_body(monkeypatch):
+    import iai_mcp.daemon as daemon_mod
+
+    monkeypatch.setattr(daemon_mod, "S4_FIRST_ITER_GRACE_SEC", 0.0)
+    called = asyncio.Event()
+    call_count = {"n": 0}
+
+    def _stub_run_offline_pass(_store):
+        call_count["n"] += 1
+        called.set()
+
+    monkeypatch.setattr(daemon_mod.s4, "run_offline_pass", _stub_run_offline_pass)
+    shutdown = asyncio.Event()
+    store = _fake_store()
+    t0 = time.monotonic()
+    task = asyncio.create_task(daemon_mod._s4_offline_loop(store, shutdown))
+    try:
+        await asyncio.wait_for(called.wait(), timeout=0.1)
+        elapsed = time.monotonic() - t0
+        assert elapsed <= 0.15, (
+            f"first run_offline_pass took {elapsed*1000:.1f}ms; expected <=100ms "
+            f"(plus ~50ms slack for to_thread schedule)"
+        )
+    finally:
+        shutdown.set()
+        try:
+            await asyncio.wait_for(task, timeout=1.0)
+        except asyncio.TimeoutError:
+            task.cancel()
+            try:
+                await task
+            except (asyncio.CancelledError, Exception):
+                pass
+    assert call_count["n"] >= 1
+
+
+# ---------------------------------------------------------------------------
+# Test 2: grace>0 deferred-path — no call before grace, ≥1 call after
+# ---------------------------------------------------------------------------
+
+def test_grace_positive_defers_first_iter(monkeypatch):
+    """D-06 (b): grace=0.5 => no call before 0.4s; ≥1 call after 0.7s."""
+    asyncio.run(_grace_positive_deferred_body(monkeypatch))
+
+
+async def _grace_positive_deferred_body(monkeypatch):
+    import iai_mcp.daemon as daemon_mod
+
+    monkeypatch.setattr(daemon_mod, "S4_FIRST_ITER_GRACE_SEC", 0.5)
+    call_count = {"n": 0}
+
+    def _stub_run_offline_pass(_store):
+        call_count["n"] += 1
+
+    monkeypatch.setattr(daemon_mod.s4, "run_offline_pass", _stub_run_offline_pass)
+    shutdown = asyncio.Event()
+    store = _fake_store()
+    task = asyncio.create_task(daemon_mod._s4_offline_loop(store, shutdown))
+    try:
+        await asyncio.sleep(0.4)
+        assert call_count["n"] == 0, (
+            f"S4 ran before 0.5s grace elapsed: call_count={call_count['n']}"
+        )
+        # Total ~0.7s — past 0.5s grace + to_thread schedule slack.
+        await asyncio.sleep(0.3)
+        assert call_count["n"] >= 1, (
+            f"S4 did not run after grace elapsed: call_count={call_count['n']}"
+        )
+    finally:
+        shutdown.set()
+        try:
+            await asyncio.wait_for(task, timeout=1.0)
+        except asyncio.TimeoutError:
+            task.cancel()
+            try:
+                await task
+            except (asyncio.CancelledError, Exception):
+                pass
+
+
+# ---------------------------------------------------------------------------
+# Test 3: shutdown during grace — clean return, no run, no exception
+# ---------------------------------------------------------------------------
+
+def test_shutdown_during_grace_returns_cleanly(monkeypatch):
+    """shutdown set during grace => loop returns cleanly, 0 calls."""
+    asyncio.run(_shutdown_during_grace_body(monkeypatch))
+
+
+async def _shutdown_during_grace_body(monkeypatch):
+    import iai_mcp.daemon as daemon_mod
+
+    monkeypatch.setattr(daemon_mod, "S4_FIRST_ITER_GRACE_SEC", 5.0)
+    call_count = {"n": 0}
+
+    def _stub_run_offline_pass(_store):
+        call_count["n"] += 1
+
+    monkeypatch.setattr(daemon_mod.s4, "run_offline_pass", _stub_run_offline_pass)
+    shutdown = asyncio.Event()
+    store = _fake_store()
+    task = asyncio.create_task(daemon_mod._s4_offline_loop(store, shutdown))
+    await asyncio.sleep(0.05)
+    shutdown.set()
+    # raises if loop did not return cleanly within 1s.
+    await asyncio.wait_for(task, timeout=1.0)
+    assert call_count["n"] == 0, (
+        f"S4 ran despite shutdown during grace: call_count={call_count['n']}"
+    )
+    assert task.done(), "loop task did not finish"
+    assert task.exception() is None, (
+        f"loop raised during shutdown-in-grace: {task.exception()!r}"
+    )
+
+
+# ---------------------------------------------------------------------------
+# Test 4: existing s4_offline_pass_error event-emit preserved
+# ---------------------------------------------------------------------------
+
+def test_run_offline_pass_error_still_emits_event(monkeypatch):
+    """Existing layered-defense preserved: run_offline_pass raises => write_event
+    called with kind='s4_offline_pass_error' + severity='warning'.
+    """
+    asyncio.run(_error_event_preserved_body(monkeypatch))
+
+
+async def _error_event_preserved_body(monkeypatch):
+    import iai_mcp.daemon as daemon_mod
+
+    monkeypatch.setattr(daemon_mod, "S4_FIRST_ITER_GRACE_SEC", 0.0)
+    events: list[tuple[str, dict, str]] = []
+
+    def _stub_run_offline_pass(_store):
+        raise RuntimeError("boom")
+
+    def _stub_write_event(_store, kind, payload, severity="info", **_kwargs):
+        events.append((kind, dict(payload) if isinstance(payload, dict) else payload, severity))
+
+    monkeypatch.setattr(daemon_mod.s4, "run_offline_pass", _stub_run_offline_pass)
+    monkeypatch.setattr(daemon_mod, "write_event", _stub_write_event)
+    shutdown = asyncio.Event()
+    store = _fake_store()
+    task = asyncio.create_task(daemon_mod._s4_offline_loop(store, shutdown))
+    # Give the loop time to: enter while-body, hit run_offline_pass raise,
+    # emit s4_offline_pass_error, then await the inter-iteration wait_for.
+    await asyncio.sleep(0.1)
+    shutdown.set()
+    try:
+        await asyncio.wait_for(task, timeout=1.0)
+    except asyncio.TimeoutError:
+        task.cancel()
+        try:
+            await task
+        except (asyncio.CancelledError, Exception):
+            pass
+    matching = [
+        e for e in events
+        if e[0] == "s4_offline_pass_error"
+        and e[2] == "warning"
+        and "boom" in str(e[1])
+    ]
+    assert matching, f"expected s4_offline_pass_error event with severity=warning + 'boom' payload, got: {events}"