Hermes-agent

tests/hermes_cli/test_picker_prewarm.py

@@ -0,0 +1,60 @@
+"""Tests for the /model picker background cache prewarm.
+
+``prewarm_picker_cache_async()`` warms the provider-models disk cache off the
+user's critical path so the first ``/model`` open in a session is fast instead
+of blocking ~1-2s on serial /v1/models fetches. These pin the two contracts
+that matter: it runs the warm path exactly once per process (no thread leak),
+and it delegates to ``list_authenticated_providers`` to do the warming.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import patch
+
+import hermes_cli.model_switch as ms
+
+
+def _reset_guard():
+    ms._picker_prewarm_done.clear()
+
+
+def test_prewarm_runs_list_authenticated_providers_once():
+    """First call spawns a thread that calls list_authenticated_providers;
+    the warm side effect is delegated there (which disk-caches per provider)."""
+    _reset_guard()
+    with patch.object(ms, "list_authenticated_providers", return_value=[]) as mock_list:
+        t = ms.prewarm_picker_cache_async()
+        assert t is not None, "first call must spawn a prewarm thread"
+        t.join(timeout=10)
+        assert not t.is_alive(), "prewarm thread should finish promptly"
+        mock_list.assert_called_once()
+    _reset_guard()
+
+
+def test_prewarm_guard_is_once_per_process():
+    """The process-level Event guard must make repeat calls no-ops so a
+    long-lived process never leaks one OS thread per call."""
+    _reset_guard()
+    with patch.object(ms, "list_authenticated_providers", return_value=[]):
+        t1 = ms.prewarm_picker_cache_async()
+        assert t1 is not None
+        t1.join(timeout=10)
+        # Subsequent calls return None (guard set) — no new thread.
+        assert ms.prewarm_picker_cache_async() is None
+        assert ms.prewarm_picker_cache_async() is None
+    _reset_guard()
+
+
+def test_prewarm_never_raises_on_failure():
+    """A failing/offline provider path must be fully swallowed — the prewarm
+    is best-effort and must never surface errors into the session."""
+    _reset_guard()
+    with patch.object(
+        ms, "list_authenticated_providers", side_effect=RuntimeError("boom")
+    ):
+        t = ms.prewarm_picker_cache_async()
+        assert t is not None
+        # join must not raise; the worker swallows the exception internally.
+        t.join(timeout=10)
+        assert not t.is_alive()
+    _reset_guard()