Add regression test for #1386 (model='unknown' init guard)

tests/test_session_import_cli_fallback_model.py

@@ -0,0 +1,69 @@
+"""Regression test for #1386: CLI session import must not crash when the
+session is missing from `get_cli_sessions()` metadata at the time of import.
+
+Before the fix, `_handle_session_import_cli` only assigned `model` inside
+the `for cs in get_cli_sessions(): if cs["session_id"] == sid` loop. If
+the session existed in the messages store but had no metadata row (or had
+been pruned after `get_cli_session_messages()` was called), `model` was
+unbound and `import_cli_session(sid, title, msgs, model, ...)` raised
+`UnboundLocalError`.
+
+The fix initializes `model = "unknown"` before the loop so the import
+proceeds with a sensible default rather than crashing.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+ROUTES_PY = (REPO / "api" / "routes.py").read_text(encoding="utf-8")
+
+
+def _extract_handler(name: str) -> str:
+    """Return the source of the handler function `name` from api/routes.py."""
+    marker = f"def {name}("
+    idx = ROUTES_PY.find(marker)
+    assert idx != -1, f"{name} not found in api/routes.py"
+    # Walk forward until a top-level `def ` (col 0) appears.
+    next_def = ROUTES_PY.find("\ndef ", idx + len(marker))
+    return ROUTES_PY[idx : next_def if next_def != -1 else len(ROUTES_PY)]
+
+
+def test_import_cli_initializes_model_before_metadata_loop():
+    """The fallback `model = 'unknown'` must be set BEFORE the
+    `for cs in get_cli_sessions()` loop so that a metadata-less session
+    cannot leave `model` unbound."""
+    handler = _extract_handler("_handle_session_import_cli")
+    init_idx = handler.find('model = "unknown"')
+    if init_idx == -1:
+        # Allow single quotes too.
+        init_idx = handler.find("model = 'unknown'")
+    assert init_idx != -1, (
+        "Expected `model = \"unknown\"` initialization in "
+        "_handle_session_import_cli before the metadata loop. Without it, "
+        "import crashes when the session has messages but no metadata row."
+    )
+    loop_idx = handler.find("for cs in get_cli_sessions()")
+    assert loop_idx != -1, "Expected `for cs in get_cli_sessions()` loop"
+    assert init_idx < loop_idx, (
+        "`model` must be initialized BEFORE the `for cs in get_cli_sessions()` "
+        "loop, otherwise a session without a metadata row leaves `model` "
+        "unbound and `import_cli_session(..., model, ...)` raises "
+        "UnboundLocalError."
+    )
+
+
+def test_import_cli_passes_model_to_import_helper():
+    """Sanity: the handler still passes the resolved model down to
+    `import_cli_session` — the regression test would not catch a refactor
+    that drops the argument entirely."""
+    handler = _extract_handler("_handle_session_import_cli")
+    assert "import_cli_session(" in handler
+    # The model variable should appear as a positional or keyword arg in
+    # the import_cli_session call.
+    call_idx = handler.find("import_cli_session(")
+    call_block = handler[call_idx : call_idx + 400]
+    assert "model" in call_block, (
+        "import_cli_session() call should still receive the `model` argument."
+    )