feat(scouts): add connector registry

app/scouts/connectors/registry.py

@@ -0,0 +1,32 @@
+"""Connector registry — single source of truth for source_type -> connector."""
+
+from __future__ import annotations
+
+from typing import Any
+
+_CONNECTORS: dict[str, Any] = {}
+
+
+def register_connector(connector: Any) -> None:
+    """Register a SourceConnector instance under its ``source_type``.
+
+    Calling twice with the same ``source_type`` replaces the prior entry —
+    useful for tests and hot-reload, but in production each connector
+    should be registered exactly once at startup.
+    """
+    if not getattr(connector, "source_type", None):
+        raise ValueError("Connector must declare a non-empty source_type")
+    _CONNECTORS[connector.source_type] = connector
+
+
+def get_connector(source_type: str) -> Any:
+    """Return the registered connector for ``source_type`` or raise KeyError."""
+    try:
+        return _CONNECTORS[source_type]
+    except KeyError as exc:
+        raise KeyError(f"No connector registered for source_type {source_type!r}") from exc
+
+
+def _reset_for_tests() -> None:
+    """Clear the registry — for use in pytest fixtures only."""
+    _CONNECTORS.clear()

tests/test_scout_connector_registry.py

@@ -0,0 +1,48 @@
+"""Tests for the connector registry."""
+
+from __future__ import annotations
+
+import pytest
+
+from app.scouts.connectors.base import ItemRef
+from app.scouts.connectors.registry import (
+    get_connector,
+    register_connector,
+    _reset_for_tests,
+)
+
+
+class _DummyConnector:
+    source_type = "dummy"
+    async def list_new(self, scout): return []
+    async def fetch_metadata(self, scout, ref): raise NotImplementedError
+    async def fetch_content(self, scout, ref): raise NotImplementedError
+    async def archive(self, scout, ref): raise NotImplementedError
+    async def setup_watch(self, scout): raise NotImplementedError
+    async def renew_watch(self, scout): raise NotImplementedError
+
+
+@pytest.fixture(autouse=True)
+def _clean_registry():
+    _reset_for_tests()
+    yield
+    _reset_for_tests()
+
+
+def test_register_and_get():
+    c = _DummyConnector()
+    register_connector(c)
+    assert get_connector("dummy") is c
+
+
+def test_unknown_source_raises():
+    with pytest.raises(KeyError):
+        get_connector("nope")
+
+
+def test_double_register_replaces():
+    a = _DummyConnector()
+    b = _DummyConnector()
+    register_connector(a)
+    register_connector(b)
+    assert get_connector("dummy") is b