fix(evidence): fail closed when BM25 is unavailable

harness/tests/test_qdrant_vector_store.py

@@ -32,6 +32,7 @@ class FakeQdrantHttp:
         self.dimension = dimension
         self.distance = distance
         self.collection = None
+        self.sparse_vectors: dict[str, dict] | None = None
         self.payload_indexes: set[str] = set()
         self.points: dict[str, dict] = {}
         self.calls: list[tuple[str, str, dict | None]] = []
@@ -56,7 +57,11 @@ class FakeQdrantHttp:
                 "result": {
                     "config": {
                         "params": {
-                            "vectors": {"size": self.dimension, "distance": self.distance}
+                            "vectors": {"size": self.dimension, "distance": self.distance},
+                            **(
+                                {"sparse_vectors": self.sparse_vectors}
+                                if self.sparse_vectors is not None else {}
+                            ),
                         }
                     },
                     "payload_schema": {
@@ -69,6 +74,7 @@ class FakeQdrantHttp:
             self.collection = json
             self.dimension = json["vectors"]["size"]
             self.distance = json["vectors"]["distance"]
+            self.sparse_vectors = json.get("sparse_vectors")
             return FakeResponse(200, {"status": "ok"})
 
         if method == "PUT" and path == "/collections/workspace-semantic/index":
@@ -182,6 +188,15 @@ def _store(
     )
 
 
+def _ready_collection_with_bm25(fake: FakeQdrantHttp) -> None:
+    fake.collection = {"vectors": {"size": 1024, "distance": "Cosine"}}
+    fake.payload_indexes = {
+        "content_hash", "document_id", "kind", "record_key", "record_kind",
+        "vector_generation", "workspace_id", "workspace_revision",
+    }
+    fake.sparse_vectors = {"bm25": {"modifier": "idf"}}
+
+
 def test_point_id_is_deterministic_uuidv5():
     assert point_id("demo", "memory", "memory:1") == str(
         uuid5(NAMESPACE_URL, "thothii:demo:memory:memory:1")
@@ -324,6 +339,20 @@ def test_health_fails_when_required_payload_indexes_are_missing_without_creating
     assert fake.payload_indexes == set()
 
 
+def test_health_reports_when_evidence_bm25_is_unavailable_without_disabling_dense_callers():
+    fake = FakeQdrantHttp()
+    fake.collection = {"vectors": {"size": 1024, "distance": "Cosine"}}
+    fake.payload_indexes = {
+        "content_hash", "document_id", "kind", "record_key", "record_kind",
+        "vector_generation", "workspace_id", "workspace_revision",
+    }
+
+    health = _store(fake).health()
+
+    assert health.ok is True
+    assert health.bm25_compatible is False
+
+
 @pytest.mark.parametrize(
     ("record", "semantic_kind"),
     [
@@ -363,6 +392,7 @@ def test_upsert_serializes_qdrant_point_payloads(record, semantic_kind):
 
 def test_evidence_upsert_sends_dense_and_server_side_italian_bm25():
     fake = FakeQdrantHttp()
+    _ready_collection_with_bm25(fake)
     store = _store(fake)
     record = _write_record(
         "demo:gen:11111111111111111111111111111111:chunk:1",
@@ -391,6 +421,7 @@ def test_evidence_upsert_sends_dense_and_server_side_italian_bm25():
 
 def test_evidence_search_uses_filtered_dense_and_bm25_prefetches_with_default_rrf():
     fake = FakeQdrantHttp()
+    _ready_collection_with_bm25(fake)
     store = _store(fake)
     generation = "gen:" + "1" * 32
     store.upsert("evidence", [
@@ -477,6 +508,19 @@ def test_evidence_search_refuses_dense_only_fallback():
         store.search(["evidence"], [0.2] * 1024, limit=5, kinds=["evidence"])
 
 
+def test_hybrid_evidence_search_refuses_a_collection_without_bm25():
+    fake = FakeQdrantHttp()
+    _ready_collection_with_bm25(fake)
+    fake.sparse_vectors = None
+    store = _store(fake)
+
+    with pytest.raises(VectorStoreError, match="BM25 collection configuration"):
+        store.search(
+            ["evidence"], [0.2] * 1024, limit=5, kinds=["evidence"],
+            query_text="cardiomiopatia", query_language="italian",
+        )
+
+
 def test_search_excludes_inconsistent_semantic_kind_in_bound_workspace():
     fake = FakeQdrantHttp()
     store = _store(fake)