test: 补充测试覆盖率 — DB/CLI/Search/Ingest + 修复 chromadb 异常兼容

tests/test_search.py

@@ -122,3 +122,25 @@ class TestSearcher:
         searcher = Searcher(db, embedder, "empty_coll")
         sources = searcher.list_sources()
         assert sources == []
+
+
+def test_list_sources_empty():
+    """空 collection 的 list_sources 返回空列表."""
+    from src.core.search import Searcher
+
+    class EmptyColl:
+        def count(self): return 0
+        def get(self, **kwargs):
+            return {"ids": [], "documents": [], "metadatas": []}
+
+    class EmptyDB:
+        def get_or_create_collection(self, name): return EmptyColl()
+        def list_collections(self): return []
+
+    class FakeEmb:
+        @property
+        def dimension(self): return 4
+        def embed(self, texts): return [[0.0] * 4]
+
+    s = Searcher(EmptyDB(), FakeEmb(), "empty")
+    assert s.list_sources() == []