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

tests/test_db.py

@@ -45,3 +45,33 @@ class TestVectorDB:
         # 再次获取会创建新的
         col = db.get_or_create_collection("tmp_col")
         assert col.count() == 0
+
+
+def test_write_guard_context_manager(tmp_path):
+    """write_guard 上下文管理器正常获取和释放锁."""
+    from src.core.db import VectorDB
+    vdb = VectorDB(persist_dir=str(tmp_path))
+    with vdb.write_guard():
+        pass
+
+
+def test_close(tmp_path):
+    """close 正常执行不抛异常."""
+    from src.core.db import VectorDB
+    vdb = VectorDB(persist_dir=str(tmp_path))
+    vdb.close()
+
+
+def test_delete_collection_nonexistent(tmp_path):
+    """删除不存在的 collection 不抛异常."""
+    from src.core.db import VectorDB
+    vdb = VectorDB(persist_dir=str(tmp_path))
+    vdb.delete_collection("nonexistent-collection-12345")
+
+
+def test_delete_by_source_no_match(tmp_path):
+    """删除不存在的 source 返回 False."""
+    from src.core.db import VectorDB
+    vdb = VectorDB(persist_dir=str(tmp_path))
+    result = vdb.delete_by_source("test_col", "no-such-file.md")
+    assert result is False