fix: allow empty password when reloading pgvector-family results

tests/test_pgvector_config_roundtrip.py

@@ -0,0 +1,62 @@
+"""Regression tests for issue #831 — reloading results fails validation.
+
+After a pgvector run that used an empty password (local trust/peer auth), the
+saved result JSON carries ``password: ""``. When the results page rehydrates the
+config via ``db.config_cls(**task_config["db_config"])`` (models.TestResult.
+read_file), ``DBConfig.not_empty_field`` rejected the empty password with
+``Value error, Empty field(s): password``. The same shape breaks the sibling
+postgres-connection-string configs (pgvectorscale, alloydb).
+
+These tests do not require a live database — they exercise the exact
+reconstruction step read_file performs on the saved db_config dict.
+
+Usage:
+  pytest tests/test_pgvector_config_roundtrip.py -v
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+from vectordb_bench.backend.clients import DB
+from vectordb_bench.backend.clients.alloydb.config import AlloyDBConfig
+from vectordb_bench.backend.clients.pgvector.config import PgVectorConfig
+from vectordb_bench.backend.clients.pgvectorscale.config import PgVectorScaleConfig
+
+if TYPE_CHECKING:
+    from vectordb_bench.backend.clients.api import DBConfig
+
+# The postgres-connection-string family that shares the DBConfig empty-field guard.
+PG_FAMILY = [
+    (DB.PgVector, PgVectorConfig),
+    (DB.PgVectorScale, PgVectorScaleConfig),
+    (DB.AlloyDB, AlloyDBConfig),
+]
+PG_FAMILY_IDS = ["pgvector", "pgvectorscale", "alloydb"]
+
+
+@pytest.mark.parametrize(("db", "config_cls"), PG_FAMILY, ids=PG_FAMILY_IDS)
+def test_reload_with_empty_password_present(db: DB, config_cls: type[DBConfig]):
+    """A saved config with password="" must rehydrate (issue #831)."""
+    saved = {"db_label": "", "password": "", "version": "", "note": ""}
+    cfg = db.config_cls(**saved)
+    assert isinstance(cfg, config_cls)
+    assert cfg.password.get_secret_value() == ""
+
+
+@pytest.mark.parametrize(("db", "config_cls"), PG_FAMILY, ids=PG_FAMILY_IDS)
+def test_reload_with_password_absent(db: DB, config_cls: type[DBConfig]):
+    """Older result files omit subclass fields entirely — still rehydrate."""
+    saved = {"db_label": "", "version": "", "note": ""}
+    cfg = db.config_cls(**saved)
+    assert isinstance(cfg, config_cls)
+    assert cfg.password.get_secret_value() == ""
+    assert cfg.db_name  # non-empty default so downstream connection strings hold
+
+
+def test_non_credential_empty_field_still_rejected():
+    """Negative control: the empty-field guard must still fire for other fields."""
+    with pytest.raises(ValueError, match=r"Empty field.*host"):
+        PgVectorConfig(db_label="", password="x", version="", note="", host="")  # noqa: S106

vectordb_bench/backend/clients/alloydb/config.py

@@ -1,6 +1,6 @@
 from abc import abstractmethod
 from collections.abc import Mapping, Sequence
-from typing import Any, LiteralString, TypedDict
+from typing import Any, ClassVar, LiteralString, TypedDict
 
 from pydantic import BaseModel, SecretStr
 
@@ -21,11 +21,15 @@ class AlloyDBConfigDict(TypedDict):
 
 
 class AlloyDBConfig(DBConfig):
+    # An empty password is valid (local trust/peer auth), and it is what a
+    # reloaded result carries when the run used no password — don't reject it.
+    _extra_empty_skip: ClassVar[frozenset[str]] = frozenset({"password"})
+
     user_name: SecretStr = SecretStr("postgres")
-    password: SecretStr
+    password: SecretStr = SecretStr("")
     host: str = "localhost"
     port: int = 5432
-    db_name: str
+    db_name: str = "postgres"
 
     def to_dict(self) -> AlloyDBConfigDict:
         user_str = self.user_name.get_secret_value()

vectordb_bench/backend/clients/pgvector/config.py

@@ -1,6 +1,6 @@
 from abc import abstractmethod
 from collections.abc import Mapping, Sequence
-from typing import Any, LiteralString, TypedDict
+from typing import Any, ClassVar, LiteralString, TypedDict
 
 from pydantic import BaseModel, SecretStr
 
@@ -21,8 +21,12 @@ class PgVectorConfigDict(TypedDict):
 
 
 class PgVectorConfig(DBConfig):
+    # An empty password is valid (local trust/peer auth), and it is what a
+    # reloaded result carries when the run used no password — don't reject it.
+    _extra_empty_skip: ClassVar[frozenset[str]] = frozenset({"password"})
+
     user_name: SecretStr = "postgres"
-    password: SecretStr
+    password: SecretStr = SecretStr("")
     host: str = "localhost"
     port: int = 5432
     db_name: str = "vectordb"

vectordb_bench/backend/clients/pgvectorscale/config.py

@@ -1,5 +1,5 @@
 from abc import abstractmethod
-from typing import LiteralString, TypedDict
+from typing import ClassVar, LiteralString, TypedDict
 
 from pydantic import BaseModel, SecretStr
 
@@ -20,11 +20,15 @@ class PgVectorScaleConfigDict(TypedDict):
 
 
 class PgVectorScaleConfig(DBConfig):
+    # An empty password is valid (local trust/peer auth), and it is what a
+    # reloaded result carries when the run used no password — don't reject it.
+    _extra_empty_skip: ClassVar[frozenset[str]] = frozenset({"password"})
+
     user_name: SecretStr = SecretStr("postgres")
-    password: SecretStr
+    password: SecretStr = SecretStr("")
     host: str = "localhost"
     port: int = 5432
-    db_name: str
+    db_name: str = "vectordb"
 
     def to_dict(self) -> PgVectorScaleConfigDict:
         user_str = self.user_name.get_secret_value()