Fix connection string, unset PG env vars in tests

There were tests failing when running under the windows-latest
environment in GitHub Actions. This is due to PGUSER and PGPASSWORD
being set as part of he image build (https://github.com/actions/runner-images/blob/870d08d9cbff9a9a2b0e805c7e41e5238c184bf0/images/windows/scripts/build/Install-PostgreSQL.ps1#L11-L12).
This change explicitly unsets these environment variables in the tests
to avoid failures in that environment.

python/tests/conftest.py

@@ -434,7 +434,7 @@ def postgres_unit_test_env(monkeypatch, exclude_list, override_env_param_dict):
     if override_env_param_dict is None:
         override_env_param_dict = {}
 
-    env_vars = {"POSTGRES_CONNECTION_STRING": "host=localhost port=5432 dbname=postgres user=postgres password=example"}
+    env_vars = {"POSTGRES_CONNECTION_STRING": "host=localhost port=5432 dbname=postgres user=testuser password=example"}
 
     env_vars.update(override_env_param_dict)
 

python/tests/unit/connectors/memory/test_postgres.py

@@ -248,9 +248,16 @@ async def test_get_records(vector_store: PostgresStore, mock_cursor: Mock) -> No
 # Test settings
 
 
-def test_settings_connection_string() -> None:
-    settings = PostgresSettings(connection_string="postgresql://user:password@localhost:5432/dbname")
+def test_settings_connection_string(monkeypatch) -> None:
+    monkeypatch.delenv("PGHOST", raising=False)
+    monkeypatch.delenv("PGPORT", raising=False)
+    monkeypatch.delenv("PGDATABASE", raising=False)
+    monkeypatch.delenv("PGUSER", raising=False)
+    monkeypatch.delenv("PGPASSWORD", raising=False)
+
+    settings = PostgresSettings(connection_string="host=localhost port=5432 dbname=dbname user=user password=password")
     conn_info = settings.get_connection_args()
+
     assert conn_info["host"] == "localhost"
     assert conn_info["port"] == 5432
     assert conn_info["dbname"] == "dbname"
@@ -259,7 +266,15 @@ def test_settings_connection_string() -> None:
 
 
 def test_settings_env_connection_string(monkeypatch) -> None:
-    monkeypatch.setenv("POSTGRES_CONNECTION_STRING", "postgresql://user:password@localhost:5432/dbname")
+    monkeypatch.delenv("PGHOST", raising=False)
+    monkeypatch.delenv("PGPORT", raising=False)
+    monkeypatch.delenv("PGDATABASE", raising=False)
+    monkeypatch.delenv("PGUSER", raising=False)
+    monkeypatch.delenv("PGPASSWORD", raising=False)
+
+    monkeypatch.setenv(
+        "POSTGRES_CONNECTION_STRING", "host=localhost port=5432 dbname=dbname user=user password=password"
+    )
 
     settings = PostgresSettings()
     conn_info = settings.get_connection_args()