Allow setup_credentials to work with selected dbs

src/pystatis/config.py

@@ -151,9 +151,26 @@ def config_exists() -> bool:
     return config_file.exists()
 
 
-def setup_credentials() -> None:
-    """Setup credentials for all supported databases."""
-    for db_name in get_supported_db():
+def setup_credentials(db_names: list[str] | None = None) -> None:
+    """
+    Setup credentials for all supported databases.
+
+    Args:
+        db_names (list[str]): Names of the databases to setup
+    """
+    if db_names is None:
+        db_names = get_supported_db()
+
+    for db_name in db_names:
+        # despite this check, we should consider using literals as the type hint for
+        # db_names.
+        if db_name not in get_supported_db():
+            raise KeyError(
+                f"Provided db_name '{db_name}' no regnized. "
+                f"Valid options are {get_supported_db()}"
+            )
+
+    for db_name in db_names:
         config.set(db_name, "username", _get_user_input(db_name, "username"))
         config.set(db_name, "password", _get_user_input(db_name, "password"))
         if not db.check_credentials_are_valid(db_name):

tests/test_config.py

@@ -83,6 +83,25 @@ def test_setup_credentials(mocker, config_):
         assert config_[db_name]["password"] == "test123!"
 
 
+def test_setup_credentials_with_db_names_subset(mocker, config_):
+    mocker.patch.object(db, "check_credentials_are_valid", return_value=True)
+
+    os.environ["PYSTATIS_GENESIS_API_USERNAME"] = "test"
+    os.environ["PYSTATIS_GENESIS_API_PASSWORD"] = "test123!"
+
+    config.setup_credentials(db_names=["genesis"])
+
+    # Only the specified DB should be set
+    assert config_["genesis"]["username"] == "test"
+    assert config_["genesis"]["password"] == "test123!"
+
+
+def test_setup_credentials_invalid_credentials_raises(mocker, config_):
+    mocker.patch.object(db, "check_credentials_are_valid", return_value=False)
+
+    with pytest.raises(KeyError) as _exc_info:
+        config.setup_credentials(db_names=["regio_s"])
+
 @pytest.mark.parametrize(
     "mock_return, check_result",
     [