WPConfigTransformer::get_value() never returns an array, but array is the return type being hinted in the associated docblock. I suggest changing it to string|null. I'm not aware of a situation in which it can return anything else. Feel free to correct me if I'm wrong, but through testing with int, float, string, array, stdClass and undefined variables I haven't managed to get anything else out of it.
WPConfigTransformer::get_value()never returns an array, but array is the return type being hinted in the associated docblock. I suggest changing it tostring|null. I'm not aware of a situation in which it can return anything else. Feel free to correct me if I'm wrong, but through testing with int, float, string, array, stdClass and undefined variables I haven't managed to get anything else out of it.