expect_snapshot_data(): snapshot testing for data frames (saves as CSV).expect_snapshot_object(): snapshot testing for any R object (RDS, JSON, deparse, or CSV formats).compare_file_object(): compare RDS files by deserializing and comparing the underlying R objects.save_rds(), save_json(), save_deparse(), save_csv(): writer helpers for expect_snapshot_object().system_os(), darwin_variant(), platform_variant(): helper functions for creating platform-specific snapshot variants.Started development