Methods and systems for performing mainframe batch testing and/or property-based validation testing using a finite-state machine are provided. According to certain aspects, a validation server may receive a set of batch data designed to validate a property under test, such as during mainframe batch testing. A validation server may validate that the set of batch data is in a proper format. The validation server may then cause a finite-state machine to process instructions contained within the set of batch data. Once the finite-state machine processes the set of batch data, the validation server may then validate that the finite-state machine adheres to the property under test. If the validation fails, the validation server may generate an error report describing the failure.