This PHP assertion library is a runtime data validator used to verify method inputs and outputs. It provides a toolkit for validating data types, numeric ranges, and string patterns during program execution to prevent invalid states.
The project serves as a static analysis helper by providing type hints and annotations that improve the accuracy of formal verification tools. It includes a collection validation utility for applying rules across arrays or iterable collections, and a filesystem validation tool to verify path existence and read or write permissions.
The library covers a broad range of validation capabilities, including object structure inspection, function behavior verification, and array structure validation. It also supports custom assertion logic and deferred error message computation.