should.js Utility Functions

should-util is a foundational utility library within the should.js assertion ecosystem. It provides a collection of core helper functions, primarily type-checking utilities (e.g., `isString`, `isArray`, `isFunction`) and a `deepEqual` comparison function. The package itself is highly stable, having been at version 1.0.1 since its initial releases over a decade ago, with the last code commit occurring 7 years prior. As such, it follows a 'maintenance' release cadence, receiving no active development or new features. Its primary differentiator is its integral role in the should.js assertion library, offering common, reusable functionalities that are robust and well-tested, though not independently maintained for general-purpose use. It is predominantly a CommonJS module, reflecting its age.