Type-Safe Assertion Library for TypeScript

typed-assert is a lightweight, zero-dependency assertion library designed specifically for TypeScript 3.7+ environments. It leverages TypeScript's assertion functions feature to perform runtime checks that simultaneously narrow types at compile-time, promoting the use of `unknown` for untrusted input instead of `any`. The library provides a suite of common assertion functions (`isString`, `isNumber`, `isRecord`, etc.) and combinators (`isArrayOf`, `isOneOf`, `isOption`), allowing developers to build robust type guards and custom composite assertions. As of version 1.0.9, it's a stable release with no explicit major release cadence, but it's actively maintained. A key differentiator is its compile-time type narrowing alongside runtime validation, contrasting with traditional assertion libraries like Chai or Jest's `expect` which primarily offer runtime validation without type inference benefits. For more complex schema validation needs, the documentation explicitly recommends considering `zod` as an alternative due to `typed-assert`'s simpler scope.