TypeScript Simple Type Checker

ts-simple-type is a TypeScript utility library (current stable version 1.0.7, last published July 2020) designed to provide essential helper functions for analyzing and comparing TypeScript types. It aims to bridge gaps in the native TypeScript compiler API, particularly for direct assignability checks and programmatically constructing types, as noted by discussions in TypeScript GitHub issues #9879 and #29432. The library works by converting native TypeScript `ts.Type` objects into its own `SimpleType` interface, which offers a more standardized and easily serializable representation. This `SimpleType` abstraction facilitates advanced type analysis, comparison, and even serialization for use in various environments, including browsers. A key differentiator is its extensive test suite, comprising over 35,000 tests that validate its type-checking results against actual TypeScript diagnostics. Despite its usefulness, the package shows a slower release cadence, with the last update in 2020, suggesting it is now in a maintenance state rather than active development.