Optique: A TypeScript library that eliminates CLI validation code through parser combinators and type inference

Summary

The article introduces Optique, a new TypeScript library for CLI argument parsing that uses parser combinators and type inference to eliminate the need for manual validation code. The author was motivated by observing repetitive validation patterns (dependent options, mutually exclusive options, defaults) across countless CLI tools. Optique allows developers to describe CLI configurations declaratively, with TypeScript automatically inferring types and constraints at compile time, catching bugs before runtime. The author shares their experience of deleting large validation code blocks and simplifying refactoring, positioning Optique as a more robust and maintainable alternative to traditional CLI parsing approaches.