Personally I really enjoy Typanion [0] since it's very similar to Yup [1] which I previously had extensive experience with. You can find more alternatives and a

Personally I really enjoy Typanion [0] since it's very similar to Yup [1] which I previously had extensive experience with. You can find more alternatives and a lengthy discussion about the whole problem space and its history in [2]. [0] https://github.com/arcanis/typanion https://github.com/arcanis/typanion [1] https://github.com/jquense/yup https://github.com/jquense/yup [2] https://github.com/microsoft/TypeScript/issues/3628 https://github.com/microsoft/TypeScript/issues/3628