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Comment by sbjs | Hacker News Reader

TypeScript can do runtime checks like this! Granted it uses a TypeScript framework (similar to AJV) that both does the runtime checks and preserves type information for your IDE and type checker. I wrote about it here:

https://medium.com/@stevenbradleyconsulting/from-0-to-type-s...

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Aw, man - I'd hoped you'd found something to make this less of a stone-cold pain to do. Instead, it's io-ts again. Which is...interesting...but it really sucks to actually use when you have to manually define every in/out yourself. It's 2018. There's no good reason TypeScript can't emit the type information to just build these (and I don't really mean decorator metadata).

You can add another build step right after the `tsc -w` compilation phase, which takes your .ts files, parses them to find our your types, and emits runtime code that checks your types. That's what you're describing that TypeScript should be doing on its own. But I don't see why you'd want to do this instead of using io-ts? This is more complicated overall.

Runtime type information is important. TypeScript is in the best place to provide it. So...it should. Boilerplating our way through io-ts is a waste of my time and yours.

been using io-to in my latest project, fantastic bit of code hats off to gcanti...Only thing is IntelliJ can’t keep up with the types generated (got an open bug with them)

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