What is the “proper” way to do error-handling in TypeScript?

Question

Folks, I feel like I'm losing my mind. Typescript's concept that `error` is either `any` or `unknown` feels like such a massive gaping problem. I get that it's Javascript's fault for not having a rigorous error typing system. What are some strategies you guys use to expose the kinds of errors your libs throw, or capture the errors other people's code throws?

satvikpendem · Accepted Answer

I use fp-ts with its Either type (like Result in other languages like Rust), works great.https://gcanti.github.io/fp-ts/

raydiatian · Answer

I have already considered using Errors in return type unions, that is function getIntOrFailMiserably(): number | Error { .. } Is that really the best there is? Obviously, I can't control OPC (other people's code. you down with OPC? yeah you know me) with this, unless I wrap it and search like a hawk for the error.

raydiatian · Answer

Had a chat with some of the `typescript` discord folks. Apparently the accepted belief is that &ldquo;all exceptions are treated as unchecked and there&rsquo;s not much buyin that exposing the thrown error types add value. Basically it&rsquo;s &ldquo;bring your own research&rdquo; to handing errors, or configure a default catcher.

bwestergard · Answer

On my team we use Rust-style Result/Option types for any unrecoverable exceptions.https://github.com/supermacro/neverthrow

schwartzworld · Answer

I created my own npm package with a Result type. https://www.npmjs.com/package/schtate

moystard · Answer

I usually use the unknown type and leverage type guards for isolating the exact type and processing it. If it falls down the type guards, process as generic error.

shams93 · Answer

catch (e) { const error = e as ; }

What is the “proper” way to do error-handling in TypeScript?

I use fp-ts with its Either type (like Result in other languages like Rust), works great.
https://gcanti.github.io/fp-ts/

On my team we use Rust-style Result/Option types for any unrecoverable exceptions.
https://github.com/supermacro/neverthrow

I created my own npm package with a Result type. https://www.npmjs.com/package/schtate

I usually use the unknown type and leverage type guards for isolating the exact type and processing it. If it falls down the type guards, process as generic error.

catch (e) { const error = e as ; }