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Me, migrating my code from JavaScript to TypeScript:
(lemmy.world)
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this post was submitted on 18 Oct 2023
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It's a good way to get started, and then incrementally type as much as you can, preferably everything.
Later on, or if you start a new project with TypeScript, it's a good idea to turn on
noImplicitAnyand only allow explicitanyin very specific framework level code, unit tests or if you interface with an untyped framework.The hassle really pays off later.
this is terrible advise - you should be using
unknown. usinganyyou're basically disabling TS and will be under the false assumption that your code is ok while it's most likely missing a lot of runtime checksBut if your code ever integrates with javascript you still need any everywhere so it's pretty pointless
Not true, in the absolute worst case,
unknownis what you should be reaching for, but it's pretty rare that you can't create some kind of type to interface with JS if it's not already got types. You can even use jsdoc comments as type hints in the JS too if you own that code.My not particularly hot hot-take: There's basically no legitimate use case for
anyapart from "I don't have time to type all this now, because I'm converting a massive project from JS to TS"There are some cases where
anymust be used instead ofunknownbut they usually involve generic constraints and seem more like a bug than intended behaviorAh you're right there, and I also agree, that feels more like a bug than by design
Not necessarily, depending on your situation you can type the JS code yourself.
If the team making the JS code were using jsdoc then the Typescript compiler can recognize the comments and use it for type checking.
In some instances the compiler can infer types from JS code to do some basic validation.
Even if the external JS code is recognized as
any, your own code that's using it still has types, so it's better than nothing.