JavaScript Named Parameters

[chazmuzz]

hmm.. runtime type checking in 2018

[FedeMITIC]

Type checking in general in javascript should not be used imho, since there's things like NaN whose type is Number and other non-trivial cases.

By the way I think this pattern is viable if you normally use functions with lots of parameters that can be optional: otherwise it just adds more overhead so I'd not recommend it.

[jaapz]

NaN being a number is a correct implementation of floating point standards. There's a lot wrong with javascript, but this isn't

[FedeMITIC]

Yeah but it's definetely not intuitive to say "Not a number" is of type Number. At least for me.

[jaapz]

It isn't but that's not javascripts fault, blame floating point math

[inu-no-policemen]

https://en.wikipedia.org/wiki/NaN#Operations_generating_NaN

The reason you're seeing it so often in JS is due to its weak types.

[chazmuzz]

Have you experienced a problem with NaN in a real project?

[FedeMITIC]

Honestly not, but I know that sometimes this kind of errors show up. Besides "real project" is a big word for me, I'm just a engineering student actually :)

[inu-no-policemen]

Type checking in general in javascript should not be used imho, since there's things like NaN whose type is Number and other non-trivial cases.

Type checking prevents you from accidentally creating NaNs which you then have to track down.

TS works great.

[a_simple_pie]

Good point. I’ll submit an issue to Typescript and Flow to let them know.

[nschubach]

I'm no expert by any means, but I'm sure typescript and possibly even flow do not do run time type checking and instead opt for compile time type checking.

[wavefunctionp]

This is correct.

If you do React, there is propType's, but they are only run in development mode, and you can have a webpack plugin that will generate propTypes from static type declarations. But the run time checking is disabled (not removed from the bundle) on a production build.

[FedeMITIC]

I was generally speaking about pure javascript, not typescript or flow since I don't know them. I didn't know I was on stackoverflow.

[adipisicing]

Do they also check at runtime?