My understanding of this is that this is trading a build step for just in time (JIT) compilation, which seems, ok? But it seems to me that you've just moved the problem around and I'm sure there are additional trade-offs (as with anything).

"Build" in JS circles usually means transpile, not a replacement for JIT which will still happen at runtime.

In addition to that, often there are other concerns addressed at build time such as linting.

kldavis4

yeah, exactly. So I wonder if ultimately they want to have the browser handle transpiling things like typescript? And I definitely think there are other concerns (such as linting) that you want to happen as part of your development pipeline.

whstl

There is an ES39 proposal to allow type annotations in Javascript, that would allow the browser to handle TS/Flow files without needing a compile step:

https://github.com/tc39/proposal-type-annotations

(That's only to allow the type annotations to be there, not to have static checking in the browser)

IMO: I would love to see this implemented. Linting and typechecking should be ran before committing code or deploying, but I want to be able to stop transpiling/bundling in all cases.