[scrollaway]

What's the point? If you're going to use typescript, you will want to do typechecking. And if you do typechecking, you might as well compile your project properly.

I'd honestly rather have browser support less than more and I'm happy with type annotations remaining a language superset. The current typescript situation is actually fantastic and as a python dev, I envy it a lot.

[yayana]

If TS becomes the majority, it seems to me like the browser debuggers could start using types at run time to catch some interesting things that aren't so obvious when compiling the pieces. I.e. help the people who add the final touches to a site check that they have not messed it all up without the project writer needing to decide how many guards to compile in to the project interfaces.

Probably the largest problem I have with modern projects is how unfriendly they are to experiment with on the page, even if there's no intention to prevent it.

[scrollaway]

Hmm, I can't quite see what kind of thing browsers could catch that typescript itself couldn't, since the whole point of types is to be useful at compile-time.

That said I could see some type introspection being useful in the devtools. This is probably already feasible though, as devtools are sourcemap aware. And typescript is written in typescript after all, so it couldn't be that hard to pull in support for it in the devtools, could it? :)

Cool idea!