[lucacasonato]

No, I think this will eventually stop. JavaScript is getting more mature. I would not be surprised if the TypeScript syntax will be legacy in a few years, because JS caught up.

[megaman821]

Is there some proposal for making the type syntax valid? No type checking just JavaScript parsing code with types and ignoring it.

[lucacasonato]

No such proposal exists right now, but this will be a point of immediate focus for me.

[pier25]

How will Deno react if that happens?

[lucacasonato]

Deno will behave just like Chrome or Firefox would: we ignore the checks when running your code. We would have a `deno check` subcommand to perform a typecheck. You could optionally run this automatically before a `deno run` by passing a `--check` flag.