Declare type to be an import depending on a string literal argument: typeof import(name);

[llgcode]

Hello,
It's seems to be difficult to do but there's now a lot of possibilities with the typescript compiler that I wouldn't have thought possible before, so I prefer to ask.

Is there a chance to have this kind of definition:

declare function require(name: string): typeof import(name) | undefined;

I mean declaring the return type as the type coming from the import of module "name". So we could have the type returned by require:

var module = require("my module");

I guess if it's feasible, it will also be possible to add more typing on this kind of javascript code

define("myModule, ["deps1", "deps2", "deps3"], (deps1, deps2, deps3) => {
// deps1, deps2, deps3 have the right type !!
});

like this

define("myModule, ["deps1", "deps2", "deps3"], (deps1: typeof import("deps1"), deps2: typeof import("deps2"), deps3: : typeof import("deps3")) => {
// deps1, deps2, deps3 have the right type !!
});

Thanks for your help,

--
Laurent

[jdom]

I'm also interested in this exact same thing. Is it possible to do?

[RyanCavanaugh]

This currently isn't architecturally possible: There's one pass that collects all the files to be parsed, then type checking happens on a subsequent pass. We'd have to make the file-reading pass re-entrant to support this (which, given two comments in two years, isn't an architectural change we'd have much appetite for).

[jdom]

sounds good, we do have a workaround, where we do this mapping from a particular string literal to the typeof import, and that works ok. I was just hoping to clean up this manual mapping of hundreds of lines (1 line per module we have).
Thanks for the reply