as operator doesn't work correctly with CommonJS

[oryol]

I'm trying to use generic class in the TSX file and generic class is implemented in the another module. I have tried to use code like in the #3960 (comment) but it doesn't work because old style casting is not allowed in the TSX file. Ok, I have changed it to the as operator but it emits incorrect code. It refers to the generic class directly without using require.

After that I have created simple example without JSX which demonstrates that old style casting and as operator are different.

File generic.ts: export default class Generic<T> {}

File sample.ts:

import Generic from "./generic";
type Ctor = new() => Generic<number>;
const x = Generic as Ctor;

Compile tsc sample.ts --module commonjs. Result:

var generic_1 = require("./generic");
var x = Generic;

As you see generic_1 variable isn't used at all and undeclared Generic variable is assigned to x.

Workaround:

import Generic from "./generic";
type Ctor = new () => Generic<number>;
const x = Generic;
const y = x as Ctor;

Also please note that using old-style casting also helps:

import Generic from "./generic";
type Ctor = new() => Generic<number>;
const x = <Ctor>Generic;

So it looks like it is the problem in the as operator only.

[RyanCavanaugh]

Duplicate of #4832