alias imports of namespaced types are failing when using ts-loader with fork-ts-checker-webpack-plugin

[alfrescian]

I've created a simple example repository to reproduce the issue:
https://github.com/alfrescian/fork-ts-checker-issue

I've an index.ts that does the following alias import of a type defined in a namespace:
import foo = myNamespace.foo;
const myFoo: foo = {foo: 'foo'};

when using ts-loader with fork-ts-checker-webpack-plugin then the output is (run npm run fork and check dist/index.js):
var foo = myNamespace.foo;
var myFoo = { foo: 'check' };

JS runtime will complain about myNamespace is undefined.

when using ts-loader without fork-ts-checker-webpack-plugin then the output is (run npm run no-fork and check dist/index.no-fork.js):
var myFoo = { foo: 'check' };

we are heavily using namespaces & these kinds of alias imports in our project & that currently blocks us using fork-ts-checker-webpack-plugin.

it does not make any difference if an ambient or non-ambient namespace is used. (see index.ts in my example)

[johnnyreilly]

I think this may be a fork-ts-checker-webpack-plugin issue rather than a ts-loader one. Do you want to raise your issue there?

[alfrescian]

yeah - wasn't sure about it and don't want to cross post. I'll open an issue there

[johnnyreilly]

It's worth saying that I believe namespaces are not advised to be used with modules BTW. I don't have the relevant link but I'm pretty sure that's the case

[alfrescian]

hm - would be interesting to get a link for that.
The alias import we're doing is e.g. mentioned here (scroll down to Aliases)
http://www.typescriptlang.org/docs/handbook/namespaces.html

[johnnyreilly]

Yeah - I checked there too. Interestingly I believe the context there is internal modules. Could be worth looking on stackoverflow - I believe one of the core team answers and question about this. Or something like that