Built in Symbol and shimming Symbol

[kitsonk]

TypeScript Version:

1.8.10

Code

import Symbol from './Symbol';

export interface Iterable<T> {
    [Symbol.iterator](): Iterator<T>;
}

In Dojo 2, we provide a shim for Symbol. One of the things we have decided to do as a matter of principal is not modify the global namespace with any of our shims, but provide them as modules where the consumer has to make an explicit dependency on that shim. At runtime, we offload to the native API if present, otherwise we provide replicate functionality.

This pattern works effectively, even when targeting ES6, except for Symbol because of the TypeScript's compiler's insistence that we reference the native one.

Is there a good reason why TypeScript disallows this when targeting ES6? If so, is there any way to provide a transparent shim without modifying the global namespace anyone can think of?

Expected behavior:

No errors when targeting es6.

Actual behavior:

When target is es6 we get the following error:

'Symbol' reference does not refer to the global Symbol constructor object.

[mhegazy]

looks like a duplicate of #8099

also see #5579 and #2012