Follows @giltayar's proposed API:
> `register` can pass any data it wants to the loader, which will be
passed to the exported `initialize` function of the loader.
Additionally, if the user of `register` wants to communicate with the
loader, it can just create a `MessageChannel` and pass the port to the
loader as data.
The `register` API is now:
```ts
interface Options {
parentUrl?: string;
data?: any;
transferList?: any[];
}
function register(loader: string, parentUrl?: string): any;
function register(loader: string, options?: Options): any;
```
This API is backwards compatible with the old one (new arguments are
optional and at the end) and allows for passing data into the new
`initialize` hook. If this hook returns data it is passed back to
`register`:
```ts
function initialize(data: any): Promise<any>;
```
**NOTE**: Currently there is no mechanism for a loader to exchange
ownership of something back to the caller.
Refs: https://github.com/nodejs/loaders/issues/147
PR-URL: https://github.com/nodejs/node/pull/48842
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
6ad8318373