Exported variable <variable name> has or is using private name <private name> from external library

[ryasmi]

Hey guys not really sure what to do about this. I know this is a duplicate of #6307, but I didn't really want to comment on a closed issue. I can't really use @DanielRosenwasser's solution here because the class is exported from the library. I guess I could extend that class in my code and use that instead. Completely understand the issues with this, I guess I'm just looking for a recommendation and I wanted to report this for other people.

Error:

(4,1): error TS4082: Default export of the module has or is using private name 'Warning'.

My code:

import { optional } from 'rulr';
import { stringValue, mailto, sha1, iri, account } from '../factory';

export default {
  objectType: optional(stringValue),
  name: optional(stringValue),
  mbox: optional(mailto),
  mbox_sha1sum: optional(sha1),
  openid: optional(iri),
  account: optional(account),
};

Rulr's type definitions (generated by the TypeScript compiler):

export declare type Path = string[];
export declare class Warning {
    data: any;
    path: Path;
    constructor(data: any, path: Path);
}
export declare type Rule = (data: any, path: Path) => Warning[];
export declare const optional: (rule: Rule) => Rule;

[ryasmi]

Actually I can't extend the class, that makes no sense. I'd have to recreate every function in that library haha

[ryasmi]

Ok as to the rescue haha, I don't think this is ideal, but it does work.

import { optional, Rule } from 'rulr';
import { stringValue, mailto, sha1, iri, account } from '../factory';

export default {
  objectType: optional(stringValue) as Rule,
  name: optional(stringValue),
  mbox: optional(mailto),
  mbox_sha1sum: optional(sha1),
  openid: optional(iri),
  account: optional(account),
};

[mhegazy]

I am not able to get this to repro locally using your input file. can you share more context?

[mhegazy]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.

[ryasmi]

Hey @mhegazy, no worries, I'd do the same, I'm on holiday for a few more days, I'll get back to this when I'm home 😄

[ryasmi]

Ok @mhegazy, what context do you need? 😄

[mhegazy]

can you share a self-contained sample that reproduces the issue?

[ryasmi]

Yeah I'll give that a try.

[ryasmi]

How's this @mhegazy? https://github.com/ryansmith94/ts-15947

[mhegazy]

This is the same issue as #9944. The declaration emitter tried to serialize the type of the property foobar, which is Rule, which is an alias to (data: any, path: Path) => Warning[];, it tried to write Warning but that would be invalid, since Warning is not imported.
The emitter does not add imports automatically to avoid divulging implementation details that the user did not intend to expose. #9944 tracks relaxing this rule.

To avoid this warning, write an explicit type annotation for the type of your property. something like this would work:

import { optional, Rule } from 'rulr';

export default <{foobar: Rule;}> {
  foobar: optional(() => []),
}

[ryasmi]

Hey @mhegazy, I did understand that already from other issues I'd found before creating this one, but thank you for the explanation anyway and thanks for referencing the duplicate issue (sorry I didn't find that in my search) 😄 I'll subscribe to that issue going forward.

Thanks for the fix too! 👍