Unexpected declaration error when using symbols and intersections

🔎 Search Terms

• declarations

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about generating declarations.

⏯ Playground Link

https://www.typescriptlang.org/dev/bug-workbench/?#code/PTAEAEDMEsBsFMB2BDAtvAXKWB7A5nvAE4B0ALgM4BQ8AHgA45FmgDGOiFLAMvoUQFUASgElQAXlABlAJ6oARjlgAKAES8CxVQEoA3FRoMmLMjPrxQG-lOIA3aKwuSA3qEg4cWLkWiI8oAF9QADJQZypQUABtK2JhEQBdLFd5ZCIvMh8-QP0A-SoQCBgEFHQsZHpocmpoVEZmUAAqUGQKSz5iNyIcVFBVEmBcTSJVfLp6lgATeFZYNIt2ThZIRAB1LAAeAEEAGlAAIQA+ZWQsLe0JQ9BleSx9i-ErrZCD-XHjUGnZ+bYOLjdEJstsdTqBzpdrrcwQ8nvkvnMiAs-ixaFhYqR0TYiPZHPlCoAZckAfBuAel2CmAAKJGZjwSagWxpaDIeQIUAAcmQrNAAAtWqAmKBoG0AK4UXz+UoWVno+KcyDdXp0MjEFCwUCoHCTIUs1TFTAgQYdEageRClisZCIRA4FjyCwSyYkZQAFgADAAmADM2kME1+SxaEgBq2UtD0ZNAgFByH0fRb-eSBlYhsNAA

💻 Code

// @filename: logger.ts
export const LoggerURI = Symbol("Logger");

export type LoggerService = { foo: string } & {
  [LoggerURI]: { bar: string };
};

// @filename: api.ts
import * as Logger from "./logger";

export declare const fnW: <A, B>(a: A) => (b: B) => A & B;
export declare const fn: <A>(a: A) => (b: A) => A;

declare const x: Logger.LoggerService;

// ❌🤯
// Exported variable 'a' has or is using name 'LoggerURI' from external module "file:///logger" but cannot be named.(4023)
export const a = fnW(x);
// ✅
export const b = fn(x);

🙁 Actual behavior

Unexpected type error:

Exported variable 'a' has or is using name 'LoggerURI' from external module "file:///logger" but cannot be named.(4023)

🙂 Expected behavior

No type error. LoggerURI is exported so it can be named.

Additional information about the issue

No response

Commencez par le lien Playground et la reproduction avec logger.ts et api.ts, en comparant les résultats exportés de fnW(x) et fn(x). Vérifiez la génération des déclarations et le diagnostic 4023 signalé ; le travail est terminé lorsque le cas fnW ne produit aucune erreur inattendue tout en conservant des déclarations exportées utilisables.