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

Playground のリンクと logger.ts および api.ts の再現から始め、fnW(x) と fn(x) のエクスポートされた結果を比較します。宣言の生成と報告された診断 4023 を確認します。fnW のケースで予期しないエラーが発生せず、使用可能なエクスポート宣言が維持されれば完了です。