Repository navigation
"unique symbol" is generated to multiple .d.ts files #40786
Description
TypeScript Version: 4.0.3
Search Terms:
unique symbol, declaration, .d.ts, invalid, TS4023
Code
a.ts
type AX = { readonly A: unique symbol };
export const A: AX = 0 as any;b.ts
import { A } from './a';
export const A1 = A;tsconfig.json
{
"compilerOptions": {
"declaration": true,
"strict": true,
"noImplicitAny": true,
"rootDir": "src",
"outDir": "lib"
}
}Expected behavior:
Typescript should either throw TS4023, or generate the following code for b.d.ts:
import { A } from './a';
export declare const A1: typeof A;Actual behavior:
Typescript generates "unique symbol" to both a.d.ts and b.d.ts:
a.d.ts
declare type AX = {
readonly A: unique symbol;
};
export declare const A: AX;
export {};b.d.ts
export declare const A1: {
readonly A: unique symbol;
};Project Link:
project.zip
Activity
weswigham commentedon Oct 1, 2020
Hm. I suppose we should issue an error here? The local type from
aisn't reachable inb, so we print the type anonymously; however it contains aunique symbolwhich, by rights, refers to a symbol in a different file; so we can't really serialize it. The only thing you could write out is something likeexport declare const A1: typeof A, like you propose, but our declaration emit generally doesn't write outtypeofqueries on its own (simply because it doesn't generalize - it'd only work for exactly declarations of the formvar x = some.dotted.name, which is an odd syntactic carve-out to make for TS code), which is why it's more in-line with our normal behavior to report an error on the attempted usage of a private symbol, and require an annotation.weswigham commentedon Oct 1, 2020
In fact, the error already exists, and is simply failing to trigger due to an unfortunate bug.