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globalThis sometimes being stripped from type emition can leads to errors in emited definition #48783
Description
Bug Report
🔎 Search Terms
globalThis, removed, remove, stripped, 2502, own type annotation, referenced, definition, .d.ts
🕗 Version & Regression Information
- This is the behavior in every version I tried, since 3.5.1, and I reviewed the FAQ for entries about globalThis, 2502, own type annotation
⏯ Playground Link
Playground link with relevant code, mainly using the D.TS tab
💻 Code
export const fetchSomething = (
fetch: typeof globalThis.fetch
): typeof globalThis.fetch => fetch🙁 Actual behavior
This code will generate the following .d.ts file, which contains the 'fetch' is referenced directly or indirectly in its own type annotation. (2502) error
export declare const fetchSomething: (fetch: typeof fetch) => typeof fetch;🙂 Expected behavior
Generated d.ts file should keep the reference to globalThis
export declare const fetchSomething: (fetch: typeof globalThis.fetch) => typeof globalThis.fetch;as it does when declaring a function, type or class:
export type FetchSomething = {
fetch: typeof globalThis.fetch
}
export class FetchSomethingClass {
fetch?: typeof globalThis.fetch
}
export type FetchSomethingFunction = (fetch: typeof globalThis.fetch) => typeof globalThis.fetch
// .d.ts
export declare type FetchSomething = {
fetch: typeof globalThis.fetch;
};
export declare class FetchSomethingClass {
fetch?: typeof globalThis.fetch;
}
export declare type FetchSomethingFunction = (fetch: typeof globalThis.fetch) => typeof globalThis.fetch;🤔 Workaround
Typing the const instead of the anonymous function works as expected.
export const fetchSomething: (fetch: typeof globalThis.fetch) => typeof globalThis.fetch = (fetch) => fetch;
Activity
jakebailey commentedon Jun 21, 2022
It looks like this applies to in any case where the function type is inferred from an arrow function (and probably function expression too?). The below shows a number of variations that break in
d.tsemit, but also show the wrong thing in the tooltip (shown via// ^?). It also affects things if you have(foo: number, bar: typeof globalThis.foo)or something.Playground Link
The main issue seems to be that we don't set the enclosingDeclaration to the arrow function when converting its signature to a type node; doing so almost fixes the bug but changes all sorts of other tests (honestly, many in positive ways, with a few confusing breaks). However, we then emit
global.fetch(or similar) and notglobalThis.fetch. The former errors out saying thatglobalis not available.You can actually see this result if you declare something at the module level with the same name; then we do the right thing (because we see the arrow function's parent and decide to write it explicitly) except that
globalThisbecomesglobalwhich is weird. My example above shows this if the last line is uncommented.