Microsoft/TypeScript
GitHub ã§èŠãNon-exported recursive type alias is inlined until it falls back to any in declarations
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#58,696 opened on 2024幎5æ29æ¥
BugDomain: Declaration EmitHelp Wanted
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説æ
ð Search Terms
declarations recursive types
ð Version & Regression Information
- This is the behavior in every version I tried (before 4.4 it was either a stack overflow crash or an error on the recursive type)
⯠Playground Link
ð» Code
// @declaration: true
// @filename: utils.ts
type Recursive<T> = T extends Array<infer V>? Recursive<V>: T;
export const f = <T>(): Recursive<T> => { return null! }
// @filename: index.ts
import { f } from './utils';
export const a = f;
ð Actual behavior
In declarations, the type for a is printed as a: () => T extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? V extends (infer V)[] ? any : V : V : V : V : V : V : V : V : V : V : T;
ð Expected behavior
Recursive can't be represented without falling back to any (as seen above) so it should just be an error instead of silently to any
Additional information about the issue
Related to #55832