Microsoft/TypeScript

Non-exported recursive type alias is inlined until it falls back to any in declarations

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#58,696 创建于 2024年5月29日

 (3 条评论) (0 个反应) (0 位负责人)TypeScript (13,395 个派生)batch import
BugDomain: Declaration EmitHelp Wanted

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描述

🔎 Search Terms

declarations recursive types

🕗 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

Playground Link

💻 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;

🙁 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;

🙂 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

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