sindresorhus/type-fest

Remove redundant code for compatibility with older versions of typescript

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#1,142 建立於 2025年5月16日

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 (7 留言) (0 反應) (0 負責人)TypeScript (12,328 star) (471 fork)batch import
enhancementgood first issue

描述

In some previously supported but now unsupported versions of typescript, there would be some incorrect circular check, and in order to bypass the circular check, we have to add some non-essential code, for example:

type A<T> = 
 SomeToolType<T> extends infer B 
  ? B
  : never // Never happen

The above code can be simplified now:

type A<T> = SomeToolType<T>

貢獻者指南

技術棧
typescript
領域
toolingdeveloper experience
議題類型
refactor
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
2
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
under 1 hour
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
fresh
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
familiarity with TypeScript genericsunderstanding of type fest patterns
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
85
研究方向
Search the codebase for patterns like `SomeToolType<T> extends infer B ? B : never` where the conditional type is unnecessary due to removed support for older TypeScript versions. Look in source type definitions for such redundant patterns and simplify them to directly use `SomeToolType<T>`. The issue provides an example; apply similar logic to other occurrences. Check the repository's CONTRIBUTING.md for contribution guidelines.