Bug: Accessing private statics in a class via its derived class is allowed

描述

class FooBase {
    private static privateStatic: string = "";

    testBase(): void {
        console.log(FooBase.privateStatic);

        // Should error, but doesn't
        console.log(Foo.privateStatic);
   }
}

class Foo extends FooBase {
    test() {
        // Should error, and does
        console.log(Foo.privateStatic);
    }
}

貢獻者指南

技術棧

typescript

領域

tooling

議題類型

bug

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。

3

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。

1-3 hours

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。

stale

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

Basic TypeScriptAccess modifiersTypeScript compiler building process

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。

50

研究方向

The issue is in the TypeScript checker, specifically in how private static members are accessed from derived classes. The expected fix is to ensure that a base class cannot access a derived class's private static member. Look at the accessibility checking logic in checker.ts, around the handling of property access expressions. The bug is that when accessing Foo.privateStatic from FooBase, the checker incorrectly allows it because it considers FooBase as the declaring class for the purpose of private access. The fix should involve ensuring that the declaring class is exactly the class where the member is defined, not any base class. There are no linked PRs, but the discussion in the issue may provide additional insights.