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);
    }
}

贡献者指南

技术栈

typescript

领域

tooling

议题类型

bug

难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。

3

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1-3 hours

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stale

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clear

前置要求

Basic TypeScriptAccess modifiersTypeScript compiler building process

新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。

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.