Hacktoberfest 2026:维护者为十月标记出来的 issue,仍然开放、适合新手。 浏览 Hacktoberfest issue

[TS] Evaluate instanceof against the runtime constructor value

未关闭
#457 0 条评论 0 个 reaction 已指派 0 人 在 GitHub 查看

维护者通常 1 天内回复

还没有人认领这个 Issue。

评估

难度
4/5
预计耗时
3-5 天
新手友好度
45/100
Issue 类型
功能
描述清晰度
基本清楚
活跃度
活跃
技术栈
kotlin, node.js, typescript

调研方向

Start at the current instanceof evaluator and its use of the static EtsIR checkType, then review the focused symbolic-test entry point described in the issue. Account for dependencies JacoDB #390 and UnitTestBot/jacodb#396 before testing. Done means both outcomes share one static RHS type, direct checks remain covered, and generated inputs and results replay in Node.js.

由索引模型根据 Issue 内容生成。

描述

enhancement

Problem

The current instanceof evaluator uses the static checkType from EtsIR. For a dynamic right-hand side, that type does not identify which constructor object the program actually selected. JacoDB PR #395 therefore marks dynamic checks unsupported instead of reporting a possibly false Boolean.

Minimal TypeScript example

class A {}
class B {}
export function check(useA: boolean): boolean {
  const ctor = useA ? A : B;
  return new A() instanceof ctor;
}

Node.js returns true for check(true) and false for check(false). The ctor expression must be evaluated once; the membership check must use that runtime value, not its static union type.

Expected support

Use the right-hand constructor value and the left-hand object's prototype chain for the supported class-constructor model. Preserve JavaScript behavior for a non-callable RHS (TypeError) where that value is representable. If custom Symbol.hasInstance is outside the current model, report that case as unsupported explicitly.

Acceptance criteria

  • A focused symbolic test obtains both outcomes with the same static RHS type and distinguishes unsupported from failure.
  • Generated inputs and results replay in Node.js.
  • Direct value instanceof A remains covered and correct.

Dependencies: JacoDB #390 (RHS evaluation) and UnitTestBot/jacodb#396 (declared class runtime values). Implement this as a separate USVM PR.

主要语言
Kotlin
星标
33
派生
27
平均合并
2 天 20 小时
30 天内合并 PR
10

环境准备

这个项目没有提供开发容器、Dockerfile 或贡献指南,环境需要你自己搭建:先看它的 README,通用步骤见我们的新手贡献指南。

从这里开始

  1. 先读完整个 Issue,再读项目的贡献指南。
  2. 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
  3. Fork 仓库,在一个分支上完成修改。
  4. 提交 Pull Request,并在描述里引用这个 Issue 编号。

UnitTestBot/usvm 的其他 Issue

查看 UnitTestBot/usvm 的全部 Issue

相似的 Issue

更多 Kotlin Issue

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。