microsoft / microsoft/TypeScript
TypeScript fails to detect self-reference issue in "Parameter Properties" of constructors
- 主要语言
- Go
- 星标
- 111k
- 派生
- 14.3k
- 平均合并
- 2 天 4 小时
- 30 天内合并 PR
- 132
描述
### 🔎 Search Terms
* private property self reference
* private property self reference constructor
* Parameter Properties constructor self reference
### 🕗 Version & Regression Information
- This is reproducible at least between v4.9.5 and nightly -- I have not tried earlier versions
### ⏯ Playground Link
https://www.typescriptlang.org/play/?target=9&module=1&ts=5.9.2#code/JYWwDg9gTgLgBAbzgKwsAdnAhgZzgfQDM4BfOQqCEOAcnQgBMBTALjCxgAsaBuAKD5YARjhhQsAY3gSANrjwBZAJ4BhOThwAhXE0QC4BuAHojcLsDwB3YDJlwJWAK45dFnI9eYA5gAoAlACEfIb2EOiiUI5S0HA+YFDAAG4cuoQsZkpgTBDERHAAvOR+eiEk+oZesQB0NVhQXjjpERheANoAusUIwSGGUEwwjlCY5jhVhD41VXUNfvylAj0GRgBUxqajcAwQTHj08JbQANYANHCcEJZMiUxQS3AgSgBijpg+aRlZOQTEhYRd9xCEzm9xIKyMfDKAlk8jgADkmJY1LCmAAPGBMdAMRSqdRaHQlQyoDDVWr1RpwZroNqdQm9MycCxVXxTGY4EELKESMKiewFODoRHwxHIjT+fjc8IQGRMKoyCC+CRVYnoHw0LA0M40ISa2gSGh+OZwIA
### 💻 Code
```ts
import { join as _f } from 'node:path';
abstract class MyClassBase {
// this will cause issue in g()!
constructor (private f: typeof _f = f) {
}
g (...args: string[]) {
return this.f(...args);
}
/* // this does not work, however
myFun (f: typeof _f = f) {
f();
}*/
}
class NewClass extends MyClassBase {
join (...args: string[]) {
this.g(...args);
}
}
const c = new NewClass();
console.log(c.join('a', 'b', 'c'));
```
### 🙁 Actual behavior
TypeScript compiler does not report any errors.
if you copy transpiled JS file and run that with Node.js, you will see
```
constructor(f = f) {
^
ReferenceError: Cannot access 'f' before initialization
```
### 🙂 Expected behavior
TypeScript clearly shows an error, similar to what would have been seen in regular function parameters
```
Parameter 'f' cannot reference itself.
```
### Additional information about the issue
The issue originated from this -- https://github.com/microsoft/vscode-js-debug-browsers/issues/19, and I just discovered that the issue in the project or TypeScript has never been fixed. If someone at Microsoft could do a favor and ping the maintainer of that repo as well, it will be much appreciated.
贡献指南
调研方向
从链接的 Playground 复现开始,研究 compiler 对构造函数参数属性的处理,并将其与普通函数参数的自引用检查进行比较。确认生成的 JavaScript 失败,并为 compiler 添加覆盖测试,使构造函数情况报告类似“Parameter 'f' cannot reference itself.”的错误。
由索引模型根据 Issue 内容生成。
评估
- 技术栈
- typescript
- 领域
- compilers
- Issue 类型
- 缺陷
- 难度
- 4/5
- 预计耗时
- 3-5 天
- 活跃度
- 停滞
- 描述清晰度
- 基本清楚
- 新手友好度
- 35/100