microsoft / microsoft/TypeScript
__esDecorate transpiled code uses "Symbol" even of this is shadowed by a local variable
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Descripción
### 🔎 Search Terms
helper symbol tslib
### 🕗 Version & Regression Information
- This changed between versions 5.1.6 and 5.2.2
Tested via playground and reading its debug output.
### ⏯ Playground Link
https://www.typescriptlang.org/play/?ts=5.9.0-dev.20250617#code/GYVwdgxgLglg9mABMOcAiBTCcBOBDKXAClxgHMYw8AbAWQygAs4ATALkTzAE8AaRbGCgYAHlA5duASkQBvAL4AoRaIAOuKAOp4AzjsQBlbgFsARnGpyBCHVBwhoxGbMTzXygAIp0WXAVwqIuo4mhDaeojG3ADC4fqyiohJgrb2jjhEzoiJSbkpmgD6YBgA7kbGiAC8iMUlhibm1JkA3DnuSkA
### 💻 Code
```ts
function fooDecorator(originalMethod: any, context: any) {}
export class Symbol { constructor() { } }
@fooDecorator
export class myClass {
constructor() {
const _newSym = new Symbol();
}
}
```
### 🙁 Actual behavior
The generated js code for `myClass` contains
```ts
const _metadata = typeof Symbol === "function" && Symbol.metadata ? Object.create(null) : void 0;
```
Which will access my local variable `Symbol` instead of `window.Symbol`/`globalThis.Symbol`.
### 🙂 Expected behavior
The generated code should access `globalThis.Symbol` in any case or perhaps only if the file contains a local variable (from `class`, `const` or `import`) with a colliding name.
### Additional information about the issue
I found this with an `import { Symbol } from "./service";` call (roughly modelled via this [Bug Workbench](https://www.typescriptlang.org/dev/bug-workbench/#code/PTAEAEDMEsBsFMB2BDAtvAXKAzvATgG7QDG8AdAC7YBQwAVHaABKrSgDKAnqgEYD2sUHWDV4ADwAOfPBVDFYybNg7d+ggN6g5fRNgp4ArsQrSAFAEpQmgL6hr1WmChwkaTKGQSJlGtFRSZKxVeATtQSDw+VFAAIjJgXEISeBiAbgdIA0RjaB1wvj4AEXhiaWQTPFNS3X0jCqwAMSycnUt1eygC4tK8culRSWlZeUVlVE4AYQUlK2otbRrDYzM20Dn5rWq9UAB9SALQAF5QRHgAd2C1C3T5+3sgA)) but this should not change the main problem.
We started to use the class name `Symbol` in our code (and public API) since 2014.
Right now we circumvent this issue by using different names inside the local file via alias names in `import`/`export`
But this is hard to understand and maintain.
Guía de contribución
Línea de trabajo
Comienza con el playground de TypeScript enlazado e inspecciona el código __esDecorate generado en busca de la declaración o importación local de Symbol. Sigue cómo el helper de metadatos de decorator elige la referencia a Symbol y, después, verifica que el código emitido ya no resuelva el binding local y siga manejando el ejemplo de decorator mostrado.
Escrito por el modelo de indexación a partir del texto del issue.
Evaluación
- Stack tecnológico
- typescript
- Área
- compilers
- Tipo de issue
- Error
- Dificultad
- 4/5
- Tiempo estimado
- 3-5 días
- Estado de actividad
- Estancado
- Claridad
- Bastante claro
- Aptitud para principiantes
- 45/100