Incorrect reference `this` in static context with `experimentalDecorators` enabled

[yavanosta]

🔎 Search Terms

"static this", "experimental decorators"

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about static

⏯ Playground Link

https://www.typescriptlang.org/play/?experimentalDecorators=true&target=7&ts=5.9.3&emitDecoratorMetadata=true#code/GYVwdgxgLglg9mABAEQKYTgJwIZS4gCim0wHNUoAuRAMXGnjABpEBrVAT2oGcpMYwpRAB9E4ACapgA1OJYDJAD2pgQAWwBGqTAEpEAbwC+AKGMQANtm7dEAWQ4BhADJWb+44kS9cMCIkyo2OII5hxexLAQACoAFjDcAEpSiAC8iFBx3ADcHogYYLyYINBYBAACaBg4eJiIwHBwKupaugYmJkA

💻 Code

function Decorator (target: Function, key: string | undefined, index: number) {}

class MyClass {
  static readonly staticThisRef = this;
  constructor(@Decorator foo: number) {}
}

🙁 Actual behavior

MyClass.staticThisRef = (void 0);

🙂 Expected behavior

staticThisRef points to the class.

Additional information about the issue

Enabling or disabling experimentalDecorators fixes the issue.

With experimentalDecorators:

let MyClass = class MyClass {
    constructor(foo) { }
};
MyClass.staticThisRef = (void 0);
MyClass = __decorate([
    __param(0, Decorator)
], MyClass);

Without experimentalDecorators:

class MyClass {
    constructor(foo) { }
}
_a = MyClass;
MyCLass.staticThisRef = _a;

However only experimental decorators support decorating parameters.

Also TypeScript compiler behavior here is different from esbuild with experimentalDecorators feature enabled:

https://esbuild.github.io/try/#dAAwLjI3LjMALS1sb2FkZXI9dHMgIi0tdHNjb25maWctcmF3PXtcImNvbXBpbGVyT3B0aW9uc1wiOntcImV4cGVyaW1lbnRhbERlY29yYXRvcnNcIjp0cnVlfX0iAGZ1bmN0aW9uIERlY29yYXRvciAodGFyZ2V0OiBGdW5jdGlvbiwga2V5OiBzdHJpbmcgfCB1bmRlZmluZWQsIGluZGV4OiBudW1iZXIpIHt9CgpjbGFzcyBNeUNMYXNzIHsKICBzdGF0aWMgcmVhZG9ubHkgc3RhdGljVGhpc1JlZiA9IHRoaXM7CiAgY29uc3RydWN0b3IoQERlY29yYXRvciBmb286IG51bWJlcikge30KfQ

[RyanCavanaugh]

🤖 Thank you for your issue! I've done some analysis to help get you started. This response is automatically generated; feel free to 👍 or 👎 this comment according to its usefulness.

Similar Issues

Here are the most similar issues I found

• (69%) microsoft/typescript#52004: ES2022 Class Decorators not working when Class has self-static member
• (69%) microsoft/typescript#52258: Static properties are not correctly transpiled when using decorators and target ES2022
• (68%) microsoft/typescript#56503: `this` is incorrect for static fields and static accessors within decorators
• (68%) microsoft/typescript#57366: Using static members in class decorator
• (67%) microsoft/typescript#8074: [Transforms] References to decorated classes in static functions does not refer to the renamed entity
• (67%) microsoft/typescript#38756: this should be able to use in static property initializer
• (66%) microsoft/typescript#6285: Reference to own class in static variable initialization to a decorated class references undecorated class instead of decorated class
• (66%) microsoft/typescript#57309: Class decorators can't be used with static private identifier (using 'experimentalDecorators' and 'emitDecoratorMetadata')
• (66%) microsoft/typescript#9957: class with static method and decorator outputs broken JavaScript
• (66%) microsoft/typescript#61128: Resolution of "this" on method decorators not behaving properly
• (66%) microsoft/typescript#46335: Passing Class as a parameter of creation function for static field in decorated class will result into passing undefined instead of a class
• (66%) microsoft/typescript#6331: 'this' reference from static method should be possible
• (65%) microsoft/typescript#44908: Bad esnext emit for static property that references another static property when the class has a decorator
• (65%) microsoft/typescript#25754: Class decorator works weird with static properties
• (65%) microsoft/typescript#10537: Find-all-references for class should find static uses of `this`

If your issue is a duplicate of one of these, feel free to close this issue. Otherwise, no action is needed.

Possibly Working as Intended

It looks like this behavior might be intentional. Here's what a computer had to say about it.

[RyanCavanaugh]

Looks like a duplicate of #56503

[yavanosta]

I don't think it's duplicate of #56503

This one is about this in static members, and the other one is about this in the decorator itself.