Merging Classes With Getters Converts Into a Property

[LukeAbby]

🔎 Search Terms

Mixin class, getter merging, property, is defined as a property in class but is overridden here in 'Test' as an accessor.

🕗 Version & Regression Information

• This changed in commit or PR 3ffe253

However, given that the title of this commit is "Always error when property overrides accessor or vice versa" I would say this issue likely originated earlier but was not reported.

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.8.3#code/CYUwxgNghgTiAEAzArgOzAFwJYHtXwCMoBnLMAWSwA8tUAeAFXhCoxFWGPhwICtwMAGngBVZq3adufAQD4AFBgBc8BsOQqRAShVMAZKIDcAKGOhIsBBeJcA4iAxsYAQXgBvY-C9g8xDDGRMHBh5ADpw2ABzYhUoVABPAG0AXS1TL3hIh3haAGEcAFsAB0ksZAL5HUIcHAgQOJMAX1NzaDh4azsHJwAhd09vX39AjGCwiJho2ISUtIHM7LzCko4yiqqCGrq442azcDaraBtVED8+ljYOLiJSCmpaeXtHEBdhZ96tfoycADdXmBYUALDA5VD5YqlcqVFSbWr1VAmDIAemRGXR6IAevAAORLSGrco4nJcUCIWggYDwEjU+BFGA4EowDDxMEdY5cHEfV6uAzcmA9HHCAjIUFYLh-AFA0D4AAWrwQtFxDDOGEF1K4cWpYDAZ2IwVCuyAA

💻 Code

declare function basicMixin<T extends object, U extends object>(t: T, u: U): T & U;

declare class GetterA {
   constructor(...args: any[])

   get inCompendium(): boolean;
}

declare class GetterB {
   constructor(...args: any[])

   get inCompendium(): boolean
}

declare class TestB extends basicMixin(GetterA, GetterB) {
   override get inCompendium(): boolean;
   //           ^ 'inCompendium' is defined as a property in class 'GetterA & GetterB', but is overridden here in 'TestB' as an accessor.
}

🙁 Actual behavior

The error 'inCompendium' is defined as a property in class 'GetterA & GetterB', but is overridden here in 'TestB' as an accessor. due to get inCompendium(): boolean being converted to inCompendium: boolean when computing GetterA & GetterB

🙂 Expected behavior

No error.

Additional information about the issue

No response

[Andarist]

duplicate of #44938
it's being fixed by #60853