TS4055 when generating declaration for return type that uses type of paramter for protected methods

🔎 Search Terms

TS4055 declaration protected return typeof parameter

🕗 Version & Regression Information

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

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.8.3#code/KYDwDg9gTgLgBASwHY2FAZgQwMbDgBSgjDRgWAGc4BvAKDjjCJNgE8BBALjiQFcBbAEZoA3PUbNSrAELcKMKMgDmYgL61aoSLDjpeSbGQhI4S4DELEpANUwAbXsAD6AeQDWACnFMrschW5LFjJKABpvSTYAOUx+YG43YFYIdAJIkIpwgEpA9P8AbRhWEhSJXyKYuIBdGnEoc14oEx9ggpapSuAqtQ0taHhsO0wKKnZahjBeQTsEbFNzIJt7R1dPcQm8ylzy-3CGDfLWToSk0sW-MPEctJ3KQuLgUvbo2K7x-fqYRubNinzniqvbridTiAD0YLgaCIUDgABUAMoAFgADABWNHcABKDSacCKJDgTymMzmcRgAAsIAATXREfhQ8D9YC0wbDKgU4ZE2EIKi8CjKCQIABumFQPFecAA5ACjq8pQA6CIQVCGFnzCzpVi2BzOACiUBhXn2ZVaWxuZsy61NHVeJ2SqXOGT2cGuToKBMeqVlnRqdBNn2+Noufx9QLEDFBDAhUMN0HhyJRAHYAMyBTBQV6oWEyrU6xxSonekmzODkqm09D0xnaVCsoYjOCcqjx3lwfmCpgisV4JCS3OHTqK5WqutwCgLPPLfVxqDG-YA-zbS0ug7BOVxe1nX6r4NFfPxC2kD0PJ5a30urLvaOQuEuAAiLhBtHUQA

💻 Code

export interface Properties {
  propertyA: number;
  propertyB: string;
}

export function getPropertyValue_Ok(
  properties: Properties,
  propertyName: keyof Properties,
): Properties[typeof propertyName] {
  return properties[propertyName];
}

export class A {
  public getPropertyValue_Ok(
    properties: Properties,
    propertyName: keyof Properties,
  ): Properties[typeof propertyName] {
    return properties[propertyName];
  }

  // error TS4055: Return type of public method from exported class has or is using private name 'propertyName'.
  protected getPropertyValue_Error(
    properties: Properties,
    propertyName: keyof Properties,
  ): Properties[typeof propertyName] {
    return properties[propertyName];
  }

  // error TS4073: Parameter 'propertyValue' of public method from exported class has or is using private name 'propertyName'.
  protected setPropertyValue_Error(
    properties: Properties,
    propertyName: keyof Properties,
    propertyValue: Properties[typeof propertyName],
  ) {
    // TODO
  }
}

🙁 Actual behavior

The protected methods fail to generate declaration with TS4055 or TS4073.

🙂 Expected behavior

The protected methods should be able to generate declaration similar to the public method or function.

Additional information about the issue

I wonder if there's a way to temporarily suppress this error, becuase ts-ignore doesn't seem to work when generating declaration.

Commencez par le TypeScript Playground lié et la reproduction fournie de la génération de déclarations, en vous concentrant sur les méthodes protégées de class A et les diagnostics TS4055/TS4073. Comparez leur comportement avec celui de la méthode publique et de la fonction autonome ; le travail est terminé lorsque la génération de déclarations réussit pour les méthodes protégées sans ces erreurs.