Is it possible to restrict the parameter of an inherited method in TypeScript?

I have a scenario here where I am extending a node called EventEmitter with my class. The goal is to restrict the events that can be registered.

class Foo extends EventEmitter {
  on(event: 'myEvent', listener: Function): this;
  emit(event: 'myEvent', ...args: any[]): boolean
}
var foo = new Foo();
foo.on('wrongEvent', ()=>{}); // Ideally, this should trigger a compilation error

Do you think this can be done?

Currently facing an issue:

t.ts(6,3): error TS2391: Function implementation is missing or not immediately following the declaration.
t.ts(7,3): error TS2391: Function implementation is missing or not immediately following the declaration.
t.ts(10,8): error TS2345: Argument of type '"wrongEvent"' is not assignable to parameter of type '"myEvent"'.

Any suggestions on how to handle the TS2391 error effectively?

typescript

Answer №1

Based on the feedback from @AlekseyL., I will provide my own solution:

class Bar extends EventDispatcher {
  handleEvent(event: 'customEvent', callback: Function): this {
    return super.handleEvent(event, callback);
  };
  dispatchEvent(event: 'customEvent'): boolean {
    return super.dispatchEvent(event);
  }
}

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