MyElementTagNameMap.ts

type MyElementTagNameLookup<T extends string> =
  T extends keyof HTMLElementTagNameMap ? HTMLElementTagNameMap[T] :
  T extends keyof SVGElementTagNameMap ? SVGElementTagNameMap[T] :
  Element;

type MyElementTagNameMapWithSuffix<T extends string> =
  T extends `${infer TagName}[${infer _Attr}`
    ? MyElementTagNameLookup<TagName>
    : T extends `${infer TagName}.${infer _ClassName}`
    ? MyElementTagNameLookup<TagName>
    : MyElementTagNameLookup<T>;

type MyElementTagNameMap<T extends string> =
    T extends `${infer _Head} ${infer Tail}`
    ? MyElementTagNameMap<Tail>
    : MyElementTagNameMapWithSuffix<T>;

declare global {
  interface ParentNode {
    querySelectorAll<T extends string>(
      selectors: T
    ): NodeListOf<MyElementTagNameMap<T>>;
    querySelector<T extends string>(
      selectors: T
    ): MyElementTagNameMap<T> | null
  }
}

document.querySelectorAll(`a[href^="#"]`).forEach((e) => { alert(e.href) });
document.querySelector(`input[name="nickname"]`)?.value;

export {};