// https://stackoverflow.com/a/68783088/1133344

interface MolinPasteDetail {
  text: string;
  timestamp: string;
}

interface CustomEventMap {
  'molin:paste': CustomEvent<MolinPasteDetail>;
}

declare global {
  interface Document {
    // adds definition to Document, but you can do the same with HTMLElement
    addEventListener<K extends keyof CustomEventMap>(type: K, listener: (this: Document, ev: CustomEventMap[K]) => void): void;
    dispatchEvent<K extends keyof CustomEventMap>(ev: CustomEventMap[K]): void;
  }
}

export {}; // keep that for TS compiler

// function onCustomEvent(event: CustomEvent<CustomParams>){
//   this.[...] // this is Document
//   event.detail ... //is your CustomParams type.
// }
// document.addEventListener('anothercustomevent', onCustomEvent);

// Three small changes for completeness sake.
// 1) The addEventListener declaration should include the third options parameter: options?: boolean | AddEventListenerOptions.
// 2) The return type of the listener param should be any to match the one in lib.dom.d.ts
// 3) You should include the declaration for removeEventListener (including the above points): removeEventListener<K extends keyof CustomEventMap>(       type: K,       listener: (this: HTMLElement, ev: CustomEventMap[K]) => any,       options?: boolean | EventListenerOptions,     ): void;