please-forgive-me.js

  async *scraper() {
    let noMorePages = false;
    let currentPageURL = this._searchURL;

    while (!noMorePages) {
      try {
        
        let listingsForCurrentPage = await this._getListingsFromPage(
          currentPageURL
        );

        const isLimited =
          this._maxNumberOfPages &&
          this._maxNumberOfPages === this._currentPageNumber;

        const isLastPage =
          listingsForCurrentPage && !listingsForCurrentPage.hasNext;

        if (isLimited || isLastPage) {
          noMorePages = !noMorePages;
          return listingsForCurrentPage.listings;
        } else {
          yield listingsForCurrentPage.listings;
          currentPageURL = listingsForCurrentPage.hasNext;
        }
      } catch (exception) {
        throw exception;
      }
    }
  }

class IncompleteImplementation {
	constructor(firstUrl) {
		this.resultListeners = [];
		this.isDone = false;
		this.next = firstUrl;
	}
	
	async fetchPages() {
		const page = await getPageSomehow(this.next);
		this.resultListeners.forEach(listener => listener(page));
		
		if(!page.hasNext) {
			this.isDone = true;
		} else {
			this.next = page.hasNext;
			return await this.fetchPages();
		}	
	}
}

const whatever = new IncompleteImplementation('www.whatever.com');
whatever.resultListeners.push((page) => console.log(page));
whatever.fetchPages().then(() => console.log('All pages fetched!'));