gistfile1.txt

// And here is the solution I'm trying to implement

// page object file

"use strict";

const defaultTimeout = 10000;

class RoomActivity {
    constructor () {
        this.activityList = element(by.css("room-activity"));
        this.roomActivityButton = element(by.css(".roomactivity"));
        this.favoriteRooms = this.activityList.element(by.css("favorite-rooms"));
        this.favoritesTitle = this.favoriteRooms.element(by.css("h1"));
        this.favoritesTitleIcon = this.favoritesTitle.element(by.css(".favorite-room-icon"));
        this.favoritesExplanationParagraph = this.favoriteRooms.element(by.css("p.empty-list-message"));
        this.favoritesItems = element.all(by.css("favorite-rooms ul li"));
        this.listItems = element.all(by.css(".room-list-item-wrapper .room-name"));
        this.refreshButton = element(by.css(".refresh-button"));
    }

    removeFirstItem() {
        browser.executeScript('document.querySelector(".room-list-item-wrapper .close-button").click();');
    }

    waitForActivityListToHaveSpecificNumberOfItems(numberOfItems, timeout = defaultTimeout) {
        browser.wait(this.activityListHasSpecificNumberOfItems(numberOfItems), timeout);
    }

    activityListHasSpecificNumberOfItems(numberOfItems) {
        return this.listItems.count().then((numberOfItemsCounted) => {
            return numberOfItemsCounted === numberOfItems;
        });
    }
}

module.exports = RoomActivity;
------------------------------------------------------------------------------------------
// spec.js file

"use strict";

const AppearInRoom = require("../page-objects/appearInRoom");
const Helper = require("../helper");
const RoomActivity = require("../page-objects/roomActivity");
const shortid = require("shortid");

describe("Activity list", () => {
    const appearInRoom = new AppearInRoom();
    const helper = new Helper();
    const roomActivity = new RoomActivity();
    let randomRoomName;

    beforeEach(() => {
        randomRoomName = shortid.generate();
        appearInRoom.visit(randomRoomName);
        helper.clickWhenClickable(roomActivity.refreshButton);
        helper.sleepForNSeconds(3);
    });

    it("should remove item from the activity list", () => {
        roomActivity.listItems.count().then((numberOfItemsBeforeRemoval) => {
            roomActivity.removeFirstItem();
            helper.waitForActivityListToHaveSpecificNumberOfItems(roomActivity.listItems, numberOfItemsBeforeRemoval - 1);

            roomActivity.listItems.count().then((numberOfItemsAfterRemoval) => {
                roomActivity.waitForActivityListToHaveSpecificNumberOfItems(numberOfItemsBeforeRemoval - 1);
                expect(numberOfItemsAfterRemoval).toEqual(numberOfItemsBeforeRemoval - 1);
            });
        });
    });
});