example protractor test class for the Promact/md2 md2-select mutiple (multiselect)

example.e2e-spec.ts

import {Md2MultiSelect} from "./components/md2/md2-multi-select";

describe('example test usage of md2-select multiple test class', () => {

    it("md2-select: should be able to check all options", () => {
        const md2Select = new Md2MultiSelect('[name=anotherSelect]');
        md2Select.checkAll();
        md2Select.open();
        expect(element.all(by.css('.md2-select-content .md2-option')).count()).toEqual(element.all(by.css('.md2-selected')).count());
    });

    it("md2-select: should be able to select multiple items from the options", () => {
        const list = ['A', 'B', 'C', '1', '2', '3'];
        const md2select = new Md2MultiSelect('[name=selectedCaseStatuses]');
        md2select.uncheckAll().click(list);
        expect(md2select.getStringValue()).toContain('A, B, C, 1, 2, 3');
    });

});

md2-multi-select.ts

import {by, ElementFinder, $, $$} from "protractor";
import {promise} from "selenium-webdriver";

export class Md2MultiSelect {
    component: ElementFinder;

    constructor(selector: string) {
        this.component = $(selector);
    }

    uncheckAll(): Md2MultiSelectPage {
        this.open();
        this.selectedOptions().then((selector) => {
            $$(selector).each((elem) => elem.click());
            this.close();
        });
        this.close();
        return this;
    }

    checkAll(): any {
        this.open();
        this.notSelectedOptions().then((selector) => {
            $$(selector).each((elem) => elem.click());
            this.close();
        });
        return this;
    }

    click(array: string[]): Md2MultiSelectPage {
        this.open();
        this.allOptions().then((selector) => {
            $$(selector).each((elem) => {
                elem.getAttribute("innerText").then((text) => {
                    if (array.indexOf(text) >= 0) {
                        elem.click();
                    }
                });
            });
        });
        this.close();
        return this;
    }

    getStringValue(): any {
        return this.component.element(by.className('md2-select-value-text')).getAttribute("innerText");
    }

    private selectedOptions(): promise.Promise<string> {
        return this.filterOptionIds().then((ids) => {
            return ids.split(' ').map((id) => {
                return "#" + id + '.md2-selected';
            }).toString();
        });
    }

    private notSelectedOptions(): promise.Promise<string> {
        return this.filterOptionIds().then((ids) => {
            return ids.split(' ').map((id) => {
                return "#" + id + ":not(md2-selected)";
            }).toString();
        });
    }

    private allOptions(): promise.Promise<string>  {
        return this.filterOptionIds().then((ids) => {
            return ids.split(' ').map((id) => {
                return "#" + id;
            }).toString();
        });
    }

    private filterOptionIds(): promise.Promise<string>  {
        return this.component.getAttribute('aria-owns').then((promise) => {
            return promise
        });
    }

    open() {
        this.close();
        this.component.click();
        return this;
    }

    close() {
        $('body').click();
        return this;
    }
}