Jest Web Components Setup

jest-setup.ts

import 'jest-preset-angular';
import 'mutationobserver-shim';

// Mock environment
var mockedRegistry = new Map();
var win = <any>window;
win.alert = () => {};
win.customElements = {
    define: (elementName, elementClass) => {},
    get: tagName => mockedRegistry.get(tagName)
};

// mock XHR
// e.g. for api/config/keycloak
const xhrMockClass = () => ({
    open: jest.fn(),
    abort: jest.fn(),
    send: jest.fn(),
    setRequestHeader: jest.fn(),
    addEventListener: jest.fn(),
    removeEventListener: jest.fn()
});

win.XMLHttpRequest = jest.fn().mockImplementation(xhrMockClass);