test.ts

import 'jest-preset-angular/setup-jest';

Object.defineProperty(window, 'CSS', { value: null });
Object.defineProperty(window, 'getComputedStyle', {
    value: () => {
        return {
            display: 'none',
            appearance: ['-webkit-appearance'],
        };
    },
});

Object.defineProperty(document, 'doctype', {
    value: '<!DOCTYPE html>',
});
Object.defineProperty(document.body.style, 'transform', {
    value: () => {
        return {
            enumerable: true,
            configurable: true,
        };
    },
});