accounts-frontend/packages/app/polyfills.test.js

import expect from 'app/test/unexpected';

describe('promise.prototype.finally', () => {
    it('should be invoked after promise resolved', () =>
        expect(new Promise((resolve) => Promise.resolve().finally(resolve)), 'to be fulfilled'));

    it('should be invoked after promise rejected', () =>
        expect(
            new Promise((resolve) => expect(Promise.reject().finally(resolve), 'to be rejected')),
            'to be fulfilled',
        ));
});