在单元测试中处理momentjs弃用警告

Question

我使用moment.js

编写格式化日期的单元测试用例

打字稿代码：

formatDate(date) {
  date ? moment(date).format('DD-MM-YYYY') : '';
}

    单元测试案例：

it('should return `Invalid date`', () => {
  const date = '20111011000000Z';

  expect(component.formatDate(date)).toBe('Invalid date');
});

我在运行此单元测试时收到以下警告，如何避免此警告。

WARN: 'Deprecation warning: value provided is not in a recognized RFC2822 or 
ISO format. moment construction falls back to js Date(), which is not 
reliable across all browsers and versions. Non RFC2822/ISO date forma
ts are discouraged and will be removed in an upcoming major release. Please 
refer to http://momentjs.com/guides/#/warnings/js-date/ for more info.
Arguments:
[0] _isAMomentObject: true, _isUTC: false, _useUTC: false, _l: undefined, 
_i: 20111011000000Z, _f: undefined, _strict: undefined, _locale: [object 
Object]
undefined'

请您告诉我解决方案。