对节点使用mocha测试。此错误：TypeError：无法设置未定义的属性“文件”

Question

我正在制作摩卡测试用例。但是当我运行我的文件给错误。这是我的错误。 TypeError：无法设置未定义的属性“文件”

这是我的代码

const describe = require('mocha');
const assert = require('assert');

    describe('Array', () => {
      describe('#indexOf()', () => {
        it('should return -1 when the value is not present', () => {
          // assert.equal([1, 2, 3].indexOf(4), -1);
          assert.equal([1, 2, 3].indexOf(4), -1);
        });
      });
    });

这是错误

E:\Node\Angular-node-mysql\server\node_modules\mocha\lib\mocha.js:85
  this.files = [];
             ^

TypeError: Cannot set property 'files' of undefined
    at Mocha (E:\Node\Angular-node-mysql\server\node_modules\mocha\lib\mocha.js:85:14)
    at Object.<anonymous> (E:\Node\Angular-node-mysql\server\routes\userRoute\user.spec.js:5:1)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Function.Module.runMain (module.js:693:10)
    at startup (bootstrap_node.js:191:16)
    at bootstrap_node.js:612:3