WebStorm中的JavaScript未导出元素警告

Question

我不明白为什么我会在element is not exported行的以下JavaScript中收到WebStorm IDE中的this.errors。

function FooBar(userId, email) {
  if (!util.isString(userId) || !userId.length) {
    throw Error('FooBar(): requires a non-empty userId:String');
  }

  if (this instanceof FooBar) {
    this.id = generateId();
    this.userId = userId;
    this.email = email;
    this.curStep = WORKER_STEPS[0];
    this.completed = false;
    this.failed = false;
    this.createDate = new Date();
    this.errors = {};
    for (let step of WORKER_STEPS) {
      this.errors[step] = 0;
    }
  } else {
    return new FooBar(userId, email);
  }
}

Answer 1

我知道我可以获得许多投票，因为它超出了问题的范围。

但现在是时候切换到ES6了 所以我会给你更好的解决方案（：

1）启用EcmaScript 6支持：

2）切换到class以避免使用function

来定义庞大的老派课程定义

将它添加到js文件的顶部，它将使nodejs解释器提醒内存韭菜或不必要的变量定义等等。

/* jshint strict: true */

'use strict';

这是你的FooBar：

const
  _ = require('lodash');

class Entity {
  hasError() {
    return !_.isEmpty(this.errors);
  }

  addError(step, error) {
    this.errors[step] = error;
  }

  getErrors() {
    return this.errors;
  }
} 

class FooBar extends Entity {

  constructor(userId, email, steps = []) {
    if (_.isEmpty(userId) || !_.isString(userId))
      throw Error('FooBar(): requires a non-empty userId:String');

    this.id = generateId();
    this.userId = userId;
    this.email = email;
    this.curStep = _.first(steps);
    this.completed = false;
    this.failed = false;
    this.createDate = new Date();
    this.errors = {};
  }
}

用法：

let 
  fooBar = new FooBar(
             '1f049de1-b592-4f17-9a7d-3f2097477b23',
             'somebody@gmail.com', 
             WORKER_STEPS);

  fooBar.addError(0, "Something happen"); // or fooBarInstance.addError("Somewhere", "Something happen");

if(fooBar.hasError()) {
  console.error(fooBarInstance.getErrors());
}