babel-jest ES2015导入声明 [英] babel-jest ES2015 import statements

问题描述

有人用es2015语法编写茉莉花/开玩笑的测试吗?它需要多少匀场/填充/胶接?

has anyone been writing jasmine / jest tests using es2015 syntax? how much shimming / polyfill / gerrymandering does it require?

我无法正确导入功能.我有一个模块: ..../utils/TweetUtils.js

i’m having trouble importing functions correctly. i have one module: …./utils/TweetUtils.js

'use strict';

export function getListOfTweetIds (tweets) {
  return Object.keys(tweets);
};

和一个测试套件:

..../__ tests __/TweetUtils-test.js

'use strict';
jest.dontMock('../TweetUtils');
import * as TweetUtils from '../TweetUtils';

describe('Tweet utilities module', () => {

  it('has access to the TweetUtils methods', () => {

    let testObj = {a:'a',b:'b',c:'c'};
    // Passes
    expect(TweetUtils.getListOfTweetIds).toBeDefined();
    // Passes
    expect(typeof TweetUtils.getListOfTweetIds).toBe('function');
    // Fails
    expect(TweetUtils.getListOfTweetIds(testObj)).toBeTruthy();
  });
});

如果我将控制台输出侵入套件，如下所示:expect(‘’).toBe(TweetUtils);

If I hack a console output into the suite with something like this:expect(‘’).toBe(TweetUtils);

茉莉花报告了这一点:

- Expected: '' toBe: {
      default: {
          getListOfTweetIds: Function
      },
      getListOfTweetIds: Function
  }

所以看起来import语句正在做某事，但是显然不是诚实地导入我的方法.使用命名函数语法导入时，我得到相同的结果:import {getListOfTweetIds} from ‘../TweetUtils’; 但是，如果我使用默认语法:import getListOfTweetIds from ‘../TweetUtils’; 第二个规范失败-不再是typeof function，而是typeof object // => {default: Function}

So it seems like the import statement is doing something, but it’s clearly not importing my methods honestly. I get the same results when I import using the named function syntax: import {getListOfTweetIds} from ‘../TweetUtils’; But if I use the default syntax: import getListOfTweetIds from ‘../TweetUtils’; The second spec fails - it’s no longer typeof function, but typeof object // => {default: Function}

我一直在整理文档和公开问题.已经有相关问题几个月了，但是已知问题似乎并不正确.我尝试导入我的jest.dontMock语句来避免吊起，大约是: https://github .com/babel/babel-jest/issues/16 但没有骰子.

I’ve been combing the docs and open-issues. There’ve been related issues for a few months, but the known issues don’t seem right. I’ve tried importing my jest.dontMock statements to avoid hoisting, circa: https://github.com/babel/babel-jest/issues/16 but no dice.

如果我将 TweetUtils.js 修改为使用module.exports = function…并使用const myFunction = require(‘../TweetUtils’)将其带入套件，则一切正常，但是感觉不像是在传播真正的ES2015魔术.在生态系统赶上新语法的同时，每个人现在都只是在处理一些怪异的解决方法吗?

Everything works if I modify TweetUtils.js to use module.exports = function… and bring it into the suite using const myFunction = require(‘../TweetUtils’), but it doesn’t feel like I’m channeling the true ES2015 magic. Is everyone just dealing with wonky work-arounds right now while the ecosystem catches up to the new syntax?

推荐答案

正如您所说，import语句被吊起，并且会导致开玩笑的自动嘲笑功能出现问题(该模块先于导入 >您告诉玩笑要取消嘲笑).

As you said, import statements are hoisted and it causes problems with the jest auto-mocking feature (the module is imported before you tell jest to unmocked it).

TweetUtils.getListOfTweetIds已正确导入，但已被模拟，因此每个调用都返回undefined.这就是第三个期望失败的原因.

TweetUtils.getListOfTweetIds is correctly imported but it's mocked, so each calls return undefined. That's why the third expectation fails.

导入jest.dontMock语句可以工作(我对其进行了测试)，但对我来说听起来很脏(您是否真的要为每个测试模块创建一个"dontmock模块"文件?)

Importing jest.dontMock statement could work (I tested it) but it sounds dirty to me (do you really want to create a "dontmock module" file for each test modules ?)

您必须对测试的模块使用require语法.替换

You have to use the require syntax for the tested module. Replace

import * as TweetUtils from '../TweetUtils';

通过

const TweetUtils = require('../TweetUtils');

在修复问题之前，在笑话示例中是相同的: jest#379

It was the same in jest example before I fixed it : jest#379

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