未定义RegeneratorRuntime

问题描述

我正在尝试运行和一个直接的ES6生成器：

I am trying to run Karma-babel-preprocessor and a straight forward ES6 generator:

//require('babel/polyfill');

  describe("how Generators work", function() {
    it("will allow generator functions", function() {
      /*function * numbers() {
        yield 1;
        yield 2;
        yield 3;
      };*/


      let numbers = {
        [Symbol.iterator]:function*(){
            yield 1;
            yield 2;
            yield 3;
          }
      }

      let sum = 0;

      for(n of numbers){
        sum += n;
      }

      expect(sum).toBe(6);
    });
  });

从这里我用babel生成了我的测试文件（ES6 => ES5）：

From this I generated my test files (ES6 => ES5) with babel:

babel src --watch --out-dir tests

然后我运行 karma start 我收到错误：

Then I run karma start I get error:

karma.conf.js中的相关位：

Relevant bits in karma.conf.js:

  // list of files / patterns to load in the browser
    files: [
      'test-main.js',
      {pattern: 'tests/*.js', included: true}
    ],


    // list of files to exclude
    exclude: [
    ],


    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: {
            'src/*.js': ['babel']
    },
        'babelPreprocessor': {
      options: {
        sourceMap: 'inline'
      },
      filename: function(file) {
        return file.originalPath.replace(/\.js$/, '.es5.js');
      },
      sourceFileName: function(file) {
        return file.originalPath;
      }
    },


// test results reporter to use
// possible values: 'dots', 'progress'
// available reporters: https://npmjs.org/browse/keyword/karma-reporter
reporters: ['progress'],

我能够使用许多ES6功能，包括箭头。只是没有继续发电机。

I am able to use many ES6 features including arrows. Just no go on Generators.

推荐答案

虽然我采取了不同的方法**在我的项目中使用Karma和Babel，我怀疑你遇到了同样的问题：没有加载 ，所以你没有得到它支持的功能（包括Babel用来使生成器工作的自定义再生器运行时）。

While I'm taking a different approach** to using Karma with Babel in my project, I suspect you're having the same problem I was: the Babel polyfill is not being loaded, and so you're not getting the functionality it supports (including the custom regenerator runtime that Babel uses to make generators work).

一种方法是找到一种方法包括polyfill，也许是通过文件数组将它送到Karma：

One approach would be to find a way to include the polyfill, perhaps by feeding it to Karma via the files array:

files: [
  'path/to/browser-polyfill.js', // edited: polyfill => browser-polyfill per P.Brian.Mackey's answer
  ...

另一种方法可能是使用Babel的 [编辑：重新阅读文档，除非你浏览/ webpack / etc，否则这将无效。处理变换器创建的 require（）调用];根据其文档，

An alternate approach may be to use Babel's runtime transformer [edit: on rereading the docs, this will not work unless you then browserify/webpack/etc. to process the require() calls created by the transformer]; per its docs,

• 使用generator / async函数时，自动需要 babel-runtime / regenerator 。


• 自动要求 babel-runtime / core-js 并映射ES6静态方法和内置函数。


• 删除内联babel助手并改为使用模块babel-runtime / helpers 。

• Automatically requires babel-runtime/regenerator when you use generators/async functions.
• Automatically requires babel-runtime/core-js and maps ES6 static methods and built-ins.
• Removes the inline babel helpers and uses the module babel-runtime/helpers instead.

我没有这方面的经验，但我怀疑你会这样做，包括可选：['runtime'] 选项来自您的 babelPreprocessor 配置中的Babel文档，即：

I have no experience with this, but I suspect you would do so by including the optional: ['runtime'] option from the Babel docs in your babelPreprocessor config, viz.:

'babelPreprocessor': {
  options: {
    optional: ['runtime'],  // per http://babeljs.io/docs/usage/options/
    sourceMap: 'inline'
  },
...

（ **我目前我们使用jspm + jspm-karma +一些配置来获取SystemJS中加载的Babel polyfill;询问是否相关，我会解释。）

这篇关于未定义RegeneratorRuntime的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！