https://github.com/karma-runner/karma-traceur-preprocessor

A Karma plugin. Compile ES6 script on the fly using traceur-compiler.
https://github.com/karma-runner/karma-traceur-preprocessor

Last synced: 3 months ago
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A Karma plugin. Compile ES6 script on the fly using traceur-compiler.

• Host: GitHub
• URL: https://github.com/karma-runner/karma-traceur-preprocessor
• Owner: karma-runner
• License: mit
• Archived: true
• Created: 2013-12-21T23:06:42.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2016-05-11T13:23:09.000Z (over 8 years ago)
• Last Synced: 2024-07-05T14:16:25.204Z (4 months ago)
• Language: JavaScript
• Size: 31.3 KB
• Stars: 13
• Watchers: 11
• Forks: 10
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

Awesome Lists containing this project

• es6-tools - karma-traceur-preprocessor

README

        
# karma-traceur-preprocessor

> Preprocessor to compile ES6 JavaScript on the fly using [traceur-compiler].

## Installation

Install `karma-traceur-preprocessor` as a devDependency for your project:

```bash

npm install karma --save-dev

npm install karma-traceur-preprocessor --save-dev

```

## Configuration

The following example configuration shows some of the required settings for enabling Traceur support.  Traceur compiles source files into either AMD or Node.js modules.  Since Karma is testing in a browser you need to [configure RequireJS][configure-requirejs].

```js

// karma.conf.js

module.exports = function(config) {

  config.set({

    // at a minimum need requirejs + traceur

    frameworks: ['jasmine', 'requirejs', 'traceur'],

    preprocessors: {

      'src/**/*.es6': ['traceur']

    },

    files: [

      {pattern: 'src/**/*.es6', included: false},

      {pattern: 'test/**/*Spec.es6', included: false},

      'test/test-main.js'

    ],

    // default configuration, not required

    traceurPreprocessor: {

      // options passed to the traceur-compiler

      // see traceur --longhelp for list of options

      options: {

        sourceMaps: false,

        modules: 'amd'

      },

      // custom filename transformation function

      transformPath: function(path) {

        return path.replace(/\.es6$/, '.js');

      }

    }

  });

};

```

## Source Maps

If you set the `sourceMaps`  preprocessor option to `true` then the generated source map will be inlined as a data-uri.

[Source maps][source-map-overview] allow the browser to map the generated JavaScript back to the original ES6 code. You can then set breakpoints in the source ES6 code instead of the generated code.  In the browser you should see two files for each source file: .es6 and .js. The .js is the compiled output from Traceur and .es6 is the original source file.

## Supported Karma Launchers

Traceur is an ES6 to ES5 transpiler, and as such, does not support older browsers without ES5 support like IE8 or PhantomJS. (This is the case for any Traceur-compiled code, not just that produced by karma-traceur-preprocessor.)

----

For more information on Karma see the [homepage].

For an example of a project configured to test ES6 code check out [karma-traceur-test].

[homepage]: http://karma-runner.github.com

[traceur-compiler]: https://github.com/google/traceur-compiler

[karma-traceur-test]: https://github.com/tpodom/karma-traceur-test

[source-map-overview]: https://hacks.mozilla.org/2013/05/compiling-to-javascript-and-debugging-with-source-maps/

[configure-requirejs]: http://karma-runner.github.io/0.10/plus/requirejs.html