grunt-traceur-simple

Grunt task that uses the Google Traceur compiler to transpile source files from ECMAScript 6 to ECMAScript 5 syntax. It supports the passing of arbitrary Traceur options and the use of either the dependent Traceur version or an arbitrary peer-installed Traceur version.

The independence of the Traceur internals (which options are supported) and the independence of the Traceur version is the killer feature of this Grunt plugin -- in contrast to similar Grunt Traceur integration plugins.

Getting Started

This plugin requires Grunt ~0.4.0

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

npm install grunt-traceur-simple --save-dev

Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:

grunt.loadNpmTasks("grunt-traceur-simple");

Options

• traceurRuntime: The path to the traceur-runtime.js file of Traceur. It can be usually found in the path bin/traceur-runtime.js of a Traceur distribution. The default is the path to the traceur-runtime.js file of the dependent traceur module. Use path.resolve(path.join(__dirname, "node_modules/traceur/bin/traceur-runtime.js")) if you want to use a peer-installed Traceur.

• traceurCommand: Either the path to the traceur executable of a Traceur installation or distribution or the path to the src/node/command.js file of a Traceur distribution. The default is the path to the command.js file of the dependent traceur module. Use path.resolve(path.join(__dirname, "node_modules/traceur/src/node/command.js")) if you want to use a peer-installed Traceur.

• traceurOptions: The additional command-line options passed to the traceur executable. Usually used to enable or disable certain transpiling options. The default is "". Use, e.g., --experimental --source-maps for enabling all experimental transpiling features and generate a source-map file.

• includeRuntime: Set to true for including the Traceur runtime (see traceurRuntime for the path) into the generated output file. Alternatively install the Twitter Bower component traceur-runtime with bower install traceur-runtime and load its traceur-runtime.js yourself in the application. Dependending of the used ECMAScript 6 funtionality in the code, this runtime is needed or not.

Task Calling

Run this task with the grunt traceur command.

Task targets, files and options may be specified according to the Grunt Configuring tasks guide.

Usage Example

Assuming we have the following build environment:

• Gruntfile.js:

// [...]
grunt.initConfig({
    traceur: {
        options: {
            includeRuntime: true,
            traceurOptions: "--experimental --source-maps"
        },
        "app": {
            files: {
                "out/app.js": [ "src/**/*.js" ]
            }
        }
    }
});
grunt.registerTask("default", [ "traceur" ]);
// [...]

Then running grunt traceur is functionality-wise somewhat equivalent to running traceur --experimental --source-maps --out out/app.js src/*.js.