Getting Started

Installation of the client

Grunt is a Node.js tool, and you use npm to install it. There are two packages to install: grunt-cli and grunt.

First, you need to install grunt-cli globally. This will enable the use of the grunt command in the shell, so you can use Grunt in any project in your machine:

$ npm install -g grunt-cli

You can test it by running:

$ grunt --version

To add Grunt to your project, just install grunt locally. Remember to setup your project as a NPM package with npm init so you can have an initial package.json created.

$ npm init
$ npm install grunt --save-dev

The flag --save-dev will update your package.json to add Grunt as a development dependency. This is how it will look:

{
  // ...
  "devDependencies": {
    "grunt": "~0.4.2"
  }
}

And that's enough npm! If you try to run grunt now, you will see an error message complaining about the lack of a Gruntfile.js… It's time to fix this.

Your Gruntfile.js

By default, Grunt comes with no tasks and no configuration at all. It's up to you to add this to your project. You do that by creating a Gruntfile.js file (or Gruntfile.coffee for you coffeescripters).

Here's an example of a Gruntfile.js with a task that will print the version of our project (as stated in package.json):

module.exports = function (grunt) {
    // create 'version' custom task
    grunt.registerTask('version', 'Shows version number', function () {
        var pkg = grunt.file.readJSON('package.json');
        grunt.log.writeln(pkg.name + ' version ' + pkg.version);
    });
};

You can now run this task with:

$ grunt version

Grunt plugins

Grunt has been around for a while, and there are a lot of plugins with pre-built tasks that you can use out of the box with a minimal configuration. Some of these common tasks provided by plugins include: minifying, concatenating, linting, etc.

Grunt plugins are Node.js packages that you install with npm as usual. For example, to install the grunt-contrib-jshint[^jshint] plugin:

$ npm install --save-dev grunt-contrib-jshint

[^jshint]: JSHint is a JavaScript linter – a tool that analyses your code and spots syntax errors and bad practises and formatting.

In order to use a plugin, we need to load its tasks in the Gruntfile.js, and provide some configuration in it as well. Here's an example of a Gruntfile.js that makes use of the grunt-contrib-jshint[^contrib] plugin:

module.exports = function (grunt) {
  // load plugin tasks
  grunt.loadNpmTasks('grunt-contrib-jshint');

  // tasks configuration
  grunt.initConfig({
    jshint: {
      files: ['Gruntfile.js'], // files to run JSHint on
      options: { // options for JShint
        globals: {
          module: true // allow the use of 'module' global
        }
      }
    }
  });
};

[^contrib]: Plugins which package name start with grunt-contrib are plugins mantained by the Grunt project. You should favor these plugins (they are the most popular ones –that potentially means more bug reporting & fixing) over a non-contrib version.

You can execute the jshint task, and it will lint the Gruntfile.js itself, with the options that we have specified in the task configuration:

$ grunt jshint