Wordpress i18n Grunt: create .pot, update .po, generate .mo

Gruntfile.js

module.exports = function(grunt) {

    require('load-grunt-tasks')(grunt);

    grunt.initConfig({
        pkg: grunt.file.readJSON('package.json'),

        wpi18nkeywords: [
            '__:1',
            '_e:1',
            '_x:1,2c',
            'esc_html__:1',
            'esc_html_e:1',
            'esc_html_x:1,2c',
            'esc_attr__:1',
            'esc_attr_e:1',
            'esc_attr_x:1,2c',
            '_ex:1,2c',
            '_n:1,2',
            '_nx:1,2,4c',
            '_n_noop:1,2',
            '_nx_noop:1,2,3c'
        ],

        pot: {
            options:{
                text_domain: 'my-plugin',
                dest: 'i18n/',
                keywords: '<%= wpi18nkeywords %>'
            },
            files:{
                src:  [ 'plugin.php', 'inc/**/*.php' ],
                expand: true,
            }
        },

        updatepo:{
            files:{
                src:['i18n/*.po'],
                pot:'<%= pot.options.dest + pot.options.text_domain + ".pot" %>'
            }
        }

        po2mo: {
            files: {
                src: 'i18n/*.po',
                expand: true,
            },
        },
    );

    grunt.registerMultiTask('updatepo', "Update .po files with .pot", function()
    {
        this.requiresConfig('pot');
        var data = this.data;
        this.files[0].src.forEach( function(val,idx,array) {
            // generate new target in the 'exec' config, and wrap the cmd with a logger:
            grunt.config(  'exec.update_po_' + idx + '.cmd', function() {
                var cmd ="msgmerge -U " + val + " " + data.pot;
                console.log("exec:", cmd );
                return cmd;
            } );
            grunt.task.run( ['exec:update_po_'+idx] );
        } );
    });
    
    grunt.registerTask( 'default', ['pot', 'updatepo', 'po2mo'] );
};

package.json

{
  ...
  "devDependencies": {
    "grunt": "~0.4.4",
    "load-grunt-tasks": "~0.4.0",
    "grunt-checktextdomain": "^0.1.1",
    "grunt-pot": "^0.1.2",
    "grunt-exec": "~0.4.5"
    "grunt-po2mo": "^0.1.0",
  },
}