This is the way to insert initial data into MongoDB via grunt task. Thx to this plugin: https://github.com/sindresorhus/grunt-shell

A-way-to-initial-mongodb-data-with-grunt.js

//this is json array that MongoDB will easier read and import into it
//for the record if you didn't use json array MongoDB will read data per line so don't forget to re-format it
[
    { name: "Widget 1", desc: "This is Widget 1" },
    { name: "Widget 2", desc: "This is Widget 2" }
]

Gruntfile.js

//I assume that you install grunt-shell
shell: {
    options: {                      // Put this option if you want to see output when run shell script
        stdout: true,
        stderr: true,
        failOnError: true
    },
    //remove exitisting database
    remove_init_data: {
        command: 'mongo vCommerce --eval "db.dropDatabase()"'
    },
    //create database/ import data from init_data.json into databse 
    add_init_data: {
        command: 'mongoimport --db vCommerce --collection initData  --type json --file server/init_data.json --jsonArray'
    }
}

//grunt prepare-db
//run once use anywhere ... this task should run once when you prepare your project 
//because if you run it again exitisting data you store it will deleted too. 
grunt.registerTask('prepare-db', [
    'shell:remove_init_data',
    'shell:add_init_data'
]);

Nicely done! Thanks :)