var formatJson = require('format-json-pretty');

var user = {
  id: 1,
  name: 'fengliner',
  color: {
    id: 1,
    name: 'fengliner'
  },
  font: [{id: 1, name: 'fengliner'}]
};

console.log(formatJson(user));

/**
{
  "id": 1,
  "name": "fengliner",
  "color": {
    "id": 1,
    "name": "fengliner"
  },
  "font": [{
    "id": 1,
    "name": "fengliner"
  }]
}
*/

 console.log(foramtJson(user, 4));

 /**
 {
    "id": 1,
    "name": "fengliner",
    "color": {
        "id": 1,
        "name": "fengliner"
    },
    "font": [{
        "id": 1,
        "name": "fengliner"
    }]
}
*/