Validating JSON schemas

validateSchema.js

var Validator = require('jsonschema').Validator;
var v = new Validator();

var collectSchema = {
    "$schema": "http://iglucentral.com/schemas/com.snowplowanalytics.self-desc/schema/jsonschema/1-0-0#",
    "description": "Additional properties about how audio/video was consumed when embedded in other content (such as in an article)",
    "self": {
        "vendor": "au.net.abc.snowplow",
        "name": "embed_context",
        "format": "jsonschema",
        "version": "1-0-0"
    },
    "type": "object",
    "properties": {
        "contentid": {
            "type" : "string",
            "maxLength": 100
        },
        "contentsource": {
            "type" : "string",
            "maxLength": 255
        },
        "contenttype": {
            "type" : "string",
            "maxLength": 255
        }
    },
    "required": ["contentid","contentsource","contenttype"],
    "additionalProperties": false
}

var instance = {
   "contentid": "test",
   "contentsource": "test2",
   "contenttype": "test3"
}

v.addSchema(collectSchema, '/collect');
console.log(v.validate(instance, collectSchema));