NodeJS validation library for json objects - json

Question

I need to validate some object in my NodeJS app. I have already used an awesome library express-validator, it works perfectly, but now I need to validate different object, not only requests and as far as express validator leverages validator library, that in turn doesn't support types other than the string type.
I have found different variants like Jsonschema, Ajv
They offer great features, but I need to be able to set error message and than just catch an exception or parse it from return object.
Like that
var schema = {
"id": "/SimplePerson",
"type": "object",
"properties": {
"name": {"type": "string", "error": "A name should be provided"},
"address": {"$ref": "/SimpleAddress"},
"votes": {"type": "integer", "minimum": 1}
}
};
So I can set an error message for every property.
Is there any existing solution to achieve this functionality ?
POSSIBLE SOLUTION
I have found a great library JSEN It provides necessary features.

Answer 1

Three powerful and popular libraries you can use for JSON validation are
AJV: https://github.com/epoberezkin/ajv
JOI: https://github.com/hapijs/joi
JSON validator: https://github.com/tdegrunt/jsonschema
All of these libraries allow you to validate different data types, do conditional validation, as well as set custom error messages.

Answer 2

One solution is to use Joi library :
https://github.com/hapijs/joi
This library is well maintained, used and offer lots of flexibility and possible actions.
Example :
const Joi = require('joi');
const schema = Joi.object().keys({
name: Joi.string().error(new Error('A name should be provided')),
address: Joi.ref('$SimpleAddress'),
votes: Joi.number().min(1),
});
// Return result.
const result = Joi.validate(yourObject, schema);

Answer 3

I use Json Pattern Validator
npm install jpv --save
usage
const jpv = require('jpv');
// your json object
var json = {
status: "OK",
id: 123,
type: {}
}
// validation pattern
var pattern = {
status: /OK/i,
id: '(number)',
type: '(object)'
};
var result = jpv.validate( json , pattern)

Answer 4

You can also try nonvalid, a library that supports callback-based validation with custom checks and errors (disclaimer: it is written by me).

Answer 5

I'm about to embark on validation of JSON submissions to my web service and will be using tcomb-validation. It's a lightweight alternative to JSON schema and is based on type combinators.
Example of 'intersections':
var t = require('tcomb-validation');
var Min = t.refinement(t.String, function (s) { return s.length > 2; }, 'Min');
var Max = t.refinement(t.String, function (s) { return s.length < 5; }, 'Max');
var MinMax = t.intersection([Min, Max], 'MinMax');
MinMax.is('abc'); // => true
MinMax.is('a'); // => false
MinMax.is('abcde'); // => false