jsonschema-formatter

NPM Package For Formatting jsonschema Validation Error

Get jsonschema npm package validation error in more readable and usable format.

You don't need to install jsonschema package seperately, just install this jsonschema-formatter package and start using.

This package internally call jsonschema function and then formats its validation response in more readable format.

This package returns a Promise. For promise we are using q package.

Installation

Install with the node package manager npm:

$ npm install jsonschema-formatter

How To Use?

Import/require package in your application

const validateSchema = require('jsonschema-formatter').validateSchema;

Example Schema And Input Data

// Input Body Validation Schema
let schema = {
  'id': '/SimplePerson',
  'type': 'object',
  'properties': {
    'name': {'type': 'string'},
    'address': {
      'type': 'object',
      'properties': {
        'lines': {
          'type': 'array',
          'items': {'type': 'string'}
        },
        'zip': {'type': 'string'},
        'city': {'type': 'string'},
        'country': {'type': 'string'}
      },
      'required': ['country']
    },
    'votes': {'type': 'integer', 'minimum': 1}
  },
  'required': ['name']
}
 
// Input Body
let p = {
  'names': 'Barack Obama',
  'address': {
    'lines': [ '1600 Pennsylvania Avenue Northwest' ],
    'zip': 'DC 20500',
    'city': 'Washington',
    'country': 1
  },
  'votes': 0
}
 
// Custom Defined Error Codes
let resCode = {
  REQUIRED_NAME: 'CUST_ERR0001',
  TYPE_COUNTRY: 'CUST_ERR0002'
}
 

Call validateSchema Function

/*
  here p and schema refers to above step, resCode is optional if you define your custom error codes
  then pass it else pre-defined error codes will be assigned
*/
 
validateSchema(p, schema, resCode)
.then((validationResult) => {
  console.log('RESULT: ', validationResult)
})
.catch((err) => {
  console.log('VALIDATION ERR: ', err)
})
.done()

Output Of Above Vaidation

VALIDATION ERR: {
  status: 'fail',
  errors: [ { code: 'CUST_ERR0002', // CODE FROM resCode YOUR DEFINED
    error: 'country is not of a type(s) string',
    parameter: 'country',
    line: null },
  { code: 'ERR0006',
    error: 'votes must have a minimum value of 1',
    parameter: 'votes',
    line: null },
  { code: 'ERR0001',
    error: 'property name is missing',
    parameter: 'name',
    line: null } ]
}

Output Parameter Definition

• code: User Defined Or Pre-defined Error Code To Uniquely Identify Specific Error
• error: Text Explaining What Error Occured
• parameter: Request Body Parameter(Key) For Which Error Occured
• line: In Case Of Array Which Index Element Has Error

How To Define Custom Error Codes

Error Codes	Error Type	Example (from body used above)
REQUIRED_<your-parameter-name-in-uppercase>	Required field error	For missing name property { REQUIRED_NAME: 'CUST_ERR001' }
TYPE_<your-parameter-name-in-uppercase>	Field type error	For country peoperty type error { TYPE_COUNTRY: 'CUST_ERR002' }
FORMAT_<your-parameter-name-in-uppercase>	Field format error	Email format error
MINITEMS_<your-parameter-name-in-uppercase>	Array minimum item check	Empty array check
UNIQUEITEMS_<your-parameter-name-in-uppercase>	Array element duplication	Duplicate item check
MINIMUM_<your-parameter-name-in-uppercase>	Field minimum value check	For votes peoperty min value error { MINIMUM_VOTES: 'CUST_ERR003' }
ANYOF_<your-parameter-name-in-uppercase>	Either-or field check	Any one of fields should be present

Changelog

• 1.0.3 q lib removed and implemented new Promise()
• 1.0.2 Fuction output changes
• 1.0.0 Initial version