Valdiating JSON schema using JSON Schema validator (AJV)

ajv-example.js

// Install package before running this file : npm install ajv

// Node.js require:
var Ajv = require('ajv');

var schema = {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "$id": "http://example.com/example1.json",
    "title": "Core schema meta-schema",
    "definitions": {
        "schemaArray": {
            "type": "array",
            "minItems": 1,
            "items": { "$ref": "#" }
        },
        "nonNegativeInteger": {
            "type": "integer",
            "minimum": 0
        },
        "nonNegativeIntegerDefault0": {
            "allOf": [
                { "$ref": "#/definitions/nonNegativeInteger" },
                { "default": 0 }
            ]
        },
        "simpleTypes": {
            "enum": [
                "array",
                "boolean",
                "integer",
                "null",
                "number",
                "object",
                "string"
            ]
        },
        "stringArray": {
            "type": "array",
            "items": { "type": "string" },
            "uniqueItems": true,
            "default": []
        }
    },
    "type": ["object", "boolean"],
    "properties": {
        "$id": {
            "type": "string",
            "format": "uri-reference"
        },
        "$schema": {
            "type": "string",
            "format": "uri"
        },
        "$ref": {
            "type": "string",
            "format": "uri-reference"
        },
        "$comment": {
            "type": "string"
        },
        "title": {
            "type": "string"
        },
        "description": {
            "type": "string"
        },
        "default": true,
        "readOnly": {
            "type": "boolean",
            "default": false
        },
        "writeOnly": {
            "type": "boolean",
            "default": false
        },
        "examples": {
            "type": "array",
            "items": true
        },
        "multipleOf": {
            "type": "number",
            "exclusiveMinimum": 0
        },
        "maximum": {
            "type": "number"
        },
        "exclusiveMaximum": {
            "type": "number"
        },
        "minimum": {
            "type": "number"
        },
        "exclusiveMinimum": {
            "type": "number"
        },
        "maxLength": { "$ref": "#/definitions/nonNegativeInteger" },
        "minLength": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
        "pattern": {
            "type": "string",
            "format": "regex"
        },
        "additionalItems": { "$ref": "#" },
        "items": {
            "anyOf": [
                { "$ref": "#" },
                { "$ref": "#/definitions/schemaArray" }
            ],
            "default": true
        },
        "maxItems": { "$ref": "#/definitions/nonNegativeInteger" },
        "minItems": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
        "uniqueItems": {
            "type": "boolean",
            "default": false
        },
        "contains": { "$ref": "#" },
        "maxProperties": { "$ref": "#/definitions/nonNegativeInteger" },
        "minProperties": { "$ref": "#/definitions/nonNegativeIntegerDefault0" },
        "required": { "$ref": "#/definitions/stringArray" },
        "additionalProperties": { "$ref": "#" },
        "definitions": {
            "type": "object",
            "additionalProperties": { "$ref": "#" },
            "default": {}
        },
        "properties": {
            "type": "object",
            "additionalProperties": { "$ref": "#" },
            "default": {}
        },
        "patternProperties": {
            "type": "object",
            "additionalProperties": { "$ref": "#" },
            "propertyNames": { "format": "regex" },
            "default": {}
        },
        "dependencies": {
            "type": "object",
            "additionalProperties": {
                "anyOf": [
                    { "$ref": "#" },
                    { "$ref": "#/definitions/stringArray" }
                ]
            }
        },
        "propertyNames": { "$ref": "#" },
        "const": true,
        "enum": {
            "type": "array",
            "items": true,
            "minItems": 1,
            "uniqueItems": true
        },
        "type": {
            "anyOf": [
                { "$ref": "#/definitions/simpleTypes" },
                {
                    "type": "array",
                    "items": { "$ref": "#/definitions/simpleTypes" },
                    "minItems": 1,
                    "uniqueItems": true
                }
            ]
        },
        "format": { "type": "string" },
        "contentMediaType": { "type": "string" },
        "contentEncoding": { "type": "string" },
        "if": { "$ref": "#" },
        "then": { "$ref": "#" },
        "else": { "$ref": "#" },
        "allOf": { "$ref": "#/definitions/schemaArray" },
        "anyOf": { "$ref": "#/definitions/schemaArray" },
        "oneOf": { "$ref": "#/definitions/schemaArray" },
        "not": { "$ref": "#" }
    },
    "default": true
};

var data = {
    "$schema": "http://json-schema.org/draft-07/schema",
    "$id": "http://example.com/example.json",
    "type": "object",
    "title": "The root schema",
    "description": "The root schema comprises the entire JSON document.",
    "default": {},
    "examples": [
        {
            "checked": false
        }
    ],
    "required": [
        "checked"
    ],
    "properties": {
        "checked": {
            "$id": "#/properties/checked",
            "type": "boolean",
            "title": "The checked schema",
            "description": "An explanation about the purpose of this instance.",
            "default": false,
            "examples": [
                false
            ],
            "integration_hub": {
                "secret": false
            }
        }
    },
    "additionalProperties": true
};



var ajv = new Ajv();

// Using ajv's validate schema to validate JSON Schema
if(!ajv.validateSchema(data)){
    console.log("not ok");
}
else{
    console.log("ok");
}

// Using JSON schema's meta schema to validate JSON schema
var validate = ajv.compile(schema);
var valid = validate(data);
if (!valid) console.log(validate.errors);