rest-api-starter/app/validator.js

Rest API starter kit.

/**
 * Created by svinci on 8/24/16.
 */
'use strict';

const Promise = require('bluebird');
const SchemaValidator = require('jsonschema').Validator;

const schemaValidator = new SchemaValidator();

/**
 * Validator builder.
 * @param schema JSON schema compliant object which will define the validated structure.
 * @param customValidations Custom validations to be made. (schema, object, id, errors, finishValidation) => void.
 * The fifth parameter (finishValidation) is a function that must be called once custom validations ended.
 */
const validator = (schema, customValidations) => ({
    'validate': (object, id) => new Promise((resolve, reject) => {
        const errors = [];

        schemaValidator.validate(object, schema).errors.forEach((err) => {
            if (err.name === 'additionalProperties') {
                const validationErrorMessage = `validation.error.${schema.description}.schema.unknown.property`;
                if (errors.indexOf(validationErrorMessage) < 0) {
                    errors.push(validationErrorMessage);
                }
            } else {
                errors.push(`validation.error.${schema.description}.schema.${err.property}`);
            }
        });

        if (id && !object.id) {
            errors.push(`validation.error.${schema.description}.schema.instance.id`);
        } else if (id && id !== object.id) {
            errors.push(`validation.error.${schema.description}.id.match`);
        }

        const finishValidation = () => {
            if (errors.length === 0) {
                resolve(object);
            } else {
                const errorResponse = {
                    'name': 'validation.error',
                    'errors': errors
                };
                reject(errorResponse);
            }
        };

        if (customValidations) {
            customValidations(schema, object, id, errors, finishValidation);
        } else {
            finishValidation();
        }
    })
});

module.exports = validator;