Thin JOI Classes

base.js

/**
 * @module base.js - COINSTAC Model
 */
'use strict';

const assign = require('lodash/assign');
const joi = require('joi');
const pick = require('lodash/pick');

/**
 * @class Base
 *
 * @example <caption>Extending Base</caption>
 * // my-class.js
 * const Base = require('./path/to/base.js');
 * const util = require('util');
 * const joi = require('joi');
 *
 * function MyClass(attributes) {
 *   // Call `Base` with `MyClass`’s arguments:
 *   Base.apply(this, arguments);
 * }
 *
 * // Use Node's built-in inheritance:
 * util.inherits(Base, MyClass);
 *
 * // Define `MyClass`’s `schema` on its prototype:
 * MyClass.prototype.schema = {
 *   data: joi.object().required(),
 *   myString: joi.string().default('my-string'),
 *   myInteger: joi.string().integer().positive(),
 * };
 *
 * module.exports = MyClass;
 *
 * @param {object} attributes
 */
function Base(attributes) {
    assign(this, this.validate(attributes));
};

/**
 * Get schema.
 *
 * @returns {object}
 */
Base.prototype.getSchema = function() {
    return assign({}, this.schema, Base.prototype.schema);
}

/**
 * Base class's schema.
 *
 * @type {object}
 */
Base.prototype.schema = {
    _id: joi.string(),
};

/**
 * Serialize model.
 *
 * @returns {object}
 */
Base.prototype.serialize = function() {
    return pick(this, Object.keys(this.getSchema));
};

/**
 * To JSON.
 *
 * @returns {string}
 */
Base.prototype.toJSON = function() {
    return JSON.stringify(this.serialize());
};

/**
 * Validate based on sub-class's schema.
 * {@link  https://github.com/hapijs/joi/blob/v7.2.3/API.md#validatevalue-schema-options-callback}
 *
 * @param {object} attributes
 * @returns {object} Validated attributes
 */
Base.prototype.validate = function(attributes) {
    if (typeof attributes === 'undefined') {
        attributes = {};
    }

    const result = joi.validate(
        attributes,
        this.getSchema(),
        { convert: false }
    );

    if (result.error) {
        throw new Error(result.error);
    }

    return result.value;
};

module.exports = Base;