burhan-req-validator/index.js

A lightweight and customizable field validation library using Joi, inspired by Laravel's validation rules. Simplifies data validation with intuitive rule-based syntax.

const Joi = require('joi');

/**
 * Validate fields based on rules
 * @param {Object} data - The data to validate
 * @param {Object} rules - The validation rules
 * @returns {Object} - Validation result with error if validation fails
 */
const validateFields = (data, rules) => {
    const joiSchema = {};

    // Loop through each rule and create a Joi validation schema
    Object.keys(rules).forEach((field) => {
        const rule = rules[field];
        const validations = rule.split('|');

        // Start with an uninitialized Joi schema
        let joiValidation;

        validations.forEach((validation) => {
            const [ruleType, ruleValue] = validation.split(':');

            switch (ruleType) {
                case 'required':
                    joiValidation = (Joi.string()).required();
                    break;
                case 'email':
                    joiValidation = (Joi.string()).email();
                    break;
                case 'max':
                    joiValidation = (Joi.string()).max(parseInt(ruleValue, 10));
                    break;
                case 'min':
                    joiValidation = (Joi.string()).min(parseInt(ruleValue, 10));
                    break;
                case 'string':
                    joiValidation = Joi.string();
                    break;
                case 'integer':
                    joiValidation = Joi.number().integer();
                    break;
                case 'number':
                    joiValidation = Joi.number();
                    break;
                case 'boolean':
                    joiValidation = Joi.boolean();
                    break;
                case 'date':
                    joiValidation = Joi.date();
                    break;
                case 'object':
                    joiValidation = Joi.object();
                    break;
                case 'array':
                    joiValidation = Joi.array();
                    break;
                case 'nullable':
                    joiValidation = (joiValidation || Joi.any()).allow(null);
                    break;
                case 'regex':
                    joiValidation = (joiValidation || Joi.string()).pattern(new RegExp(ruleValue));
                    break;
                case 'items': // Specify array item type, e.g., `array|items:string`
                    if (joiValidation && joiValidation.type === 'array') {
                        const itemType = ruleValue;
                        switch (itemType) {
                            case 'string':
                                joiValidation = joiValidation.items(Joi.string());
                                break;
                            case 'number':
                                joiValidation = joiValidation.items(Joi.number());
                                break;
                            case 'object':
                                joiValidation = joiValidation.items(Joi.object());
                                break;
                            default:
                                break;
                        }
                    }
                    break;
                default:
                    break;
            }
        });

        joiSchema[field] = joiValidation;
    });

    // Validate the data against the Joi schema
    const schema = Joi.object(joiSchema);
    return schema.validate(data, { abortEarly: false });
};

module.exports = { validateFields };