create-nodeapi-backend/template/javascript/src/middleware/validate.js

A powerful Node.js backend boilerplate with Express, MongoDB, Firebase, JWT auth, Nodemailer, cron jobs, input validation (Joi), and serverless support for Vercel. Scaffold a full-featured API backend in seconds.

const Joi = require("joi");
const pick = require("../utils/pick");

const validate = (schema) => (req, res, next) => {
  const validSchema = pick(schema, ["params", "query", "body"]);
  const object = pick(req, Object.keys(validSchema));
  const { value, error } = Joi.compile(validSchema)
    .prefs({ errors: { label: "key" }, abortEarly: false })
    .validate(object);

  if (error) {
    const errorMessage = error.details
      .map((details) => details.message)
      .join(", ");
    return res.status(400).send({ errorMessage });
  }

  Object.assign(req, value);
  return next();
};

module.exports = validate;