opt-cc/server/middleware/validators.js

'use strict';

// HTTP status codes by name
const codes = require('../routes/http-codes');

// library to check image dimensions from file buffer
const sizeOf = require('buffer-image-size');

/**
 * check if id has valid UUID format
 *
 * @param {object} req
 * @param {function} res
 * @param {function} next
 * @return {boolean}
 */
const idValidator = (req, res, next) => {
  const reqId = req.params.id;

  if (!reqId.match(/^[0-9a-fA-F]{24}$/)) {
    const err = new Error('Invalid request id format');
    err.status = codes.notfound;
    return next(err);
  }
  next();
};

const imageDimensionValidator = (imageFileBuf, maxWidth, maxHeight) => {
  const dimensions = sizeOf(imageFileBuf);
  if (dimensions.width > maxWidth || dimensions.height > maxHeight) {
    let err = new Error(`Image exceeds maximum dimensions of ${maxWidth}px width and ${maxHeight}px height`);
    err.status = codes.wrongrequest;
    return err;
  }
};

exports.idValidator = idValidator;
exports.imageDimensionValidator = imageDimensionValidator;