Validate alter image.

validator-middleware-extra.js

//...

export const validateRequest = (req, res, next)=>{
  async.applyEachSeries([
    validateHeaders,
    validateUrlParams,
    validateResizeRequest,
    validateAlterImageRequest
  ], req, res, next);
};

//...

export const validateAlterImageRequest = (req, res, next)=>{
  const {q:quality, b:blur} = req.query;

  const qualityParsed:number = parseInt(quality);
  let qualityValue = 100;
  if (_.isFinite(qualityParsed) && _.inRange(qualityParsed, 1, 101)) {
    qualityValue = qualityParsed
  }
  let blurValue = null;
  if (blur === "true") {
    blurValue = true
  }else {
    const blurParsed = parseInt(blur);
    if (_.isFinite(blurParsed)) {
      blurValue = blurParsed;
    }
  }

  res.props = {
    ...res.props,
    quality: qualityValue,
    blur: blurValue
  };
  next();
};