Basic url redirector on Azure functions

index.js

module.exports = async function(context, req) {
  context.log("JavaScript HTTP trigger function processed a request.");
  if (req.query.url) {
    context.res
      .status(302)
      .set("location", req.query.url)
      .send();
  } else {
    context.res
    .status(400)
    .body("Please pass a url on the query string")
    .send();
  }
};