add simple email validation

app/controllers/querySubmit.js

@@ -1,20 +1,29 @@
 const { currentRERequest } = require('../helpers/url');
+const { isValidEmail } = require('../helpers/email');
 
 const getQuerySubmit = async (req,res) => {
   const nextStep = req.query.nextStep;
+  const error = req.query.error;
 
   res.render('querySubmit', {
-    nextStep
+    nextStep,
+    error
   });
 };
 
 const postQuerySubmit = async (req, res) => {
   const request = await currentRERequest(req);
   const nextStep = req.query.nextStep || '/ponovo';
-  //TODO: validate email
-  request.email = req.body.email;
-  await request.save();
-  res.redirect(nextStep);
+
+  const emailInput = req.body.email;
+
+  if (isValidEmail(emailInput)){
+    request.email = req.body.email;
+    await request.save();
+    res.redirect(nextStep);
+  } else {
+    res.redirect('?error=1');
+  }
 };
 
 module.exports = {