User schema

app/schemas/user.js

@@ -0,0 +1,25 @@
+const Joi = require('joi');
+
+module.exports = (req, res, next) => {
+  const schema = Joi.object().keys({
+    firstname: Joi.string().min(2).required(),
+    lastname: Joi.string().min(2).required(),
+    username: Joi.string().alphanum().min(3).max(30)
+      .required(),
+    password: Joi.string().required(),
+  });
+
+  Joi.validate({
+    firstname: req.body.firstname,
+    lastname: req.body.lastname,
+    username: req.body.username,
+    password: req.body.password,
+  },
+  schema, (validateErr) => {
+    if (validateErr) {
+      return next({ status: 400, message: 'Form is invalid.', error: validateErr });
+    }
+
+    return next();
+  });
+};