diff --git a/api/chatHistory.js b/api/controllers/chatController.js
similarity index 68%
rename from api/chatHistory.js
rename to api/controllers/chatController.js
index 9578176..fb3d8b6 100644
--- a/api/chatHistory.js
+++ b/api/controllers/chatController.js
@@ -8,19 +8,23 @@ const getAllHistory = (req, res) => {
 
   return history(page, limit)
     .then(messages => res.json(messages))
-    .catch(error =>  res.status(500).json({
-      message: error.message,
-      success: false
-    }));
+    .catch(error =>
+      res.status(500).json({
+        message: error.message,
+        success: false
+      })
+    );
 };
 
 const deleteHistory = (req, res) => {
   return clearHistory()
     .then(message => res.json(message))
-    .catch(error => res.status(500).json({
-      message: error.message,
-      success: false
-    }));
+    .catch(error =>
+      res.status(500).json({
+        message: error.message,
+        success: false
+      })
+    );
 };
 
 module.exports = {
diff --git a/api/controllers/userController.js b/api/controllers/userController.js
new file mode 100644
index 0000000..5e6ed96
--- /dev/null
+++ b/api/controllers/userController.js
@@ -0,0 +1,49 @@
+const path = require("path");
+const userRepository = require(path.join(__dirname, "../user"));
+
+function register(req, res, next) {
+  const { username, password } = req.body;
+
+  return userRepository
+    .register(username, password)
+    .then(user => userRepository.login(req, user))
+    .then(_ =>
+      res.send({
+        messsage: `Bruker registrert. Velkommen ${username}`,
+        success: true
+      })
+    )
+    .catch(error => {
+      const { statusCode, message } = error;
+
+      return res.status(statusCode || 500).send({
+        message: message || "Unable to sign in with given username and passowrd",
+        success: false
+      });
+    });
+}
+
+const login = (req, res, next) => {
+  return userRepository
+    .authenticate(req)
+    .then(user => userRepository.login(req, user))
+    .then(user => {
+      res.send({
+        message: `Velkommen ${user.username}`,
+        success: true
+      });
+    })
+    .catch(error => {
+      const { statusCode, message } = error;
+
+      return res.status(statusCode || 500).send({
+        message: message || "Unable to sign in with given username and passowrd",
+        success: false
+      });
+    });
+};
+
+module.exports = {
+  register,
+  login
+};
diff --git a/api/user.js b/api/user.js
index 7a2ce9e..654cb43 100644
--- a/api/user.js
+++ b/api/user.js
@@ -1,42 +1,86 @@
 const passport = require("passport");
 const path = require("path");
 const User = require(path.join(__dirname, "/schemas/User"));
-const router = require("express").Router();
 
-const register = (req, res, next) => {
-  User.register(
-    new User({ username: req.body.username }),
-    req.body.password,
-    function(err) {
-      if (err) {
-        if (err.name == "UserExistsError")
-          res.status(409).send({ success: false, message: err.message })
-        else if (err.name == "MissingUsernameError" || err.name == "MissingPasswordError")
-          res.status(400).send({ success: false, message: err.message })
-        return next(err);
-      }
+class UserExistsError extends Error {
+  constructor(message = "Username already exists.") {
+    super(message);
+    this.name = "UserExists";
+    this.statusCode = 409;
+  }
+}
 
-      return res.status(200).send({ message: "Bruker registrert. Velkommen " + req.body.username, success: true })
-     }
-  );
+class MissingUsernameError extends Error {
+  constructor(message = "No username given.") {
+    super(message);
+    this.name = "MissingUsernameError";
+    this.statusCode = 400;
+  }
+}
+
+class MissingPasswordError extends Error {
+  constructor(message = "No password given.") {
+    super(message);
+    this.name = "MissingPasswordError";
+    this.statusCode = 400;
+  }
+}
+
+class IncorrectUserCredentialsError extends Error {
+  constructor(message = "Incorrect username or password") {
+    super(message);
+    this.name = "IncorrectUserCredentialsError";
+    this.statusCode = 404;
+  }
+}
+
+function userAuthenticationErrorHandler(err) {
+  if (err.name == "UserExistsError") {
+    throw new UserExistsError(err.message);
+  } else if (err.name == "MissingUsernameError") {
+    throw new MissingUsernameError(err.message);
+  } else if (err.name == "MissingPasswordError") {
+    throw new MissingPasswordError(err.message);
+  }
+
+  throw err;
+}
+
+const register = (username, password) => {
+  return User.register(new User({ username: username }), password).catch(userAuthenticationErrorHandler);
 };
 
-const login = (req, res, next) => {
-  passport.authenticate("local", function(err, user, info) {
-    if (err) {
-      if (err.name == "MissingUsernameError" || err.name == "MissingPasswordError")
-        return res.status(400).send({ message: err.message, success: false })
-      return next(err);
-    }
+const authenticate = req => {
+  return new Promise((resolve, reject) => {
+    const { username, password } = req.body;
 
-    if (!user) return res.status(404).send({ message: "Incorrect username or password", success: false })
+    if (username == undefined) throw new MissingUsernameError();
+    if (password == undefined) throw new MissingPasswordError();
 
-    req.logIn(user, (err) => {
-      if (err) { return next(err) }
+    passport.authenticate("local", function(err, user, info) {
+      if (err) {
+        reject(err);
+      }
 
-      return res.status(200).send({ message: "Velkommen " + user.username, success: true })
-    })
-  })(req, res, next);
+      if (!user) {
+        reject(new IncorrectUserCredentialsError());
+      }
+
+      resolve(user);
+    })(req);
+  });
+};
+
+const login = (req, user) => {
+  return new Promise((resolve, reject) => {
+    req.logIn(user, err => {
+      if (err) {
+        reject(err);
+      }
+
+      resolve(user);
+    });
+  });
 };
 
 const logout = (req, res) => {
@@ -46,6 +90,7 @@ const logout = (req, res) => {
 
 module.exports = {
   register,
+  authenticate,
   login,
   logout
 };