feat: add rate limit for authentication

* improve error handling in frontend

app/src/utils/auth.js

@@ -1,5 +1,11 @@
 import api from './api'
 
+import {
+  TooManyRequestsError,
+  UnauthorizedError,
+  ValidationError,
+} from './errors'
+
 export async function isLoggedIn() {
   const res = await api.get('/auth/check-session')
   const { loggedIn } = res.data
@@ -12,18 +18,52 @@ export const login = async (username, password) => {
     return true
   } catch (err) {
     if (err.response?.status === 401) {
-      return false
+      throw new UnauthorizedError(err.response.data.message)
+    }
+    if (err.response?.status === 429) {
+      throw new TooManyRequestsError(err.response.data.message)
+    }
+    if (err.response?.status === 400) {
+      throw new ValidationError(err.response.data.message)
     }
     throw err
   }
 }
 
-export const register = (username, email, password) => {
-  return api.post('/auth/register', {
-    username,
-    password,
-    email,
-  })
+export const register = async (username, email, password) => {
+  try {
+    await api.post('/auth/register', {
+      username,
+      password,
+      email,
+    })
+    return true
+  } catch (err) {
+    const status = err.response?.status
+    if (status === 429) {
+      throw new TooManyRequestsError(err.response.data.message)
+    }
+    if (status === 401) {
+      throw new UnauthorizedError(err.response.data.message)
+    }
+    if (status === 400) {
+      const { errors } = err.response.data
+      if (errors?.length > 0) {
+        const { path, msg } = errors[0]
+        switch (path) {
+          case 'username':
+            throw new ValidationError('Username is already taken')
+          case 'email':
+            throw new ValidationError('Email is already taken')
+          case 'password':
+            throw new ValidationError('Password is too weak')
+          default:
+            throw new ValidationError(msg)
+        }
+      }
+    }
+    throw err
+  }
 }
 
 export const logout = () => {

app/src/utils/errors.js

@@ -0,0 +1,27 @@
+/* eslint-disable max-classes-per-file */
+export class TooManyRequestsError extends Error {
+  constructor(message) {
+    super(message)
+    this.name = 'TooManyRequestsError'
+  }
+}
+
+export class ValidationError extends Error {
+  constructor(message) {
+    super(message)
+    this.name = 'ValidationError'
+  }
+}
+
+export class UnauthorizedError extends Error {
+  constructor(message) {
+    super(message)
+    this.name = 'UnauthorizedError'
+  }
+}
+
+export default {
+  TooManyRequestsError,
+  ValidationError,
+  UnauthorizedError,
+}