feat: ✨ add authentication exception

Added InvalidCredentialsException for failed authentication attempts

Author: andrewdyer

README.md

@@ -130,14 +130,13 @@ $jwtAuth = new JWTAuth($authProvider, $jwtProvider, $claims);
 
 ### Attempt Authentication
 
-Authenticate a user by providing their credentials. If successful, a JWT token will be returned.
+Authenticate a user by providing their credentials. If successful, a JWT token will be returned. If the credentials are invalid, an `InvalidCredentialsException` will be thrown.
 
 ```php
-$token = $jwtAuth->attempt('admin', 'secret');
-
-if ($token) {
+try {
+    $token = $jwtAuth->attempt('admin', 'secret');
     echo "Token: " . $token;
-} else {
+} catch (\Anddye\JWTAuth\Exceptions\InvalidCredentialsException $e) {
     echo "Invalid credentials";
 }
 ```

src/Exceptions/InvalidCredentialsException.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Anddye\JWTAuth\Exceptions;
+
+use Exception;
+
+class InvalidCredentialsException extends Exception
+{
+    protected $message = 'Invalid credentials provided.';
+}

src/JwtAuth.php

@@ -25,7 +25,7 @@ public function __construct(AuthProviderInterface $authProvider, JWTProviderInte
     public function attempt(string $username, string $password): ?string
     {
         if (!$user = $this->authProvider->byCredentials($username, $password)) {
-            return null;
+            throw new Exceptions\InvalidCredentialsException();
         }
 
         return $this->fromSubject($user);

tests/JWTAuthTest.php

@@ -2,6 +2,7 @@
 
 namespace Anddye\JWTAuth\Tests;
 
+use Anddye\JWTAuth\Exceptions\InvalidCredentialsException;
 use Anddye\JWTAuth\Factory\ClaimsFactory;
 use Anddye\JWTAuth\JWTAuth;
 use Anddye\JWTAuth\Tests\Stubs\Providers\AuthProvider;
@@ -42,11 +43,11 @@ public function testCanGetTokenWithValidLoginCredentials()
 
     public function testCantGetTokenWithIncorrectLoginCredentials()
     {
+        $this->expectException(InvalidCredentialsException::class);
+
         $username = 'andrewdyer';
         $password = 'pa55w0rd';
 
-        $token = $this->jwtAuth->attempt($username, $password);
-
-        $this->assertNull($token);
+        $this->jwtAuth->attempt($username, $password);
     }
 }