"Refactor error handling in NotifyAdminOfError listener

This commit eliminates an unnecessary newline, adds an initial value of 0 to the `$coolDownPeriod` variable to avoid uninitialized variable errors, and refines the process of error hashing and mailing in context of exception existence. Now, the code attempts to create an `errorHash` only if there is an exception in the event context, reducing the likelihood of errors when context does not include an exception."

Author: hugomyb

src/Listeners/NotifyAdminOfError.php

@@ -3,7 +3,6 @@
 namespace Hugomyb\ErrorMailer\Listeners;
 
 
-
 use Hugomyb\ErrorMailer\Notifications\ErrorOccurred;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Config;
@@ -29,19 +28,21 @@ public function __construct()
      */
     public function handle($event)
     {
+        $coolDownPeriod = 0;
+
         if (!in_array(env('APP_ENV'), config('error-mailer.disabledOn'))) {
 
             $recipient = config()->has('error-mailer.email.recipient')
                 ? config('error-mailer.email.recipient')
                 : '[email protected]';
 
-            $errorHash = md5($event->context['exception']->getMessage() . $event->context['exception']->getFile());
+            if (isset($event->context['exception'])) {
+                $errorHash = md5($event->context['exception']->getMessage() . $event->context['exception']->getFile());
 
-            $cacheKey = 'error_mailer_' . $errorHash;
-            $coolDownPeriod = 15;
+                $cacheKey = 'error_mailer_' . $errorHash;
+                $coolDownPeriod = 15;
 
-            if (!Cache::has($cacheKey)) {
-                if (isset($event->context['exception'])) {
+                if (!Cache::has($cacheKey)) {
                     Mail::to($recipient)->send(new ErrorOccurred($event->context['exception']));
                     Cache::put($cacheKey, true, now()->addMinutes($coolDownPeriod));
                 }