[12.x] Enhance eventStream to Support Custom Events and Start Messages

src/Illuminate/Http/StreamedEvent.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Illuminate\Http;
+
+class StreamedEvent
+{
+    /**
+     * The name of the event.
+     */
+    public string $event;
+
+    /**
+     * The data of the stream.
+     */
+    public mixed $data;
+
+    /**
+     * Create a new streamed event instance.
+     *
+     * @return void
+     */
+    public function __construct(string $event, mixed $data)
+    {
+        $this->event = $event;
+        $this->data = $data;
+    }
+}

src/Illuminate/Routing/ResponseFactory.php

@@ -7,6 +7,7 @@
 use Illuminate\Contracts\View\Factory as ViewFactory;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Response;
+use Illuminate\Http\StreamedEvent;
 use Illuminate\Routing\Exceptions\StreamedResponseException;
 use Illuminate\Support\Js;
 use Illuminate\Support\Str;
@@ -124,35 +125,51 @@ public function jsonp($callback, $data = [], $status = 200, array $headers = [],
      *
      * @param  \Closure  $callback
      * @param  array  $headers
-     * @param  string  $endStreamWith
+     * @param  \Illuminate\Http\StreamedEvent|string  $endStreamWith
      * @return \Symfony\Component\HttpFoundation\StreamedResponse
      */
-    public function eventStream(Closure $callback, array $headers = [], string $endStreamWith = '</stream>')
+    public function eventStream(Closure $callback, array $headers = [], StreamedEvent|string|null $endStreamWith = '</stream>')
     {
         return $this->stream(function () use ($callback, $endStreamWith) {
             foreach ($callback() as $message) {
                 if (connection_aborted()) {
                     break;
                 }
 
+                $event = 'update';
+
+                if ($message instanceof StreamedEvent) {
+                    $event = $message->event;
+                    $message = $message->data;
+                }
+
                 if (! is_string($message) && ! is_numeric($message)) {
                     $message = Js::encode($message);
                 }
 
-                echo "event: update\n";
+                echo "event: $event\n";
                 echo 'data: '.$message;
                 echo "\n\n";
 
                 ob_flush();
                 flush();
             }
 
-            echo "event: update\n";
-            echo 'data: '.$endStreamWith;
-            echo "\n\n";
+            if (filled($endStreamWith)) {
+                $endEvent = 'update';
+
+                if ($endStreamWith instanceof StreamedEvent) {
+                    $endEvent = $endStreamWith->event;
+                    $endStreamWith = $endStreamWith->data;
+                }
+
+                echo "event: $endEvent\n";
+                echo 'data: '.$endStreamWith;
+                echo "\n\n";
 
-            ob_flush();
-            flush();
+                ob_flush();
+                flush();
+            }
         }, 200, array_merge($headers, [
             'Content-Type' => 'text/event-stream',
             'Cache-Control' => 'no-cache',