Adds getResponseUrl helper to payload

Also fixes a bug in ShellExecDeferrer that prevented logs from working in deferred processes.

Author: jeremeamia

src/Context.php

@@ -342,8 +342,9 @@ public function error(string $error): void
      */
     public function respond($message, ?string $url = null): void
     {
-        if (!$url) {
-            $url = (string) $this->payload->getOneOf(['response_url', 'response_urls.0.response_url'], true);
+        $url ??= $this->payload->getResponseUrl();
+        if ($url === null) {
+            throw new Exception('Cannot respond: Response URL must be available in the payload or explicitly provided');
         }
 
         if (!isset($this->respondClient)) {

src/Contexts/Payload.php

@@ -179,6 +179,30 @@ public function getMetadata(): PrivateMetadata
         return PrivateMetadata::decode($this->get('view.private_metadata', true));
     }
 
+    /**
+     * Get the response URL from the payload, if present.
+     *
+     * Is present for anything that has a conversation context.
+     *
+     * @return string|null
+     */
+    public function getResponseUrl(): ?string
+    {
+        $responseUrl = $this->getOneOf(['response_url', 'response_urls.0.response_url']);
+        if ($responseUrl === null) {
+            $metadata = $this->get('view.private_metadata');
+            if ($metadata !== null) {
+                $responseUrl = PrivateMetadata::decode($metadata)->get('response_url');
+            }
+        }
+
+        if ($responseUrl !== null) {
+            $responseUrl = (string) $responseUrl;
+        }
+
+        return $responseUrl;
+    }
+
     /**
      * Gets indentifying information about the payload for the purposes of logging/debugging.
      *

src/Deferral/ShellExecDeferrer.php

@@ -41,7 +41,7 @@ public function defer(Context $context): void
     {
         $context->logger()->debug('Deferring processing by running a command with shell_exec in the background');
         $data = escapeshellarg($this->serializeContext($context));
-        $command = "cd {$this->dir};nohup {$this->script} {$data} > /dev/null 2>&1 &";
+        $command = "cd {$this->dir};nohup {$this->script} {$data} > /dev/null &";
         shell_exec($command);
     }