From a5b6d2982b84fb6bc0e833a148e9f2ddc4976e3d Mon Sep 17 00:00:00 2001
From: Tim <git@loken.nl>
Date: Thu, 28 Aug 2025 23:01:16 +0200
Subject: [PATCH] Add checking when adding a stage class string

---
 src/Pipeline/OptionsProcessor/OptionsStageBuilder.php | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/Pipeline/OptionsProcessor/OptionsStageBuilder.php b/src/Pipeline/OptionsProcessor/OptionsStageBuilder.php
index 9b5ea07..bfb0ccf 100644
--- a/src/Pipeline/OptionsProcessor/OptionsStageBuilder.php
+++ b/src/Pipeline/OptionsProcessor/OptionsStageBuilder.php
@@ -22,7 +22,13 @@ class OptionsStageBuilder
     public function add(string|OptionsStageInterface $stageClass): self
     {
         if (is_string($stageClass)) {
-            $this->stages[] = $this->bag->get($stageClass);
+            if (new \ReflectionClass($stageClass)->implementsInterface(OptionsStageInterface::class)) {
+                $this->stages[] = $this->bag->get($stageClass);
+            } else {
+                throw new \InvalidArgumentException(
+                    sprintf('Stage must be an instance of OptionsStageInterface, %s given', get_debug_type($stage))
+                );
+            }
         } else {
             $this->stages[] = $stageClass;
         }
@@ -41,4 +47,4 @@ class OptionsStageBuilder
     {
         return new ItemsOptionsPipeline(new OptionsProcessor($this->options), ...$this->stages);
     }
-}
\ No newline at end of file
+}