From df0aea63c8da153512ce2a961cef306ddcfb92d1 Mon Sep 17 00:00:00 2001
From: pmcclory <patrick.mcclory@prizepicks.com>
Date: Mon, 27 Apr 2026 15:09:14 -0400
Subject: [PATCH] feat: surface handler results to middleware chain

---
 lib/leopard/message_processor.rb | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/leopard/message_processor.rb b/lib/leopard/message_processor.rb
index fad9bfa..ae9845f 100644
--- a/lib/leopard/message_processor.rb
+++ b/lib/leopard/message_processor.rb
@@ -56,9 +56,13 @@ def base_app(handler, callbacks)
         lambda do |wrapper|
           result = execute_handler.call(wrapper, handler)
           process_result(wrapper, result, callbacks)
+          # TODO document that middleware functions are expected to propagate result
+          # https://github.com/rubyists/leopard/issues/48
+          result
         rescue StandardError => e
           logger.error 'Error processing message: ', e
           callbacks[:on_error].call(wrapper, e)
+          Dry::Monads::Result::Failure.new(e)
         end
       end