From 8ce950721b57366c1b0bf170b780822f7afe91cc Mon Sep 17 00:00:00 2001
From: PlumBlossomMaid <108660099+PlumBlossomMaid@users.noreply.github.com>
Date: Sun, 12 Apr 2026 03:35:59 +0800
Subject: [PATCH] Refactor error handling to improve parameter checks

---
 lua/express/router/layer.lua | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/lua/express/router/layer.lua b/lua/express/router/layer.lua
index 3e8ac93..bfca222 100644
--- a/lua/express/router/layer.lua
+++ b/lua/express/router/layer.lua
@@ -41,26 +41,28 @@ LAYER_MT.__index = LAYER_MT
 
 -- Handle the error for the layer.
 function LAYER_MT:handle_error(err, req, res, next)
-	local fn = self.handle
-	if debug.getinfo(fn, "Su").nparams ~= 4 then
-		-- not a standard error handler
-		return next(err)
-	end
-
-	local ok, er = pcall(fn, err, req, res, next)
-	if not ok then next(er) end
+    local fn = self.handle
+    local info = debug.getinfo(fn, "Su")
+    if not info or not info.nparams or info.nparams ~= 4 then
+        -- not a standard error handler
+        return next(err)
+    end
+
+    local ok, er = pcall(fn, err, req, res, next)
+    if not ok then next(er) end
 end
 
 -- Handle the request for the layer.
 function LAYER_MT:handle_request(req, res, next)
-	local fn = self.handle
-	if debug.getinfo(fn, "Su").nparams > 3 then
-		-- not a standard error handler
-		return next()
-	end
-
-	local ok, err = pcall(fn, req, res, next)
-	if not ok then next(err) end -- если ошибка в app:get() хендлере, то не останавливаемся, а идем к следующему, передавая ошибку дальше
+    local fn = self.handle
+    local info = debug.getinfo(fn, "Su")
+    if info and info.nparams and info.nparams > 3 then
+        -- not a standard request handler
+        return next()
+    end
+
+    local ok, err = pcall(fn, req, res, next)
+    if not ok then next(err) end
 end
 
 -- Check if this route matches `path`, if so populate `.params`.