From b9bb8d1cecd5af1619b1ea8b4765331cf6cfee1d Mon Sep 17 00:00:00 2001
From: OHZEKI Naoki <0h23k1.n40k1@gmail.com>
Date: Sun, 19 Jan 2025 01:15:39 +0900
Subject: [PATCH] refactor(recovery): smart error comparison

---
 recovery.go | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/recovery.go b/recovery.go
index 515f9d2a..f8e9583a 100644
--- a/recovery.go
+++ b/recovery.go
@@ -10,12 +10,12 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"net"
 	"net/http"
 	"net/http/httputil"
 	"os"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 )
 
@@ -55,19 +55,13 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 	}
 	return func(c *Context) {
 		defer func() {
-			if err := recover(); err != nil {
+			if rec := recover(); rec != nil {
 				// Check for a broken connection, as it is not really a
 				// condition that warrants a panic stack trace.
-				var brokenPipe bool
-				if ne, ok := err.(*net.OpError); ok {
-					var se *os.SyscallError
-					if errors.As(ne, &se) {
-						seStr := strings.ToLower(se.Error())
-						if strings.Contains(seStr, "broken pipe") ||
-							strings.Contains(seStr, "connection reset by peer") {
-							brokenPipe = true
-						}
-					}
+				var isBrokenPipeOrConnReset bool
+				err, ok := rec.(error)
+				if ok {
+					isBrokenPipeOrConnReset = errors.Is(err, syscall.EPIPE) || errors.Is(err, syscall.ECONNRESET)
 				}
 				if logger != nil {
 					stack := stack(3)
@@ -80,22 +74,22 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 						}
 					}
 					headersToStr := strings.Join(headers, "\r\n")
-					if brokenPipe {
-						logger.Printf("%s\n%s%s", err, headersToStr, reset)
+					if isBrokenPipeOrConnReset {
+						logger.Printf("%s\n%s%s", rec, headersToStr, reset)
 					} else if IsDebugging() {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s\n%s%s",
-							timeFormat(time.Now()), headersToStr, err, stack, reset)
+							timeFormat(time.Now()), headersToStr, rec, stack, reset)
 					} else {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s%s",
-							timeFormat(time.Now()), err, stack, reset)
+							timeFormat(time.Now()), rec, stack, reset)
 					}
 				}
-				if brokenPipe {
+				if isBrokenPipeOrConnReset {
 					// If the connection is dead, we can't write a status to it.
-					c.Error(err.(error)) //nolint: errcheck
+					c.Error(err) //nolint: errcheck
 					c.Abort()
 				} else {
-					handle(c, err)
+					handle(c, rec)
 				}
 			}
 		}()