cleanup: typo and code

router_serve.go

@@ -2,6 +2,7 @@ package mux
 
 import (
 	"context"
+	"errors"
 	"log/slog"
 	"net/http"
 	"os"
@@ -10,7 +11,7 @@ import (
 
 type ServeCB func(srv *http.Server) error
 
-// Serve with gracefull shutdown
+// Serve with graceful shutdown
 func (r *Router) Serve(cb ServeCB) {
 	srv := &http.Server{
 		Handler: r,
@@ -32,7 +33,7 @@ func (r *Router) Serve(cb ServeCB) {
 		close(idleConnsClosed)
 	}()
 
-	if err := cb(srv); err != http.ErrServerClosed {
+	if err := cb(srv); !errors.Is(err, http.ErrServerClosed) {
 		// Error starting or closing listener:
 		slog.Error("start server error", "error", err)
 	}