From 032259baf192d2aed42c2be554e51bd87621f0d9 Mon Sep 17 00:00:00 2001
From: Jozef Kralik <jojo.lwin@gmail.com>
Date: Wed, 18 Oct 2023 06:40:15 +0000
Subject: [PATCH] Add a //go:build directive to support Go 1.18

---
 udp/isRunninigInterface_1.18_test.go | 9 +++++++++
 udp/isRunninigInterface_1.20_test.go | 9 +++++++++
 udp/server_test.go                   | 2 +-
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 udp/isRunninigInterface_1.18_test.go
 create mode 100644 udp/isRunninigInterface_1.20_test.go

diff --git a/udp/isRunninigInterface_1.18_test.go b/udp/isRunninigInterface_1.18_test.go
new file mode 100644
index 00000000..28d462fb
--- /dev/null
+++ b/udp/isRunninigInterface_1.18_test.go
@@ -0,0 +1,9 @@
+//go:build go1.18 || go1.19
+
+package udp_test
+
+import "net"
+
+func isRunningInterface(net.Interface) bool {
+	return true
+}
diff --git a/udp/isRunninigInterface_1.20_test.go b/udp/isRunninigInterface_1.20_test.go
new file mode 100644
index 00000000..ca5d6604
--- /dev/null
+++ b/udp/isRunninigInterface_1.20_test.go
@@ -0,0 +1,9 @@
+//go:build !go1.18 && !go1.19
+
+package udp_test
+
+import "net"
+
+func isRunningInterface(i net.Interface) bool {
+	return i.Flags&net.FlagRunning == net.FlagRunning
+}
diff --git a/udp/server_test.go b/udp/server_test.go
index 37f9f613..0ec3e22a 100644
--- a/udp/server_test.go
+++ b/udp/server_test.go
@@ -91,7 +91,7 @@ func TestServerDiscover(t *testing.T) {
 	log.Printf("ifs:%v", ifs)
 	var iface net.Interface
 	for _, i := range ifs {
-		if i.Flags&net.FlagMulticast == net.FlagMulticast && i.Flags&net.FlagUp == net.FlagUp && i.Flags&net.FlagRunning == net.FlagRunning {
+		if i.Flags&net.FlagMulticast == net.FlagMulticast && i.Flags&net.FlagUp == net.FlagUp && isRunningInterface(i) {
 			iface = i
 			log.Printf("first available multicast if:%v", iface)
 			break