Adding tests and always use brackets in IPV6 addresses

Code also ensures that brackets are properly added when encoding an IPV6 address.

network_test.go

@@ -0,0 +1,35 @@
+package xmpp
+
+import (
+	"testing"
+)
+
+type params struct {
+}
+
+func TestParseAddr(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{name: "ipv4-no-port-1", input: "localhost", want: "localhost:5222"},
+		{name: "ipv4-with-port-1", input: "localhost:5555", want: "localhost:5555"},
+		{name: "ipv4-no-port-2", input: "127.0.0.1", want: "127.0.0.1:5222"},
+		{name: "ipv4-with-port-2", input: "127.0.0.1:5555", want: "127.0.0.1:5555"},
+		{name: "ipv6-no-port-1", input: "1::", want: "[1::]:5222"},
+		{name: "ipv6-no-port-2", input: "[1::]", want: "[1::]:5222"},
+		{name: "ipv6-no-port-3", input: "1::2008", want: "[1::2008]:5222"},
+		{name: "ipv6-no-port-4", input: "1::2008:1", want: "[1::2008:1]:5222"},
+		{name: "ipv6-with-port-1", input: "[1::]:5555", want: "[1::]:5555"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(st *testing.T) {
+			addr := ensurePort(tc.input, 5222)
+
+			if addr != tc.want {
+				st.Errorf("incorrect Result: %v (!= %v)", addr, tc.want)
+			}
+		})
+	}
+}