Add support for custom DNS resolvers

network/v2/dns_test.go

@@ -0,0 +1,68 @@
+package network_test
+
+import (
+	"context"
+	"net"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/9seconds/mtg/v2/network/v2"
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+)
+
+type DNSTestSuite struct {
+	suite.Suite
+}
+
+func (suite *DNSTestSuite) TestDefault() {
+	resolver, err := network.GetDNS(nil)
+	suite.NoError(err)
+	suite.doTest(resolver)
+}
+
+func (suite *DNSTestSuite) TestDoH() {
+	for _, addr := range []string{"1.1.1.1", "cloudflare-dns.com"} {
+		suite.Run(addr, func() {
+			u, err := url.Parse("https://" + addr)
+			require.NoError(suite.T(), err)
+
+			resolver, err := network.GetDNS(u)
+			suite.NoError(err)
+			suite.doTest(resolver)
+		})
+	}
+}
+
+func (suite *DNSTestSuite) TestDoT() {
+	u, err := url.Parse("tls://dns.google")
+	require.NoError(suite.T(), err)
+
+	resolver, err := network.GetDNS(u)
+	suite.NoError(err)
+	suite.doTest(resolver)
+}
+
+func (suite *DNSTestSuite) TestUDP() {
+	u, err := url.Parse("8.8.8.8")
+	require.NoError(suite.T(), err)
+
+	resolver, err := network.GetDNS(u)
+	suite.NoError(err)
+	suite.doTest(resolver)
+}
+
+func (suite *DNSTestSuite) doTest(resolver *net.Resolver) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	ips, err := resolver.LookupIP(ctx, "ip4", "dns.google")
+	suite.NoError(err)
+	suite.Greater(len(ips), 0)
+}
+
+func TestGetDNS(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &DNSTestSuite{})
+}