move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/telegram/dcs/dns_test.go

@@ -0,0 +1,92 @@
+package dcs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func testTXTResponse() []string {
+	return []string{
+		"LcmEoukF2bVjKwz3E+J9BsDdL+rv9lGqLQWIGXrWACT2ESk5xuOpA6Cz6klKRbhbwSiHOd2zC5PiR57j/OJHPpj4i+tw==",
+		"umjjLFLpOKtPeW9zHLq2ypbMzg/zkqvPhvhr0bxrLZlgPQ04l2GpO/4qZgAx3tk3BDHbY6/gmG1e8eaFBq3YSqR5SZ5hQ1Cm5f4/" +
+			"o67GYcPJClaf1TiHq3wVfsQ5OLnyJRw9A2ZfUfzIXxoSklPJrVdF/4hM1ZdUE0eWDAbmYf7JCeao8ecVVwKndd4CZHZS9wyf1T7DIUh95VpQ" +
+			"sn2klLPA6gA/2YNXOh9gITvjZrKuXLwwh9hBHhPvxv",
+	}
+}
+
+func Test_ParseDNSConfig(t *testing.T) {
+	t.Run("Good", func(t *testing.T) {
+		a := require.New(t)
+
+		cfg, err := ParseDNSConfig(testTXTResponse())
+		a.NoError(err)
+		a.Equal(1565541126, cfg.Expires)
+		a.Equal(1562949126, cfg.Date)
+		a.Len(cfg.Rules, 1)
+
+		rule := cfg.Rules[0]
+		a.Equal(2, rule.DCID)
+	})
+
+	t.Run("Bad", func(t *testing.T) {
+		tests := []struct {
+			name  string
+			input []string
+		}{
+			{"Empty", nil},
+			{"InvalidHash", func() []string {
+				r := testTXTResponse()
+				first := r[0]
+				r[0] = string(first[0]+1) + first[1:]
+				return r
+			}()},
+			{"InvalidBase64", func() []string {
+				r := testTXTResponse()
+				first := r[0]
+				r[0] = string('#') + first[1:]
+				return r
+			}()},
+		}
+
+		for _, tt := range tests {
+			t.Run(tt.name, func(t *testing.T) {
+				_, err := ParseDNSConfig(tt.input)
+				require.Error(t, err)
+			})
+		}
+	})
+}
+
+func BenchmarkDNSConfig(b *testing.B) {
+	message := testTXTResponse()
+
+	b.ResetTimer()
+	b.ReportAllocs()
+
+	var (
+		err     error
+		cfgSink DNSConfig
+	)
+	for i := 0; i < b.N; i++ {
+		cfgSink, err = ParseDNSConfig(message)
+		if cfgSink.Date == 0 || err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func TestDNSConfig_Options(t *testing.T) {
+	a := require.New(t)
+
+	cfg, err := ParseDNSConfig(testTXTResponse())
+	a.NoError(err)
+
+	options := cfg.Options()
+	a.Len(options, 1)
+	option := options[0]
+	a.Equal(2, option.ID)
+	a.Equal(14544, option.Port)
+	a.Equal("98.210.59.139", option.IPAddress)
+	a.True(option.TCPObfuscatedOnly)
+}