use the new packet number format

internal/wire/extended_header_test.go

@@ -21,12 +21,6 @@ var _ = Describe("Header", func() {
 			buf = &bytes.Buffer{}
 		})
 
-		appendPacketNumber := func(data []byte, pn protocol.PacketNumber, pnLen protocol.PacketNumberLen) []byte {
-			buf := &bytes.Buffer{}
-			utils.WriteVarIntPacketNumber(buf, pn, pnLen)
-			return append(data, buf.Bytes()...)
-		}
-
 		Context("Long Header", func() {
 			srcConnID := protocol.ConnectionID{1, 2, 3, 4, 5, 6, 7, 8}
 
@@ -41,17 +35,17 @@ var _ = Describe("Header", func() {
 						Length:           0xcafe,
 					},
 					PacketNumber:    0xdecaf,
-					PacketNumberLen: protocol.PacketNumberLen4,
+					PacketNumberLen: protocol.PacketNumberLen3,
 				}).Write(buf, versionIETFHeader)).To(Succeed())
 				expected := []byte{
-					0xc0 ^ 0x2<<4,
+					0xc0 | 0x2<<4 | 0x2,
 					0x1, 0x2, 0x3, 0x4, // version number
 					0x35,                               // connection ID lengths
 					0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe, // dest connection ID
 					0xde, 0xca, 0xfb, 0xad, 0x0, 0x0, 0x13, 0x37, // source connection ID
 				}
-				expected = append(expected, encodeVarInt(0xcafe)...) // length
-				expected = appendPacketNumber(expected, 0xdecaf, protocol.PacketNumberLen4)
+				expected = append(expected, encodeVarInt(0xcafe)...)    // length
+				expected = append(expected, []byte{0xd, 0xec, 0xaf}...) // packet number
 				Expect(buf.Bytes()).To(Equal(expected))
 			})
 
@@ -180,27 +174,27 @@ var _ = Describe("Header", func() {
 					PacketNumberLen: protocol.PacketNumberLen2,
 					PacketNumber:    0x765,
 				}).Write(buf, versionIETFHeader)).To(Succeed())
-				expected := []byte{0x40}
-				expected = appendPacketNumber(expected, 0x765, protocol.PacketNumberLen2)
+				expected := []byte{0x40 | 0x1}
+				expected = append(expected, []byte{0x7, 0x65}...) // packet number
 				Expect(buf.Bytes()).To(Equal(expected))
 			})
 
 			It("writes a header with a 4 byte packet number", func() {
 				Expect((&ExtendedHeader{
 					PacketNumberLen: protocol.PacketNumberLen4,
-					PacketNumber:    0x123456,
+					PacketNumber:    0x12345678,
 				}).Write(buf, versionIETFHeader)).To(Succeed())
-				expected := []byte{0x40}
-				expected = appendPacketNumber(expected, 0x123456, protocol.PacketNumberLen4)
+				expected := []byte{0x40 | 0x3}
+				expected = append(expected, []byte{0x12, 0x34, 0x56, 0x78}...)
 				Expect(buf.Bytes()).To(Equal(expected))
 			})
 
 			It("errors when given an invalid packet number length", func() {
 				err := (&ExtendedHeader{
-					PacketNumberLen: 3,
+					PacketNumberLen: 5,
 					PacketNumber:    0xdecafbad,
 				}).Write(buf, versionIETFHeader)
-				Expect(err).To(MatchError("invalid packet number length: 3"))
+				Expect(err).To(MatchError("invalid packet number length: 5"))
 			})
 
 			It("writes the Key Phase Bit", func() {