From dc2a14a5f7b460b481a9c6e8124024edf5f168f3 Mon Sep 17 00:00:00 2001
From: Lucas Clemente <lucas@clemente.io>
Date: Tue, 17 May 2016 00:31:18 +0200
Subject: [PATCH] add error code string representation to QuicError.Error

---
 errorcodes/error_codes.go      |  2 ++
 errorcodes/errorcode_string.go | 38 ++++++++++++++++++++++++++++++++++
 packet_unpacker_test.go        |  2 +-
 protocol/quic_error.go         |  4 +++-
 protocol/quic_error_test.go    | 16 ++++++++++++++
 5 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 errorcodes/errorcode_string.go
 create mode 100644 protocol/quic_error_test.go

diff --git a/errorcodes/error_codes.go b/errorcodes/error_codes.go
index 0fe904d0f..707b4bdc0 100644
--- a/errorcodes/error_codes.go
+++ b/errorcodes/error_codes.go
@@ -6,6 +6,8 @@ package errorcodes
 type ErrorCode uint32
 
 // The error codes defined by QUIC
+// Remeber to run go generate ./... whenever the error codes change.
+//go:generate stringer -type=ErrorCode
 const (
 	InternalError      ErrorCode = 1
 	InvalidFrameData   ErrorCode = 4
diff --git a/errorcodes/errorcode_string.go b/errorcodes/errorcode_string.go
new file mode 100644
index 000000000..7914f8f61
--- /dev/null
+++ b/errorcodes/errorcode_string.go
@@ -0,0 +1,38 @@
+// Code generated by "stringer -type=ErrorCode"; DO NOT EDIT
+
+package errorcodes
+
+import "fmt"
+
+const (
+	_ErrorCode_name_0 = "InternalError"
+	_ErrorCode_name_1 = "InvalidFrameData"
+	_ErrorCode_name_2 = "DecryptionFailure"
+	_ErrorCode_name_3 = "PeerGoingAway"
+	_ErrorCode_name_4 = "NetworkIdleTimeout"
+)
+
+var (
+	_ErrorCode_index_0 = [...]uint8{0, 13}
+	_ErrorCode_index_1 = [...]uint8{0, 16}
+	_ErrorCode_index_2 = [...]uint8{0, 17}
+	_ErrorCode_index_3 = [...]uint8{0, 13}
+	_ErrorCode_index_4 = [...]uint8{0, 18}
+)
+
+func (i ErrorCode) String() string {
+	switch {
+	case i == 1:
+		return _ErrorCode_name_0
+	case i == 4:
+		return _ErrorCode_name_1
+	case i == 12:
+		return _ErrorCode_name_2
+	case i == 16:
+		return _ErrorCode_name_3
+	case i == 25:
+		return _ErrorCode_name_4
+	default:
+		return fmt.Sprintf("ErrorCode(%d)", i)
+	}
+}
diff --git a/packet_unpacker_test.go b/packet_unpacker_test.go
index 3ea96d914..c9f1c2554 100644
--- a/packet_unpacker_test.go
+++ b/packet_unpacker_test.go
@@ -163,6 +163,6 @@ var _ = Describe("Packet unpacker", func() {
 	It("errors on invalid type", func() {
 		setReader([]byte{0x08})
 		_, err := unpacker.Unpack(hdrBin, hdr, r)
-		Expect(err).To(MatchError("unknown type byte 0x8"))
+		Expect(err).To(MatchError("InvalidFrameData: unknown type byte 0x8"))
 	})
 })
diff --git a/protocol/quic_error.go b/protocol/quic_error.go
index 6e83adc02..39c5716f6 100644
--- a/protocol/quic_error.go
+++ b/protocol/quic_error.go
@@ -1,6 +1,8 @@
 package protocol
 
 import (
+	"fmt"
+
 	"github.com/lucas-clemente/quic-go/errorcodes"
 )
 
@@ -19,7 +21,7 @@ func Error(errorCode errorcodes.ErrorCode, errorMessage string) *QuicError {
 }
 
 func (e *QuicError) Error() string {
-	return e.ErrorMessage
+	return fmt.Sprintf("%s: %s", e.ErrorCode.String(), e.ErrorMessage)
 }
 
 var _ error = &QuicError{}
diff --git a/protocol/quic_error_test.go b/protocol/quic_error_test.go
new file mode 100644
index 000000000..6e2acf858
--- /dev/null
+++ b/protocol/quic_error_test.go
@@ -0,0 +1,16 @@
+package protocol_test
+
+import (
+	"github.com/lucas-clemente/quic-go/errorcodes"
+	"github.com/lucas-clemente/quic-go/protocol"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Quic error", func() {
+	It("has a string representation", func() {
+		err := protocol.Error(errorcodes.InternalError, "foobar")
+		Expect(err.Error()).To(Equal("InternalError: foobar"))
+	})
+})