add error code string representation to QuicError.Error

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{}

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"))
+	})
+})