From fd57c55d87f2702fc85020fd269f2399379bdcb9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ra=C3=BAl=20Kripalani?= <raul@protocol.ai>
Date: Fri, 30 Nov 2018 16:09:25 +0000
Subject: [PATCH] document custom gogo types; reorg code.

---
 pb/custom.go | 41 +++++++++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 10 deletions(-)

diff --git a/pb/custom.go b/pb/custom.go
index e51b2ca..711963c 100644
--- a/pb/custom.go
+++ b/pb/custom.go
@@ -3,19 +3,28 @@ package pstore_pb
 import (
 	"encoding/json"
 
+	proto "github.com/gogo/protobuf/proto"
 	peer "github.com/libp2p/go-libp2p-peer"
 	pt "github.com/libp2p/go-libp2p-peer/test"
 	ma "github.com/multiformats/go-multiaddr"
 )
 
+// customGogoType aggregates the interfaces that custom Gogo types need to implement.
+// it is only used for type assertions.
+type customGogoType interface {
+	proto.Marshaler
+	proto.Unmarshaler
+	json.Marshaler
+	json.Unmarshaler
+	proto.Sizer
+}
+
+// ProtoAddr is a custom type used by gogo to serde raw peer IDs into the peer.ID type, and back.
 type ProtoPeerID struct {
 	peer.ID
 }
 
-func NewPopulatedProtoPeerID(r randyPstore) *ProtoPeerID {
-	id, _ := pt.RandPeerID()
-	return &ProtoPeerID{ID: id}
-}
+var _ customGogoType = (*ProtoPeerID)(nil)
 
 func (id ProtoPeerID) Marshal() ([]byte, error) {
 	return []byte(id.ID), nil
@@ -36,26 +45,24 @@ func (id *ProtoPeerID) Unmarshal(data []byte) (err error) {
 }
 
 func (id *ProtoPeerID) UnmarshalJSON(data []byte) error {
-	v := new([]byte)
+	var v []byte
 	err := json.Unmarshal(data, v)
 	if err != nil {
 		return err
 	}
-	return id.Unmarshal(*v)
+	return id.Unmarshal(v)
 }
 
 func (id ProtoPeerID) Size() int {
 	return len([]byte(id.ID))
 }
 
+// ProtoAddr is a custom type used by gogo to serde raw multiaddresses into the ma.Multiaddr type, and back.
 type ProtoAddr struct {
 	ma.Multiaddr
 }
 
-func NewPopulatedProtoAddr(r randyPstore) *ProtoAddr {
-	a, _ := ma.NewMultiaddr("/ip4/123.123.123.123/tcp/7001")
-	return &ProtoAddr{Multiaddr: a}
-}
+var _ customGogoType = (*ProtoAddr)(nil)
 
 func (a ProtoAddr) Marshal() ([]byte, error) {
 	return a.Bytes(), nil
@@ -87,3 +94,17 @@ func (a *ProtoAddr) UnmarshalJSON(data []byte) error {
 func (a ProtoAddr) Size() int {
 	return len(a.Bytes())
 }
+
+// NewPopulatedProtoAddr generates a populated instance of the custom gogo type ProtoAddr.
+// It is required by gogo-generated tests.
+func NewPopulatedProtoAddr(r randyPstore) *ProtoAddr {
+	a, _ := ma.NewMultiaddr("/ip4/123.123.123.123/tcp/7001")
+	return &ProtoAddr{Multiaddr: a}
+}
+
+// NewPopulatedProtoPeerID generates a populated instance of the custom gogo type ProtoPeerID.
+// It is required by gogo-generated tests.
+func NewPopulatedProtoPeerID(r randyPstore) *ProtoPeerID {
+	id, _ := pt.RandPeerID()
+	return &ProtoPeerID{ID: id}
+}