fix JSON deserialization of peer.AddrInfo

peer/addrinfo_serde.go

@@ -2,6 +2,7 @@ package peer
 
 import (
 	"encoding/json"
+	"errors"
 
 	ma "github.com/multiformats/go-multiaddr"
 )
@@ -19,19 +20,25 @@ func (pi AddrInfo) MarshalJSON() ([]byte, error) {
 
 func (pi *AddrInfo) UnmarshalJSON(b []byte) error {
 	var data map[string]interface{}
-	err := json.Unmarshal(b, &data)
-	if err != nil {
+	if err := json.Unmarshal(b, &data); err != nil {
 		return err
 	}
-	pid, err := IDB58Decode(data["ID"].(string))
-	if err != nil {
-		return err
+	id, ok := data["ID"]
+	if !ok {
+		return errors.New("no peer ID")
+	}
+	if idString, ok := id.(string); ok {
+		pid, err := IDB58Decode(idString)
+		if err != nil {
+			return err
+		}
+		pi.ID = pid
 	}
-	pi.ID = pid
-	addrs, ok := data["Addrs"].([]interface{})
-	if ok {
-		for _, a := range addrs {
-			pi.Addrs = append(pi.Addrs, ma.StringCast(a.(string)))
+	if addrsEntry, ok := data["Addrs"]; ok {
+		if addrs, ok := addrsEntry.([]interface{}); ok {
+			for _, a := range addrs {
+				pi.Addrs = append(pi.Addrs, ma.StringCast(a.(string)))
+			}
 		}
 	}
 	return nil

peer/addrinfo_test.go

@@ -133,3 +133,30 @@ func TestAddrInfosFromP2pAddrs(t *testing.T) {
 		delete(expected, info.ID.Pretty())
 	}
 }
+
+func TestAddrInfoJSON(t *testing.T) {
+	t.Run("valid AddrInfo", func(t *testing.T) {
+		ai := AddrInfo{ID: testID, Addrs: []ma.Multiaddr{maddrFull}}
+		out, err := ai.MarshalJSON()
+		if err != nil {
+			t.Fatal(err)
+		}
+		var addrInfo AddrInfo
+		if err := addrInfo.UnmarshalJSON(out); err != nil {
+			t.Fatal(err)
+		}
+		if addrInfo.ID != testID {
+			t.Fatalf("expected ID to equal %s, got %s", testID.Pretty(), addrInfo.ID.Pretty())
+		}
+		if len(addrInfo.Addrs) != 1 || !addrInfo.Addrs[0].Equal(maddrFull) {
+			t.Fatalf("expected addrs to match %v, got %v", maddrFull, addrInfo.Addrs)
+		}
+	})
+	t.Run("missing ID", func(t *testing.T) {
+		s := []byte(`{"Addrs":["/ip4/127.0.0.1/tcp/1234/p2p/QmS3zcG7LhYZYSJMhyRZvTddvbNUqtt8BJpaSs6mi1K5Va"]}`)
+		var addrInfo AddrInfo
+		if err := addrInfo.UnmarshalJSON(s); err == nil || err.Error() != "no peer ID" {
+			t.Fatalf("expected no peer ID error, got %v", err)
+		}
+	})
+}