Raft: fix problems reported by golint.

raft/node.go

@@ -11,6 +11,8 @@ import (
 
 var (
 	emptyState = pb.HardState{}
+
+	// ErrStopped is returned by methods on Nodes that have been stopped.
 	ErrStopped = errors.New("raft: stopped")
 )
 
@@ -68,10 +70,12 @@ func isHardStateEqual(a, b pb.HardState) bool {
 	return a.Term == b.Term && a.Vote == b.Vote && a.Commit == b.Commit
 }
 
+// IsEmptyHardState returns true if the given HardState is empty.
 func IsEmptyHardState(st pb.HardState) bool {
 	return isHardStateEqual(st, emptyState)
 }
 
+// IsEmptySnap returns true if the given Snapshot is empty.
 func IsEmptySnap(sp pb.Snapshot) bool {
 	return sp.Index == 0
 }
@@ -81,6 +85,7 @@ func (rd Ready) containsUpdates() bool {
 		len(rd.Entries) > 0 || len(rd.CommittedEntries) > 0 || len(rd.Messages) > 0
 }
 
+// Node represents a node in a raft cluster.
 type Node interface {
 	// Tick increments the internal logical clock for the Node by a single tick. Election
 	// timeouts and heartbeat timeouts are in units of ticks.

raft/raft.go

@@ -8,6 +8,7 @@ import (
 	pb "github.com/coreos/etcd/raft/raftpb"
 )
 
+// None is a placeholder node ID used when there is no leader.
 const None int64 = 0
 
 type messageType int64
@@ -42,12 +43,14 @@ func (mt messageType) String() string {
 
 var errNoLeader = errors.New("no leader")
 
+// Possible values for StateType.
 const (
 	StateFollower StateType = iota
 	StateCandidate
 	StateLeader
 )
 
+// StateType represents the role of a node in a cluster.
 type StateType int64
 
 var stmap = [...]string{

raft/raft_test.go

@@ -91,13 +91,13 @@ func TestLogReplication(t *testing.T) {
 				t.Errorf("#%d.%d: committed = %d, want %d", i, j, sm.raftLog.committed, tt.wcommitted)
 			}
 
-			ents := make([]pb.Entry, 0)
+			ents := []pb.Entry{}
 			for _, e := range nextEnts(sm) {
 				if e.Data != nil {
 					ents = append(ents, e)
 				}
 			}
-			props := make([]pb.Message, 0)
+			props := []pb.Message{}
 			for _, m := range tt.msgs {
 				if m.Type == msgProp {
 					props = append(props, m)
@@ -1237,7 +1237,7 @@ func (nw *network) recover() {
 }
 
 func (nw *network) filter(msgs []pb.Message) []pb.Message {
-	mm := make([]pb.Message, 0)
+	mm := []pb.Message{}
 	for _, m := range msgs {
 		if nw.ignorem[m.Type] {
 			continue