diff --git a/raft/raft_test.go b/raft/raft_test.go
index e72a6371..2e5d0ca1 100644
--- a/raft/raft_test.go
+++ b/raft/raft_test.go
@@ -24,6 +24,14 @@ import (
 	pb "github.com/pingcap-incubator/tinykv/proto/pkg/eraftpb"
 )
 
+// returns a new MemoryStorage with only ents filled
+func newMemoryStorageWithEnts(ents []pb.Entry) *MemoryStorage {
+	return &MemoryStorage{
+		ents:     ents,
+		snapshot: pb.Snapshot{Metadata: &pb.SnapshotMetadata{ConfState: &pb.ConfState{}}},
+	}
+}
+
 // nextEnts returns the appliable entries and updates the applied index
 func nextEnts(r *Raft, s *MemoryStorage) (ents []pb.Entry) {
 	// Transfer all unstable entries to "stable" storage.
@@ -372,7 +380,7 @@ func TestDuelingCandidates2AB(t *testing.T) {
 	// 3 will be follower again since both 1 and 2 rejects its vote request since 3 does not have a long enough log
 	nt.send(pb.Message{From: 3, To: 3, MsgType: pb.MessageType_MsgHup})
 
-	wlog := newLog(&MemoryStorage{ents: []pb.Entry{{}, {Data: nil, Term: 1, Index: 1}}})
+	wlog := newLog(newMemoryStorageWithEnts([]pb.Entry{{}, {Data: nil, Term: 1, Index: 1}}))
 	wlog.committed = 1
 	tests := []struct {
 		sm      *Raft
@@ -429,7 +437,7 @@ func TestCandidateConcede2AB(t *testing.T) {
 	if g := a.Term; g != 1 {
 		t.Errorf("term = %d, want %d", g, 1)
 	}
-	wlog := newLog(&MemoryStorage{ents: []pb.Entry{{}, {Data: nil, Term: 1, Index: 1}, {Term: 1, Index: 2, Data: data}}})
+	wlog := newLog(newMemoryStorageWithEnts([]pb.Entry{{}, {Data: nil, Term: 1, Index: 1}, {Term: 1, Index: 2, Data: data}}))
 	wlog.committed = 2
 	wantLog := ltoa(wlog)
 	for i, p := range tt.peers {
@@ -508,7 +516,7 @@ func TestProposal2AB(t *testing.T) {
 
 		wantLog := newLog(NewMemoryStorage())
 		if tt.success {
-			wantLog = newLog(&MemoryStorage{ents: []pb.Entry{{}, {Data: nil, Term: 1, Index: 1}, {Term: 1, Index: 2, Data: data}}})
+			wantLog = newLog(newMemoryStorageWithEnts([]pb.Entry{{}, {Data: nil, Term: 1, Index: 1}, {Term: 1, Index: 2, Data: data}}))
 			wantLog.committed = 2
 		}
 		base := ltoa(wantLog)
@@ -629,7 +637,7 @@ func TestRecvMessageType_MsgRequestVote2AA(t *testing.T) {
 		sm := newTestRaft(1, []uint64{1}, 10, 1, NewMemoryStorage())
 		sm.State = tt.state
 		sm.Vote = tt.voteFor
-		sm.RaftLog = newLog(&MemoryStorage{ents: []pb.Entry{{}, {Index: 1, Term: 2}, {Index: 2, Term: 2}}})
+		sm.RaftLog = newLog(newMemoryStorageWithEnts([]pb.Entry{{}, {Index: 1, Term: 2}, {Index: 2, Term: 2}}))
 
 		// raft.Term is greater than or equal to raft.RaftLog.lastTerm. In this
 		// test we're only testing MessageType_MsgRequestVote responses when the campaigning node
@@ -928,7 +936,7 @@ func TestRecvMessageType_MsgBeat2AA(t *testing.T) {
 
 	for i, tt := range tests {
 		sm := newTestRaft(1, []uint64{1, 2, 3}, 10, 1, NewMemoryStorage())
-		sm.RaftLog = newLog(&MemoryStorage{ents: []pb.Entry{{}, {Index: 1, Term: 0}, {Index: 2, Term: 1}}})
+		sm.RaftLog = newLog(newMemoryStorageWithEnts([]pb.Entry{{}, {Index: 1, Term: 0}, {Index: 2, Term: 1}}))
 		sm.Term = 1
 		sm.State = tt.state
 		sm.Step(pb.Message{From: 1, To: 1, MsgType: pb.MessageType_MsgBeat})