diff --git a/blockindex/actionindex.go b/blockindex/actionindex.go
index 4af87c9752..4e5fe31232 100644
--- a/blockindex/actionindex.go
+++ b/blockindex/actionindex.go
@@ -13,22 +13,23 @@ import (
 	"github.com/iotexproject/iotex-core/pkg/util/byteutil"
 )
 
-type actionIndex struct {
+// ActionIndex change private to public for mock Indexer
+type ActionIndex struct {
 	blkHeight uint64
 }
 
 // Height returns the block height of action
-func (a *actionIndex) BlockHeight() uint64 {
+func (a *ActionIndex) BlockHeight() uint64 {
 	return a.blkHeight
 }
 
 // Serialize into byte stream
-func (a *actionIndex) Serialize() []byte {
+func (a *ActionIndex) Serialize() []byte {
 	return byteutil.Must(proto.Marshal(a.toProto()))
 }
 
 // Desrialize from byte stream
-func (a *actionIndex) Deserialize(buf []byte) error {
+func (a *ActionIndex) Deserialize(buf []byte) error {
 	pb := &indexpb.ActionIndex{}
 	if err := proto.Unmarshal(buf, pb); err != nil {
 		return err
@@ -37,14 +38,14 @@ func (a *actionIndex) Deserialize(buf []byte) error {
 }
 
 // toProto converts to protobuf
-func (a *actionIndex) toProto() *indexpb.ActionIndex {
+func (a *ActionIndex) toProto() *indexpb.ActionIndex {
 	return &indexpb.ActionIndex{
 		BlkHeight: a.blkHeight,
 	}
 }
 
 // fromProto converts from protobuf
-func (a *actionIndex) fromProto(pbIndex *indexpb.ActionIndex) error {
+func (a *ActionIndex) fromProto(pbIndex *indexpb.ActionIndex) error {
 	if pbIndex == nil {
 		return errors.New("empty protobuf")
 	}
diff --git a/blockindex/blockindex.go b/blockindex/blockindex.go
index 733302e132..b8d4c565f2 100644
--- a/blockindex/blockindex.go
+++ b/blockindex/blockindex.go
@@ -15,34 +15,35 @@ import (
 	"github.com/iotexproject/iotex-core/pkg/util/byteutil"
 )
 
-type blockIndex struct {
+// BlockIndex change private to public for mock Indexer
+type BlockIndex struct {
 	hash      []byte
 	numAction uint32
 	tsfAmount *big.Int
 }
 
 // Hash returns the hash
-func (b *blockIndex) Hash() []byte {
+func (b *BlockIndex) Hash() []byte {
 	return b.hash
 }
 
 // NumAction returns number of actions
-func (b *blockIndex) NumAction() uint32 {
+func (b *BlockIndex) NumAction() uint32 {
 	return b.numAction
 }
 
 // TsfAmount returns transfer amount
-func (b *blockIndex) TsfAmount() *big.Int {
+func (b *BlockIndex) TsfAmount() *big.Int {
 	return b.tsfAmount
 }
 
 // Serialize into byte stream
-func (b *blockIndex) Serialize() []byte {
+func (b *BlockIndex) Serialize() []byte {
 	return byteutil.Must(proto.Marshal(b.toProto()))
 }
 
 // Desrialize from byte stream
-func (b *blockIndex) Deserialize(buf []byte) error {
+func (b *BlockIndex) Deserialize(buf []byte) error {
 	pb := &indexpb.BlockIndex{}
 	if err := proto.Unmarshal(buf, pb); err != nil {
 		return err
@@ -51,7 +52,7 @@ func (b *blockIndex) Deserialize(buf []byte) error {
 }
 
 // toProto converts to protobuf
-func (b *blockIndex) toProto() *indexpb.BlockIndex {
+func (b *BlockIndex) toProto() *indexpb.BlockIndex {
 	index := &indexpb.BlockIndex{
 		NumAction: b.numAction,
 		Hash:      b.hash,
@@ -63,7 +64,7 @@ func (b *blockIndex) toProto() *indexpb.BlockIndex {
 }
 
 // fromProto converts from protobuf
-func (b *blockIndex) fromProto(pbIndex *indexpb.BlockIndex) error {
+func (b *BlockIndex) fromProto(pbIndex *indexpb.BlockIndex) error {
 	if pbIndex == nil {
 		return errors.New("empty protobuf")
 	}
diff --git a/blockindex/index_test.go b/blockindex/index_test.go
index 1cf18fa1c9..837ca1623a 100644
--- a/blockindex/index_test.go
+++ b/blockindex/index_test.go
@@ -11,14 +11,14 @@ import (
 func TestActionIndex(t *testing.T) {
 	require := require.New(t)
 
-	ad := []*actionIndex{
+	ad := []*ActionIndex{
 		{1048000},
 		{1048001},
 	}
 
 	for i := range ad {
 		s := ad[i].Serialize()
-		bd2 := &actionIndex{}
+		bd2 := &ActionIndex{}
 		require.NoError(bd2.Deserialize(s))
 		require.Equal(ad[i], bd2)
 	}
@@ -28,7 +28,7 @@ func TestBlockIndex(t *testing.T) {
 	require := require.New(t)
 
 	h, _ := hex.DecodeString("d1ff0e7fe2a54600a171d3bcc9e222c656d584b3a0e7b33373e634de3f8cd010")
-	bd := []*blockIndex{
+	bd := []*BlockIndex{
 		{
 			h, 1048000, big.NewInt(1048000),
 		},
@@ -42,7 +42,7 @@ func TestBlockIndex(t *testing.T) {
 
 	for i := range bd {
 		s := bd[i].Serialize()
-		bd2 := &blockIndex{}
+		bd2 := &BlockIndex{}
 		require.NoError(bd2.Deserialize(s))
 		require.Equal(bd[i], bd2)
 	}
diff --git a/blockindex/indexer.go b/blockindex/indexer.go
index 7ebf7ae220..109e32c30f 100644
--- a/blockindex/indexer.go
+++ b/blockindex/indexer.go
@@ -53,8 +53,8 @@ type (
 		Height() (uint64, error)
 		GetBlockHash(height uint64) (hash.Hash256, error)
 		GetBlockHeight(hash hash.Hash256) (uint64, error)
-		GetBlockIndex(uint64) (*blockIndex, error)
-		GetActionIndex([]byte) (*actionIndex, error)
+		GetBlockIndex(uint64) (*BlockIndex, error)
+		GetActionIndex([]byte) (*ActionIndex, error)
 		GetTotalActions() (uint64, error)
 		GetActionHashFromIndex(uint64, uint64) ([][]byte, error)
 		GetActionCountByAddress(hash.Hash160) (uint64, error)
@@ -103,7 +103,7 @@ func (x *blockIndexer) Start(ctx context.Context) error {
 	}
 	if x.tbk.Size() == 0 {
 		// insert genesis block
-		if err = x.tbk.Add((&blockIndex{
+		if err = x.tbk.Add((&BlockIndex{
 			x.genesisHash[:],
 			0,
 			big.NewInt(0)}).Serialize(), false); err != nil {
@@ -218,7 +218,7 @@ func (x *blockIndexer) GetBlockHeight(hash hash.Hash256) (uint64, error) {
 }
 
 // GetBlockIndex return the index of block
-func (x *blockIndexer) GetBlockIndex(height uint64) (*blockIndex, error) {
+func (x *blockIndexer) GetBlockIndex(height uint64) (*BlockIndex, error) {
 	x.mutex.RLock()
 	defer x.mutex.RUnlock()
 
@@ -226,7 +226,7 @@ func (x *blockIndexer) GetBlockIndex(height uint64) (*blockIndex, error) {
 	if err != nil {
 		return nil, err
 	}
-	b := &blockIndex{}
+	b := &BlockIndex{}
 	if err := b.Deserialize(v); err != nil {
 		return nil, err
 	}
@@ -234,7 +234,7 @@ func (x *blockIndexer) GetBlockIndex(height uint64) (*blockIndex, error) {
 }
 
 // GetActionIndex return the index of action
-func (x *blockIndexer) GetActionIndex(h []byte) (*actionIndex, error) {
+func (x *blockIndexer) GetActionIndex(h []byte) (*ActionIndex, error) {
 	x.mutex.RLock()
 	defer x.mutex.RUnlock()
 
@@ -242,7 +242,7 @@ func (x *blockIndexer) GetActionIndex(h []byte) (*actionIndex, error) {
 	if err != nil {
 		return nil, err
 	}
-	a := &actionIndex{}
+	a := &ActionIndex{}
 	if err := a.Deserialize(v); err != nil {
 		return nil, err
 	}
@@ -310,7 +310,7 @@ func (x *blockIndexer) putBlock(ctx context.Context, blk *block.Block) error {
 	x.batch.Put(_blockHashToHeightNS, hash[_hashOffset:], byteutil.Uint64ToBytesBigEndian(height), "failed to put hash -> height mapping")
 
 	// index height --> block hash, number of actions, and total transfer amount
-	bd := &blockIndex{
+	bd := &BlockIndex{
 		hash:      hash[:],
 		numAction: uint32(len(blk.Actions)),
 		tsfAmount: blk.CalculateTransferAmount()}
@@ -322,7 +322,7 @@ func (x *blockIndexer) putBlock(ctx context.Context, blk *block.Block) error {
 	}
 
 	// store height of the block, so getReceiptByActionHash() can use height to directly pull receipts
-	ad := (&actionIndex{
+	ad := (&ActionIndex{
 		blkHeight: blk.Height()}).Serialize()
 	if err := x.tac.UseBatch(x.batch); err != nil {
 		return err