refactor: adapting transfer metadata bytes field to memo string (backport #2595)

CHANGELOG.md

@@ -48,7 +48,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
-* (apps/transfer) [\#2305](https://github.com/cosmos/ibc-go/pull/2305) Added optional metadata field to `FungibleTokenPacketData` and `MsgTransfer`.
+* (apps/transfer) [\#2595](https://github.com/cosmos/ibc-go/pull/2595) Adding optional memo field to `FungibleTokenPacketData` and `MsgTransfer`.
 
 ### Bug Fixes
 

docs/ibc/proto-docs.md

@@ -946,7 +946,7 @@ https://github.com/cosmos/ibc/tree/master/spec/app/ics-020-fungible-token-transf
 | `receiver` | [string](#string) |  | the recipient address on the destination chain |
 | `timeout_height` | [ibc.core.client.v1.Height](#ibc.core.client.v1.Height) |  | Timeout height relative to the current block height. The timeout is disabled when set to 0. |
 | `timeout_timestamp` | [uint64](#uint64) |  | Timeout timestamp in absolute nanoseconds since unix epoch. The timeout is disabled when set to 0. |
-| `metadata` | [bytes](#bytes) |  | optional metadata |
+| `memo` | [string](#string) |  | optional memo |
 
 
 
@@ -1008,7 +1008,7 @@ https://github.com/cosmos/ibc/tree/master/spec/app/ics-020-fungible-token-transf
 | `amount` | [string](#string) |  | the token amount to be transferred |
 | `sender` | [string](#string) |  | the sender address |
 | `receiver` | [string](#string) |  | the recipient address on the destination chain |
-| `metadata` | [bytes](#bytes) |  | optional metadata |
+| `memo` | [string](#string) |  | optional memo |
 
 
 

modules/apps/transfer/client/cli/tx.go

@@ -22,7 +22,7 @@ const (
 	flagPacketTimeoutHeight    = "packet-timeout-height"
 	flagPacketTimeoutTimestamp = "packet-timeout-timestamp"
 	flagAbsoluteTimeouts       = "absolute-timeouts"
-	flagMetadata               = "metadata"
+	flagMemo                   = "memo"
 )
 
 // NewTransferTxCmd returns the command to create a NewMsgTransfer transaction
@@ -77,7 +77,7 @@ corresponding to the counterparty channel. Any timeout set to 0 is disabled.`),
 				return err
 			}
 
-			metadataStr, err := cmd.Flags().GetString(flagMetadata)
+			memo, err := cmd.Flags().GetString(flagMemo)
 			if err != nil {
 				return err
 			}
@@ -119,7 +119,7 @@ corresponding to the counterparty channel. Any timeout set to 0 is disabled.`),
 			msg := types.NewMsgTransfer(
 				srcPort, srcChannel, coin, sender, receiver, timeoutHeight, timeoutTimestamp,
 			)
-			msg.Metadata = []byte(metadataStr)
+			msg.Memo = memo
 
 			return tx.GenerateOrBroadcastTxCLI(clientCtx, cmd.Flags(), msg)
 		},
@@ -128,7 +128,7 @@ corresponding to the counterparty channel. Any timeout set to 0 is disabled.`),
 	cmd.Flags().String(flagPacketTimeoutHeight, types.DefaultRelativePacketTimeoutHeight, "Packet timeout block height. The timeout is disabled when set to 0-0.")
 	cmd.Flags().Uint64(flagPacketTimeoutTimestamp, types.DefaultRelativePacketTimeoutTimestamp, "Packet timeout timestamp in nanoseconds from now. Default is 10 minutes. The timeout is disabled when set to 0.")
 	cmd.Flags().Bool(flagAbsoluteTimeouts, false, "Timeout flags are used as absolute timeouts.")
-	cmd.Flags().String(flagMetadata, "", "Metadata to be sent along with the packet. The CLI accepts only strings here but you can construct a packet with arbitrary bytes via code.")
+	cmd.Flags().String(flagMemo, "", "Memo to be sent along with the packet.")
 	flags.AddTxFlagsToCmd(cmd)
 
 	return cmd

modules/apps/transfer/ibc_module.go

@@ -1,7 +1,6 @@
 package transfer
 
 import (
-	"encoding/hex"
 	"fmt"
 	"math"
 
@@ -195,7 +194,7 @@ func (im IBCModule) OnRecvPacket(
 			sdk.NewAttribute(types.AttributeKeyReceiver, data.Receiver),
 			sdk.NewAttribute(types.AttributeKeyDenom, data.Denom),
 			sdk.NewAttribute(types.AttributeKeyAmount, data.Amount),
-			sdk.NewAttribute(types.AttributeKeyMetadata, hex.EncodeToString(data.Metadata)),
+			sdk.NewAttribute(types.AttributeKeyMemo, data.Memo),
 			sdk.NewAttribute(types.AttributeKeyAckSuccess, fmt.Sprintf("%t", ack.Success())),
 		),
 	)
@@ -232,7 +231,7 @@ func (im IBCModule) OnAcknowledgementPacket(
 			sdk.NewAttribute(types.AttributeKeyReceiver, data.Receiver),
 			sdk.NewAttribute(types.AttributeKeyDenom, data.Denom),
 			sdk.NewAttribute(types.AttributeKeyAmount, data.Amount),
-			sdk.NewAttribute(types.AttributeKeyMetadata, hex.EncodeToString(data.Metadata)),
+			sdk.NewAttribute(types.AttributeKeyMemo, data.Memo),
 			sdk.NewAttribute(types.AttributeKeyAck, ack.String()),
 		),
 	)
@@ -279,7 +278,7 @@ func (im IBCModule) OnTimeoutPacket(
 			sdk.NewAttribute(types.AttributeKeyRefundReceiver, data.Sender),
 			sdk.NewAttribute(types.AttributeKeyRefundDenom, data.Denom),
 			sdk.NewAttribute(types.AttributeKeyRefundAmount, data.Amount),
-			sdk.NewAttribute(types.AttributeKeyMetadata, hex.EncodeToString(data.Metadata)),
+			sdk.NewAttribute(types.AttributeKeyMemo, data.Memo),
 		),
 	)
 

modules/apps/transfer/keeper/msg_server.go

@@ -21,7 +21,7 @@ func (k Keeper) Transfer(goCtx context.Context, msg *types.MsgTransfer) (*types.
 
 	sequence, err := k.sendTransfer(
 		ctx, msg.SourcePort, msg.SourceChannel, msg.Token, sender, msg.Receiver, msg.TimeoutHeight, msg.TimeoutTimestamp,
-		msg.Metadata)
+		msg.Memo)
 	if err != nil {
 		return nil, err
 	}

modules/apps/transfer/keeper/msg_server_test.go

@@ -55,7 +55,7 @@ func (suite *KeeperTestSuite) TestMsgTransfer() {
 			coin, suite.chainA.SenderAccount.GetAddress().String(), suite.chainB.SenderAccount.GetAddress().String(),
 			suite.chainB.GetTimeoutHeight(), 0, // only use timeout height
 		)
-		msg.Metadata = []byte("custom metadata")
+		msg.Memo = "memo"
 
 		tc.malleate()
 

modules/apps/transfer/keeper/relay.go

@@ -69,7 +69,7 @@ func (k Keeper) SendTransfer(
 		receiver,
 		timeoutHeight,
 		timeoutTimestamp,
-		nil,
+		"",
 	)
 	return err
 }
@@ -84,7 +84,7 @@ func (k Keeper) sendTransfer(
 	receiver string,
 	timeoutHeight clienttypes.Height,
 	timeoutTimestamp uint64,
-	metadata []byte,
+	memo string,
 ) (uint64, error) {
 	if !k.GetSendEnabled(ctx) {
 		return 0, types.ErrSendDisabled
@@ -177,7 +177,7 @@ func (k Keeper) sendTransfer(
 	packetData := types.NewFungibleTokenPacketData(
 		fullDenomPath, token.Amount.String(), sender.String(), receiver,
 	)
-	packetData.Metadata = metadata
+	packetData.Memo = memo
 
 	packet := channeltypes.NewPacket(
 		packetData.GetBytes(),

modules/apps/transfer/keeper/relay_test.go

@@ -162,7 +162,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacket() {
 		trace    types.DenomTrace
 		amount   sdk.Int
 		receiver string
-		metadata []byte
+		memo     string
 	)
 
 	testCases := []struct {
@@ -172,12 +172,12 @@ func (suite *KeeperTestSuite) TestOnRecvPacket() {
 		expPass      bool
 	}{
 		{"success receive on source chain", func() {}, true, true},
-		{"success receive on source chain with metadata", func() {
-			metadata = []byte("metadata")
+		{"success receive on source chain with memo", func() {
+			memo = "memo"
 		}, true, true},
 		{"success receive with coin from another chain as source", func() {}, false, true},
-		{"success receive with coin from another chain as source with metadata", func() {
-			metadata = []byte("metadata")
+		{"success receive with coin from another chain as source with memo", func() {
+			memo = "memo"
 		}, false, true},
 		{"empty coin", func() {
 			trace = types.DenomTrace{}
@@ -219,7 +219,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacket() {
 			suite.coordinator.Setup(path)
 			receiver = suite.chainB.SenderAccount.GetAddress().String() // must be explicitly changed in malleate
 
-			metadata = []byte{}      // can be explicitly changed in malleate
+			memo = ""                // can be explicitly changed in malleate
 			amount = sdk.NewInt(100) // must be explicitly changed in malleate
 			seq := uint64(1)
 
@@ -246,14 +246,14 @@ func (suite *KeeperTestSuite) TestOnRecvPacket() {
 
 			// send coin from chainA to chainB
 			transferMsg := types.NewMsgTransfer(path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, sdk.NewCoin(trace.IBCDenom(), amount), suite.chainA.SenderAccount.GetAddress().String(), receiver, clienttypes.NewHeight(0, 110), 0)
-			transferMsg.Metadata = metadata
+			transferMsg.Memo = memo
 			_, err := suite.chainA.SendMsgs(transferMsg)
 			suite.Require().NoError(err) // message committed
 
 			tc.malleate()
 
 			data := types.NewFungibleTokenPacketData(trace.GetFullDenomPath(), amount.String(), suite.chainA.SenderAccount.GetAddress().String(), receiver)
-			data.Metadata = metadata
+			data.Memo = memo
 			packet := channeltypes.NewPacket(data.GetBytes(), seq, path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID, clienttypes.NewHeight(0, 100), 0)
 
 			err = suite.chainB.GetSimApp().TransferKeeper.OnRecvPacket(suite.chainB.GetContext(), packet, data)

modules/apps/transfer/spec/04_messages.md

@@ -17,7 +17,7 @@ type MsgTransfer struct {
   Receiver          string
   TimeoutHeight     ibcexported.Height
   TimeoutTimestamp  uint64
-  Metadata          []byte
+  Memo              string
 }
 ```
 

modules/apps/transfer/spec/05_events.md

@@ -22,7 +22,7 @@ order: 5
 | fungible_token_packet | denom         | {denom}         |
 | fungible_token_packet | amount        | {amount}        |
 | fungible_token_packet | success       | {ackSuccess}    |
-| fungible_token_packet | metadata      | {metadata}      |
+| fungible_token_packet | memo          | {memo}          |
 | denomination_trace    | trace_hash    | {hex_hash}      |
 
 ## OnAcknowledgePacket callback
@@ -33,7 +33,7 @@ order: 5
 | fungible_token_packet | receiver        | {receiver}        |
 | fungible_token_packet | denom           | {denom}           |
 | fungible_token_packet | amount          | {amount}          |
-| fungible_token_packet | metadata        | {metadata}        |
+| fungible_token_packet | memo            | {memo}            |
 | fungible_token_packet | acknowledgement | {ack.String()}    |
 | fungible_token_packet | success | error | {ack.Response}    |
 
@@ -45,4 +45,4 @@ order: 5
 | fungible_token_packet | refund_receiver | {receiver}      |
 | fungible_token_packet | denom           | {denom}         |
 | fungible_token_packet | amount          | {amount}        |
-| fungible_token_packet | metadata        | {metadata}      |
+| fungible_token_packet | memo            | {memo}          |

modules/apps/transfer/types/events.go

@@ -18,5 +18,5 @@ const (
 	AttributeKeyAck            = "acknowledgement"
 	AttributeKeyAckError       = "error"
 	AttributeKeyTraceHash      = "trace_hash"
-	AttributeKeyMetadata       = "metadata"
+	AttributeKeyMemo           = "memo"
 )