feat: add metadata for IBC tokens

docs/migrations/v7-to-v8.md

@@ -74,6 +74,10 @@ TODO: https://github.com/cosmos/ibc-go/pull/3505 (extra parameter added to trans
 	)
 ```
 
+### Transfer migration
+
+An automatic migration handler (TODO: add link after https://github.com/cosmos/ibc-go/pull/3104 is merged) is configured in the transfer module to set the [denomination metadata](https://github.com/cosmos/cosmos-sdk/blob/95178ce036741ae6aa7af131fa9fccf3e13fff7a/proto/cosmos/bank/v1beta1/bank.proto#L96-L125) for the IBC denominations of all vouchers minted by the transfer module.
+
 ## IBC Apps
 
 TODO: 

modules/apps/transfer/keeper/genesis.go

@@ -14,6 +14,7 @@ func (k Keeper) InitGenesis(ctx sdk.Context, state types.GenesisState) {
 
 	for _, trace := range state.DenomTraces {
 		k.SetDenomTrace(ctx, trace)
+		k.SetDenomMetadata(ctx, trace)
 	}
 
 	// Only try to bind to port if it is not already bound, since we may already own

modules/apps/transfer/keeper/migrations.go

@@ -55,6 +55,7 @@ func (m Migrator) MigrateTraces(ctx sdk.Context) error {
 			if !equalTraces(newTrace, dt) {
 				newTraces = append(newTraces, newTrace)
 			}
+
 			return false
 		})
 
@@ -65,6 +66,21 @@ func (m Migrator) MigrateTraces(ctx sdk.Context) error {
 	return nil
 }
 
+// MigrateMigrateDenomMetadataMetadata sets token metadata for all the IBC denom traces
+func (m Migrator) MigrateDenomMetadata(ctx sdk.Context) error {
+	m.keeper.IterateDenomTraces(ctx,
+		func(dt types.DenomTrace) (stop bool) {
+			// check if the metadata for the given denom trace already exists
+			if !m.keeper.bankKeeper.HasDenomMetaData(ctx, dt.IBCDenom()) {
+				m.keeper.SetDenomMetadata(ctx, dt)
+			}
+			return false
+		})
+
+	m.keeper.Logger(ctx).Info("successfully added metadata to IBC voucher denominations")
+	return nil
+}
+
 // MigrateTotalEscrowForDenom migrates the total amount of source chain tokens in escrow.
 func (m Migrator) MigrateTotalEscrowForDenom(ctx sdk.Context) error {
 	var totalEscrowed sdk.Coins

modules/apps/transfer/keeper/migrations_test.go

@@ -7,6 +7,7 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	banktestutil "github.com/cosmos/cosmos-sdk/x/bank/testutil"
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
 	transferkeeper "github.com/cosmos/ibc-go/v7/modules/apps/transfer/keeper"
 	transfertypes "github.com/cosmos/ibc-go/v7/modules/apps/transfer/types"
@@ -235,3 +236,82 @@ func (suite *KeeperTestSuite) TestMigrateTotalEscrowForDenom() {
 		})
 	}
 }
+
+func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
+	var (
+		denomTrace       transfertypes.DenomTrace
+		expectedMetadata banktypes.Metadata
+	)
+
+	testCases := []struct {
+		msg      string
+		malleate func()
+	}{
+		{
+			"success with denom trace with one hop",
+			func() {
+				denomTrace = transfertypes.DenomTrace{
+					BaseDenom: "foo",
+					Path:      "transfer/channel-0",
+				}
+
+				expectedMetadata = banktypes.Metadata{
+					Description: "IBC token from transfer/channel-0/foo",
+					DenomUnits: []*banktypes.DenomUnit{
+						{
+							Denom:    "foo",
+							Exponent: 0,
+						},
+					},
+					Base:    denomTrace.IBCDenom(), // ibc/EB7094899ACFB7A6F2A67DB084DEE2E9A83DEFAA5DEF92D9A9814FFD9FF673FA
+					Display: "transfer/channel-0/foo",
+					Name:    "transfer/channel-0/foo IBC token",
+					Symbol:  "FOO",
+				}
+			},
+		},
+		{
+			"success with denom trace with two hops",
+			func() {
+				denomTrace = transfertypes.DenomTrace{
+					BaseDenom: "ubar",
+					Path:      "transfer/channel-1/transfer/channel-2",
+				}
+
+				expectedMetadata = banktypes.Metadata{
+					Description: "IBC token from transfer/channel-1/transfer/channel-2/ubar",
+					DenomUnits: []*banktypes.DenomUnit{
+						{
+							Denom:    "ubar",
+							Exponent: 0,
+						},
+					},
+					Base:    denomTrace.IBCDenom(), // ibc/8243B3EAA19BAB1DB3B0020B81C0C5A953E7B22C042CEE44E639A11A238BA57C
+					Display: "transfer/channel-1/transfer/channel-2/ubar",
+					Name:    "transfer/channel-1/transfer/channel-2/ubar IBC token",
+					Symbol:  "UBAR",
+				}
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(fmt.Sprintf("Case %s", tc.msg), func() {
+			suite.SetupTest() // reset
+			ctx := suite.chainA.GetContext()
+
+			tc.malleate()
+
+			suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(ctx, denomTrace)
+
+			// run migration
+			migrator := transferkeeper.NewMigrator(suite.chainA.GetSimApp().TransferKeeper)
+			err := migrator.MigrateDenomMetadata(suite.chainA.GetContext())
+			suite.Require().NoError(err)
+
+			denomMetadata, ok := suite.chainA.GetSimApp().BankKeeper.GetDenomMetaData(ctx, expectedMetadata.Base)
+			suite.Require().True(ok)
+			suite.Require().Equal(expectedMetadata, denomMetadata)
+		})
+	}
+}

modules/apps/transfer/keeper/relay.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/telemetry"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
 	"github.com/cosmos/ibc-go/v7/modules/apps/transfer/types"
 	clienttypes "github.com/cosmos/ibc-go/v7/modules/core/02-client/types"
@@ -277,6 +278,10 @@ func (k Keeper) OnRecvPacket(ctx sdk.Context, packet channeltypes.Packet, data t
 		return errorsmod.Wrap(err, "failed to mint IBC tokens")
 	}
 
+	if !k.bankKeeper.HasDenomMetaData(ctx, voucherDenom) {
+		k.SetDenomMetadata(ctx, denomTrace)
+	}
+
 	// send to receiver
 	if err := k.bankKeeper.SendCoinsFromModuleToAccount(
 		ctx, types.ModuleName, receiver, sdk.NewCoins(voucher),
@@ -423,3 +428,37 @@ func (k Keeper) DenomPathFromHash(ctx sdk.Context, denom string) (string, error)
 	fullDenomPath := denomTrace.GetFullDenomPath()
 	return fullDenomPath, nil
 }
+
+// SetDenomMetadata sets an IBC token's denomination metadata
+func (k Keeper) SetDenomMetadata(ctx sdk.Context, denomTrace types.DenomTrace) {
+	metadata := banktypes.Metadata{
+		Description: getMetadataDescription(denomTrace),
+		DenomUnits: []*banktypes.DenomUnit{
+			{
+				Denom:    denomTrace.BaseDenom,
+				Exponent: 0,
+			},
+		},
+		// Setting base as IBC hash denom since bank keepers's SetDenomMetaData uses
+		// Base as storeKey and the bank keeper will only have the IBC hash to get
+		// the denom metadata
+		Base:    denomTrace.IBCDenom(),
+		Display: denomTrace.GetFullDenomPath(),
+		Name:    getMetadataName(denomTrace),
+		Symbol:  getMetadataSymbol(denomTrace),
+	}
+
+	k.bankKeeper.SetDenomMetaData(ctx, metadata)
+}
+
+func getMetadataDescription(denomTrace types.DenomTrace) string {
+	return fmt.Sprintf("IBC token from %s", denomTrace.GetFullDenomPath())
+}
+
+func getMetadataName(denomTrace types.DenomTrace) string {
+	return fmt.Sprintf("%s IBC token", denomTrace.GetFullDenomPath())
+}
+
+func getMetadataSymbol(denomTrace types.DenomTrace) string {
+	return strings.ToUpper(denomTrace.BaseDenom)
+}

modules/apps/transfer/module.go

@@ -117,6 +117,10 @@ func (am AppModule) RegisterServices(cfg module.Configurator) {
 	if err := cfg.RegisterMigration(types.ModuleName, 3, m.MigrateParams); err != nil {
 		panic(fmt.Sprintf("failed to migrate transfer app version 3 to 4 (self-managed params migration): %v", err))
 	}
+
+	if err := cfg.RegisterMigration(types.ModuleName, 4, m.MigrateDenomMetadata); err != nil {
+		panic(fmt.Sprintf("failed to migrate transfer app from version 4 to 5 (set denom metadata migration): %v", err))
+	}
 }
 
 // InitGenesis performs genesis initialization for the ibc-transfer module. It returns
@@ -136,7 +140,7 @@ func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.Raw
 }
 
 // ConsensusVersion implements AppModule/ConsensusVersion defining the current version of transfer.
-func (AppModule) ConsensusVersion() uint64 { return 4 }
+func (AppModule) ConsensusVersion() uint64 { return 5 }
 
 // BeginBlock implements the AppModule interface
 func (AppModule) BeginBlock(ctx sdk.Context, req abci.RequestBeginBlock) {

modules/apps/transfer/types/expected_keepers.go

@@ -3,6 +3,7 @@ package types
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
 	capabilitytypes "github.com/cosmos/ibc-go/modules/capability/types"
 	connectiontypes "github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
@@ -25,6 +26,8 @@ type BankKeeper interface {
 	SendCoinsFromAccountToModule(ctx sdk.Context, senderAddr sdk.AccAddress, recipientModule string, amt sdk.Coins) error
 	BlockedAddr(addr sdk.AccAddress) bool
 	IsSendEnabledCoin(ctx sdk.Context, coin sdk.Coin) bool
+	HasDenomMetaData(ctx sdk.Context, denom string) bool
+	SetDenomMetaData(ctx sdk.Context, denomMetaData banktypes.Metadata)
 	GetBalance(ctx sdk.Context, addr sdk.AccAddress, denom string) sdk.Coin
 	GetAllBalances(ctx sdk.Context, addr sdk.AccAddress) sdk.Coins
 }