Add func convert token to coin ibc (#6584)

* add func convert token to coin ibc

* fix command: change func to ToCoin and add godoc

* add unit test

* Revert using ToCoin on Recv where trace manipulation occurs.
Use ToCoin while forwarding.
Update tests as per Carlos's review.

* rename variable

---------

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>
Co-authored-by: DimitrisJim <d.f.hilliard@gmail.com>

Author: 3 people

modules/apps/transfer/keeper/forwarding.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 
 	errorsmod "cosmossdk.io/errors"
-	sdkmath "cosmossdk.io/math"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
@@ -72,11 +71,10 @@ func (k Keeper) revertForwardedPacket(ctx sdk.Context, prevPacket channeltypes.P
 	// we can iterate over the received tokens of prevPacket by iterating over the sent tokens of failedPacketData
 	for _, token := range failedPacketData.Tokens {
 		// parse the transfer amount
-		transferAmount, ok := sdkmath.NewIntFromString(token.Amount)
-		if !ok {
-			return errorsmod.Wrapf(types.ErrInvalidAmount, "unable to parse transfer amount (%s) into math.Int", transferAmount)
+		coin, err := token.ToCoin()
+		if err != nil {
+			return err
 		}
-		coin := sdk.NewCoin(token.Denom.IBCDenom(), transferAmount)
 
 		// check if the token we received originated on the sender
 		// given that the packet is being reversed, we check the DestinationChannel and DestinationPort

modules/apps/transfer/keeper/relay.go

@@ -331,13 +331,11 @@ func (k Keeper) refundPacketTokens(ctx sdk.Context, packet channeltypes.Packet,
 	// NOTE: packet data type already checked in handler.go
 
 	for _, token := range data.Tokens {
-		transferAmount, ok := sdkmath.NewIntFromString(token.Amount)
-		if !ok {
-			return errorsmod.Wrapf(types.ErrInvalidAmount, "unable to parse transfer amount (%s) into math.Int", transferAmount)
+		coin, err := token.ToCoin()
+		if err != nil {
+			return err
 		}
 
-		coin := sdk.NewCoin(token.Denom.IBCDenom(), transferAmount)
-
 		sender, err := sdk.AccAddressFromBech32(data.Sender)
 		if err != nil {
 			return err

modules/apps/transfer/types/token.go

@@ -3,6 +3,8 @@ package types
 import (
 	errorsmod "cosmossdk.io/errors"
 	sdkmath "cosmossdk.io/math"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
 // Tokens is a slice of Tokens
@@ -25,3 +27,18 @@ func (t Token) Validate() error {
 
 	return nil
 }
+
+// ToCoin converts a Token to an sdk.Coin.
+//
+// The function parses the Amount field of the Token into an sdkmath.Int and returns a new sdk.Coin with
+// the IBCDenom of the Token's Denom field and the parsed Amount.
+// If the Amount cannot be parsed, an error is returned with a wrapped error message.
+func (t Token) ToCoin() (sdk.Coin, error) {
+	transferAmount, ok := sdkmath.NewIntFromString(t.Amount)
+	if !ok {
+		return sdk.Coin{}, errorsmod.Wrapf(ErrInvalidAmount, "unable to parse transfer amount (%s) into math.Int", transferAmount)
+	}
+
+	coin := sdk.NewCoin(t.Denom.IBCDenom(), transferAmount)
+	return coin, nil
+}

modules/apps/transfer/types/token_test.go

@@ -5,6 +5,10 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+
+	sdkmath "cosmossdk.io/math"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
 const (
@@ -149,3 +153,52 @@ func TestValidate(t *testing.T) {
 		})
 	}
 }
+
+func TestToCoin(t *testing.T) {
+	testCases := []struct {
+		name     string
+		token    Token
+		expCoin  sdk.Coin
+		expError error
+	}{
+		{
+			"success: convert token to coin",
+			Token{
+				Denom: Denom{
+					Base:  denom,
+					Trace: []Trace{},
+				},
+				Amount: amount,
+			},
+			sdk.NewCoin(denom, sdkmath.NewInt(100)),
+			nil,
+		},
+		{
+			"failure: invalid amount string",
+			Token{
+				Denom: Denom{
+					Base:  denom,
+					Trace: []Trace{},
+				},
+				Amount: "value",
+			},
+			sdk.Coin{},
+			ErrInvalidAmount,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			coin, err := tc.token.ToCoin()
+
+			require.Equal(t, tc.expCoin, coin, tc.name)
+
+			expPass := tc.expError == nil
+			if expPass {
+				require.NoError(t, err, tc.name)
+			} else {
+				require.ErrorContains(t, err, tc.expError.Error(), tc.name)
+			}
+		})
+	}
+}