add func to do eth transfers

Signed-off-by: Guillem Bonet <[email protected]>

test/common.go

@@ -1,6 +1,7 @@
 package test
 
 import (
+	"context"
 	"crypto/ecdsa"
 	"fmt"
 	"math/big"
@@ -186,3 +187,34 @@ func DeployHermes(opts *bind.TransactOpts, backend bind.ContractBackend, timeout
 		HermesAddress:         hermesAddress,
 	}, nil
 }
+
+func TransferEth(opts *bind.TransactOpts, backend bind.ContractBackend, chainID *big.Int, to common.Address, value *big.Int, timeout time.Duration) error {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	nonce, err := backend.PendingNonceAt(ctx, opts.From)
+	if err != nil {
+		return fmt.Errorf("failed to get nonce: %w", err)
+	}
+	gasFeeCap, err := backend.SuggestGasPrice(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to get gas price: %w", err)
+	}
+	tx := types.NewTx(&types.DynamicFeeTx{
+		Nonce:     nonce,
+		ChainID:   chainID,
+		To:        &to,
+		Value:     value,
+		Gas:       21000,
+		GasFeeCap: gasFeeCap,
+	})
+	signedTx, err := opts.Signer(opts.From, tx)
+	if err != nil {
+		return fmt.Errorf("failed to sign transaction: %w", err)
+	}
+	err = backend.SendTransaction(ctx, signedTx)
+	if err != nil {
+		return fmt.Errorf("failed to send transaction: %w", err)
+	}
+	return nil
+}

test/common_test.go

@@ -9,8 +9,11 @@ import (
 	"testing"
 	"time"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/magefile/mage/sh"
+	"github.com/mysteriumnetwork/payments/units"
+	"github.com/stretchr/testify/assert"
 )
 
 var client *ethclient.Client
@@ -30,6 +33,27 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
+func TestTransferEth(t *testing.T) {
+	address, privateKey, err := GetKeyPair(privateKey0)
+	assert.NoError(t, err)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	chainID, err := client.ChainID(ctx)
+	assert.NoError(t, err)
+
+	t.Run("transfer", func(t *testing.T) {
+		to := common.HexToAddress("0x123452222222")
+		value := units.FloatEthToBigIntWei(1)
+		err := TransferEth(GetTransactOpts(address, privateKey, chainID), client, chainID, to, value, 10*time.Second)
+		assert.NoError(t, err)
+
+		balance, err := client.BalanceAt(context.Background(), to, nil)
+		assert.NoError(t, err)
+		assert.Equal(t, balance.String(), value.String())
+	})
+}
+
 func startCompose() error {
 	_, err := sh.Output("docker-compose", "-f", "docker-compose.yml", "up", "-d")
 	if err != nil {