client_simulated.go

package main

import (
	"context"
	"fmt"
	"log"
	"math/big"

	"github.com/ethereum/go-ethereum/accounts/abi/bind"
	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
)

func main() {
	privateKey, err := crypto.GenerateKey()
	if err != nil {
		log.Fatal(err)
	}

	auth := bind.NewKeyedTransactor(privateKey)

	balance := new(big.Int)
	balance.SetString("10000000000000000000", 10) // 10 eth in wei

	address := auth.From
	genesisAlloc := map[common.Address]core.GenesisAccount{
		address: {
			Balance: balance,
		},
	}

	blockGasLimit := uint64(4712388)
	client := backends.NewSimulatedBackend(genesisAlloc, blockGasLimit)

	fromAddress := auth.From
	nonce, err := client.PendingNonceAt(context.Background(), fromAddress)
	if err != nil {
		log.Fatal(err)
	}

	value := big.NewInt(1000000000000000000) // in wei (1 eth)
	gasLimit := uint64(21000)                // in units
	gasPrice, err := client.SuggestGasPrice(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	toAddress := common.HexToAddress("0x4592d8f8d7b001e72cb26a73e4fa1806a51ac79d")
	var data []byte
	tx := types.NewTransaction(nonce, toAddress, value, gasLimit, gasPrice, data)
	signedTx, err := types.SignTx(tx, types.HomesteadSigner{}, privateKey)
	if err != nil {
		log.Fatal(err)
	}

	err = client.SendTransaction(context.Background(), signedTx)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("tx sent: %s\n", signedTx.Hash().Hex()) // tx sent: 0xec3ceb05642c61d33fa6c951b54080d1953ac8227be81e7b5e4e2cfed69eeb51

	client.Commit()

	receipt, err := client.TransactionReceipt(context.Background(), signedTx.Hash())
	if err != nil {
		log.Fatal(err)
	}
	if receipt == nil {
		log.Fatal("receipt is nil. Forgot to commit?")
	}

	fmt.Printf("status: %v\n", receipt.Status) // status: 1
}