uniswap swap logic

.env.example

@@ -0,0 +1,2 @@
+INFURA_ETHEREUM_MAINNET=""
+PRIVATE_KEY=""

.gitignore

@@ -1 +1,3 @@
-.env
+.env
+tmp
+anvil-state.json

Makefile

@@ -1,8 +1,9 @@
 INFURA_ETHEREUM_MAINNET=""
+BLOCK_NUMBER=21432092
 
 start-network:
 	anvil --fork-url $(INFURA_ETHEREUM_MAINNET) \
-	--fork-block-number 21422200 \
+	--fork-block-number $(BLOCK_NUMBER) \
 	--accounts 10 --balance 1000000 \
 	--mnemonic "test test test test test test test test test test test junk" \
 	--state anvil-state.json

go.mod

@@ -0,0 +1,34 @@
+module github.com/LimeChain/vulti-mono
+
+go 1.23.3
+
+require github.com/ethereum/go-ethereum v1.14.12
+
+require (
+	github.com/Microsoft/go-winio v0.6.2 // indirect
+	github.com/StackExchange/wmi v1.2.1 // indirect
+	github.com/bits-and-blooms/bitset v1.13.0 // indirect
+	github.com/consensys/bavard v0.1.13 // indirect
+	github.com/consensys/gnark-crypto v0.12.1 // indirect
+	github.com/crate-crypto/go-ipa v0.0.0-20240223125850-b1e8a79f509c // indirect
+	github.com/crate-crypto/go-kzg-4844 v1.0.0 // indirect
+	github.com/deckarep/golang-set/v2 v2.6.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/ethereum/c-kzg-4844 v1.0.0 // indirect
+	github.com/ethereum/go-verkle v0.1.1-0.20240829091221-dffa7562dbe9 // indirect
+	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/go-ole/go-ole v1.3.0 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
+	github.com/holiman/uint256 v1.3.1 // indirect
+	github.com/mmcloughlin/addchain v0.4.0 // indirect
+	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
+	github.com/supranational/blst v0.3.13 // indirect
+	github.com/tklauser/go-sysconf v0.3.12 // indirect
+	github.com/tklauser/numcpus v0.6.1 // indirect
+	golang.org/x/crypto v0.22.0 // indirect
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa // indirect
+	golang.org/x/sync v0.7.0 // indirect
+	golang.org/x/sys v0.22.0 // indirect
+	rsc.io/tmplfunc v0.0.3 // indirect
+)

main.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"log"
+	"math/big"
+	"time"
+
+	"os"
+
+	"github.com/LimeChain/vulti-mono/uniswap"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+const (
+	rpcURL = "http://127.0.0.1:8545"
+)
+
+var (
+	uniswapV2RouterAddress = common.HexToAddress("0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D")
+
+	tokenInAddress  = common.HexToAddress("0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2") // WETH
+	tokenOutAddress = common.HexToAddress("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48") // UCDC
+
+	swapAmountIn = big.NewInt(1e18)
+	amountOutMin = big.NewInt(1)
+)
+
+var (
+	signerPrivateKey = os.Getenv("PRIVATE_KEY")
+)
+
+func logTokenBalances(client *uniswap.Client) {
+	tokenInBalance, err := client.GetTokenBalance(tokenInAddress)
+	if err != nil {
+		log.Printf("Error getting input token balance: %v", err)
+		return
+	}
+	log.Printf("input token balance: %s", tokenInBalance.String())
+
+	tokenOutBalance, err := client.GetTokenBalance(tokenOutAddress)
+	if err != nil {
+		log.Printf("Error getting output token balance: %v", err)
+		return
+	}
+	log.Printf("output token balance: %s", tokenOutBalance.String())
+}
+
+func main() {
+	cfg := uniswap.Config{
+		GasLimitBuffer:   50000,
+		SwapGasLimit:     1000000,
+		DeadlineDuration: 15 * time.Minute,
+	}
+
+	uniswapClient, err := uniswap.NewClient(rpcURL, uniswapV2RouterAddress, signerPrivateKey, cfg)
+	if err != nil {
+		log.Fatalf("Failed to initialize Uniswap client: %v", err)
+	}
+
+	tokensPair := []common.Address{tokenInAddress, tokenOutAddress}
+
+	// fetch token pair amount out
+	expectedAmountOut, err := uniswapClient.GetExpectedAmountOut(swapAmountIn, tokensPair)
+	if err != nil {
+		log.Fatalf("Failed to get expected amount out: %v", err)
+	}
+	log.Println("Expected amount out:", expectedAmountOut.String())
+
+	// calculate output amount with slippage
+	slippagePercentage := 1.0
+	amountOutMin := uniswapClient.CalculateAmountOutMin(expectedAmountOut, slippagePercentage)
+
+	// mint WETH
+	log.Println("Minting WETH...")
+	logTokenBalances(uniswapClient)
+	if err := uniswapClient.MintWETH(swapAmountIn, tokenInAddress); err != nil {
+		log.Fatalf("Failed to mint WETH: %v", err)
+	}
+	logTokenBalances(uniswapClient)
+
+	// approve Router to spend input token
+	log.Printf("Approving Uniswap Router to spend %s...", tokenInAddress.Hex())
+	if err := uniswapClient.ApproveERC20Token(tokenInAddress, uniswapV2RouterAddress, swapAmountIn); err != nil {
+		log.Fatalf("Failed to approve token: %v", err)
+	}
+
+	// swap tokens
+	if err := uniswapClient.SwapTokens(swapAmountIn, amountOutMin, tokensPair); err != nil {
+		log.Fatalf("Failed to swap tokens: %v", err)
+	}
+	logTokenBalances(uniswapClient)
+}