Reduce faucet payout to 0.1 LSK (#20)

* 🔨 Add support for non-integer payout values

* 🌱 Add fork sync workflow

.env

@@ -3,4 +3,4 @@ PRIVATE_KEY=
 KEYSTORE=
 ERC20_TOKEN_ADDRESS=
 HCAPTCHA_SITEKEY=
-HCAPTCHA_SECRET=
+HCAPTCHA_SECRET=

.github/workflows/fork-sync.yml

@@ -0,0 +1,20 @@
+name: Sync Fork
+
+on:
+  schedule:
+    - cron: "0 0 * * 1" # once a week on Monday
+  workflow_dispatch: # on button click
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: tgymnich/[email protected]
+        with:
+          owner: chainflag
+          repo: eth-faucet
+          head: main
+          base: main
+          pr_title: Sync forked repo
+          pr_message: Merge latest changes from upstream repo

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:lts-alpine as frontend
+FROM node:lts-alpine AS frontend
 
 WORKDIR /frontend-build
 
@@ -8,7 +8,7 @@ RUN yarn install
 COPY web ./
 RUN yarn build
 
-FROM golang:1.22-alpine as backend
+FROM golang:1.22-alpine AS backend
 
 RUN apk add --no-cache gcc musl-dev linux-headers
 

Makefile

@@ -40,7 +40,7 @@ generate-binding: generate-abi
 test: # Runs tests
 	@echo "Test packages"
 	go test -race -shuffle=on -coverprofile=coverage.out -cover $(PKGS)
-	
+
 lint: # Runs golangci-lint on the repo
 	@go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
 	golangci-lint run
@@ -66,4 +66,4 @@ docker-stop:
 
 .PHONY: help
 help: # Show help for each of the Makefile recipes
-	@grep -E '^[a-zA-Z0-9 -]+:.*#'  Makefile | sort | while read -r l; do printf "$(GREEN)$$(echo $$l | cut -f 1 -d':')$(COLOR_END):$$(echo $$l | cut -f 2- -d'#')\n"; done
+	@grep -E '^[a-zA-Z0-9 -]+:.*#'  Makefile | sort | while read -r l; do printf "$(GREEN)$$(echo $$l | cut -f 1 -d':')$(COLOR_END):$$(echo $$l | cut -f 2- -d'#')\n"; done

README.md

@@ -47,7 +47,7 @@ make generate-binding ERC20_CONTRACT_FILE_PATH=<erc20-contract-file-path>
 
 **NOTE**: Please make sure to generate the Go binding corresponding to your contract before building the project.
 
-4. Build Go project 
+4. Build Go project
 ```bash
 make build-backend
 ```
@@ -102,6 +102,7 @@ The following are the available command-line flags(excluding above wallet flags)
 | -httpport         | Listener port to serve HTTP connection              | 8080                                       |
 | -proxycount       | Count of reverse proxies in front of the server     | 0                                          |
 | -token.address    | Token contract address                              | 0x8a21CF9Ba08Ae709D64Cb25AfAA951183EC9FF6D |
+| -token.decimals   | Token decimals                                      | 18                                         |
 | -faucet.amount    | Number of ERC20 tokens to transfer per user request | 1                                          |
 | -faucet.minutes   | Number of minutes to wait between funding rounds    | 10080 (1 week)                             |
 | -faucet.name      | Network name to display on the frontend             | sepolia                                    |

cmd/server.go

@@ -20,13 +20,14 @@ var (
 	appVersion = "v1.1.0"
 	chainIDMap = map[string]int{"lisk_sepolia": 4202}
 
-	tokenAddress = flag.String("token.address", os.Getenv("ERC20_TOKEN_ADDRESS"), "Contract address of ERC20 token")
+	tokenAddress      = flag.String("token.address", os.Getenv("ERC20_TOKEN_ADDRESS"), "Contract address of ERC20 token")
+	tokenDecimalsFlag = flag.Int("token.decimals", 18, "Token decimals")
 
 	httpPortFlag = flag.Int("httpport", 8080, "Listener port to serve HTTP connection")
 	proxyCntFlag = flag.Int("proxycount", 0, "Count of reverse proxies in front of the server")
 	versionFlag  = flag.Bool("version", false, "Print version number")
 
-	payoutFlag   = flag.Int("faucet.amount", 1, "Number of ERC20 tokens to transfer per user request")
+	payoutFlag   = flag.Float64("faucet.amount", 0.1, "Number of ERC20 tokens to transfer per user request")
 	intervalFlag = flag.Int("faucet.minutes", 10080, "Number of minutes to wait between funding rounds")
 	netnameFlag  = flag.String("faucet.name", "lisk_sepolia", "Network name to display on the frontend")
 	symbolFlag   = flag.String("faucet.symbol", "LSK", "Token symbol to display on the frontend")
@@ -65,7 +66,7 @@ func Execute() {
 	if err != nil {
 		panic(fmt.Errorf("cannot connect to web3 provider: %w", err))
 	}
-	config := server.NewConfig(*netnameFlag, *symbolFlag, *httpPortFlag, *intervalFlag, *payoutFlag, *proxyCntFlag, *hcaptchaSiteKeyFlag, *hcaptchaSecretFlag, *explorerURL, *explorerTxPath)
+	config := server.NewConfig(*netnameFlag, *symbolFlag, *payoutFlag, *tokenDecimalsFlag, *httpPortFlag, *intervalFlag, *proxyCntFlag, *hcaptchaSiteKeyFlag, *hcaptchaSecretFlag, *explorerURL, *explorerTxPath)
 	go server.NewServer(txBuilder, config).Run()
 
 	c := make(chan os.Signal, 1)

internal/chain/util.go

@@ -1,16 +1,12 @@
 package chain
 
 import (
+	"math"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 )
 
-func EtherToWei(amount int64) *big.Int {
-	ether := new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil)
-	return new(big.Int).Mul(big.NewInt(amount), ether)
-}
-
 func Has0xPrefix(str string) bool {
 	return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X')
 }
@@ -22,11 +18,16 @@ func IsValidAddress(address string, checksummed bool) bool {
 	return !checksummed || common.HexToAddress(address).Hex() == address
 }
 
-func LSKToWei(amount int64) *big.Int {
-	oneLskInWei := new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil)
-	return new(big.Int).Mul(big.NewInt(amount), oneLskInWei)
-}
-
 func addLeftPadding(input []byte) []byte {
 	return common.LeftPadBytes(input, 32)
 }
+
+func TokenToWei(amount float64, decimals int) *big.Int {
+	ethDecimals := 18
+	oneEthToWei := math.Pow10(ethDecimals)
+
+	amountInt := int64(amount * oneEthToWei)
+
+	oneTokenInWei := new(big.Int).Exp(big.NewInt(10), big.NewInt(int64(decimals)), nil)
+	return new(big.Int).Div(new(big.Int).Mul(big.NewInt(amountInt), oneTokenInWei), big.NewInt(int64(oneEthToWei)))
+}

internal/chain/util_test.go

@@ -34,40 +34,24 @@ func TestIsValidAddress(t *testing.T) {
 	}
 }
 
-func TestEtherToWei(t *testing.T) {
+func TestTokenToWei(t *testing.T) {
 	tests := []struct {
-		name   string
-		amount int64
-		want   *big.Int
+		name          string
+		amount        float64
+		tokenDecimals int
+		want          *big.Int
 	}{
-		{name: "1ether", amount: 1, want: new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil)},
+		{name: "1ether", amount: 1, tokenDecimals: 18, want: new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil)},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := EtherToWei(tt.amount); !reflect.DeepEqual(got, tt.want) {
+			if got := TokenToWei(tt.amount, tt.tokenDecimals); !reflect.DeepEqual(got, tt.want) {
 				t.Errorf("EtherToWei() = %v, want %v", got, tt.want)
 			}
 		})
 	}
 }
 
-func Test_LSKToWei(t *testing.T) {
-	tests := []struct {
-		name   string
-		amount int64
-		want   *big.Int
-	}{
-		{name: "should convert 1 LSK to 10^18 Wei", amount: 1, want: big.NewInt(1000000000000000000)},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := LSKToWei(tt.amount); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("LSKToWei() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
 func Test_addLeftPadding(t *testing.T) {
 	tests := []struct {
 		name  string

internal/server/config.go

@@ -3,23 +3,25 @@ package server
 type Config struct {
 	network         string
 	symbol          string
+	payout          float64
+	tokenDecimals   int
 	httpPort        int
 	interval        int
-	payout          int
 	proxyCount      int
 	hcaptchaSiteKey string
 	hcaptchaSecret  string
 	explorerURL     string
 	explorerTxPath  string
 }
 
-func NewConfig(network, symbol string, httpPort, interval, payout, proxyCount int, hcaptchaSiteKey, hcaptchaSecret, explorerURL, explorerTxPath string) *Config {
+func NewConfig(network, symbol string, payout float64, tokenDecimals, httpPort, interval, proxyCount int, hcaptchaSiteKey, hcaptchaSecret, explorerURL, explorerTxPath string) *Config {
 	return &Config{
 		network:         network,
 		symbol:          symbol,
 		httpPort:        httpPort,
 		interval:        interval,
 		payout:          payout,
+		tokenDecimals:   tokenDecimals,
 		proxyCount:      proxyCount,
 		hcaptchaSiteKey: hcaptchaSiteKey,
 		hcaptchaSecret:  hcaptchaSecret,

internal/server/server.go

@@ -65,7 +65,7 @@ func (s *Server) handleClaim() http.HandlerFunc {
 			currBalance = big.NewInt(0)
 		}
 
-		txHash, err := s.TransferERC20(ctx, address, chain.LSKToWei(int64(s.cfg.payout)), currBalance)
+		txHash, err := s.TransferERC20(ctx, address, chain.TokenToWei(s.cfg.payout, s.cfg.tokenDecimals), currBalance)
 		if err != nil {
 			log.WithError(err).Error("failed to send transaction")
 			renderJSON(w, claimResponse{Message: err.Error()}, http.StatusInternalServerError)
@@ -91,7 +91,7 @@ func (s *Server) handleInfo() http.HandlerFunc {
 			Account:         s.Sender().String(),
 			Network:         s.cfg.network,
 			Symbol:          s.cfg.symbol,
-			Payout:          strconv.Itoa(s.cfg.payout),
+			Payout:          strconv.FormatFloat(s.cfg.payout, 'f', -1, 64),
 			HcaptchaSiteKey: s.cfg.hcaptchaSiteKey,
 			ExplorerURL:     s.cfg.explorerURL,
 			ExplorerTxPath:  s.cfg.explorerTxPath,