add check sufficient balance for amount with gas price

Author: Puneethkumarck

ethereum-app/src/main/java/com/blockchain/api/domain/service/transfer/TransferService.java

@@ -30,8 +30,10 @@ public class TransferService {
 
   public void transfer(TransferRequest transactionRequest) {
     var toAddress = transactionRequest.to();
+    var transactionFee = transactionFeeService.getTransactionFee();
     var amount = transactionRequest.amount();
-    isBalanceSufficient(amount);
+    var totalAmount = new BigDecimal(amount).add(transactionFee);
+    isBalanceSufficient(totalAmount);
     var fromAddress = credentialService.getCredential().getAddress();
     var nonce = transferClient.getNonce(fromAddress).join();
     var gasPrice = transferClient.getGasPrice().join();
@@ -69,9 +71,9 @@ private byte[] signTransaction(RawTransaction transaction) {
         transaction, SEPOLIA_CHAIN_ID, credentialService.getCredential());
   }
 
-  private void isBalanceSufficient(String amount) {
+  private void isBalanceSufficient(BigDecimal amount) {
     var toAddress = credentialService.getCredential().getAddress();
-    if (!balanceService.isBalanceSufficient(toAddress, new BigDecimal(amount))) {
+    if (!balanceService.isBalanceSufficient(toAddress, amount)) {
       throw InsufficientBalanceException.create(
           "Insufficient balance for address: %s".formatted(toAddress));
     }

ethereum-app/src/test/java/com/blockchain/api/application/controller/businesstest/TransferControllerBusinessTest.java

@@ -92,7 +92,7 @@ void shouldTransferEth() {
     var transferRequestDto =
         EthTransferRequestDto.builder()
             .to("0x5d940f3947c4ab1fbdbf1f540a10019931065f7a")
-            .amount("0.1")
+            .amount("0.0001")
             .build();
     stubGetNonce();
     stubGasPrice();

ethereum-app/src/test/java/com/blockchain/api/domain/service/transfer/TransactionFeeServiceITest.java

@@ -0,0 +1,32 @@
+package com.blockchain.api.domain.service.transfer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.blockchain.api.infrastructure.client.BaseEthereumTest;
+import java.math.BigDecimal;
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+@SpringBootTest
+@ActiveProfiles("test")
+@Slf4j
+class TransactionFeeServiceITest extends BaseEthereumTest {
+
+  @Autowired private TransactionFeeService transactionFeeService;
+
+  @Test
+  void shouldReturnTransactionFee_whenTransactionFeeIsCalculated() {
+    // given
+    stubGasPrice();
+    var expectedTransactionFee = new BigDecimal("0.000234686314653000");
+
+    // when
+    var transactionFee = transactionFeeService.getTransactionFee();
+
+    // then
+    assertThat(transactionFee).isEqualByComparingTo(expectedTransactionFee);
+  }
+}

ethereum-app/src/test/java/com/blockchain/api/domain/service/transfer/TransferServiceTest.java

@@ -44,7 +44,8 @@ void shouldTransferEth() {
     when(transferClient.getNonce(fromAddress)).thenReturn(completedFuture(BigInteger.ONE));
     when(transferClient.getGasPrice()).thenReturn(completedFuture(BigInteger.ONE));
     when(credentialService.getCredential()).thenReturn(Credentials.create("0x123"));
-    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.1"))).thenReturn(true);
+    when(transactionFeeService.getTransactionFee()).thenReturn(new BigDecimal("0.1"));
+    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.2"))).thenReturn(true);
 
     // when
     transferService.transfer(transactionRequest);
@@ -66,7 +67,8 @@ void shouldThrowNonceRetrievalException() {
     when(transferClient.getNonce(fromAddress))
         .thenReturn(failedFuture(new NonceRetrievalException(address)));
     when(credentialService.getCredential()).thenReturn(Credentials.create("0x123"));
-    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.1"))).thenReturn(true);
+    when(transactionFeeService.getTransactionFee()).thenReturn(new BigDecimal("0.1"));
+    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.2"))).thenReturn(true);
 
     // when
     var thrownException =
@@ -91,7 +93,9 @@ void shouldThrowGasPriceRetrievalException() {
 
     when(transferClient.getNonce(fromAddress)).thenReturn(completedFuture(BigInteger.ONE));
     when(credentialService.getCredential()).thenReturn(Credentials.create("0x123"));
-    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.1"))).thenReturn(true);
+    when(transactionFeeService.getTransactionFee()).thenReturn(new BigDecimal("0.1"));
+    when(balanceService.isBalanceSufficient(fromAddress, new BigDecimal("0.2"))).thenReturn(true);
+    when(transferClient.getGasPrice()).thenReturn(failedFuture(new RuntimeException("RPC error")));
     when(transferClient.getGasPrice())
         .thenReturn(CompletableFuture.failedFuture(new RuntimeException("RPC error")));