From c7d85002292719e8d1d5bf28d4e1d3be45eaf568 Mon Sep 17 00:00:00 2001
From: jouzo <jdesclercs@gmail.com>
Date: Mon, 15 May 2023 13:19:20 +0100
Subject: [PATCH] Restore check account balance on EvmOut RPC call

---
 lib/ain-evm/src/backend.rs     |  6 ++---
 lib/ain-evm/src/evm.rs         | 45 +++++++++++++++++++++++-----------
 test/functional/feature_evm.py |  2 +-
 3 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/lib/ain-evm/src/backend.rs b/lib/ain-evm/src/backend.rs
index 6aae6816a3..f829d0c309 100644
--- a/lib/ain-evm/src/backend.rs
+++ b/lib/ain-evm/src/backend.rs
@@ -283,9 +283,9 @@ use std::{error::Error, fmt, sync::Arc};
 
 #[derive(Debug)]
 pub struct InsufficientBalance {
-    address: H160,
-    account_balance: U256,
-    amount: U256,
+    pub address: H160,
+    pub account_balance: U256,
+    pub amount: U256,
 }
 
 #[derive(Debug)]
diff --git a/lib/ain-evm/src/evm.rs b/lib/ain-evm/src/evm.rs
index c50c85b50a..df3e9c6831 100644
--- a/lib/ain-evm/src/evm.rs
+++ b/lib/ain-evm/src/evm.rs
@@ -1,9 +1,9 @@
-use crate::backend::{EVMBackend, EVMBackendError, Vicinity};
+use crate::backend::{EVMBackend, EVMBackendError, InsufficientBalance, Vicinity};
 use crate::executor::TxResponse;
 use crate::storage::traits::{BlockStorage, PersistentState, PersistentStateError};
 use crate::storage::Storage;
 use crate::transaction::bridge::{BalanceUpdate, BridgeTx};
-use crate::tx_queue::{QueueTx, TransactionQueueMap};
+use crate::tx_queue::{QueueError, QueueTx, TransactionQueueMap};
 use crate::{
     executor::AinExecutor,
     traits::{Executor, ExecutorContext},
@@ -196,12 +196,7 @@ impl EVMHandler {
 }
 
 impl EVMHandler {
-    pub fn queue_tx(
-        &self,
-        context: u64,
-        tx: QueueTx,
-        hash: NativeTxHash,
-    ) -> Result<(), Box<dyn Error>> {
+    pub fn queue_tx(&self, context: u64, tx: QueueTx, hash: NativeTxHash) -> Result<(), EVMError> {
         self.tx_queues.queue_tx(context, tx, hash)?;
         Ok(())
     }
@@ -211,7 +206,7 @@ impl EVMHandler {
         address: H160,
         amount: U256,
         hash: NativeTxHash,
-    ) -> Result<(), Box<dyn Error>> {
+    ) -> Result<(), EVMError> {
         let queue_tx = QueueTx::BridgeTx(BridgeTx::EvmIn(BalanceUpdate { address, amount }));
         self.tx_queues.queue_tx(context, queue_tx, hash)?;
         Ok(())
@@ -223,17 +218,31 @@ impl EVMHandler {
         address: H160,
         amount: U256,
         hash: NativeTxHash,
-    ) -> Result<(), Box<dyn Error>> {
-        let queue_tx = QueueTx::BridgeTx(BridgeTx::EvmOut(BalanceUpdate { address, amount }));
-        self.tx_queues.queue_tx(context, queue_tx, hash)?;
-        Ok(())
+    ) -> Result<(), EVMError> {
+        let block_number = self
+            .storage
+            .get_latest_block()
+            .map_or(U256::default(), |block| block.header.number);
+        let balance = self.get_balance(address, block_number)?;
+        if balance < amount {
+            Err(EVMBackendError::InsufficientBalance(InsufficientBalance {
+                address,
+                account_balance: balance,
+                amount,
+            })
+            .into())
+        } else {
+            let queue_tx = QueueTx::BridgeTx(BridgeTx::EvmOut(BalanceUpdate { address, amount }));
+            self.tx_queues.queue_tx(context, queue_tx, hash)?;
+            Ok(())
+        }
     }
 
     pub fn get_context(&self) -> u64 {
         self.tx_queues.get_context()
     }
 
-    pub fn clear(&self, context: u64) -> Result<(), Box<dyn Error>> {
+    pub fn clear(&self, context: u64) -> Result<(), EVMError> {
         self.tx_queues.clear(context)?;
         Ok(())
     }
@@ -316,6 +325,7 @@ use std::fmt;
 #[derive(Debug)]
 pub enum EVMError {
     BackendError(EVMBackendError),
+    QueueError(QueueError),
     NoSuchAccount(H160),
     TrieError(String),
 }
@@ -324,6 +334,7 @@ impl fmt::Display for EVMError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             EVMError::BackendError(e) => write!(f, "EVMError: Backend error: {e}"),
+            EVMError::QueueError(e) => write!(f, "EVMError: Queue error: {e}"),
             EVMError::NoSuchAccount(address) => {
                 write!(f, "EVMError: No such acccount for address {address:#x}")
             }
@@ -340,4 +351,10 @@ impl From<EVMBackendError> for EVMError {
     }
 }
 
+impl From<QueueError> for EVMError {
+    fn from(e: QueueError) -> Self {
+        EVMError::QueueError(e)
+    }
+}
+
 impl std::error::Error for EVMError {}
diff --git a/test/functional/feature_evm.py b/test/functional/feature_evm.py
index b75d98477e..4b77bd547b 100755
--- a/test/functional/feature_evm.py
+++ b/test/functional/feature_evm.py
@@ -102,7 +102,7 @@ def run_test(self):
         assert_raises_rpc_error(-32600, "sum of inputs (from) != sum of outputs (to)", self.nodes[0].transferdomain, 1, {address:["100@BTC"]}, {ethAddress:["100@DFI"]})
         assert_raises_rpc_error(-32600, "sum of inputs (from) != sum of outputs (to)", self.nodes[0].transferdomain, 1, {address:["100@DFI"]}, {ethAddress:["100@BTC"]})
         assert_raises_rpc_error(-32600, "For \"evmin\" transfers, only DFI token is currently supported", self.nodes[0].transferdomain, 1, {address:["100@BTC"]}, {ethAddress:["100@BTC"]})
-        #assert_raises_rpc_error(-32600, "Not enough balance in " + ethAddress + " to cover \"evmout\" transfer", self.nodes[0].transferdomain, 2, {ethAddress:["100@DFI"]}, {address:["100@DFI"]})
+        assert_raises_rpc_error(-32600, "Not enough balance in " + ethAddress + " to cover \"evmout\" transfer", self.nodes[0].transferdomain, 2, {ethAddress:["100@DFI"]}, {address:["100@DFI"]})
 
         self.nodes[0].transferdomain(1,{address:["100@DFI"]}, {ethAddress:["100@DFI"]})
         self.nodes[0].generate(1)