Check contract account's nonce directly (#1402)

Author: quasiyoke

utils/e2e-tests/ts/tests/eth/preserveNonceOnZeroContractBalance.ts

@@ -1,7 +1,7 @@
 import { describe, it, expect, assert } from "vitest";
 import { RunNodeState, runNode } from "../../lib/node";
 import * as eth from "../../lib/ethViem";
-import contractsFactory from "../../lib/abis/deposit";
+import deposit from "../../lib/abis/deposit";
 import "../../lib/expect";
 import { beforeEachWithCleanup } from "../../lib/lifecycle";
 
@@ -18,12 +18,13 @@ describe("contract account's nonce", () => {
     devClients = eth.devClientsFromNodeWebSocket(node, cleanup.push);
   }, 60 * 1000);
 
+  // See also: https://github.com/humanode-network/humanode/issues/1402
   it("is being preserved after zeroing the balance", async () => {
     const [alice, _] = devClients;
 
     const deployContractTxHash = await alice.deployContract({
-      abi: contractsFactory.abi,
-      bytecode: contractsFactory.bytecode,
+      abi: deposit.abi,
+      bytecode: deposit.bytecode,
       value: 1n, // Even the smallest deposit is enough
       gas: 150_274n,
     });
@@ -33,20 +34,38 @@ describe("contract account's nonce", () => {
         timeout: 18_000,
       });
     expect(deployContractTxReceipt.status).toBe("success");
-    const factoryAddress = deployContractTxReceipt.contractAddress;
-    assert(factoryAddress);
+    const contract = deployContractTxReceipt.contractAddress;
+    assert(contract);
 
-    // If there's a bug in the EVM, it will clear the contract state after `withdrawAll`.
+    // The nonce of the contract account immediately after creation.
+    const INITIAL_NONCE = 1;
+
+    // EIP-161 https://eips.ethereum.org/EIPS/eip-161:
+    //
+    // > At the end of the transaction, any account touched by ... that transaction which is now *empty*
+    // > SHALL instead become non-existent (i.e. deleted).
+    // > Where: ...
+    // > An account is considered *empty* when it has no code and zero nonce and zero balance.
+    //
+    // So once the balance is zeroed below, the account state shouldn't be deleted because
+    // the account contains the contract code.
     const withdrawalTx = await alice.writeContract({
-      address: factoryAddress,
-      abi: contractsFactory.abi,
+      address: contract,
+      abi: deposit.abi,
       functionName: "withdrawAll",
       gas: 30_585n,
     });
     const withdrawalReceipt = await publicClient.waitForTransactionReceipt({
       hash: withdrawalTx,
       timeout: 18_000,
     });
-    expect(withdrawalReceipt.status).toBe("success");
+    expect(withdrawalReceipt.status, "status of withdrawal").toBe("success");
+
+    // Ethereum RPC returns the account nonce in the `eth_getTransactionCount` RPC call.
+    // https://github.com/humanode-network/frontier/blob/1afab28e8d5aebe7d44f9043b3ba19e9555123dc/client/rpc/src/eth/state.rs#L116-L169
+    const nonce = await publicClient.getTransactionCount({
+      address: contract,
+    });
+    expect(nonce).toBe(INITIAL_NONCE);
   });
 });