E2E: make sure that contract account's state doesn't vanish after emptying its wallet

utils/e2e-tests/ts/lib/abis/deposit.ts

@@ -0,0 +1,29 @@
+// pragma solidity ^0.8.13;
+//
+// contract Deposit {
+//     constructor() payable {}
+//
+//     function withdrawAll() external {
+//         (bool success, ) = msg.sender.call{value: address(this).balance}("");
+//         require(success, "Transfer failed!");
+//     }
+// }
+
+export default {
+  abi: [
+    {
+      type: "constructor",
+      inputs: [],
+      stateMutability: "payable",
+    },
+    {
+      type: "function",
+      name: "withdrawAll",
+      inputs: [],
+      outputs: [],
+      stateMutability: "nonpayable",
+    },
+  ],
+  bytecode:
+    "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",
+} as const;

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

@@ -0,0 +1,71 @@
+import { describe, it, expect, assert } from "vitest";
+import { RunNodeState, runNode } from "../../lib/node";
+import * as eth from "../../lib/ethViem";
+import deposit from "../../lib/abis/deposit";
+import "../../lib/expect";
+import { beforeEachWithCleanup } from "../../lib/lifecycle";
+
+describe("contract account's nonce", () => {
+  let node: RunNodeState;
+  let publicClient: eth.PublicClientWebSocket;
+  let devClients: eth.DevClientsWebSocket;
+  beforeEachWithCleanup(async (cleanup) => {
+    node = runNode({ args: ["--dev", "--tmp"] }, cleanup.push);
+
+    await node.waitForBoot;
+
+    publicClient = eth.publicClientFromNodeWebSocket(node, cleanup.push);
+    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: deposit.abi,
+      bytecode: deposit.bytecode,
+      value: 1n, // Even the smallest deposit is enough
+      gas: 150_274n,
+    });
+    const deployContractTxReceipt =
+      await publicClient.waitForTransactionReceipt({
+        hash: deployContractTxHash,
+        timeout: 18_000,
+      });
+    expect(deployContractTxReceipt.status).toBe("success");
+    const contract = deployContractTxReceipt.contractAddress;
+    assert(contract);
+
+    // 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: contract,
+      abi: deposit.abi,
+      functionName: "withdrawAll",
+      gas: 30_585n,
+    });
+    const withdrawalReceipt = await publicClient.waitForTransactionReceipt({
+      hash: withdrawalTx,
+      timeout: 18_000,
+    });
+    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);
+  });
+});