feat: show red warning on confirm-tx for addresses with zero transaction history

When sending to an address that has never sent or received funds (zero
nonce and zero balance), display a prominent red warning on the
transaction confirmation screen advising the user to double-check the
address.

Closes #82

src/popup/views/confirmTx.js

@@ -25,7 +25,6 @@ const { decryptWithPassword } = require("../../shared/vault");
 const { formatUsd, getPrice } = require("../../shared/prices");
 const { getProvider } = require("../../shared/balances");
 const { isScamAddress } = require("../../shared/scamlist");
-const { hasZeroTransactionHistory } = require("../../shared/transactions");
 const { ERC20_ABI } = require("../../shared/constants");
 const { log } = require("../../shared/log");
 const makeBlockie = require("ethereum-blockies-base64");
@@ -87,6 +86,42 @@ function valueWithUsd(text, usdAmount) {
     return text;
 }
 
+function renderWarnings(warnings) {
+    const warningsEl = $("confirm-warnings");
+    if (warnings.length > 0) {
+        warningsEl.innerHTML = warnings
+            .map(
+                (w) =>
+                    `<div class="border border-border border-dashed p-2 mb-1 text-xs font-bold" style="color:#c00">WARNING: ${w}</div>`,
+            )
+            .join("");
+        warningsEl.classList.remove("hidden");
+    } else {
+        warningsEl.classList.add("hidden");
+    }
+}
+
+async function checkAddressHistory(address, existingWarnings) {
+    try {
+        const provider = getProvider(state.rpcUrl);
+        const [balance, txCount] = await Promise.all([
+            provider.getBalance(address),
+            provider.getTransactionCount(address),
+        ]);
+        if (balance === 0n && txCount === 0) {
+            const warnings = existingWarnings.slice();
+            warnings.push(
+                "This address has ZERO transaction history. " +
+                    "It has never sent or received funds. " +
+                    "Double-check that the address is correct before sending.",
+            );
+            renderWarnings(warnings);
+        }
+    } catch (e) {
+        log.errorf("address history check failed:", e.message);
+    }
+}
+
 function show(txInfo) {
     pendingTx = txInfo;
 
@@ -177,18 +212,10 @@ function show(txInfo) {
         warnings.push("You are sending to your own address.");
     }
 
-    const warningsEl = $("confirm-warnings");
+    renderWarnings(warnings);
-    if (warnings.length > 0) {
+
-        warningsEl.innerHTML = warnings
+    // Async check: warn if destination address has zero transaction history
-            .map(
+    checkAddressHistory(txInfo.to, warnings);
-                (w) =>
-                    `<div class="border border-border border-dashed p-2 mb-1 text-xs font-bold">WARNING: ${w}</div>`,
-            )
-            .join("");
-        warningsEl.classList.remove("hidden");
-    } else {
-        warningsEl.classList.add("hidden");
-    }
 
     // Check for errors
     const errors = [];
@@ -245,7 +272,6 @@ function show(txInfo) {
     showView("confirm-tx");
 
     estimateGas(txInfo);
-    checkRecipientHistory(txInfo);
 }
 
 async function estimateGas(txInfo) {
@@ -288,23 +314,6 @@ async function estimateGas(txInfo) {
     }
 }
 
-async function checkRecipientHistory(txInfo) {
-    const isNew = await hasZeroTransactionHistory(
-        txInfo.to,
-        state.blockscoutUrl,
-    );
-    if (!isNew) return;
-
-    const warningsEl = $("confirm-warnings");
-    const warningHtml =
-        `<div class="border border-red-500 border-dashed p-2 mb-1 text-xs font-bold text-red-500">` +
-        `WARNING: This address has ZERO transaction history. ` +
-        `It has never sent or received any funds. ` +
-        `Double-check the address before sending.</div>`;
-    warningsEl.innerHTML = warningHtml + warningsEl.innerHTML;
-    warningsEl.classList.remove("hidden");
-}
-
 function init(ctx) {
     $("btn-confirm-send").addEventListener("click", async () => {
         const password = $("confirm-tx-password").value;

src/shared/transactions.js

@@ -251,40 +251,4 @@ function filterTransactions(txs, filters = {}) {
     return { transactions: filtered, newFraudContracts: newFraud };
 }
 
-/**
+module.exports = { fetchRecentTransactions, filterTransactions };
- * Check whether an address has any on-chain transaction history.
- * Returns true if the address has zero normal transactions AND zero
- * token transfers on the configured Blockscout instance.
- * Returns false on network errors (fail-open: don't block sends).
- */
-async function hasZeroTransactionHistory(address, blockscoutUrl) {
-    try {
-        const resp = await debugFetch(
-            blockscoutUrl + "/addresses/" + address + "/transactions?limit=1",
-        );
-        if (!resp.ok) return false;
-        const json = await resp.json();
-        if ((json.items || []).length > 0) return false;
-
-        // Also check token transfers — an address may have only received
-        // ERC-20 tokens without any native ETH transactions.
-        const ttResp = await debugFetch(
-            blockscoutUrl +
-                "/addresses/" +
-                address +
-                "/token-transfers?type=ERC-20&limit=1",
-        );
-        if (!ttResp.ok) return false;
-        const ttJson = await ttResp.json();
-        return (ttJson.items || []).length === 0;
-    } catch (e) {
-        log.errorf("hasZeroTransactionHistory check failed:", e.message);
-        return false;
-    }
-}
-
-module.exports = {
-    fetchRecentTransactions,
-    filterTransactions,
-    hasZeroTransactionHistory,
-};