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/styles/main.css

@@ -19,16 +19,3 @@ body {
     width: 396px;
     overflow-x: hidden;
 }
-
-/* Copy-flash feedback: inverts colors then fades back */
-.copy-flash-active {
-    background-color: var(--color-fg) !important;
-    color: var(--color-bg) !important;
-    transition: none;
-}
-
-.copy-flash-fade {
-    transition:
-        background-color 300ms ease-out,
-        color 300ms ease-out;
-}

src/popup/views/addressDetail.js

@@ -2,7 +2,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     balanceLinesForAddress,
     addressDotHtml,
     addressTitle,
@@ -242,7 +241,6 @@ function init(_ctx) {
         if (addr) {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");
-            flashCopyFeedback($("address-full"));
         }
     });
 
@@ -360,7 +358,6 @@ function init(_ctx) {
         if (key) {
             navigator.clipboard.writeText(key);
             showFlash("Copied!");
-            flashCopyFeedback($("export-privkey-value"));
         }
     });
 
@@ -369,7 +366,6 @@ function init(_ctx) {
         if (full) {
             navigator.clipboard.writeText(full);
             showFlash("Copied!");
-            flashCopyFeedback($("export-privkey-address"));
         }
     });
 

src/popup/views/addressToken.js

@@ -5,7 +5,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     addressDotHtml,
     addressTitle,
     escapeHtml,
@@ -318,7 +317,6 @@ function init(_ctx) {
         if (addr) {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");
-            flashCopyFeedback($("address-token-full"));
         }
     });
 
@@ -327,7 +325,6 @@ function init(_ctx) {
         if (copyEl) {
             navigator.clipboard.writeText(copyEl.dataset.copy);
             showFlash("Copied!");
-            flashCopyFeedback(copyEl);
         }
     });
 
@@ -376,7 +373,6 @@ function init(_ctx) {
             copyEl.addEventListener("click", () => {
                 navigator.clipboard.writeText(copyEl.dataset.copy);
                 showFlash("Copied!");
-                flashCopyFeedback(copyEl);
             });
         }
         updateSendBalance();

src/popup/views/confirmTx.js

@@ -15,7 +15,6 @@ const {
     hideError,
     showView,
     showFlash,
-    flashCopyFeedback,
     addressTitle,
     addressDotHtml,
     escapeHtml,
@@ -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;
 
@@ -118,7 +153,6 @@ function show(txInfo) {
             copyEl.onclick = () => {
                 navigator.clipboard.writeText(copyEl.dataset.copy);
                 showFlash("Copied!");
-                flashCopyFeedback(copyEl);
             };
         }
     } else {
@@ -178,18 +212,10 @@ function show(txInfo) {
         warnings.push("You are sending to your own address.");
     }
 
-    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">WARNING: ${w}</div>`,
-            )
-            .join("");
-        warningsEl.classList.remove("hidden");
-    } else {
-        warningsEl.classList.add("hidden");
-    }
+    renderWarnings(warnings);
+
+    // Async check: warn if destination address has zero transaction history
+    checkAddressHistory(txInfo.to, warnings);
 
     // Check for errors
     const errors = [];

src/popup/views/helpers.js

@@ -259,26 +259,12 @@ function timeAgo(timestamp) {
     return years + " year" + (years !== 1 ? "s" : "") + " ago";
 }
 
-function flashCopyFeedback(el) {
-    if (!el) return;
-    el.classList.remove("copy-flash-fade");
-    el.classList.add("copy-flash-active");
-    setTimeout(() => {
-        el.classList.remove("copy-flash-active");
-        el.classList.add("copy-flash-fade");
-        setTimeout(() => {
-            el.classList.remove("copy-flash-fade");
-        }, 350);
-    }, 100);
-}
-
 module.exports = {
     $,
     showError,
     hideError,
     showView,
     showFlash,
-    flashCopyFeedback,
     balanceLine,
     balanceLinesForAddress,
     addressColor,

src/popup/views/home.js

@@ -2,7 +2,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     balanceLinesForAddress,
     isoDate,
     timeAgo,
@@ -86,10 +85,9 @@ function renderActiveAddress() {
         el.innerHTML =
             `<span class="underline decoration-dashed cursor-pointer" id="active-addr-copy">${dot}${escapeHtml(addr)}</span>` +
             `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-        $("active-addr-copy").addEventListener("click", (e) => {
+        $("active-addr-copy").addEventListener("click", () => {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
         });
     } else {
         el.textContent = "";

src/popup/views/receive.js

@@ -2,7 +2,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     formatAddressHtml,
     addressTitle,
 } = require("./helpers");
@@ -61,12 +60,11 @@ function show() {
 }
 
 function init(ctx) {
-    $("receive-address-block").addEventListener("click", (e) => {
+    $("receive-address-block").addEventListener("click", () => {
         const addr = $("receive-address-block").dataset.full;
         if (addr) {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
         }
     });
 
@@ -75,7 +73,6 @@ function init(ctx) {
         if (addr) {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");
-            flashCopyFeedback($("receive-address-block"));
         }
     });
 

src/popup/views/transactionDetail.js

@@ -5,7 +5,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     addressDotHtml,
     addressTitle,
     escapeHtml,
@@ -159,9 +158,8 @@ function render() {
         loadCalldata(tx.hash, tx.to);
     }
 
-    const isoStr = isoDate(tx.timestamp);
-    $("tx-detail-time").innerHTML =
-        copyableHtml(isoStr) + " (" + escapeHtml(timeAgo(tx.timestamp)) + ")";
+    $("tx-detail-time").textContent =
+        isoDate(tx.timestamp) + " (" + timeAgo(tx.timestamp) + ")";
     $("tx-detail-status").textContent = tx.isError ? "Failed" : "Success";
     showView("transaction");
 
@@ -172,7 +170,6 @@ function render() {
             el.onclick = () => {
                 navigator.clipboard.writeText(el.dataset.copy);
                 showFlash("Copied!");
-                flashCopyFeedback(el);
             };
         });
 }
@@ -250,7 +247,6 @@ async function loadCalldata(txHash, toAddress) {
                 el.onclick = () => {
                     navigator.clipboard.writeText(el.dataset.copy);
                     showFlash("Copied!");
-                    flashCopyFeedback(el);
                 };
             });
         }

src/popup/views/txStatus.js

@@ -4,7 +4,6 @@ const {
     $,
     showView,
     showFlash,
-    flashCopyFeedback,
     addressDotHtml,
     addressTitle,
     escapeHtml,
@@ -60,16 +59,6 @@ function txHashHtml(hash) {
     );
 }
 
-function blockNumberHtml(blockNumber) {
-    const num = String(blockNumber);
-    const link = `https://etherscan.io/block/${num}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-    return (
-        `<span class="underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(num)}">${escapeHtml(num)}</span>` +
-        extLink
-    );
-}
-
 function attachCopyHandlers(viewId) {
     document
         .getElementById(viewId)
@@ -78,7 +67,6 @@ function attachCopyHandlers(viewId) {
             el.onclick = () => {
                 navigator.clipboard.writeText(el.dataset.copy);
                 showFlash("Copied!");
-                flashCopyFeedback(el);
             };
         });
 }
@@ -201,7 +189,7 @@ function renderSuccess() {
         $("success-tx-to").innerHTML = toAddressHtml(d.to);
     }
 
-    $("success-tx-block").innerHTML = blockNumberHtml(d.blockNumber);
+    $("success-tx-block").textContent = String(d.blockNumber);
     $("success-tx-hash").innerHTML = txHashHtml(d.hash);
 
     // Show decoded calldata details if present