fix: show balances and fees below 0.000001 as nonzero on the send screens (closes #343)

The stored ETH and token balances and the send-confirm screen's fee were each
cut to six decimal places, so a value below 0.000001 read as zero. Balances are
now stored exactly; a token declaring more than 18 decimals is cut to 18, the
most the balance check reads. A token holding below 0.000001 is still left off
the lists as dust, except for a token the user tracks, whose holding now
reaches the Send screen and is what the send is checked against. The send and
send-confirm screens' balances, reserve and insufficient-balance messages go
through truncateAmountNeverZero(). The send-confirm and approval screens both
render the fee through formatFee(), which prices the exact fee in USD. The
balance lists still round with toFixed(4).

Model: opus-5-5

README.md

@@ -892,12 +892,22 @@ shows is a V4 exact-in `amountIn` of zero.
 The rule and its exception live in `src/shared/amountDisplay.js` as
 `truncateAmount()` and `truncateAmountNeverZero()`. Everything the approval and
 confirmation screens display goes through the floored one — the ERC-20 amount,
-the ETH value and max fee (`src/popup/views/approval.js`), and the swap's
-`Amount` and `Min. received` lines (`src/shared/uniswap.js`). The history and
-balance lists (`src/shared/transactions.js`) use the unfloored one: the
-transaction detail view is the authoritative record and already shows exact
-precision. The 4-decimal rule is unchanged everywhere else, including for
-amounts at or above the floor on the approval screens.
+the ETH value and max fee (`src/popup/views/approval.js`), the swap's `Amount`
+and `Min. received` lines (`src/shared/uniswap.js`), the Send screen's
+`Current balance` (`src/popup/views/send.js`), and the balance and network fee
+on the confirmation screen for the wallet's own send
+(`src/popup/views/confirmTx.js`). Both screens render a network fee through
+`formatFee()` in `src/popup/views/helpers.js`, which prices the exact fee in USD
+rather than its truncated figure, so the same fee reads the same on both, USD
+value included. Balances are stored exactly (`src/shared/balances.js`), so a
+balance below the floor reaches these screens as it is; the one cut is that a
+token declaring more than 18 decimals is stored to 18, the most the confirmation
+screen's balance check reads. The history list (`src/shared/transactions.js`)
+uses the unfloored one: the transaction detail view is the authoritative record
+and already shows exact precision. The balance lists use neither: they round to
+four places with `toFixed(4)` (`balanceLine()` in `src/popup/views/helpers.js`).
+The 4-decimal rule is unchanged everywhere else, including for amounts at or
+above the floor on the approval screens.
 
 The floor applies only where the token's scale is known. Where it is not, the
 approval screen states base units instead of a quantity — see Unknown token
@@ -1050,13 +1060,15 @@ Which tokens an address shows is decided by `fetchTokenBalances()` in
 `src/shared/balances.js`, from the Blockscout `token-balances` response, so
 tokens do appear without the user adding them. An ERC-20 is shown when its
 balance is nonzero and it is in the bundled known-token list, is tracked by the
-user, or has 1,000 or more holders; a token claiming a symbol from the bundled
-list from any other contract address is always dropped, and so is any token
-claiming a symbol that belongs to the native asset and therefore has no
-legitimate contract at all (`"ETH"`). That filter is unconditional — the "Hide
-tokens with fewer than 1,000 holders" setting governs the transaction history
-and the send-screen token selector, not this list. Tracked tokens with a zero
-balance are listed as well while "Show tracked tokens with zero balance" is on.
+user, or has 1,000 or more holders. A holding below 0.000001 of a token the user
+does not track is dust and is not shown; a tracked token's holding is shown
+whatever its size. A token claiming a symbol from the bundled list from any
+other contract address is always dropped, and so is any token claiming a symbol
+that belongs to the native asset and therefore has no legitimate contract at all
+(`"ETH"`). That filter is unconditional — the "Hide tokens with fewer than 1,000
+holders" setting governs the transaction history and the send-screen token
+selector, not this list. Tracked tokens with a zero balance are listed as well
+while "Show tracked tokens with zero balance" is on.
 
 #### Stored state and its version
 
@@ -1582,8 +1594,14 @@ view would leave a wallet one click from deletion.
           a value carrying its unit, hex (`0x10`) or exponent (`1e3`) notation —
           is refused with a flash message and the field snaps back to the stored
           threshold, so a number the user did not type is never stored.
-    - Allowed Sites: list with remove buttons
-    - Denied Sites: list with remove buttons
+    - Allowed Sites: the hostnames remembered as allowed, under any address,
+      with remove buttons
+    - Connected Sites: the hostnames of the sites allowed without "Remember my
+      choice" that are still connected, with remove buttons. Only the background
+      holds these, in memory, and Settings asks it for them with
+      `AUTISTMASK_GET_CONNECTED_SITES`
+    - Denied Sites: the hostnames remembered as denied, under any address, with
+      remove buttons
     - About: project link, license, author, version, release date, and the
       commit, which links to the commit in the repository
     - Debug: hidden until revealed, then an "Enable debug mode" checkbox that
@@ -1594,8 +1612,15 @@ view would leave a wallet one click from deletion.
     - `[recovery phrase]` on an HD wallet → **ShowRecoveryPhrase**
     - `[x]` on a wallet → **DeleteWallet**
     - Tap wallet name → inline rename field (no screen change)
-    - `[x]` on a tracked token or a site → removes it in place (no screen
-      change)
+    - `[x]` on a tracked token → removes it in place (no screen change)
+    - `[x]` on an allowed or connected site → disconnects that site, in place:
+      its hostname is dropped from Allowed Sites under every address, and
+      `AUTISTMASK_REMOVE_SITE` has the background end every connection approved
+      without "Remember" from an origin with that hostname, under any address,
+      and send `accountsChanged` with an empty list to the site's open tabs.
+      Only the extension's own pages may send either message
+    - `[x]` on a denied site → forgets the refusal, in place; it connects
+      nothing and tells the background nothing
     - Ten clicks on the version → reveals the Debug well (no screen change)
     - "Back" (or Settings gear again) → previous screen (Home)
 
@@ -1790,7 +1815,8 @@ view would leave a wallet one click from deletion.
 - **Transitions**:
     - "Allow" / "Deny" → closes popup (returns result to background script; the
       choice is persisted to the allowed or denied list when "Remember" is
-      checked)
+      checked, and an "Allow" without it is listed under Connected Sites in
+      **Settings**)
     - Popup closed without answering → treated as a denial
 
 #### TxApproval (`approve-tx`)

TODO.md

@@ -45,6 +45,34 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-04: The Send and confirmation screens no longer show an ETH balance, a
+  token balance or a network fee below 0.000001 as zero
+  ([#343](https://git.eeqj.de/sneak/AutistMask/issues/343)). The stored balances
+  (`src/shared/balances.js`) and the confirmation screen's fee were each cut to
+  six decimal places by a rule of their own. Balances are now stored exactly,
+  except that a token declaring more than 18 decimals is stored to 18, the most
+  the balance check reads. A token holding below 0.000001 is still not listed,
+  but only for a token the user does not track, so a tracked token's holding
+  reaches the Send screen and the send is checked against it. The Send screen's
+  `Current balance`, and the confirmation screen's balance, fee, reserve and
+  insufficient-balance messages, go through `truncateAmountNeverZero()` in
+  `src/shared/amountDisplay.js`, the helper the approval screen already used.
+  The confirmation and approval screens both render the fee through
+  `formatFee()` in `src/popup/views/helpers.js`, which prices the exact fee in
+  USD, so the same fee reads the same on both, USD value included.
+- 2026-10-04: Settings lists the sites connected without "Remember", and
+  removing a site there disconnects it
+  ([#406](https://git.eeqj.de/sneak/AutistMask/issues/406)). Such a connection
+  lives only in the background's in-memory `connectedSites` map, so Settings
+  never showed it and the user could not end it; `AUTISTMASK_REMOVE_SITE`, sent
+  on every remove, did nothing. Settings now asks the background for those sites
+  (`AUTISTMASK_GET_CONNECTED_SITES`) and lists them under Connected Sites.
+  Removing a site from Allowed Sites or Connected Sites drops its remembered
+  entry under every address and sends `AUTISTMASK_REMOVE_SITE` with the
+  hostname; the background deletes every `connectedSites` entry for that
+  hostname and sends `accountsChanged` with an empty list to its open tabs. Only
+  the extension's own pages may send either message. Removing a denied site no
+  longer sends it, since forgetting a refusal ends no connection.
 - 2026-10-04: Removing an address or deleting a wallet ends every site
   connection approved without "Remember" for the addresses removed
   ([#245](https://git.eeqj.de/sneak/AutistMask/issues/245)). Such a connection

src/background/index.js

@@ -1110,6 +1110,24 @@ async function broadcastAccountsChanged() {
     }
 }
 
+// Tell every open tab of a site Settings removed that it has no account.
+async function broadcastSiteRemoved(hostname) {
+    let tabs;
+    try {
+        tabs = await tabsQuery({});
+    } catch {
+        return;
+    }
+    for (const tab of tabs) {
+        if (!tab.url || extractHostname(tab.url) !== hostname) continue;
+        tabsSendMessage(tab.id, {
+            type: "AUTISTMASK_EVENT",
+            eventName: "accountsChanged",
+            data: [],
+        }).catch(() => {});
+    }
+}
+
 // Background balance refresh: every 60 seconds when the popup isn't open.
 // When the popup IS open, its 10-second interval keeps lastBalanceRefresh
 // fresh, so this naturally skips.
@@ -1306,6 +1324,8 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         "AUTISTMASK_TX_RESPONSE",
         "AUTISTMASK_SIGN_RESPONSE",
         "AUTISTMASK_ADDRESSES_REMOVED",
+        "AUTISTMASK_GET_CONNECTED_SITES",
+        "AUTISTMASK_REMOVE_SITE",
     ];
     if (POPUP_ONLY_TYPES.includes(msg.type) && !isExtensionSender(sender)) {
         sendResponse({ error: "Unauthorized sender" });
@@ -1662,8 +1682,28 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
         return false;
     }
 
+    // Settings lists the sites connected without "Remember", which only this
+    // worker knows. The origin is what precedes the key's last colon.
+    if (msg.type === "AUTISTMASK_GET_CONNECTED_SITES") {
+        sendResponse(
+            Object.keys(connectedSites).map((key) =>
+                extractHostname(key.slice(0, key.lastIndexOf(":"))),
+            ),
+        );
+        return false;
+    }
+
+    // Settings removed this site and has already dropped its remembered
+    // entries. Its connections approved without "Remember" end here, under
+    // every address, and its open tabs are told it has no account.
     if (msg.type === "AUTISTMASK_REMOVE_SITE") {
-        // Popup already saved state; nothing else needed
+        for (const key of Object.keys(connectedSites)) {
+            const origin = key.slice(0, key.lastIndexOf(":"));
+            if (extractHostname(origin) === msg.hostname) {
+                delete connectedSites[key];
+            }
+        }
+        broadcastSiteRemoved(msg.hostname);
         return false;
     }
 });

src/popup/index.html

@@ -1064,6 +1064,15 @@
                     <div id="settings-allowed-sites"></div>
                 </div>
 
+                <div class="bg-well p-3 mx-1 mb-3">
+                    <h3 class="font-bold mb-1">Connected Sites</h3>
+                    <p class="text-xs text-muted mb-2">
+                        Sites you allowed without "Remember my choice".
+                        Switching address disconnects them.
+                    </p>
+                    <div id="settings-connected-sites"></div>
+                </div>
+
                 <div class="bg-well p-3 mx-1 mb-3">
                     <h3 class="font-bold mb-1">Denied Sites</h3>
                     <p class="text-xs text-muted mb-2">

src/popup/views/approval.js

@@ -8,6 +8,7 @@ const {
     renderAddressHtml,
     attachCopyHandlers,
     onViewLeave,
+    formatFee,
 } = require("./helpers");
 const { state, saveState } = require("../../shared/state");
 const { networkByChainId } = require("../../shared/networks");
@@ -207,7 +208,7 @@ function showPhishingWarning(elementId, isPhishing) {
 // and the nonce. The background compares every one of them against the signed
 // artifact, so every one of them has to be on the screen — a number that is
 // verified but never displayed is verified against nothing the user agreed to.
-function showTxFee(approvedTx, ethPrice) {
+function showTxFee(approvedTx) {
     const network = networkByChainId(approvedTx.chainId);
     $("approve-tx-network").textContent = network
         ? network.name
@@ -215,12 +216,9 @@ function showTxFee(approvedTx, ethPrice) {
 
     const gasLimit = BigInt(approvedTx.gasLimit);
     const feePerGas = BigInt(approvedTx.maxFeePerGas || approvedTx.gasPrice);
-    const maxFeeEth = formatTxValue(formatEther(gasLimit * feePerGas));
-    const usdStr = formatUsd(
-        ethPrice ? parseFloat(maxFeeEth) * ethPrice : null,
-    );
-    $("approve-tx-fee").textContent =
-        maxFeeEth + " ETH" + (usdStr ? " (" + usdStr + ")" : "");
+    // Through formatFee(), as the confirmation screen's fee is, so the same
+    // fee reads the same on both.
+    $("approve-tx-fee").textContent = formatFee(gasLimit * feePerGas);
 
     let detail =
         gasLimit.toString() +
@@ -332,7 +330,7 @@ function showTxApproval(details) {
     $("approve-tx-value").textContent =
         ethValueFormatted + " ETH" + (usdStr ? " (" + usdStr + ")" : "");
 
-    showTxFee(approvedTx, ethPrice);
+    showTxFee(approvedTx);
 
     // Decode calldata (reuse decoded from above)
     const decodedEl = $("approve-tx-decoded");

src/popup/views/confirmTx.js

@@ -15,6 +15,7 @@ const {
     attachCopyHandlers,
     goBack,
     onViewLeave,
+    formatFee,
 } = require("./helpers");
 const { state } = require("../../shared/state");
 const { getSignerForAddress } = require("../../shared/wallet");
@@ -31,6 +32,9 @@ const {
     transferAmountUnits,
 } = require("../../shared/transferAmount");
 const { assertWithinCeilings } = require("../../shared/approvalVerify");
+// The balance lines, the fee reserve and the insufficient-balance messages go
+// through it, as the approval screen's amounts do.
+const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
 const {
     CODES,
     FEE_PENDING,
@@ -150,11 +154,17 @@ function show(txInfo) {
         $("confirm-balance").textContent =
             bal == null
                 ? "unknown (" + symbol + ")"
-                : valueWithUsd(bal + " " + symbol, balUsd);
+                : valueWithUsd(
+                      truncateAmountNeverZero(bal) + " " + symbol,
+                      balUsd,
+                  );
     } else {
         const bal = txInfo.balance || "0";
         const balUsd = ethPrice ? parseFloat(bal) * ethPrice : null;
-        $("confirm-balance").textContent = valueWithUsd(bal + " ETH", balUsd);
+        $("confirm-balance").textContent = valueWithUsd(
+            truncateAmountNeverZero(bal) + " ETH",
+            balUsd,
+        );
     }
 
     // Check for warnings (synchronous local checks)
@@ -249,7 +259,7 @@ function renderValidation(txInfo) {
                 : "Insufficient " +
                       symbol +
                       " balance. You have " +
-                      txInfo.tokenBalance +
+                      truncateAmountNeverZero(txInfo.tokenBalance) +
                       " " +
                       symbol +
                       " but are trying to send " +
@@ -262,7 +272,7 @@ function renderValidation(txInfo) {
     if (codes.includes(CODES.INSUFFICIENT_ETH)) {
         messages.push(
             "Insufficient balance. You have " +
-                txInfo.balance +
+                truncateAmountNeverZero(txInfo.balance || "0") +
                 " ETH but are trying to send " +
                 txInfo.amount +
                 " ETH.",
@@ -305,14 +315,6 @@ function setVisible(id, visible) {
     $(id).style.visibility = visible ? "visible" : "hidden";
 }
 
-// A fee in wei as an ETH string, truncated to 6 decimal places.
-function formatFeeEth(wei) {
-    const parts = formatEther(wei).split(".");
-    const dec =
-        parts.length > 1 ? parts[1].slice(0, 6).replace(/0+$/, "") || "0" : "0";
-    return parts[0] + "." + dec + " ETH";
-}
-
 async function estimateGas(txInfo) {
     try {
         const provider = getProvider(state.rpcUrl, state.networkId);
@@ -359,26 +361,20 @@ async function estimateGas(txInfo) {
         // flight; a stale fee must not reach the screen or the balance check.
         if (pendingTx !== txInfo) return;
 
-        const ethPrice = getPrice("ETH");
-        const usd = (wei) =>
-            ethPrice ? parseFloat(formatEther(wei)) * ethPrice : null;
-
+        // The fee lines go through formatFee(), as the approval screen's
+        // does, so the same fee reads the same on both.
         if (estimateWei !== null && estimateWei < gasCostWei) {
-            $("confirm-fee-amount").textContent = valueWithUsd(
-                "~" + formatFeeEth(estimateWei),
-                usd(estimateWei),
-            );
+            $("confirm-fee-amount").textContent = "~" + formatFee(estimateWei);
             $("confirm-fee-reserve").textContent =
-                "up to " + formatFeeEth(gasCostWei) + " reserved";
+                "up to " +
+                truncateAmountNeverZero(formatEther(gasCostWei)) +
+                " ETH reserved";
             setVisible("confirm-fee-reserve", true);
         } else {
             // No spread to report: either there is no estimate, or the node
             // quotes a gas price at or above maxFeePerGas, so the expected
             // cost is not below the reserve. Show the reserve alone.
-            $("confirm-fee-amount").textContent = valueWithUsd(
-                formatFeeEth(gasCostWei),
-                usd(gasCostWei),
-            );
+            $("confirm-fee-amount").textContent = formatFee(gasCostWei);
             setVisible("confirm-fee-reserve", false);
         }
         feeStatus = FEE_KNOWN;

src/popup/views/helpers.js

@@ -12,6 +12,8 @@
 // escapeHtml lives in src/shared/html.js, where the escape and the
 // reasoning behind it are; it is re-exported below so views keep importing
 // it from here.
+const { formatEther } = require("ethers");
+const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
 const { DEBUG } = require("../../shared/constants");
 const { escapeHtml } = require("../../shared/html");
 const { isDebug } = require("../../shared/log");
@@ -243,6 +245,19 @@ function unknownableAmount(balance) {
     return Number.isFinite(n) ? n : null;
 }
 
+// A network fee in wei as the confirmation and approval screens both show it:
+// the ETH figure through truncateAmountNeverZero(), then its USD value when the
+// ETH price is known. The USD value is of the exact fee, not of the truncated
+// figure, so it never understates what the fee costs.
+function formatFee(wei) {
+    const eth = formatEther(wei);
+    const ethPrice = getPrice("ETH");
+    const usd = ethPrice ? formatUsd(parseFloat(eth) * ethPrice) : "";
+    return (
+        truncateAmountNeverZero(eth) + " ETH" + (usd ? " (" + usd + ")" : "")
+    );
+}
+
 // One row of the balance list: symbol, quantity, fiat value.
 //
 // `symbol` is the ERC-20's own symbol() as the block explorer reported it,
@@ -610,6 +625,7 @@ module.exports = {
     balanceLinesForAddress,
     addressHoldsFunds,
     unknownableAmount,
+    formatFee,
     addressColor,
     addressDotHtml,
     escapeHtml,

src/popup/views/send.js

@@ -16,6 +16,7 @@ const { resolveTokenDecimals } = require("../../shared/approvalAmount");
 const { resolveSymbol } = require("../../shared/tokenList");
 const { isLowHolderCount } = require("../../shared/holders");
 const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
+const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
 const { getAddress } = require("ethers");
 
 const ZERO_ADDRESS = "0x0000000000000000000000000000000000000000";
@@ -150,7 +151,9 @@ function updateSendBalance() {
     const token = state.selectedToken || $("send-token").value;
     if (token === "ETH") {
         $("send-balance").textContent =
-            "Current balance: " + (addr.balance || "0") + " ETH";
+            "Current balance: " +
+            truncateAmountNeverZero(addr.balance || "0") +
+            " ETH";
     } else {
         const tb = (addr.tokenBalances || []).find(
             (t) => t.address.toLowerCase() === token.toLowerCase(),
@@ -167,7 +170,10 @@ function updateSendBalance() {
         $("send-balance").textContent =
             bal == null
                 ? "Current balance: unknown (" + symbol + ")"
-                : "Current balance: " + bal + " " + symbol;
+                : "Current balance: " +
+                  truncateAmountNeverZero(bal) +
+                  " " +
+                  symbol;
     }
 }
 

src/popup/views/settings.js

@@ -29,46 +29,63 @@ const {
     GITEA_COMMIT_URL,
 } = require("../../shared/buildInfo");
 
-const { notify } = require("../../shared/browserApi");
+const { notify, sendMessage } = require("../../shared/browserApi");
 
 let versionClickCount = 0;
 let versionClickTimer = null;
 
-function renderSiteList(containerId, siteMap, stateKey) {
+// One row per hostname, however many addresses or origins it appears under,
+// each with an [x] that hands it to onRemove.
+function renderSiteList(containerId, hostnames, onRemove) {
     const container = $(containerId);
-    const hostnames = [...new Set(Object.values(siteMap).flat())];
-    if (hostnames.length === 0) {
+    const unique = [...new Set(hostnames)];
+    if (unique.length === 0) {
         container.innerHTML = '<p class="text-xs text-muted">None</p>';
         return;
     }
     let html = "";
-    hostnames.forEach((hostname) => {
+    unique.forEach((hostname) => {
         html += `<div class="flex justify-between items-center text-xs py-1 border-b border-border-light">`;
         // A hostname the URL parser produced cannot carry a delimiter, so
         // this is escaped for the rule rather than for a known hole — the
         // rule being that nothing reaches innerHTML unescaped.
         html += `<span>${escapeHtml(hostname)}</span>`;
-        html += `<button class="btn-remove-site border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer" data-key="${escapeHtml(stateKey)}" data-hostname="${escapeHtml(hostname)}">[x]</button>`;
+        html += `<button class="btn-remove-site border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer" data-hostname="${escapeHtml(hostname)}">[x]</button>`;
         html += `</div>`;
     });
     container.innerHTML = html;
     container.querySelectorAll(".btn-remove-site").forEach((btn) => {
-        btn.addEventListener("click", async () => {
-            const key = btn.dataset.key;
-            const host = btn.dataset.hostname;
-            for (const addr of Object.keys(state[key])) {
-                state[key][addr] = state[key][addr].filter((h) => h !== host);
-                if (state[key][addr].length === 0) {
-                    delete state[key][addr];
-                }
-            }
-            await saveState();
-            notify({ type: "AUTISTMASK_REMOVE_SITE" });
-            renderSiteList(containerId, state[key], key);
-        });
+        btn.addEventListener("click", () => onRemove(btn.dataset.hostname));
     });
 }
 
+// Drop a hostname from a remembered site list under every address.
+function forgetHostname(siteMap, hostname) {
+    for (const addr of Object.keys(siteMap)) {
+        siteMap[addr] = siteMap[addr].filter((h) => h !== hostname);
+        if (siteMap[addr].length === 0) {
+            delete siteMap[addr];
+        }
+    }
+}
+
+// Removing a site from Allowed Sites or Connected Sites disconnects it: it is
+// no longer allowed under any address, and the background ends its
+// connections approved without "Remember" and tells its open tabs.
+async function removeAllowedSite(hostname) {
+    forgetHostname(state.allowedSites, hostname);
+    await saveState();
+    notify({ type: "AUTISTMASK_REMOVE_SITE", hostname });
+    await renderSiteLists();
+}
+
+// Removing a denied site only forgets the refusal; it connects nothing.
+async function removeDeniedSite(hostname) {
+    forgetHostname(state.deniedSites, hostname);
+    await saveState();
+    await renderSiteLists();
+}
+
 function renderTrackedTokens() {
     const container = $("settings-tracked-tokens");
     if (state.trackedTokens.length === 0) {
@@ -202,13 +219,24 @@ function show() {
     showView("settings");
 }
 
-function renderSiteLists() {
+async function renderSiteLists() {
     renderSiteList(
         "settings-allowed-sites",
-        state.allowedSites,
-        "allowedSites",
+        Object.values(state.allowedSites).flat(),
+        removeAllowedSite,
+    );
+    renderSiteList(
+        "settings-denied-sites",
+        Object.values(state.deniedSites).flat(),
+        removeDeniedSite,
+    );
+    // Sites allowed without "Remember" are held only by the background, in
+    // memory, so it is asked for them.
+    renderSiteList(
+        "settings-connected-sites",
+        await sendMessage({ type: "AUTISTMASK_GET_CONNECTED_SITES" }),
+        removeAllowedSite,
     );
-    renderSiteList("settings-denied-sites", state.deniedSites, "deniedSites");
 }
 
 function init(ctx) {

src/shared/balances.js

@@ -17,6 +17,7 @@ const { LOW_HOLDER_THRESHOLD, parseHoldersCount } = require("./holders");
 const { isSpoofedSymbol } = require("./symbolSpoof");
 const { toDecimals } = require("./transferAmount");
 const { resolveTokenDecimals } = require("./approvalAmount");
+const { SCALE_DECIMALS } = require("./txValidation");
 
 // Use a static network to skip auto-detection (which can fail and cause
 // "could not coalesce error" on some RPC endpoints like Cloudflare).
@@ -52,19 +53,14 @@ function requireNetworkId(networkId) {
     return net;
 }
 
-function formatBalance(wei) {
-    const eth = formatEther(wei);
-    const parts = eth.split(".");
-    if (parts.length === 1) return eth + ".0";
-    const dec = parts[1].slice(0, 6).replace(/0+$/, "") || "0";
-    return parts[0] + "." + dec;
-}
-
+// A token balance as a decimal string, exact except for a token that declares
+// more than 18 decimals: that one is cut to 18 places, the most the balance
+// check on the confirmation screen reads (SCALE_DECIMALS in txValidation.js).
 function formatTokenBalance(raw, decimals) {
     const val = formatUnits(raw, decimals);
     const parts = val.split(".");
     if (parts.length === 1) return val + ".0";
-    const dec = parts[1].slice(0, 6).replace(/0+$/, "") || "0";
+    const dec = parts[1].slice(0, SCALE_DECIMALS).replace(/0+$/, "") || "0";
     return parts[0] + "." + dec;
 }
 
@@ -149,11 +145,7 @@ async function fetchTokenBalances(address, blockscoutUrl, trackedTokens) {
             const scale = known !== null ? known : decimals;
             // null is a holding of an amount that cannot be stated, which is
             // not the same as a holding of zero, and must never render as one.
-            // With a scale, the display filter proper applies: a balance that
-            // rounds to zero at six places is dust and is not listed. Without
-            // one there is no such judgement to make, and the row is kept.
             const bal = scale === null ? null : formatTokenBalance(raw, scale);
-            if (bal === "0.0") continue;
             // null means the explorer reported no count, which is not the
             // same as a count of zero.  This gate is not the low-holder
             // display filter: it has no user-facing off switch and governs
@@ -172,6 +164,19 @@ async function fetchTokenBalances(address, blockscoutUrl, trackedTokens) {
             // Skip spam tokens the user never asked to see
             if (!isKnown && !isTracked && !hasEnoughHolders) continue;
 
+            // Skip dust: a holding below 0.000001 of a token the user does not
+            // track. A tracked token keeps it, so the Send and confirmation
+            // screens show that holding and check the send against it rather
+            // than against zero. Without a scale there is no such judgement to
+            // make, and the row is kept.
+            if (
+                !isTracked &&
+                scale !== null &&
+                raw * 1000000n < 10n ** BigInt(scale)
+            ) {
+                continue;
+            }
+
             // Skip tokens spoofing a known symbol from a different address.
             // Every row here is an ERC-20 the explorer reported, so it has a
             // contract address; the native ETH balance is fetched over RPC in
@@ -221,7 +226,9 @@ async function refreshBalances(
                 provider
                     .getBalance(addr.address)
                     .then((bal) => {
-                        addr.balance = formatBalance(bal);
+                        // Exact, never cut: a cut here stores a small nonzero
+                        // balance as zero.
+                        addr.balance = formatEther(bal);
                         log.debugf("ETH balance", addr.address, addr.balance);
                     })
                     .catch((e) => {

tests/backgroundApproval.test.js

@@ -2101,6 +2101,16 @@ describe("a site connection decided as the popup closes", () => {
     });
 });
 
+// What a site is told when it asks which account it may use.
+async function siteAccounts(bg, origin) {
+    const { sendResponse } = bg.send(
+        { type: "AUTISTMASK_RPC", method: "eth_accounts", params: [] },
+        { origin: origin || FRESH_ORIGIN },
+    );
+    await settle();
+    return sendResponse.mock.calls[0][0];
+}
+
 // A site connected without "Remember" is held only in the background's memory,
 // keyed to the address it was connected to. Removing that address, or the
 // wallet holding it, must end the connection as part of the removal itself.
@@ -2136,16 +2146,6 @@ describe("removing an address ends a site's connection to it", () => {
         return bg;
     }
 
-    // What FRESH_ORIGIN is told when it asks which account it may use.
-    async function siteAccounts(bg) {
-        const { sendResponse } = bg.send(
-            { type: "AUTISTMASK_RPC", method: "eth_accounts", params: [] },
-            { origin: FRESH_ORIGIN },
-        );
-        await settle();
-        return sendResponse.mock.calls[0][0];
-    }
-
     test("removing the connected address ends the connection", async () => {
         const bg = await connectedBackground();
         expect(await siteAccounts(bg)).toEqual({ result: [signer.address] });
@@ -2192,3 +2192,168 @@ describe("removing an address ends a site's connection to it", () => {
         expect(await siteAccounts(bg)).toEqual({ result: [signer.address] });
     });
 });
+
+// Settings lists the sites allowed without "Remember", which only the
+// background holds, and removing a site there, from either list, disconnects
+// it. These drive the real Settings view against the real background and
+// click the [x] the user clicks.
+describe("removing a site in Settings disconnects it", () => {
+    // FRESH_ORIGIN on another port, so its hostname is FRESH_ORIGIN's.
+    const FRESH_OTHER_PORT = "https://fresh.example:8443";
+
+    // A site list's container. Its [x] buttons, data attributes and all, are
+    // read back out of the rows the view wrote into it, so clicking one runs
+    // the handler the view attached to it.
+    function fakeSiteList() {
+        const list = {
+            innerHTML: "",
+            buttons: [],
+            querySelectorAll() {
+                const tags = list.innerHTML.match(/<button[^>]*>/g) || [];
+                list.buttons = tags.map((tag) => ({
+                    dataset: Object.fromEntries(
+                        [...tag.matchAll(/data-(\w+)="([^"]*)"/g)].map(
+                            (match) => [match[1], match[2]],
+                        ),
+                    ),
+                    addEventListener(event, handler) {
+                        this[event] = handler;
+                    },
+                }));
+                return list.buttons;
+            },
+        };
+        return list;
+    }
+
+    // The hostnames a site list shows.
+    function listed(list) {
+        return [...list.innerHTML.matchAll(/data-hostname="([^"]*)"/g)].map(
+            (match) => match[1],
+        );
+    }
+
+    // A site connected the way the user does it, in the approval popup.
+    async function connect(bg, origin, remember) {
+        const pending = bg.requestSite(origin);
+        await settle();
+        bg.connectApproval(pending.id()).decide(true, remember);
+        await settle();
+        expect(pending.result()).toEqual({ result: [signer.address] });
+    }
+
+    // Settings, opened over the background's storage and wired to it the way
+    // the popup is: what Settings sends reaches the background from the
+    // extension's own page, and the answer comes back.
+    async function openSettings(bg) {
+        const lists = {};
+        const element = (id) => (lists[id] ||= fakeSiteList());
+        global.document = { getElementById: element };
+        global.chrome.runtime.sendMessage = (msg, callback) => {
+            const { sendResponse } = bg.send(msg, bg.fromPopup);
+            if (callback) callback(sendResponse.mock.calls[0]?.[0]);
+        };
+        await require("../src/shared/state").loadState();
+        await require("../src/popup/views/settings").renderSiteLists();
+        return {
+            allowed: element("settings-allowed-sites"),
+            connected: element("settings-connected-sites"),
+            // Click the [x] beside a site, and let what it sends run.
+            remove: async (list, hostname) => {
+                expect(listed(list)).toContain(hostname);
+                const button = list.buttons.find(
+                    (b) => b.dataset.hostname === hostname,
+                );
+                await button.click();
+                await settle();
+            },
+        };
+    }
+
+    afterEach(() => {
+        delete global.document;
+    });
+
+    test("Settings lists a site connected without Remember", async () => {
+        const bg = loadBackground({ actionPopup: true });
+        await connect(bg, FRESH_ORIGIN, false);
+
+        const settings = await openSettings(bg);
+
+        expect(listed(settings.connected)).toEqual(["fresh.example"]);
+        expect(listed(settings.allowed)).toEqual([HOSTNAME]);
+    });
+
+    test("removing a site connected without Remember disconnects it and tells its tabs", async () => {
+        const bg = loadBackground({ actionPopup: true });
+        await connect(bg, FRESH_ORIGIN, false);
+        const sentToTabs = [];
+        global.chrome.tabs = {
+            query: (q, cb) =>
+                cb([
+                    { id: 1, url: FRESH_ORIGIN + "/app" },
+                    { id: 2, url: ORIGIN + "/app" },
+                ]),
+            sendMessage: (tabId, msg, cb) => {
+                sentToTabs.push({ tabId, msg });
+                cb();
+            },
+        };
+        const settings = await openSettings(bg);
+
+        await settings.remove(settings.connected, "fresh.example");
+
+        expect(await siteAccounts(bg)).toEqual({ result: [] });
+        expect(sentToTabs).toEqual([
+            {
+                tabId: 1,
+                msg: {
+                    type: "AUTISTMASK_EVENT",
+                    eventName: "accountsChanged",
+                    data: [],
+                },
+            },
+        ]);
+        expect(listed(settings.connected)).toEqual([]);
+        // The other site is untouched.
+        expect(await siteAccounts(bg, ORIGIN)).toEqual({
+            result: [signer.address],
+        });
+    });
+
+    // The same hostname can hold both kinds of connection: one origin allowed
+    // without Remember, then another, on a different port, allowed with it.
+    test("removing a remembered site also ends its connection made without Remember", async () => {
+        const bg = loadBackground({ actionPopup: true });
+        await connect(bg, FRESH_ORIGIN, false);
+        await connect(bg, FRESH_OTHER_PORT, true);
+        const settings = await openSettings(bg);
+
+        await settings.remove(settings.allowed, "fresh.example");
+
+        expect(await siteAccounts(bg, FRESH_OTHER_PORT)).toEqual({
+            result: [],
+        });
+        expect(await siteAccounts(bg, FRESH_ORIGIN)).toEqual({ result: [] });
+    });
+
+    test("a page can neither remove a site nor list the connected ones", async () => {
+        const bg = loadBackground({ actionPopup: true });
+        await connect(bg, FRESH_ORIGIN, false);
+        const page = { url: FRESH_ORIGIN + "/index.html" };
+
+        const remove = bg.send(
+            { type: "AUTISTMASK_REMOVE_SITE", hostname: "fresh.example" },
+            page,
+        );
+        const list = bg.send({ type: "AUTISTMASK_GET_CONNECTED_SITES" }, page);
+
+        expect(remove.sendResponse).toHaveBeenCalledWith({
+            error: "Unauthorized sender",
+        });
+        expect(list.sendResponse).toHaveBeenCalledWith({
+            error: "Unauthorized sender",
+        });
+        expect(await siteAccounts(bg)).toEqual({ result: [signer.address] });
+    });
+});

tests/e2e/run.js

@@ -1414,9 +1414,10 @@ test("a rejected dust threshold shifts no layout (#233)", async (env) => {
 // on opposite sides of the reserve while sitting on the same side of the
 // estimate.
 
-// The balance the funded fixture serves, and the amounts sent against it.
+// The balance the funded fixture serves, as the Send and confirmation screens
+// show it, and the amounts sent against it.
 const FUNDED_ETH_WEI = 10n ** 18n;
-const FUNDED_ETH_TEXT = "1.0";
+const FUNDED_ETH_TEXT = "1.0000";
 const COMFORTABLE_AMOUNT = "0.1";
 const OVER_BALANCE_AMOUNT = "2.0";
 
@@ -1430,7 +1431,7 @@ const GAP_AMOUNT = formatEther(FUNDED_ETH_WEI - FEE_ESTIMATE_WEI);
 // fee test: it covers the expected cost to the wei and falls short of the
 // reserve, so the same swap flips this assertion too — through a different
 // balance and a different message than the ETH path uses.
-const TOKEN_BALANCE_TEXT = "1.5";
+const TOKEN_BALANCE_TEXT = "1.5000";
 const TOKEN_AMOUNT = "0.25";
 const OVER_TOKEN_AMOUNT = "9.0";
 const FEE_ONLY_ETH_WEI = FEE_ESTIMATE_WEI;
@@ -1439,16 +1440,15 @@ function toHexWei(wei) {
     return "0x" + wei.toString(16);
 }
 
-// A fee in wei as the confirmation screen writes it. Deliberately a second
-// implementation of formatFeeEth() from src/popup/views/confirmTx.js rather
-// than an import of it: that module pulls in the whole popup and cannot be
-// required outside a browser, and asserting against an independent rendering
-// is stronger than asserting a function equals itself.
+// A fee in wei as the confirmation screen writes it: truncated to four decimal
+// places (README.md, Display Consistency). Deliberately a second
+// implementation rather than an import of src/shared/amountDisplay.js:
+// asserting against an independent rendering is stronger than asserting a
+// function equals itself. The fixture's fees are above 0.0001 ETH, so the
+// nonzero floor never applies here.
 function feeEth(wei) {
-    const parts = formatEther(wei).split(".");
-    const dec =
-        parts.length > 1 ? parts[1].slice(0, 6).replace(/0+$/, "") || "0" : "0";
-    return parts[0] + "." + dec + " ETH";
+    const [whole, frac = ""] = formatEther(wei).split(".");
+    return whole + "." + (frac + "0000").slice(0, 4) + " ETH";
 }
 
 // What the confirmation screen is showing right now, read out of the DOM in
@@ -1505,11 +1505,10 @@ async function backToAddress(page) {
 
 // Drive the popup to the confirmation screen for one send.
 //
-// It waits for the send screen to be showing `balance` before filling
-// anything in. That figure is the exact number the spend gate compares
-// against, so waiting for it — rather than for a refresh to have probably
-// landed — is what keeps every assertion below deterministic after a
-// fixture change.
+// It waits for the send screen to be showing `balance`, the fixture's balance
+// as that screen displays it, before filling anything in. Waiting for it —
+// rather than for a refresh to have probably landed — is what keeps every
+// assertion below deterministic after a fixture change.
 async function goToConfirm(page, { token, balance, amount }) {
     await backToAddress(page);
     await page.click("#btn-send");

tests/sendDisplayFloor.test.js

@@ -0,0 +1,363 @@
+// The balance and fee lines of the Send and confirmation screens, and the fee
+// line they must share with the approval screen.
+//
+// An ETH balance, a token balance or a fee below 0.000001 rendered as zero on
+// these screens (https://git.eeqj.de/sneak/AutistMask/issues/343): the stored
+// balances and the fee were each cut to six decimal places, a rule of their
+// own, while the approval screen showed the same fee through
+// src/shared/amountDisplay.js with the nonzero floor. The balances are now
+// stored exactly, and the screens show them and the fee through that helper.
+//
+// Driven through the real refreshBalances(), Send screen, confirmation screen
+// and approval screen, with only the node, the explorer and the DOM stubbed: a
+// balance written onto state by hand would skip the place the cut happened.
+
+"use strict";
+
+// What the stub node answers. Each test sets what it needs.
+const mockNode = {
+    balanceWei: 0n,
+    feeData: { maxFeePerGas: 1n, gasPrice: 1n },
+};
+
+// The token rows the stub explorer reports for the address.
+const mockExplorer = { items: [] };
+
+jest.mock("ethers", () => {
+    const actual = jest.requireActual("ethers");
+    class StubProvider {
+        async getBalance() {
+            return mockNode.balanceWei;
+        }
+        async lookupAddress() {
+            return null;
+        }
+        async getFeeData() {
+            return mockNode.feeData;
+        }
+        async estimateGas() {
+            return 21000n;
+        }
+        async getCode() {
+            return "0x";
+        }
+        async getTransactionCount() {
+            return 1;
+        }
+    }
+    return {
+        ...actual,
+        JsonRpcProvider: StubProvider,
+        Network: { from: () => ({}) },
+    };
+});
+
+jest.mock("../src/shared/log", () => ({
+    log: {
+        debugf: () => {},
+        infof: () => {},
+        warnf: () => {},
+        errorf: () => {},
+    },
+    // The explorer's token list, which refreshBalances() also fetches.
+    debugFetch: jest.fn(async () => ({
+        ok: true,
+        status: 200,
+        json: async () => mockExplorer.items,
+    })),
+    setRuntimeDebug: () => {},
+    isDebug: () => false,
+}));
+
+// The confirmation screen's Etherscan label lookup is the only fetch() these
+// screens make; it fails, as it does offline.
+global.fetch = jest.fn(() => {
+    throw new Error("tests must not perform network requests");
+});
+
+// The approval the background hands the approval screen. Set per test.
+let approvalDetails = null;
+
+const { makeStorageStub } = require("./support/storageStub");
+global.chrome = {
+    storage: makeStorageStub(),
+    runtime: {
+        connect: () => ({
+            postMessage() {},
+            disconnect() {},
+            onDisconnect: { addListener() {} },
+        }),
+        sendMessage(message, callback) {
+            callback(
+                message.type === "AUTISTMASK_GET_APPROVAL"
+                    ? approvalDetails
+                    : undefined,
+            );
+        },
+    },
+};
+
+// A stub DOM: every id resolves to a recording element.
+const elements = new Map();
+
+function makeEl(id) {
+    const handlers = new Map();
+    return {
+        id,
+        textContent: "",
+        innerHTML: "",
+        value: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        classList: {
+            add() {},
+            remove() {},
+            toggle() {},
+            contains: () => false,
+        },
+        handlers,
+        addEventListener(name, fn) {
+            handlers.set(name, fn);
+        },
+        appendChild(child) {
+            return child;
+        },
+        querySelectorAll: () => [],
+        querySelector: () => null,
+        remove() {},
+        focus() {},
+    };
+}
+
+global.document = {
+    getElementById(id) {
+        if (!elements.has(id)) elements.set(id, makeEl(id));
+        return elements.get(id);
+    },
+    createElement: (tag) => makeEl(tag),
+    body: { prepend() {}, appendChild() {} },
+    addEventListener() {},
+};
+global.navigator = { clipboard: { writeText() {} } };
+
+const { refreshBalances } = require("../src/shared/balances");
+const { state } = require("../src/shared/state");
+const { prices, clearPrices } = require("../src/shared/prices");
+const send = require("../src/popup/views/send");
+const confirmTx = require("../src/popup/views/confirmTx");
+const approval = require("../src/popup/views/approval");
+
+const HOLDER = "0x" + "a".repeat(40);
+const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
+
+// 0.0000005 ETH, or 0.0000005 of an 18-decimal token.
+const HALF_MICRO_ETH = 500000000000n;
+
+// A token the bundled list does not know.
+const TOKEN = "0x" + "d".repeat(40);
+
+// The explorer's row for TOKEN, holding `value` base units. With only five
+// holders, it is listed only when the user tracks the token.
+function tokenRow(value, token = {}) {
+    return {
+        value: String(value),
+        token: {
+            type: "ERC-20",
+            address_hash: TOKEN,
+            symbol: "TOK",
+            name: "Token",
+            decimals: "18",
+            holders_count: "5",
+            ...token,
+        },
+    };
+}
+
+function text(id) {
+    return global.document.getElementById(id).textContent;
+}
+
+function errors() {
+    return global.document.getElementById("confirm-errors").innerHTML;
+}
+
+// The ETH balance the node reports and the token rows the explorer reports,
+// fetched and stored exactly where the popup stores them.
+async function refreshWith(balanceWei, tokenItems = []) {
+    mockNode.balanceWei = balanceWei;
+    mockExplorer.items = tokenItems;
+    state.wallets = [{ name: "Wallet 1", addresses: [{ address: HOLDER }] }];
+    state.selectedWallet = 0;
+    state.selectedAddress = 0;
+    await refreshBalances(
+        state.wallets,
+        "https://rpc.example.invalid",
+        "https://blockscout.example/api/v2",
+        state.trackedTokens,
+        "mainnet",
+    );
+}
+
+// Press Review on the Send screen for a send of `token` ("ETH" or a token
+// address), and show the confirmation screen it leads to with its fee estimate
+// settled.
+async function confirmSend(amount, token = "ETH") {
+    let txInfo = null;
+    send.init({ showConfirmTx: (info) => (txInfo = info) });
+    state.selectedToken = token;
+    global.document.getElementById("send-to").value = RECIPIENT;
+    global.document.getElementById("send-amount").value = amount;
+    await global.document
+        .getElementById("btn-send-review")
+        .handlers.get("click")();
+    confirmTx.show(txInfo);
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+// The approval screen for a dApp transaction of 21000 gas, the gas the stub
+// node estimates for the send above.
+async function approveTxWithFeePerGas(maxFeePerGas) {
+    approvalDetails = {
+        type: "tx",
+        hostname: "dapp.example",
+        approvedFrom: HOLDER,
+        approvedTx: {
+            to: RECIPIENT,
+            value: "0",
+            data: "0x",
+            chainId: "0x1",
+            gasLimit: "21000",
+            maxFeePerGas: String(maxFeePerGas),
+            nonce: 0,
+        },
+    };
+    await approval.show("1");
+}
+
+beforeEach(() => {
+    elements.clear();
+    state.selectedToken = null;
+    state.trackedTokens = [];
+    state.fraudContracts = [];
+    state.currentView = null;
+    mockNode.feeData = { maxFeePerGas: 1n, gasPrice: 1n };
+});
+
+describe("an ETH balance below 0.000001 never renders as zero", () => {
+    test("on the Send screen", async () => {
+        await refreshWith(HALF_MICRO_ETH);
+        state.selectedToken = "ETH";
+        send.updateSendBalance();
+        expect(text("send-balance")).toBe("Current balance: 0.0000005 ETH");
+    });
+
+    test("on the confirmation screen", async () => {
+        await refreshWith(HALF_MICRO_ETH);
+        await confirmSend("0.0000001");
+        expect(text("confirm-balance")).toBe("0.0000005 ETH");
+    });
+
+    test("while a balance above the floor keeps four decimals", async () => {
+        await refreshWith(1234567890000000000n);
+        await confirmSend("0.1");
+        expect(text("confirm-balance")).toBe("1.2345 ETH");
+    });
+});
+
+// A token the user tracks stays on the balance list when the explorer's row is
+// dropped, so a holding of it below 0.000001 reached these screens as zero, and
+// the send was checked against zero.
+describe("a tracked token holding below 0.000001 never renders as zero", () => {
+    beforeEach(() => {
+        state.trackedTokens = [
+            { address: TOKEN, symbol: "TOK", name: "Token", decimals: 18 },
+        ];
+    });
+
+    test("on the Send screen", async () => {
+        await refreshWith(10n ** 18n, [tokenRow(HALF_MICRO_ETH)]);
+        state.selectedToken = TOKEN;
+        send.updateSendBalance();
+        expect(text("send-balance")).toBe("Current balance: 0.0000005 TOK");
+    });
+
+    test("on the confirmation screen, which checks the send against it", async () => {
+        await refreshWith(10n ** 18n, [tokenRow(HALF_MICRO_ETH)]);
+        await confirmSend("0.0000005", TOKEN);
+        expect(text("confirm-balance")).toBe("0.0000005 TOK");
+        expect(errors()).toBe("");
+        await confirmSend("0.0000006", TOKEN);
+        expect(errors()).toContain(
+            "You have 0.0000005 TOK but are trying to send 0.0000006 TOK.",
+        );
+    });
+
+    // Past 18 places the stored balance is cut: the balance check reads 18,
+    // and refuses a balance string longer than that as no balance at all.
+    test("with more than 18 decimals, the send is checked against 18 of them", async () => {
+        state.trackedTokens[0].decimals = 24;
+        // 1.5 plus one base unit.
+        const value = 15n * 10n ** 23n + 1n;
+        await refreshWith(10n ** 18n, [tokenRow(value, { decimals: "24" })]);
+        await confirmSend("1.5", TOKEN);
+        expect(text("confirm-balance")).toBe("1.5000 TOK");
+        expect(errors()).toBe("");
+    });
+
+    test("while an untracked holding below 0.000001 is still not listed", async () => {
+        state.trackedTokens = [];
+        await refreshWith(10n ** 18n, [
+            tokenRow(HALF_MICRO_ETH, { holders_count: "50000" }),
+        ]);
+        expect(state.wallets[0].addresses[0].tokenBalances).toEqual([]);
+    });
+});
+
+describe("a fee below 0.000001 ETH never renders as zero", () => {
+    test("when the estimate and the reserve are the same", async () => {
+        await refreshWith(10n ** 18n);
+        await confirmSend("0.1");
+        // 21000 gas at 1 wei is 0.000000000000021 ETH, shown to its first
+        // significant digit.
+        expect(text("confirm-fee-amount")).toBe("0.00000000000002 ETH");
+    });
+
+    test("when they differ, on both lines", async () => {
+        mockNode.feeData = { maxFeePerGas: 2n, gasPrice: 1n };
+        await refreshWith(10n ** 18n);
+        await confirmSend("0.1");
+        expect(text("confirm-fee-amount")).toBe("~0.00000000000002 ETH");
+        expect(text("confirm-fee-reserve")).toBe(
+            "up to 0.00000000000004 ETH reserved",
+        );
+    });
+});
+
+// The confirmation screen shows the reserve alone when the node quotes no
+// cheaper estimate, and that reserve is the same gas limit times maximum fee
+// per gas that the approval screen calls the max fee. An ETH price is set, as
+// it is on mainnet, so the USD value has to match too.
+describe("the same fee reads the same on the confirmation and approval screens", () => {
+    beforeEach(() => {
+        prices.ETH = 3000;
+    });
+    afterEach(() => {
+        clearPrices();
+    });
+
+    test.each([
+        // 21000 gas at 1 wei.
+        ["below the floor", 1n, "0.00000000000002 ETH (< $0.01)"],
+        // 0.001235294117631 ETH, which is $3.71. Pricing the truncated
+        // 0.0012 instead would read $3.60.
+        ["with more than four decimals", 58823529411n, "0.0012 ETH ($3.71)"],
+    ])("%s", async (_label, feePerGas, expected) => {
+        mockNode.feeData = { maxFeePerGas: feePerGas, gasPrice: feePerGas };
+        await refreshWith(10n ** 18n);
+        await confirmSend("0.1");
+        expect(text("confirm-fee-amount")).toBe(expected);
+        await approveTxWithFeePerGas(feePerGas);
+        expect(text("approve-tx-fee")).toBe(expected);
+    });
+});

tests/unknownScaleSend.test.js

@@ -389,7 +389,7 @@ describe("a scale the explorer's own rows disagree about", () => {
         expect(txInfo.tokenBalance).toBe("5.0");
         confirmTx.show(txInfo);
         await settle();
-        expect(text("confirm-balance")).toBe("5.0 NOVEL");
+        expect(text("confirm-balance")).toBe("5.0000 NOVEL");
         expect(errors()).toBe("");
         expect(sendDisabled()).toBe(false);
     });
@@ -431,7 +431,7 @@ describe("the confirmation screen tells an unknown balance from a zero one", ()
         const zero = await render("0.0");
         expect(unknown.balance).not.toBe(zero.balance);
         expect(unknown.balance).toBe("unknown (NOVEL)");
-        expect(zero.balance).toBe("0.0 NOVEL");
+        expect(zero.balance).toBe("0.0000 NOVEL");
     });
 
     // Both hit INSUFFICIENT_TOKEN — an unknown balance is treated as nothing to
@@ -443,7 +443,7 @@ describe("the confirmation screen tells an unknown balance from a zero one", ()
         expect(unknown.errors).not.toBe(zero.errors);
         expect(unknown.errors).toContain("This token's balance is unknown");
         expect(unknown.errors).not.toContain("You have");
-        expect(zero.errors).toContain("You have 0.0 NOVEL");
+        expect(zero.errors).toContain("You have 0.0000 NOVEL");
         expect(zero.errors).not.toContain("balance is unknown");
     });
 });