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, and a token holding cut to zero was dropped, so a
value below 0.000001 read as zero. Balances are now stored exactly, whatever
decimals a token declares, and every nonzero token holding is kept; the balance
check reads a token balance to its first 18 places. The balance lists, the
send-screen token selector, the address total and the remove-address warning
leave out a holding below 0.000001 themselves, through isBelowOneMillionth().
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.

Model: opus-5-5

README.md

@@ -1059,17 +1059,18 @@ 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 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, also while "Show tracked tokens with zero balance" is off,
-and one too small for the list's four decimal places reads `0.0000`. 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 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. `fetchTokenBalances()` stores
+every nonzero holding of a token it admits exactly, however small, but a holding
+below 0.000001 is left out of the balance lists, the send-screen token selector,
+the address total and the remove-address warning (`isBelowOneMillionth()` in
+`src/shared/amountDisplay.js`). The Send and confirmation screens show it when
+its token is the one being sent. Tracked tokens with a zero balance are listed
+as well while "Show tracked tokens with zero balance" is on.
 
 #### Stored state and its version
 

TODO.md

@@ -49,12 +49,13 @@ but the review is broader than any of them.
   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,
-  whatever decimals a token declares; the balance check reads a token balance to
-  its first 18 places, the most an amount can have. 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
+  six decimal places by a rule of their own, and a token holding cut to zero was
+  dropped. Balances are now stored exactly, whatever decimals a token declares,
+  and every nonzero token holding is kept; the balance check reads a token
+  balance to its first 18 places, the most an amount can have. The balance
+  lists, the send-screen token selector, the address total and the
+  remove-address warning leave out a holding below 0.000001 themselves, as
+  before. 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

src/popup/views/deleteAddress.js

@@ -87,7 +87,8 @@ function recoveryPathText(wallet) {
 // AddressDetail, followed by the USD total when there is one to give — no
 // total line at all on testnet or before the first price fetch, and no figure
 // when every holding here is one with no price, since "$0.00" directly under
-// "This address holds a balance." is a contradiction.
+// "This address holds a balance." is a contradiction. A token holding below
+// 0.000001 does not count, as the lines below leave it out.
 function balanceWarningHtml(addr) {
     if (!addressHoldsFunds(addr)) return " ";
     const line = formatAddressTotal(getAddressValue(addr));

src/popup/views/helpers.js

@@ -13,7 +13,10 @@
 // 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 {
+    truncateAmountNeverZero,
+    isBelowOneMillionth,
+} = require("../../shared/amountDisplay");
 const { DEBUG } = require("../../shared/constants");
 const { escapeHtml } = require("../../shared/html");
 const { isDebug } = require("../../shared/log");
@@ -303,6 +306,9 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
     );
     const seen = new Set();
     for (const t of addr.tokenBalances || []) {
+        // A holding below 0.000001 is not listed, tracked or not. A tracked
+        // token then gets the zero row below while showZero is on.
+        if (isBelowOneMillionth(t.balance)) continue;
         // A null balance is a holding of an unstatable amount, not a holding
         // of zero, so the show-zero setting has no say over it: hiding it
         // would be asserting the zero nobody established. Anything that does
@@ -333,14 +339,16 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
 }
 
 // Whether an address holds anything at all: ETH or any ERC-20 the wallet
-// knows about. Deliberately unrounded — the rendered lines round to four
-// decimals, so a dust balance displays as 0.0000 while still being real
-// money at a real address. Callers that warn about holdings must ask this,
-// not the rendered figure.
+// knows about, except a token holding below 0.000001, which the balance list
+// under the remove-address warning leaves out too. Deliberately unrounded —
+// the rendered lines round to four decimals, so a dust balance displays as
+// 0.0000 while still being real money at a real address. Callers that warn
+// about holdings must ask this, not the rendered figure.
 function addressHoldsFunds(addr) {
     if (!addr) return false;
     if (parseFloat(addr.balance || "0") > 0) return true;
     for (const t of addr.tokenBalances || []) {
+        if (isBelowOneMillionth(t.balance)) continue;
         // A null balance is a holding whose amount could not be stated —
         // balances.js drops a row of zero base units before the scale is
         // consulted, so a row that survived with no quantity is holding

src/popup/views/send.js

@@ -16,7 +16,10 @@ 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 {
+    truncateAmountNeverZero,
+    isBelowOneMillionth,
+} = require("../../shared/amountDisplay");
 const { getAddress } = require("ethers");
 
 const ZERO_ADDRESS = "0x0000000000000000000000000000000000000000";
@@ -126,6 +129,10 @@ function renderSendTokenSelect(addr) {
         (state.fraudContracts || []).map((a) => a.toLowerCase()),
     );
     for (const t of addr.tokenBalances || []) {
+        // A holding below 0.000001 is left out, as the balance lists leave it
+        // out. Its token's own screen can still send it: there
+        // state.selectedToken picks the token, not this list.
+        if (isBelowOneMillionth(t.balance)) continue;
         if (isSpoofedSymbol(t.symbol, t.address)) continue;
         if (fraudSet.has(t.address.toLowerCase())) continue;
         // An unknown holder count does not withhold a token the user holds:

src/shared/amountDisplay.js

@@ -6,10 +6,10 @@
 // (`src/shared/uniswap.js`) — and a fix applied to one of them left the other
 // two showing a different number for the same value.
 //
-// The two functions below are the two policies, not two implementations of
-// one: summary lists truncate, and the screens that state what is being
-// authorized truncate with a floor. Keeping them adjacent is the point, so a
-// change to the rule cannot reach one screen and miss another.
+// The two truncation functions below are the two policies, not two
+// implementations of one: summary lists truncate, and the screens that state
+// what is being authorized truncate with a floor. Keeping them adjacent is the
+// point, so a change to the rule cannot reach one screen and miss another.
 
 // Truncate to exactly four decimal places. Truncation, never rounding: an
 // amount must never be displayed as larger than it is, so 0.99999 stays
@@ -43,4 +43,18 @@ function truncateAmountNeverZero(val) {
     return parts[0] + "." + parts[1].slice(0, sig + 1);
 }
 
-module.exports = { truncateAmount, truncateAmountNeverZero };
+// Whether a stored token balance is a holding below 0.000001. The balance
+// lists, the send-screen token selector, the address total and the
+// remove-address warning leave such a holding out; the Send and confirmation
+// screens show it when its token is the one being sent. Exact, because
+// src/shared/balances.js stores plain decimal digits: below 0.000001 the
+// balance reads "0.000000" and then more digits.
+function isBelowOneMillionth(balance) {
+    return typeof balance === "string" && balance.startsWith("0.000000");
+}
+
+module.exports = {
+    truncateAmount,
+    truncateAmountNeverZero,
+    isBelowOneMillionth,
+};

src/shared/balances.js

@@ -53,7 +53,10 @@ function requireNetworkId(networkId) {
 }
 
 // A token balance as an exact decimal string, never cut: a cut stores a small
-// nonzero holding as zero.
+// nonzero holding as zero. fetchTokenBalances() stores every nonzero holding of
+// a token it admits, however small; the screens that leave out one below
+// 0.000001 decide that themselves, through isBelowOneMillionth() in
+// src/shared/amountDisplay.js.
 function formatTokenBalance(raw, decimals) {
     const val = formatUnits(raw, decimals);
     const parts = val.split(".");
@@ -162,19 +165,6 @@ 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

src/shared/prices.js

@@ -1,6 +1,7 @@
 // Price fetching with 5-minute cache, USD formatting, value aggregation.
 
 const { getTopTokenPrices } = require("./tokenList");
+const { isBelowOneMillionth } = require("./amountDisplay");
 
 const PRICE_CACHE_TTL = 300000; // 5 minutes
 
@@ -78,6 +79,9 @@ function getAddressValue(addr) {
     let usd = parseFloat(addr.balance || "0") * prices.ETH;
     let partial = false;
     for (const token of addr.tokenBalances || []) {
+        // A holding below 0.000001 is left out, as the balance lists leave it
+        // out, so the total never counts a holding the list does not show.
+        if (isBelowOneMillionth(token.balance)) continue;
         // A null balance is a holding whose scale nothing knows, so it has no
         // quantity to price — but it is still a holding, and a total that
         // silently omits it would read as complete. That is exactly what

tests/sendDisplayFloor.test.js

@@ -4,9 +4,10 @@
 // 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.
+// own, and a token holding cut to zero was dropped, while the approval screen
+// showed the same fee through src/shared/amountDisplay.js with the nonzero
+// floor. The balances are now stored exactly, every nonzero token holding
+// kept, 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
@@ -117,10 +118,12 @@ function makeEl(id) {
             contains: () => false,
         },
         handlers,
+        children: [],
         addEventListener(name, fn) {
             handlers.set(name, fn);
         },
         appendChild(child) {
+            this.children.push(child);
             return child;
         },
         querySelectorAll: () => [],
@@ -143,7 +146,12 @@ global.navigator = { clipboard: { writeText() {} } };
 
 const { refreshBalances } = require("../src/shared/balances");
 const { state } = require("../src/shared/state");
-const { prices, clearPrices } = require("../src/shared/prices");
+const {
+    prices,
+    clearPrices,
+    formatAddressTotal,
+    getAddressValue,
+} = 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");
@@ -311,9 +319,8 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
 
     test("with more than 18 decimals and a holding below 10^-18", async () => {
         state.trackedTokens[0].decimals = 24;
-        // One base unit, 0.000000000000000000000001 TOK, and no ETH, so the
-        // token is all the address holds.
-        await refreshWith(0n, [tokenRow(1n, { decimals: "24" })]);
+        // One base unit, 0.000000000000000000000001 TOK.
+        await refreshWith(10n ** 18n, [tokenRow(1n, { decimals: "24" })]);
         state.selectedToken = TOKEN;
         send.updateSendBalance();
         expect(text("send-balance")).toBe(
@@ -325,20 +332,74 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
             "You have 0.000000000000000000000001 TOK but are trying to send" +
                 " 0.000000000000000001 TOK.",
         );
-        // Listed with zero balances hidden, and counted as funds.
+    });
+});
+
+// A token the user does not track, with enough holders to be admitted. The
+// balance fetch dropped a holding of it below 0.000001, but the token stays
+// selected while its own screen is open: after sending 2 of a 2.0000003
+// holding, the user is back on that screen, and Send read the missing row as
+// zero.
+describe("an untracked token holding below 0.000001 never renders as zero", () => {
+    const row = () => tokenRow(HALF_MICRO_ETH, { holders_count: "50000" });
+
+    test("on the Send screen", async () => {
+        await refreshWith(10n ** 18n, [row()]);
+        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, [row()]);
+        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.",
+        );
+    });
+});
+
+// The fetch keeps every holding, so the screens that showed only what it kept
+// leave out a holding below 0.000001 themselves, and look as they did.
+describe("a token holding below 0.000001 is still not listed", () => {
+    afterEach(() => {
+        clearPrices();
+    });
+
+    test("for a token the user does not track", async () => {
+        prices.ETH = 3000;
+        await refreshWith(0n, [
+            tokenRow(HALF_MICRO_ETH, { holders_count: "50000" }),
+        ]);
+        const addr = state.wallets[0].addresses[0];
+        expect(balanceLinesForAddress(addr, [], true)).not.toContain(TOKEN);
+        expect(balanceLinesForAddress(addr, [], false)).not.toContain(TOKEN);
+        send.renderSendTokenSelect(addr);
+        const options = global.document.getElementById("send-token").children;
+        expect(options.map((o) => o.value)).toEqual([]);
+        // Not an unpriced token in the total, and not funds on the
+        // remove-address warning.
+        expect(formatAddressTotal(getAddressValue(addr))).toBe("Total: $0.00");
+        expect(addressHoldsFunds(addr)).toBe(false);
+    });
+
+    // As a tracked token holding nothing: listed only while zero balances are
+    // shown.
+    test("for a tracked token, unless zero balances are shown", async () => {
+        state.trackedTokens = [
+            { address: TOKEN, symbol: "TOK", name: "Token", decimals: 18 },
+        ];
+        await refreshWith(0n, [tokenRow(HALF_MICRO_ETH)]);
         const addr = state.wallets[0].addresses[0];
         expect(
             balanceLinesForAddress(addr, state.trackedTokens, false),
+        ).not.toContain(TOKEN);
+        expect(
+            balanceLinesForAddress(addr, state.trackedTokens, true),
         ).toContain(`data-token="${TOKEN}"`);
-        expect(addressHoldsFunds(addr)).toBe(true);
-    });
-
-    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([]);
     });
 });