fix: every balance is cut to four decimals (closes #757)

The balance lists and Home's ETH line rounded with toFixed(4), so 0.99996
ETH read 1.0000 there and 0.9999 on Send. Send's current balance and
ConfirmTx's balance line kept the nonzero floor, so 0.00004 USDC read
0.0000 in the lists and 0.00004 on Send. All four now cut the stored
decimal string with truncateAmount(), as the history rows do.
balanceLine() takes the stored balance string instead of a parsed number,
and escapes the quantity cell. The amounts, fees and allowances a screen
asks the user to approve keep the floor of truncateAmountNeverZero().

Model: opus-5-5

README.md

@@ -264,6 +264,8 @@ The shared modules, each in one line:
   messaging, windows and the lock.
 - `buildInfo.js`: the version, license, author, commit and date compiled into
   About.
+- `calldataDecoder.js`: the ERC-20 `approve()` and `transfer()` decoder, which
+  hands other calldata to `uniswap.js`. Popup only.
 - `chainSwitch.js`: the popup's network switch.
 - `chainSwitchFields.js`: the fields a network switch changes.
 - `constants.js`: `DEBUG`, the default endpoints, the ERC-20 ABI and the burn
@@ -1187,17 +1189,28 @@ These helpers write one kind of value on every screen that shows it:
   times;
 - `renderAddressHtml()` in the same file: most addresses.
 
-Every screen shows token and ETH amounts the same way, through
+Most screens show token and ETH amounts with four decimal places. History rows
-`truncateAmountNeverZero()` in `src/shared/amountDisplay.js`:
+cut amounts to four decimals and never round up (`truncateAmount()` in
+`src/shared/amountDisplay.js`). These balances are cut the same way:
 
-- an amount is cut to four decimal places, never rounded, so 0.99996 reads
+- the balance lists;
-  `0.9999`;
+- Home's ETH balance;
-- an amount below 0.0001 is shown to its first nonzero digit, so 0.00004 reads
+- Send's current balance;
-  `0.00004`.
+- ConfirmTx's balance line.
 
-So an amount never reads as more than it is, and a nonzero amount never reads as
+So a balance below 0.0001 reads `0.0000` there.
-zero. TransactionDetail is the one exception: it shows the exact amount and its
+
-base units.
+The screens that state what is being authorized cut as the history does, and
+extend an amount below 0.0001 to its first nonzero digit
+(`truncateAmountNeverZero()`). So a nonzero amount never reads as zero there.
+Those screens are:
+
+- TxApproval;
+- SignApproval's Permit warning;
+- ConfirmTx's amount and network fee;
+- WaitTx, SuccessTx and ErrorTx.
+
+TransactionDetail shows the exact amount and its base units.
 
 An amount to send is valid when it is a number above zero, written as digits
 with at most one decimal point. Nothing but zeros may follow the token's last
@@ -1376,7 +1389,7 @@ approval screens show a red warning.
 ### Transaction decoding
 
 TxApproval and TransactionDetail try to decode calldata into a summary
-(`decodeCalldata()` in `src/popup/views/approval.js`). SuccessTx repeats
+(`decodeCalldata()` in `src/shared/calldataDecoder.js`). SuccessTx repeats
 TxApproval's summary. Decoding is a display aid. When it fails, the raw calldata
 is shown in full. No contract gets any treatment beyond a legible confirmation
 screen.
@@ -1642,11 +1655,10 @@ The development dependencies ship nowhere:
 
 ### Crypto policy
 
-Hashing, key derivation, signing and encryption go through `ethers` or
+In the extension, hashing, key derivation, signing and encryption go through
-`libsodium-wrappers-sumo`. No primitive is implemented in this repository. A new
+`ethers` or `libsodium-wrappers-sumo`. A new recovery phrase takes its random
-recovery phrase draws its random bytes from the browser's
+bytes from `ethers`. `build.js` and `script/lib/package.js` also hash files with
-`crypto.getRandomValues()`. The build tooling, `build.js` and `script/lib/`,
+`ethers`. No primitive is implemented in this repository.
-hashes files with Node's `crypto`; none of it ships in the extension.
 
 ### Content Security Policy
 

build.js

@@ -1,8 +1,8 @@
 const fs = require("fs");
 const path = require("path");
-const crypto = require("crypto");
 const { execSync } = require("child_process");
 const esbuild = require("esbuild");
+const { sha256 } = require("ethers");
 const { resolveVersion } = require("./script/lib/version");
 const {
     BACKGROUND_ENTRY_PREFIX,
@@ -314,10 +314,8 @@ function copyIcons(distDir) {
 }
 
 function sha256File(absPath) {
-    return crypto
+    // ethers prefixes the hex with 0x; the receipt holds bare hex.
-        .createHash("sha256")
+    return sha256(fs.readFileSync(absPath)).slice(2);
-        .update(fs.readFileSync(absPath))
-        .digest("hex");
 }
 
 // Write the receipt for the files this build emitted. Deliberately records no

script/lib/package.js

@@ -25,9 +25,9 @@
 
 "use strict";
 
-const crypto = require("crypto");
 const fs = require("fs");
 const path = require("path");
+const ethers = require("ethers");
 
 const { readZip, writeZip } = require("./zip");
 const { resolveVersion } = require("./version");
@@ -60,8 +60,9 @@ function fail(message) {
     throw new Error(message);
 }
 
+// Lowercase hex without the 0x prefix ethers adds, as sha256sum prints it.
 function sha256(buf) {
-    return crypto.createHash("sha256").update(buf).digest("hex");
+    return ethers.sha256(buf).slice(2);
 }
 
 // Every regular file under dir, as archive-root-relative forward-slashed
@@ -291,4 +292,9 @@ if (require.main === module) {
     }
 }
 
-module.exports = { checkSelfContained, htmlReferences, manifestReferences };
+module.exports = {
+    checkSelfContained,
+    htmlReferences,
+    manifestReferences,
+    sha256,
+};

src/popup/views/approval.js

@@ -12,9 +12,13 @@ const {
     formatFee,
     tokenLabel,
     blockscoutOffTokenNoteHtml,
-    tokenSourcesByChainId,
 } = require("./helpers");
-const { state, saveState, currentNetwork } = require("../../shared/state");
+const {
+    state,
+    saveState,
+    currentNetwork,
+    tokenSourcesByChainId,
+} = require("../../shared/state");
 const {
     networkById,
     networkByChainId,
@@ -26,21 +30,24 @@ const {
     getAddress,
     getBigInt,
     getBytes,
-    Interface,
     MaxUint256,
     toUtf8String,
 } = require("ethers");
 const { getPrice, formatUsd } = require("../../shared/prices");
-const { ERC20_ABI } = require("../../shared/constants");
 const { INVISIBLE_CHARACTERS } = require("../../shared/symbolSpoof");
 const {
     resolveTokenDecimals,
     resolveTokenSymbol,
     unknownDecimalsAmount,
 } = require("../../shared/approvalAmount");
+const {
+    decodeCalldata,
+    tokenAmountText,
+} = require("../../shared/calldataDecoder");
 // Four decimals, with the nonzero floor these screens hold: every amount this
 // view renders — the ERC-20 line, the ETH value, the max fee — and every one
-// it carries forward to the wait/success/error screens goes through it.
+// it carries forward to the wait/success/error screens goes through it. The
+// ERC-20 line gets it from tokenAmountText().
 const {
     truncateAmountNeverZero: formatTxValue,
 } = require("../../shared/amountDisplay");
@@ -54,11 +61,8 @@ const {
     typedDataChainRefusal,
 } = require("../../shared/approvalVerify");
 const txStatus = require("./txStatus");
-const uniswap = require("../../shared/uniswap");
 const { runtimeApi, sendMessage } = require("../../shared/browserApi");
 
-const erc20Iface = new Interface(ERC20_ABI);
-
 // The link opens the explorer of the network with `chainId`, or of the active
 // network when none is given. A chain id that names no network has no
 // explorer, so the address is drawn without a link.
@@ -70,141 +74,6 @@ function approvalAddressHtml(address, chainId) {
     return renderAddressHtml(address, { title, chainId });
 }
 
-// The amount line for a decoded ERC-20 call. With a known scale it is the
-// token quantity; with `decimals` null it is the base-unit integer with the
-// unknown scale stated, because formatting it with an assumed scale is what
-// showed a 5,000-token transfer as `0.0000`. `raw` is what the status screens
-// carry, `display` is what the approval screen shows.
-function tokenAmountText(rawAmount, decimals, symbol) {
-    if (decimals === null) {
-        const unknown = unknownDecimalsAmount(rawAmount);
-        return { raw: unknown, display: unknown };
-    }
-    const formatted = formatTxValue(formatUnits(rawAmount, decimals));
-    return {
-        raw: formatted,
-        display: formatted + (symbol ? " " + symbol : ""),
-    };
-}
-
-// Try to decode calldata sent from `fromAddress` to `toAddress` on the network
-// with chain id `chainId`, using known ABIs.
-// Returns { name, description, details } or null.
-function decodeCalldata(data, toAddress, chainId, fromAddress) {
-    if (!data || data === "0x" || data.length < 10) return null;
-
-    // Where a token's name and scale are looked for, for every decoder below:
-    // what the wallet knows of the tokens on the network with `chainId`, which
-    // need not be the active one. The ERC-20 amount line and the swap's Amount
-    // and Min. received lines resolve the scale the same way, and refuse to
-    // format the same way when it is nowhere.
-    const decimalsSources = tokenSourcesByChainId(chainId);
-
-    // Try ERC-20 (approve / transfer)
-    try {
-        const parsed = erc20Iface.parseTransaction({ data });
-        if (parsed) {
-            const tokenSymbol = resolveTokenSymbol(toAddress, decimalsSources);
-            // null when no source knows this token's scale. It is not
-            // defaulted to 18: an amount formatted with a guessed scale is
-            // the wrong number, and for a token with fewer decimals than the
-            // guess it is the wrong number in the direction that reads as
-            // zero. See tokenAmountText().
-            const tokenDecimals = resolveTokenDecimals(
-                toAddress,
-                decimalsSources,
-            );
-            const contractLabel = tokenSymbol
-                ? tokenSymbol + " (" + toAddress + ")"
-                : toAddress;
-
-            if (parsed.name === "approve") {
-                const spender = parsed.args[0];
-                const rawAmount = parsed.args[1];
-                const maxUint = BigInt(
-                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
-                );
-                const isUnlimited = rawAmount === maxUint;
-                // An unbounded allowance needs no scale to describe, so it is
-                // still named rather than refused.
-                const amount = isUnlimited
-                    ? { raw: "Unlimited", display: "Unlimited" }
-                    : tokenAmountText(rawAmount, tokenDecimals, tokenSymbol);
-
-                return {
-                    name: "Token Approval",
-                    description: tokenSymbol
-                        ? "Approve spending of your " + tokenSymbol
-                        : "Approve spending of an ERC-20 token",
-                    details: [
-                        {
-                            label: "Token",
-                            value: contractLabel,
-                            address: toAddress,
-                            isToken: true,
-                        },
-                        {
-                            label: "Spender",
-                            value: spender,
-                            address: spender,
-                        },
-                        {
-                            label: "Amount",
-                            value: amount.display,
-                            rawValue: amount.raw,
-                        },
-                    ],
-                };
-            }
-
-            if (parsed.name === "transfer") {
-                const to = parsed.args[0];
-                const rawAmount = parsed.args[1];
-                const amount = tokenAmountText(
-                    rawAmount,
-                    tokenDecimals,
-                    tokenSymbol,
-                );
-
-                return {
-                    name: "Token Transfer",
-                    description: tokenSymbol
-                        ? "Transfer " + tokenSymbol
-                        : "Transfer ERC-20 token",
-                    details: [
-                        {
-                            label: "Token",
-                            value: contractLabel,
-                            address: toAddress,
-                            isToken: true,
-                        },
-                        { label: "Recipient", value: to, address: to },
-                        {
-                            label: "Amount",
-                            value: amount.display,
-                            rawValue: amount.raw,
-                        },
-                    ],
-                };
-            }
-        }
-    } catch {
-        // Not ERC-20 — fall through
-    }
-
-    // Try Uniswap Universal Router
-    const routerResult = uniswap.decode(
-        data,
-        toAddress,
-        chainId,
-        decimalsSources,
-        fromAddress,
-    );
-    if (routerResult) return routerResult;
-
-    return null;
-}
-
 function showPhishingWarning(elementId, isPhishing) {
     const el = $(elementId);
     if (!el) return;
@@ -1298,7 +1167,6 @@ function init(_ctx) {
 module.exports = {
     init,
     show,
-    decodeCalldata,
     formatTypedDataHtml,
     typedDataRefusal,
 };

src/popup/views/confirmTx.js

@@ -43,9 +43,12 @@ const {
     transferAmountUnits,
 } = require("../../shared/transferAmount");
 const { assertWithinCeilings } = require("../../shared/approvalVerify");
-// The amount, the balance line and the fee reserve go through it, as the
+// The amount and the fee reserve keep the nonzero floor, as the approval
-// approval screen's amounts do.
+// screen's amounts do. The balance line is cut as the balance lists cut it.
-const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
+const {
+    truncateAmount,
+    truncateAmountNeverZero,
+} = require("../../shared/amountDisplay");
 const {
     CODES,
     FEE_PENDING,
@@ -160,7 +163,7 @@ function renderBalance(txInfo) {
     const price = getPrice(txInfo.token, txInfo.chainId);
     const balUsd = price ? parseFloat(bal) * price : null;
     $("confirm-balance").textContent = valueWithUsd(
-        truncateAmountNeverZero(bal) + " " + symbol,
+        truncateAmount(bal) + " " + symbol,
         balUsd,
     );
 }

src/popup/views/deleteAddress.js

@@ -79,8 +79,8 @@ function recoveryPathText(wallet) {
 // "Holds" means ETH or any ERC-20 the wallet knows about — an address with no
 // ETH and a five-figure stablecoin position must not get the blank line on
 // the one screen whose job is to warn. The sentence names no figure of its
-// own: the rendered lines round to four decimals, so a sentence built from a
+// own: the rendered lines cut to four decimals, so a sentence built from their
-// rounded number would report "0.0000 ETH" for an address holding real money.
+// figure would report "0.0000 ETH" for an address holding real money.
 // The lines below it carry the amounts, in the same format as Home and
 // AddressDetail, followed by the USD total when there is one to give — no
 // total line at all on testnet, before the first price fetch or while no

src/popup/views/helpers.js

@@ -18,6 +18,7 @@
 const { formatEther } = require("ethers");
 const makeBlockie = require("ethereum-blockies-base64");
 const {
+    truncateAmount,
     truncateAmountNeverZero,
     isBelowOneMillionth,
 } = require("../../shared/amountDisplay");
@@ -31,7 +32,12 @@ const { escapeHtml } = require("../../shared/html");
 const { isDebug } = require("../../shared/log");
 const { networkByChainId } = require("../../shared/networks");
 const { formatUsd, getPrice } = require("../../shared/prices");
-const { state, saveState, currentNetwork } = require("../../shared/state");
+const {
+    state,
+    saveState,
+    currentNetwork,
+    tokenSourcesByChainId,
+} = require("../../shared/state");
 const { displaySymbol } = require("../../shared/symbolDisplay");
 const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { walletHasRecoveryPhrase } = require("../../shared/wallet");
@@ -305,32 +311,6 @@ function nativeCurrency() {
     return currentNetwork().nativeCurrency;
 }
 
-// What the wallet knows of the tokens on the network with this chain id, or
-// on the active network when no chain id is given, as the `sources` that
-// resolveTokenSymbol() and resolveTokenDecimals() take. A contract address
-// names a token on one network only, and every token balance held is the
-// active network's, so another network gets the tokens tracked on it
-// (state.networkTrackedTokens, see applyChainSwitchFields()) and no balances.
-//
-// The wallets' balances hold what Blockscout reported for each token. So the
-// wallets are returned only while "Use Blockscout" is on.
-function tokenSourcesByChainId(chainId) {
-    const chainIdOrActive = chainId || currentNetwork().chainId;
-    const net = networkByChainId(chainIdOrActive);
-    if (net && net.id === state.networkId) {
-        return {
-            chainId: chainIdOrActive,
-            trackedTokens: state.trackedTokens,
-            wallets: state.useBlockscout ? state.wallets : [],
-        };
-    }
-    return {
-        chainId: chainIdOrActive,
-        trackedTokens: (net && state.networkTrackedTokens[net.id]) || [],
-        wallets: [],
-    };
-}
-
 // The line shown under a token while "Use Blockscout" is off. The token gets
 // the line only when the bundled list and the tracked tokens lack its name or
 // decimals. Otherwise this returns "". The token is a contract address on the
@@ -398,12 +378,11 @@ function formatFee(wei, symbol, chainId) {
 // whose scale nothing knows
 // (https://git.eeqj.de/sneak/AutistMask/issues/349), and for a balance no
 // refresh has read. There is no quantity to print for it and no fiat value to
-// derive from one, and printing 0.0000 for a real holding is the failure this
+// derive from one. A holding whose amount is unknown is shown as
-// whole rule exists to prevent, so the row says so instead.
+// `quantity unknown` rather than as a zero.
 function balanceLine(symbol, balance, price, tokenId) {
     const amount = unknownableAmount(balance);
-    const qty =
+    const qty = amount === null ? "quantity unknown" : truncateAmount(balance);
-        amount === null ? "quantity unknown" : truncateAmountNeverZero(balance);
     const usd =
         price && amount !== null
             ? escapeHtml(formatUsd(amount * price)) || " "
@@ -491,8 +470,10 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
 
 // Whether an address holds anything at all: ETH or any ERC-20 the wallet
 // knows about, except a token holding below 0.000001, which the balance list
-// under the remove-address warning leaves out too. Callers that warn about
+// under the remove-address warning leaves out too. Deliberately exact — the
-// holdings must ask this, not the rendered lines.
+// rendered lines cut 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;
     // A null or absent ETH balance reads as unknown, so the address may hold
@@ -867,7 +848,6 @@ module.exports = {
     keyMaterialName,
     unknownableAmount,
     nativeCurrency,
-    tokenSourcesByChainId,
     blockscoutOffTokenNoteHtml,
     tokenLabel,
     formatFee,

src/popup/views/home.js

@@ -31,7 +31,7 @@ const {
     resetSendValidation,
 } = require("./send");
 const { deriveAddressFromXpub } = require("../../shared/wallet");
-const { truncateAmountNeverZero } = require("../../shared/amountDisplay");
+const { truncateAmount } = require("../../shared/amountDisplay");
 const { canRemoveAddress } = require("../../shared/walletDelete");
 const {
     walletDefect,
@@ -82,8 +82,7 @@ function renderTotalValue() {
     if (ethBal === null) {
         el.textContent = "unknown (" + nativeCurrency() + ")";
     } else {
-        const ethStr =
+        const ethStr = truncateAmount(addr.balance) + " " + nativeCurrency();
-            truncateAmountNeverZero(addr.balance) + " " + nativeCurrency();
         const ethUsd = ethPrice
             ? " (" + formatUsd(ethBal * ethPrice) + ")"
             : "";

src/popup/views/send.js

@@ -10,9 +10,13 @@ const {
     renderAddressHtml,
     attachCopyHandlers,
     goBack,
-    tokenSourcesByChainId,
 } = require("./helpers");
-const { state, currentAddress, currentNetwork } = require("../../shared/state");
+const {
+    state,
+    currentAddress,
+    currentNetwork,
+    tokenSourcesByChainId,
+} = require("../../shared/state");
 let ctx;
 const { getProvider } = require("../../shared/balances");
 const { resolveTokenDecimals } = require("../../shared/approvalAmount");
@@ -20,7 +24,7 @@ const { resolveSymbol } = require("../../shared/tokenList");
 const { isLowHolderCount } = require("../../shared/holders");
 const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const {
-    truncateAmountNeverZero,
+    truncateAmount,
     isBelowOneMillionth,
 } = require("../../shared/amountDisplay");
 const {
@@ -235,7 +239,7 @@ function updateSendBalance() {
             addr.balance == null
                 ? "Current balance: unknown (" + nativeCurrency() + ")"
                 : "Current balance: " +
-                  truncateAmountNeverZero(addr.balance) +
+                  truncateAmount(addr.balance) +
                   " " +
                   nativeCurrency();
     } else {
@@ -254,18 +258,15 @@ function updateSendBalance() {
         $("send-balance").textContent =
             bal == null
                 ? "Current balance: unknown (" + symbol + ")"
-                : "Current balance: " +
+                : "Current balance: " + truncateAmount(bal) + " " + symbol;
-                  truncateAmountNeverZero(bal) +
-                  " " +
-                  symbol;
     }
 }
 
 // Fill the amount field with the most the selected holding can send: a
 // token's whole balance (cut to 18 decimal places), or for ETH the exact
 // balance minus the fee reserve the confirmation screen checks against, never
-// the rounded balance the screen shows. Where there is nothing to fill in, a
+// the balance the screen shows, which is cut to four decimals. Where there is
-// flash message says why.
+// nothing to fill in, a flash message says why.
 async function fillMaxAmount() {
     const addr = currentAddress();
     if (!addr) return;

src/popup/views/transactionDetail.js

@@ -27,7 +27,7 @@ const { nativeCurrencyByChainId } = require("../../shared/networks");
 const { formatEther, formatUnits } = require("ethers");
 const { log, debugFetch } = require("../../shared/log");
 const { storedSettingIsOn } = require("../../shared/storedSettings");
-const { decodeCalldata } = require("./approval");
+const { decodeCalldata } = require("../../shared/calldataDecoder");
 
 /**
  * Determine a human-readable transaction type string from tx fields.

src/shared/amountDisplay.js

@@ -1,6 +1,15 @@
-// The amount rule from README.md's Amounts section. Every screen that shows a
+// The 4-decimal amount rule from README.md's Amounts section, and
-// token or ETH amount, except TransactionDetail, shows it through
+// the one exception to it, in one place. Three call sites had grown their own
-// truncateAmountNeverZero(), so one value reads the same on every screen.
+// copy of the truncation — the history and balance lists
+// (`src/shared/transactions.js`), the approval screen's ERC-20 amount line
+// (`src/shared/calldataDecoder.js`) and its Uniswap swap detail lines
+// (`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 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
@@ -11,13 +20,12 @@ function truncateAmount(val) {
     return parts[0] + "." + (parts[1] + "0000").slice(0, 4);
 }
 
-// Four decimal places, truncated, and a nonzero amount never renders as zero.
+// The same rule, plus the invariant the approval and confirmation screens
-// Truncating alone would show an amount below 0.0001 as 0.0000, and a real
+// hold: a nonzero amount never renders as zero. Truncating to four decimals
-// holding, transfer or allowance would then read as nothing.
+// does exactly that to an amount below 0.0001 — one base unit of an 18-decimal
-//
+// token, 500 of an 8-decimal one — and a real transfer or allowance then reads
-// `val` is the exact decimal string: a stored balance, or what formatEther()
+// as "nothing is being moved" on the screen whose whole job is to say what is
-// or formatUnits() returns. Never a JavaScript number, whose own rounding
+// being authorized.
-// would happen before the truncation.
 //
 // When the truncated string carries no significant digit and the value does,
 // the amount is extended to its first significant digit instead. It stays in
@@ -46,6 +54,7 @@ function isBelowOneMillionth(balance) {
 }
 
 module.exports = {
+    truncateAmount,
     truncateAmountNeverZero,
     isBelowOneMillionth,
 };

src/shared/calldataDecoder.js

@@ -0,0 +1,155 @@
+// Decode a transaction's calldata into the summary that TxApproval and
+// TransactionDetail show: ERC-20 `approve` and `transfer` calls here, and
+// Uniswap Universal Router calls through uniswap.js. The summary is data; the
+// views turn its addresses into HTML.
+
+const { formatUnits, Interface } = require("ethers");
+const { ERC20_ABI } = require("./constants");
+const { tokenSourcesByChainId } = require("./state");
+const {
+    resolveTokenDecimals,
+    resolveTokenSymbol,
+    unknownDecimalsAmount,
+} = require("./approvalAmount");
+// Four decimals, with the nonzero floor the approval screens hold.
+const { truncateAmountNeverZero } = require("./amountDisplay");
+const uniswap = require("./uniswap");
+
+const erc20Iface = new Interface(ERC20_ABI);
+
+// The amount line for a decoded ERC-20 call. With a known scale it is the
+// token quantity; with `decimals` null it is the base-unit integer with the
+// unknown scale stated, because formatting it with an assumed scale is what
+// showed a 5,000-token transfer as `0.0000`. `raw` is what the status screens
+// carry, `display` is what the approval screen shows.
+function tokenAmountText(rawAmount, decimals, symbol) {
+    if (decimals === null) {
+        const unknown = unknownDecimalsAmount(rawAmount);
+        return { raw: unknown, display: unknown };
+    }
+    const formatted = truncateAmountNeverZero(formatUnits(rawAmount, decimals));
+    return {
+        raw: formatted,
+        display: formatted + (symbol ? " " + symbol : ""),
+    };
+}
+
+// Try to decode calldata sent from `fromAddress` to `toAddress` on the network
+// with chain id `chainId`, using known ABIs.
+// Returns { name, description, details } or null.
+function decodeCalldata(data, toAddress, chainId, fromAddress) {
+    if (!data || data === "0x" || data.length < 10) return null;
+
+    // Where a token's name and scale are looked for, for every decoder below:
+    // what the wallet knows of the tokens on the network with `chainId`, which
+    // need not be the active one. The ERC-20 amount line and the swap's Amount
+    // and Min. received lines resolve the scale the same way, and refuse to
+    // format the same way when it is nowhere.
+    const decimalsSources = tokenSourcesByChainId(chainId);
+
+    // Try ERC-20 (approve / transfer)
+    try {
+        const parsed = erc20Iface.parseTransaction({ data });
+        if (parsed) {
+            const tokenSymbol = resolveTokenSymbol(toAddress, decimalsSources);
+            // null when no source knows this token's scale. It is not
+            // defaulted to 18: an amount formatted with a guessed scale is
+            // the wrong number, and for a token with fewer decimals than the
+            // guess it is the wrong number in the direction that reads as
+            // zero. See tokenAmountText().
+            const tokenDecimals = resolveTokenDecimals(
+                toAddress,
+                decimalsSources,
+            );
+            const contractLabel = tokenSymbol
+                ? tokenSymbol + " (" + toAddress + ")"
+                : toAddress;
+
+            if (parsed.name === "approve") {
+                const spender = parsed.args[0];
+                const rawAmount = parsed.args[1];
+                const maxUint = BigInt(
+                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+                );
+                const isUnlimited = rawAmount === maxUint;
+                // An unbounded allowance needs no scale to describe, so it is
+                // still named rather than refused.
+                const amount = isUnlimited
+                    ? { raw: "Unlimited", display: "Unlimited" }
+                    : tokenAmountText(rawAmount, tokenDecimals, tokenSymbol);
+
+                return {
+                    name: "Token Approval",
+                    description: tokenSymbol
+                        ? "Approve spending of your " + tokenSymbol
+                        : "Approve spending of an ERC-20 token",
+                    details: [
+                        {
+                            label: "Token",
+                            value: contractLabel,
+                            address: toAddress,
+                            isToken: true,
+                        },
+                        {
+                            label: "Spender",
+                            value: spender,
+                            address: spender,
+                        },
+                        {
+                            label: "Amount",
+                            value: amount.display,
+                            rawValue: amount.raw,
+                        },
+                    ],
+                };
+            }
+
+            if (parsed.name === "transfer") {
+                const to = parsed.args[0];
+                const rawAmount = parsed.args[1];
+                const amount = tokenAmountText(
+                    rawAmount,
+                    tokenDecimals,
+                    tokenSymbol,
+                );
+
+                return {
+                    name: "Token Transfer",
+                    description: tokenSymbol
+                        ? "Transfer " + tokenSymbol
+                        : "Transfer ERC-20 token",
+                    details: [
+                        {
+                            label: "Token",
+                            value: contractLabel,
+                            address: toAddress,
+                            isToken: true,
+                        },
+                        { label: "Recipient", value: to, address: to },
+                        {
+                            label: "Amount",
+                            value: amount.display,
+                            rawValue: amount.raw,
+                        },
+                    ],
+                };
+            }
+        }
+    } catch {
+        // Not ERC-20 — fall through
+    }
+
+    // Try Uniswap Universal Router
+    const routerResult = uniswap.decode(
+        data,
+        toAddress,
+        chainId,
+        decimalsSources,
+        fromAddress,
+    );
+    if (routerResult) return routerResult;
+
+    return null;
+}
+
+module.exports = { decodeCalldata, tokenAmountText };

src/shared/state.js

@@ -22,7 +22,7 @@
 // same thing in the editor is fast feedback in front of the build, not the
 // guarantee.
 
-const { networkById } = require("./networks");
+const { networkById, networkByChainId } = require("./networks");
 const { copyChainSwitchFields } = require("./chainSwitchFields");
 const {
     DEFAULT_STATE,
@@ -125,6 +125,32 @@ function currentNetwork() {
     return networkById(state.networkId);
 }
 
+// What the wallet knows of the tokens on the network with this chain id, or
+// on the active network when no chain id is given, as the `sources` that
+// resolveTokenSymbol() and resolveTokenDecimals() take. A contract address
+// names a token on one network only, and every token balance held is the
+// active network's, so another network gets the tokens tracked on it
+// (state.networkTrackedTokens, see applyChainSwitchFields()) and no balances.
+//
+// The wallets' balances hold what Blockscout reported for each token. So the
+// wallets are returned only while "Use Blockscout" is on.
+function tokenSourcesByChainId(chainId) {
+    const chainIdOrActive = chainId || currentNetwork().chainId;
+    const net = networkByChainId(chainIdOrActive);
+    if (net && net.id === state.networkId) {
+        return {
+            chainId: chainIdOrActive,
+            trackedTokens: state.trackedTokens,
+            wallets: state.useBlockscout ? state.wallets : [],
+        };
+    }
+    return {
+        chainId: chainIdOrActive,
+        trackedTokens: (net && state.networkTrackedTokens[net.id]) || [],
+        wallets: [],
+    };
+}
+
 // `baseline` holds the persisted fields as this page held them when its last
 // loadState() finished, or when its last successful saveState() began.
 // takeStoredNetwork(), takeStoredTrackedTokens() and
@@ -820,5 +846,6 @@ module.exports = {
     loadState,
     currentAddress,
     currentNetwork,
+    tokenSourcesByChainId,
     StateNotLoadedError,
 };

src/shared/transactions.js

@@ -16,7 +16,10 @@ const { nativeCurrencyByChainId } = require("./networks");
 // a scale is either reported or it is unknown, and "unknown" must mean the
 // same thing here as it does on the screens that refuse to format one.
 const { toDecimals } = require("./transferAmount");
-const { truncateAmountNeverZero } = require("./amountDisplay");
+// The plain 4-decimal rule. The history and balance lists deliberately keep
+// truncation without the approval screens' nonzero floor: the transaction
+// detail view is the authoritative record and already shows exact precision.
+const { truncateAmount: formatTxValue } = require("./amountDisplay");
 const { routerRelease } = require("./uniswap");
 const { storedSettingIsOn } = require("./storedSettings");
 
@@ -37,7 +40,7 @@ function parseTx(tx, addrLower, chainId) {
 
     // For contract calls, produce a meaningful label instead of "0.0000 ETH"
     let symbol = nativeCurrencyByChainId(chainId);
-    let value = truncateAmountNeverZero(formatEther(rawWei));
+    let value = formatTxValue(formatEther(rawWei));
     let exactValue = formatEther(rawWei);
     let rawAmount = rawWei;
     let rawUnit = "wei";
@@ -119,9 +122,7 @@ function parseTokenTransfer(tt, addrLower, chainId) {
     // The exact figure is not lost — it is the base-unit line below, which is
     // the one number that needs no scale to be true.
     const formatted =
-        decimals === null
+        decimals === null ? "" : formatTxValue(formatUnits(rawVal, decimals));
-            ? ""
-            : truncateAmountNeverZero(formatUnits(rawVal, decimals));
     const exact = decimals === null ? "" : formatUnits(rawVal, decimals);
     return {
         hash: tt.transaction_hash,

src/shared/wallet.js

@@ -1,7 +1,7 @@
 // Wallet operations: mnemonic generation, HD derivation, signing.
 // All crypto delegated to ethers.js.
 
-const { Mnemonic, HDNodeWallet, Wallet } = require("ethers");
+const { Mnemonic, HDNodeWallet, Wallet, randomBytes } = require("ethers");
 const { DEBUG, DEBUG_MNEMONIC, BIP44_ETH_PATH } = require("./constants");
 
 function generateMnemonic() {
@@ -10,10 +10,7 @@ function generateMnemonic() {
     // settings toggle drives, which would let a user of a release build turn
     // the hardcoded, publicly known test phrase back on for real wallets.
     if (DEBUG) return DEBUG_MNEMONIC;
-    const m = Mnemonic.fromEntropy(
+    return Mnemonic.fromEntropy(randomBytes(16)).phrase;
-        globalThis.crypto.getRandomValues(new Uint8Array(16)),
-    );
-    return m.phrase;
 }
 
 // Every extended key (xprv or xpub) entering the app goes through this.

tests/approvalAmount.test.js

@@ -23,7 +23,7 @@ const {
     resolveTokenDecimals,
     unknownDecimalsAmount,
 } = require("../src/shared/approvalAmount");
-const { decodeCalldata } = require("../src/popup/views/approval");
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 
 const iface = new Interface(ERC20_ABI);
 

tests/approvalDisplayFloor.test.js

@@ -13,7 +13,7 @@
 // asserted on `rawValue` alongside the displayed line.
 //
 // Both amount paths of that screen are covered: the ERC-20 line decoded by
-// `src/popup/views/approval.js`, and the swap's `Amount` and `Min. received`
+// `src/shared/calldataDecoder.js`, and the swap's `Amount` and `Min. received`
 // lines decoded by `src/shared/uniswap.js`.
 
 globalThis.chrome = {
@@ -23,9 +23,8 @@ globalThis.chrome = {
 const { AbiCoder, Interface } = require("ethers");
 const { ERC20_ABI } = require("../src/shared/constants");
 const { state } = require("../src/shared/state");
-const { decodeCalldata } = require("../src/popup/views/approval");
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 const uniswap = require("../src/shared/uniswap");
-const { truncateAmountNeverZero } = require("../src/shared/amountDisplay");
 
 const iface = new Interface(ERC20_ABI);
 
@@ -180,10 +179,4 @@ describe("the four-decimal rule is otherwise unchanged", () => {
     test("a genuine zero still renders as zero", () => {
         expect(amount(transferData(0n), DAI).rawValue).toBe("0.0000");
     });
-
-    test("one base unit of an 18-decimal token reads as itself", () => {
-        expect(truncateAmountNeverZero("0.000000000000000001")).toBe(
-            "0.000000000000000001",
-        );
-    });
 });

tests/balanceTruncation.test.js

@@ -1,7 +1,6 @@
-// The balance lists and Home's ETH line show a balance as Send does (README.md,
+// The balance lists, Home's ETH line and Send's current balance show a balance
-// Amounts): cut to four decimal places, never rounded up, and a nonzero amount
+// as the history rows do (README.md, Amounts): cut to four decimal places,
-// never shown as zero
+// never rounded up (https://git.eeqj.de/sneak/AutistMask/issues/757).
-// (https://git.eeqj.de/sneak/AutistMask/issues/757).
 //
 // Driven through the real popup over a stored profile on Ethereum Mainnet.
 
@@ -54,9 +53,9 @@ describe("balanceLine", () => {
         );
     });
 
-    test("shows 0.00004 as 0.00004, not 0.0000", () => {
+    test("cuts 0.00004 to 0.0000", () => {
         expect(quantity(balanceLine("USDC", "0.00004", null, USDC))).toBe(
-            "0.00004",
+            "0.0000",
         );
     });
 });
@@ -70,9 +69,23 @@ describe("Home", () => {
         expect(quantity(homeRow(page, "ETH"))).toBe("0.9999");
     });
 
-    test("the balance list reads 0.00004 USDC as 0.00004", async () => {
+    test("the balance list reads 0.00004 USDC as 0.0000", async () => {
         const page = await bootHolding("0.99996", "0.00004");
 
-        expect(quantity(homeRow(page, USDC.toLowerCase()))).toBe("0.00004");
+        expect(quantity(homeRow(page, USDC.toLowerCase()))).toBe("0.0000");
+    });
+});
+
+describe("Send", () => {
+    test("the current balance reads 0.00004 USDC as 0.0000", async () => {
+        const page = await bootHolding("0.99996", "0.00004");
+        await page.click("btn-main-send");
+        // USDC chosen in the dropdown, as the user does.
+        const dropdown = page.node("send-token");
+        dropdown.value = USDC;
+        for (const fn of dropdown.listeners.change) await fn();
+
+        expect(page.visibleViews()).toEqual(["send"]);
+        expect(page.text("send-balance")).toBe("Current balance: 0.0000 USDC");
     });
 });

tests/deleteAddress.test.js

@@ -102,7 +102,7 @@ describe("whether an address holds anything", () => {
         expect(addressHoldsFunds(TOKEN_ONLY)).toBe(true);
     });
 
-    // 0.00001 ETH is below four decimals. It is still money.
+    // 0.00001 ETH renders as "0.0000" at four decimals. It is still money.
     test("an ETH balance below the displayed precision counts", () => {
         expect(addressHoldsFunds(DUST)).toBe(true);
     });
@@ -141,12 +141,13 @@ describe("the balance warning on the removal confirmation", () => {
         expect(html).toContain("2500.0000");
     });
 
-    // The rendered line shows the balance to its first nonzero digit, as Home
+    // The rendered line says 0.0000 for this address — that is the display
-    // and AddressDetail do (README.md, Amounts).
+    // format, shared with Home and AddressDetail — and the warning is shown
-    test("an ETH balance below 0.0001 is warned about, and reads as itself", () => {
+    // all the same, because the balance is not zero.
+    test("an ETH balance that renders as 0.0000 is warned about", () => {
         const html = balanceWarningHtml(DUST);
         expect(html).toContain("This address holds a balance.");
-        expect(html).toContain("<span>0.00001</span>");
+        expect(html).toContain("<span>0.0000</span>");
     });
 
     test("an ETH balance no refresh has read is warned about, and reads as unknown", () => {
@@ -164,9 +165,9 @@ describe("the balance warning on the removal confirmation", () => {
     });
 
     // The sentence must not assert an amount, because any amount it could
-    // assert has been rounded: "This address holds 0.0000 ETH." is what the
+    // assert has been cut to four decimals: "This address holds 0.0000 ETH." is
-    // rounded form produces for an address that holds real money.
+    // what the cut form produces for an address that holds real money.
-    test("the warning sentence asserts no rounded amount", () => {
+    test("the warning sentence asserts no cut amount", () => {
         for (const addr of [DUST, ETH_ONLY, TOKEN_ONLY]) {
             expect(balanceWarningHtml(addr)).not.toMatch(
                 /holds [\d.]+ (ETH|USDC)/,

tests/e2e/run.js

@@ -829,12 +829,11 @@ test("a common-token quick-pick fills in the contract address (#150)", async (en
     await visible(env.page, "#view-address");
 });
 
-// The native amount as the transaction list writes it (four decimals) and
+// The native amount as the transaction list writes it (cut to four decimals,
-// as the detail screen writes it (full precision). Both are rendered here
+// quantity() below) and as the detail screen writes it (full precision). Both
-// from the fixture rather than read off the screen, so the assertions
+// are rendered here from the fixture rather than read off the screen, so the
-// compare against the wei the stub served.
+// assertions compare against the wei the stub served.
-const NATIVE_ROW_TEXT =
+const NATIVE_ROW_TEXT = quantity(STUB_NATIVE_VALUE_WEI) + " ETH";
-    parseFloat(formatEther(STUB_NATIVE_VALUE_WEI)).toFixed(4) + " ETH";
 const NATIVE_DETAIL_TEXT = formatEther(STUB_NATIVE_VALUE_WEI) + " ETH";
 
 test("the native ETH transaction detail still renders (#151)", async (env) => {
@@ -2724,10 +2723,11 @@ async function goToConfirm(page, send) {
     await assertAddressesFit(page, "the confirmation screen");
 }
 
-// A balance as the main view renders it: balanceLinesForAddress() writes
+// An amount in wei as the main view's balance lines and the transaction list
-// every quantity with four decimal places.
+// write it: cut to four decimal places, never rounded, as feeEth() does.
 function quantity(wei) {
-    return parseFloat(formatEther(wei)).toFixed(4);
+    const [whole, frac = ""] = formatEther(wei).split(".");
+    return whole + "." + (frac + "0000").slice(0, 4);
 }
 
 // Wait on the main view until a changed balance fixture has been picked up.

tests/fabricatedDecimals.test.js

@@ -47,7 +47,7 @@ const { fetchTokenBalances } = require("../src/shared/balances");
 const { debugFetch } = require("../src/shared/log");
 const { state } = require("../src/shared/state");
 const { unknownDecimalsAmount } = require("../src/shared/approvalAmount");
-const { decodeCalldata } = require("../src/popup/views/approval");
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 const { TOKEN_BY_ADDRESS } = require("../src/shared/tokenList");
 
 const HOLDER = "0x" + "a".repeat(40);

tests/packaging.test.js

@@ -1,4 +1,5 @@
-// The release archives: the zip container, and the self-containment rule.
+// The release archives: the zip container, the self-containment rule, and the
+// digest format in release/SHA256SUMS.
 //
 // script/package produces one archive per browser and script/lib/package.js
 // decides what goes in it. The trap that rule exists for is real and specific:
@@ -11,12 +12,14 @@
 // So the packager resolves every reference in the manifest and in every HTML
 // document, and fails on any that leaves the extension root. These are the
 // cases for that, plus the archive format itself — new code, and the thing the
-// artifact is made of.
+// artifact is made of. One more case checks the digest format in
+// release/SHA256SUMS.
 
 const {
     checkSelfContained,
     htmlReferences,
     manifestReferences,
+    sha256,
 } = require("../script/lib/package");
 const { readZip, writeZip } = require("../script/lib/zip");
 
@@ -142,6 +145,14 @@ describe("archive self-containment", () => {
     });
 });
 
+// release/SHA256SUMS is checked with `sha256sum -c`, which needs the digest
+// as bare lowercase hex. The expected value is the FIPS 180-2 digest of "abc".
+test("sha256 prints the digest as sha256sum does", () => {
+    expect(sha256(Buffer.from("abc"))).toBe(
+        "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad",
+    );
+});
+
 describe("the zip container", () => {
     const files = [
         { name: "manifest.json", data: Buffer.from('{"a":1}') },

tests/resolveTokenSymbol.test.js

@@ -22,7 +22,7 @@ const { Interface } = require("ethers");
 const { ERC20_ABI } = require("../src/shared/constants");
 const { state } = require("../src/shared/state");
 const { resolveTokenSymbol } = require("../src/shared/approvalAmount");
-const { decodeCalldata } = require("../src/popup/views/approval");
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 
 const iface = new Interface(ERC20_ABI);
 

tests/sendDisplayFloor.test.js

@@ -6,8 +6,10 @@
 // balances and the fee were each cut to six decimal places, a rule of their
 // 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
+// floor. The balances are now stored exactly, and every nonzero token holding
-// kept, and the screens show them and the fee through that helper.
+// is kept. The fee lines show the fee through that helper with the floor. The
+// balance lines cut a balance to four decimals, as the balance lists do, so a
+// balance below 0.0001 reads 0.0000.
 //
 // Driven through the real refreshBalances(), Send screen, confirmation screen
 // and approval screen, with only the node, the explorer and the DOM stubbed: a
@@ -278,21 +280,22 @@ beforeEach(() => {
     mockNode.feeData = { maxFeePerGas: 1n, gasPrice: 1n };
 });
 
-describe("an ETH balance below 0.000001 never renders as zero", () => {
+describe("an ETH balance below 0.0001 reads 0.0000", () => {
     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");
+        expect(text("send-balance")).toBe("Current balance: 0.0000 ETH");
+        expect(state.wallets[0].addresses[0].balance).toBe("0.0000005");
     });
 
     test("on the confirmation screen", async () => {
         await refreshWith(HALF_MICRO_ETH);
         await confirmSend("0.0000001");
-        expect(text("confirm-balance")).toBe("0.0000005 ETH");
+        expect(text("confirm-balance")).toBe("0.0000 ETH");
     });
 
-    test("while a balance above the floor keeps four decimals", async () => {
+    test("while a larger balance is cut to four decimals", async () => {
         await refreshWith(1234567890000000000n);
         await confirmSend("0.1");
         expect(text("confirm-balance")).toBe("1.2345 ETH");
@@ -302,7 +305,7 @@ describe("an ETH balance below 0.000001 never renders as zero", () => {
 // 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", () => {
+describe("a tracked token holding below 0.000001 reads 0.0000", () => {
     beforeEach(() => {
         state.trackedTokens = [
             { address: TOKEN, symbol: "TOK", name: "Token", decimals: 18 },
@@ -313,13 +316,17 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
         await refreshWith(10n ** 18n, [tokenRow(HALF_MICRO_ETH)]);
         state.selectedToken = TOKEN;
         send.updateSendBalance();
-        expect(text("send-balance")).toBe("Current balance: 0.0000005 TOK");
+        expect(text("send-balance")).toBe("Current balance: 0.0000 TOK");
+        const stored = state.wallets[0].addresses[0].tokenBalances.find(
+            (t) => t.address === TOKEN,
+        );
+        expect(stored.balance).toBe("0.0000005");
     });
 
     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(text("confirm-balance")).toBe("0.0000 TOK");
         expect(errors()).toBe("");
         expect(balanceError()).toBe("");
         await confirmSend("0.0000006", TOKEN);
@@ -347,11 +354,9 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
         await refreshWith(10n ** 18n, [tokenRow(1n, { decimals: "24" })]);
         state.selectedToken = TOKEN;
         send.updateSendBalance();
-        expect(text("send-balance")).toBe(
+        expect(text("send-balance")).toBe("Current balance: 0.0000 TOK");
-            "Current balance: 0.000000000000000000000001 TOK",
-        );
         await confirmSend("0.000000000000000001", TOKEN);
-        expect(text("confirm-balance")).toBe("0.000000000000000000000001 TOK");
+        expect(text("confirm-balance")).toBe("0.0000 TOK");
         expect(balanceError()).toContain(
             "Your TOK balance does not cover this amount.",
         );
@@ -363,20 +368,20 @@ describe("a tracked token holding below 0.000001 never renders as zero", () => {
 // 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", () => {
+describe("an untracked token holding below 0.000001 reads 0.0000", () => {
     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");
+        expect(text("send-balance")).toBe("Current balance: 0.0000 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(text("confirm-balance")).toBe("0.0000 TOK");
         expect(errors()).toBe("");
         expect(balanceError()).toBe("");
         await confirmSend("0.0000006", TOKEN);

tests/transactions.test.js

@@ -1361,8 +1361,8 @@ describe("fetchRecentTransactions merge and dedup", () => {
         expect(txs[0].holders).toBe(3500000);
     });
 
-    // README.md, Amounts: a nonzero amount never reads as zero.
+    // README.md, Amounts: a history row cuts to four decimals, with no floor.
-    test("a token transfer below 0.0001 shows its first nonzero digit", async () => {
+    test("a token transfer below 0.0001 reads 0.0000", async () => {
         respondWith(
             [],
             [
@@ -1383,7 +1383,7 @@ describe("fetchRecentTransactions merge and dedup", () => {
         );
 
         const txs = await fetchRecentTransactions(VICTIM, BLOCKSCOUT, "0x1");
-        expect(txs[0].value).toBe("0.00004");
+        expect(txs[0].value).toBe("0.0000");
     });
 
     test("two transfers of the same token in one transaction collapse to one entry", async () => {

tests/uniswapRouterAddress.test.js

@@ -47,7 +47,7 @@ globalThis.chrome = {
 const { state } = require("../src/shared/state");
 const { fetchRecentTransactions } = require("../src/shared/transactions");
 const approval = require("../src/popup/views/approval");
-const { decodeCalldata } = approval;
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 const transactionDetail = require("../src/popup/views/transactionDetail");
 
 const MAINNET = "0x1";

tests/uniswapUnknownDecimals.test.js

@@ -18,7 +18,7 @@ globalThis.chrome = {
 const { AbiCoder, Interface } = require("ethers");
 const { state } = require("../src/shared/state");
 const { unknownDecimalsAmount } = require("../src/shared/approvalAmount");
-const { decodeCalldata } = require("../src/popup/views/approval");
+const { decodeCalldata } = require("../src/shared/calldataDecoder");
 
 const ROUTER = "0x66a9893cc07d91d95644aedd05d03f95e1dba8af";
 const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";