fix: Blockscout and Etherscan lookups are off until the user turns them on (closes #668)

Out of the box the wallet sent the user's addresses to Blockscout and each
recipient to Etherscan. Two settings, "Use Blockscout" and "Check recipients on
Etherscan", now gate those requests. Both are off in a new install and offered
unticked on Welcome and in Settings. While one is off, the screens that relied
on it say so in a plain line. Each gated request reads its setting from storage
before it asks and when the answer lands, and drops a late answer. An open popup
takes another page's change and draws its screens again. While "Use Blockscout"
is off, no address keeps an untracked token, and no screen names a token from
Blockscout's report. ENS lookups ask only the RPC endpoint.

Model: opus-5-5

README.md

@@ -1165,25 +1165,37 @@ with the same floor (`.5` reads `.5000`).
 
 **Specific Exception — unknown token scale:** Calldata carries base units and no
 scale, so every amount on the dApp approval screen needs the token's `decimals`.
-It is resolved from the bundled token list, then from the tokens the user tracks
-on the network the transaction is for, then, when that is the active network,
-from what the block explorer reported for the contract in the wallet's balances,
-which are the active network's only (`resolveTokenDecimals()` in
-`src/shared/approvalAmount.js`). Where none of them answers, the amount is not
-formatted: the line reads `5000000000 base units (decimals unknown)`. A guessed
-scale is not an approximation but a different number — 1,000 units of a
-6-decimal token formatted at 18 decimals reads `0.000000001` — on the screen
-whose only job is to state what is being authorized. Both amount paths of that
-screen take this rule: the ERC-20 `transfer`/`approve` line
-(`src/popup/views/approval.js`) and the swap's `Amount`, `Min. received`,
-`Moved from the sender` and `Permit2 allowance` lines and the `Paid to` line of
-a move into the router (`src/shared/uniswap.js`). The token permission warning
-on the signature screen takes the same rule for its amounts. An unbounded
-allowance or permit needs no scale to describe and is still shown as
-`Unlimited`. A source's answer counts only if it is a whole number from 0 to 80:
-`decimals()` returns a `uint8`, but `formatUnits()` cannot format more than 80
-decimal places, so a token that reports 81 to 255 is shown as one whose scale
-nothing knows.
+It is resolved from these sources, in this order (`resolveTokenDecimals()` in
+`src/shared/approvalAmount.js`):
+
+- the bundled token list
+- the tokens the user tracks on the network the transaction is for
+- what the block explorer reported for the contract in the wallet's balances.
+  These are the active network's only, and they are used only while "Use
+  Blockscout" is on (`tokenSourcesByChainId()` in `src/popup/views/helpers.js`).
+
+The token's name comes from the same sources. While "Use Blockscout" is off, a
+token's name or decimals may be missing from the bundled list and the tracked
+tokens. Then a line under the token says "This token was not looked up on
+Blockscout, because "Use Blockscout" is off in Settings." These screens show it:
+
+- TxApproval and SignApproval
+- WaitTx, SuccessTx and ErrorTx, which follow TxApproval
+
+Where none of the sources answers, the amount is not formatted: the line reads
+`5000000000 base units (decimals unknown)`. A guessed scale is not an
+approximation but a different number — 1,000 units of a 6-decimal token
+formatted at 18 decimals reads `0.000000001` — on the screen whose only job is
+to state what is being authorized. Both amount paths of that screen take this
+rule: the ERC-20 `transfer`/`approve` line (`src/popup/views/approval.js`) and
+the swap's `Amount`, `Min. received`, `Moved from the sender` and
+`Permit2 allowance` lines and the `Paid to` line of a move into the router
+(`src/shared/uniswap.js`). The token permission warning on the signature screen
+takes the same rule for its amounts. An unbounded allowance or permit needs no
+scale to describe and is still shown as `Unlimited`. A source's answer counts
+only if it is a whole number from 0 to 80: `decimals()` returns a `uint8`, but
+`formatUnits()` cannot format more than 80 decimal places, so a token that
+reports 81 to 255 is shown as one whose scale nothing knows.
 
 The rule holds only if nothing invents a scale UPSTREAM of it. Those three
 sources are read as authoritative, so a value written into one of them cannot be
@@ -1206,12 +1218,13 @@ and compare against. Reading the stored field directly instead answers `null`
 for a bundled or tracked token the explorer merely omitted, which is not a
 refusal the wallet has any reason to make.
 
-The Send screen also consults every address's explorer reports, so a contract
-two addresses report different `decimals` for has no scale there, and the stored
-balance, formatted at one of those scales, is withdrawn with it. The Send
-screen's `Current balance` and the confirmation screen's balance line then both
-read `unknown (SYMBOL)`. The balance list formats each explorer row as it is
-fetched, without that cross-address check, and shows the row's figure.
+While "Use Blockscout" is on, the Send screen also consults every address's
+explorer reports. So a contract two addresses report different `decimals` for
+has no scale there, and the stored balance, formatted at one of those scales, is
+withdrawn with it. The Send screen's `Current balance` and the confirmation
+screen's balance line then both read `unknown (SYMBOL)`. The balance list
+formats each explorer row as it is fetched, without that cross-address check,
+and shows the row's figure.
 
 **Decoded amount lines on the transaction approval screen:** the `Amount` line
 of a decoded ERC-20 call, and the `Amount` and `Min. received` lines of a
@@ -2051,6 +2064,9 @@ view would leave a wallet one click from deletion.
       `Unknown (could not be decoded)` with no symbol, not the transaction's ETH
       value. When that swap's `Token In` is `ETH (native)`, the transaction's
       ETH value in the network's currency, as for any other transaction
+    - While "Use Blockscout" is off, TxApproval's line under the amount, when
+      the token's name or decimals are missing from the bundled list and the
+      tracked tokens
     - To: color dot + full address + etherscan link; for a contract creation,
       which has no recipient, "This transaction creates a new contract. It has
       no recipient." instead
@@ -2083,7 +2099,9 @@ view would leave a wallet one click from deletion.
 - **Elements**:
     - "Transaction Confirmed" heading
     - Decoded action well (shown when the transaction carried recognized
-      calldata; the top-level Amount and To are hidden in that case)
+      calldata; the top-level Amount and To are hidden in that case). While "Use
+      Blockscout" is off, it has TxApproval's line under each token whose name
+      or decimals are missing from the bundled list and the tracked tokens.
     - Amount + symbol
     - To: color dot + full address + etherscan link, or for a contract creation
       the same sentence as on WaitTx
@@ -2106,6 +2124,7 @@ view would leave a wallet one click from deletion.
     - Amount + symbol, or for a swap the approval screen showed no `Amount` for,
       the same as on WaitTx: `Unknown (could not be decoded)`, unless its
       `Token In` is `ETH (native)`
+    - While "Use Blockscout" is off, the same line under the amount as on WaitTx
     - To: color dot + full address + etherscan link, or for a contract creation
       the same sentence as on WaitTx
     - Error message (dashed border box)
@@ -2579,6 +2598,12 @@ view would leave a wallet one click from deletion.
       a swap pays only the From address, a `Paid to` line for each other address
       it pays, or saying that a token stays in the router or who it pays is
       unknown (see Transaction Decoding)
+    - While "Use Blockscout" is off, a line under each token in the decoded
+      action whose name or decimals are missing from the bundled list and the
+      tracked tokens: "This token was not looked up on Blockscout, because "Use
+      Blockscout" is off in Settings." Blockscout's report of the user's
+      balances gives a token's name and decimals only while the setting is on
+      (see Unknown token scale).
     - From: color dot + full address + etherscan link
     - Contract: color dot + full address + etherscan link, token symbol label if
       known; for a contract creation, the same sentence as on WaitTx
@@ -2658,7 +2683,11 @@ view would leave a wallet one click from deletion.
       the site puts in the message, except a `Permit`'s token, which is the
       domain's `verifyingContract`; any those fields do not give is shown as
       `Unknown`, and the domain, type and message lines still follow. Only typed
-      data that cannot be read at all is shown as raw text.
+      data that cannot be read at all is shown as raw text. While "Use
+      Blockscout" is off, a token whose name or decimals are missing from the
+      bundled list and the tracked tokens has the same line under it as on
+      TxApproval. As there, Blockscout's report of the user's balances gives a
+      token's name and decimals only while the setting is on.
     - Raw data (`personal_sign` and `eth_sign`): the message's hex exactly as
       the site sent it. The bytes it encodes are what is signed, as an EIP-191
       personal message.
@@ -2837,6 +2866,8 @@ Sent the user's data only while the user has turned the setting on:
           for Home, AddressDetail and AddressToken
         - the balances of the ERC-20 tokens the user has not tracked, for Home,
           AddressDetail, Send and DeleteAddress
+        - the names and decimals of those tokens, for TxApproval, SignApproval,
+          WaitTx, SuccessTx and ErrorTx
         - token holder counts, for spam filtering
         - a transaction's block, network details and calldata, for
           TransactionDetail

src/popup/index.html

@@ -811,6 +811,7 @@
                 <div class="mb-3">
                     <div class="text-xs text-muted mb-1">Amount</div>
                     <div id="wait-tx-summary" class="font-bold"></div>
+                    <div id="wait-tx-token-note"></div>
                 </div>
                 <div class="mb-3">
                     <div class="text-xs text-muted mb-1">To</div>
@@ -857,6 +858,7 @@
                 <div class="mb-3">
                     <div class="text-xs text-muted mb-1">Amount</div>
                     <div id="error-tx-summary" class="font-bold"></div>
+                    <div id="error-tx-token-note"></div>
                 </div>
                 <div class="mb-3">
                     <div class="text-xs text-muted mb-1">To</div>

src/popup/views/approval.js

@@ -11,6 +11,7 @@ const {
     onViewLeave,
     formatFee,
     tokenLabel,
+    tokenLookupOffHtml,
     tokenSourcesByChainId,
 } = require("./helpers");
 const { state, saveState, currentNetwork } = require("../../shared/state");
@@ -401,6 +402,10 @@ function showTxApproval(details) {
             if (d.address) {
                 if (d.isToken) {
                     detailsHtml += `<div class="font-bold">${escapeHtml(tokenLabel(d.address, approvedTx.chainId) || "Unknown token")}</div>`;
+                    detailsHtml += tokenLookupOffHtml(
+                        d.address,
+                        approvedTx.chainId,
+                    );
                 }
                 detailsHtml += approvalAddressHtml(
                     d.address,
@@ -623,10 +628,7 @@ function permitWarningHtml(types, primaryType, domain, message) {
             return "";
     }
 
-    const sources = {
-        trackedTokens: state.trackedTokens,
-        wallets: state.wallets,
-    };
+    const sources = tokenSourcesByChainId();
     const spender = addressOrNull(
         declaredField(types, primaryType, message, "spender")?.value,
     );
@@ -655,6 +657,7 @@ function permitWarningHtml(types, primaryType, domain, message) {
         html += `<div class="mb-2"><div>Token</div>`;
         if (token) {
             html += `<div>${escapeHtml(tokenLabel(token) || "Unknown token")}</div>`;
+            html += tokenLookupOffHtml(token);
             html += approvalAddressHtml(token);
         } else {
             html += `<div>Unknown</div>`;

src/popup/views/helpers.js

@@ -21,7 +21,10 @@ const {
     truncateAmountNeverZero,
     isBelowOneMillionth,
 } = require("../../shared/amountDisplay");
-const { resolveTokenSymbol } = require("../../shared/approvalAmount");
+const {
+    resolveTokenDecimals,
+    resolveTokenSymbol,
+} = require("../../shared/approvalAmount");
 const { getProvider } = require("../../shared/balances");
 const { DEBUG } = require("../../shared/constants");
 const { escapeHtml } = require("../../shared/html");
@@ -306,10 +309,16 @@ function nativeCurrency() {
 // 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 balances give what Blockscout reported for each token. So they are given
+// only while "Use Blockscout" is on.
 function tokenSourcesByChainId(chainId) {
     const net = chainId ? networkByChainId(chainId) : currentNetwork();
     if (net && net.id === state.networkId) {
-        return { trackedTokens: state.trackedTokens, wallets: state.wallets };
+        return {
+            trackedTokens: state.trackedTokens,
+            wallets: state.useBlockscout ? state.wallets : [],
+        };
     }
     return {
         trackedTokens: (net && state.networkTrackedTokens[net.id]) || [],
@@ -317,11 +326,32 @@ function tokenSourcesByChainId(chainId) {
     };
 }
 
+// The line shown under a token while "Use Blockscout" is off, when its name or
+// decimals are missing from the bundled list and the tracked tokens. Otherwise
+// "". The token is a contract address on the network with `chainId`, or on the
+// active network when none is given. "ETH" and null are no contract, and get
+// "".
+function tokenLookupOffHtml(token, chainId) {
+    if (state.useBlockscout || !token || token === "ETH") return "";
+    const sources = tokenSourcesByChainId(chainId);
+    if (
+        resolveTokenSymbol(token, sources) !== null &&
+        resolveTokenDecimals(token, sources) !== null
+    ) {
+        return "";
+    }
+    return (
+        '<div class="text-xs text-muted">This token was not looked up on' +
+        ' Blockscout, because "Use Blockscout" is off in Settings.</div>'
+    );
+}
+
 // The symbol shown for a token line on the network with `chainId`, or on the
 // active network when none is given: from the bundled list, the tokens the
-// user tracks, and the explorer's report, the sources the amount line's scale
-// comes from. Null when no source names one, so the token lines keep saying
-// `Unknown token` for a token nothing knows.
+// user tracks, and, while "Use Blockscout" is on, the explorer's report. The
+// amount line's scale comes from the same sources. Null when no source names
+// one, so the token lines keep saying `Unknown token` for a token nothing
+// knows.
 function tokenLabel(address, chainId) {
     return resolveTokenSymbol(address, tokenSourcesByChainId(chainId));
 }
@@ -796,6 +826,7 @@ module.exports = {
     unknownableAmount,
     nativeCurrency,
     tokenSourcesByChainId,
+    tokenLookupOffHtml,
     tokenLabel,
     formatFee,
     addressDotHtml,

src/popup/views/send.js

@@ -10,6 +10,7 @@ const {
     renderAddressHtml,
     attachCopyHandlers,
     goBack,
+    tokenSourcesByChainId,
 } = require("./helpers");
 const { state, currentAddress } = require("../../shared/state");
 let ctx;
@@ -187,7 +188,9 @@ function renderSendTokenSelect(addr) {
 // so the transfer is encoded with the number the user read rather than with
 // whatever the contract answers at signing time (see
 // src/shared/transferAmount.js). balances.js is formatting one explorer row at
-// fetch time and cannot consult a state it is in the middle of replacing.
+// fetch time and cannot consult a state it is in the middle of replacing. As on
+// the approval screens, tokenSourcesByChainId() gives the wallets only while
+// "Use Blockscout" is on.
 //
 // The two resolutions can therefore differ, and where they do, the stored
 // `balance` is a quantity computed at a scale this screen has just declined to
@@ -200,10 +203,7 @@ function tokenBalanceAndDecimals(addr, token) {
     const tb = (addr.tokenBalances || []).find(
         (t) => t.address.toLowerCase() === token.toLowerCase(),
     );
-    const tokenDecimals = resolveTokenDecimals(token, {
-        trackedTokens: state.trackedTokens,
-        wallets: state.wallets,
-    });
+    const tokenDecimals = resolveTokenDecimals(token, tokenSourcesByChainId());
     if (!tb) return { tokenBalance: "0", tokenDecimals };
     if (tokenDecimals === null) return { tokenBalance: null, tokenDecimals };
     return { tokenBalance: tb.balance ?? null, tokenDecimals };

src/popup/views/settings.js

@@ -252,10 +252,12 @@ async function renderSiteLists() {
 
 // A network switch, made by the user here or saved by the background once the
 // user approved a site's request (src/popup/index.js), leaves every screen on
-// the page showing the previous network. These two leave the page as README's
-// Screen Map describes, the first before the switch is saved, so that save
-// keeps the cut for a popup closed straight after, the second once `state`
-// holds the new network.
+// the page showing the previous network. Two functions leave the page as
+// README's Screen Map describes:
+//
+// - cutViewStack(), before the switch is saved, so that save keeps the cut for
+//   a popup closed straight after
+// - showNewSettings(), once `state` holds the new network
 //
 // The stack is cut at the first screen that cannot be rendered from saved
 // state, such as Send or AddToken, and at AddressToken unless it shows the

src/popup/views/txStatus.js

@@ -14,6 +14,7 @@ const {
     displaySymbol,
     clearViewStack,
     tokenLabel,
+    tokenLookupOffHtml,
     reviewedNetworkProvider,
 } = require("./helpers");
 const { state } = require("../../shared/state");
@@ -108,6 +109,10 @@ function startWait(txInfo, txHash, broadcastTime, pollNow) {
     }
     $("wait-tx-summary").textContent =
         txInfo.amount + (symbol ? " " + symbol : "");
+    $("wait-tx-token-note").innerHTML = tokenLookupOffHtml(
+        txInfo.token,
+        txInfo.chainId,
+    );
     $("wait-tx-to").innerHTML = toAddressHtml(txInfo.to, txInfo.chainId);
     $("wait-tx-hash").innerHTML = txHashHtml(txHash, txInfo.chainId);
     attachCopyHandlers("view-wait-tx");
@@ -282,6 +287,7 @@ function decodedDetailsHtml(decoded, chainId) {
             if (d.isToken) {
                 const sym = tokenLabel(d.address, chainId) || "Unknown token";
                 html += `<div class="font-bold">${escapeHtml(sym)}</div>`;
+                html += tokenLookupOffHtml(d.address, chainId);
                 html += toAddressHtml(d.address, chainId);
             } else {
                 html += toAddressHtml(d.address, chainId);
@@ -345,6 +351,7 @@ function showError(txInfo, txHash, message) {
     state.viewData = {
         amount: txInfo.amount,
         symbol: symbol,
+        token: txInfo.token,
         to: txInfo.to,
         hash: txHash || null,
         message: message,
@@ -358,6 +365,7 @@ function renderError() {
     if (!d || !d.message) return;
     $("error-tx-summary").textContent =
         d.amount + (d.symbol ? " " + d.symbol : "");
+    $("error-tx-token-note").innerHTML = tokenLookupOffHtml(d.token, d.chainId);
     $("error-tx-to").innerHTML = toAddressHtml(d.to, d.chainId);
     $("error-tx-message").textContent = d.message;
 

tests/approvalAmount.test.js

@@ -84,6 +84,9 @@ function walletsHolding(token, decimals) {
 beforeEach(() => {
     state.trackedTokens = [];
     state.wallets = [];
+    // The approval screen reads the explorer's report only while "Use
+    // Blockscout" is on.
+    state.useBlockscout = true;
 });
 
 describe("resolveTokenDecimals", () => {

tests/approvalUseBlockscoutOff.test.js

@@ -0,0 +1,262 @@
+// While "Use Blockscout" is off, the approval screens and the screens after
+// TxApproval name a token, and scale its amount, from the bundled list and the
+// tracked tokens alone (https://git.eeqj.de/sneak/AutistMask/issues/668). A
+// token they lack gets a line saying it was not looked up on Blockscout. While
+// the setting is on, what Blockscout reported for a token the user holds names
+// and scales it, as before.
+//
+// Booted through the real popup entry point, as the approval window or as a
+// popup reopened onto SuccessTx. The vault is mocked so that no password has to
+// be hashed: the stored secret decrypts to the test key below.
+
+jest.mock("../src/shared/vault", () => ({
+    decryptWithPassword: jest.fn(),
+    encryptWithPassword: jest.fn(),
+}));
+
+const { Interface, Wallet } = require("ethers");
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+// A published test key, never used for real funds.
+const SIGNER_KEY =
+    "0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d";
+const signer = new Wallet(SIGNER_KEY);
+const ORIGIN = "https://dapp.example";
+const RECIPIENT = "0x2222222222222222222222222222222222222222";
+const TX_HASH = "0x" + "ab".repeat(32);
+// Outside the bundled list, and not tracked.
+const TOKEN = "0xE2E0000000000000000000000000000000000E2e";
+// In the bundled list, at 6 decimals.
+const USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
+
+const LINE =
+    'This token was not looked up on Blockscout, because "Use Blockscout" is off in Settings.';
+
+// TOKEN as Blockscout reports the user's holding of it.
+const TOKEN_ROW = {
+    address: TOKEN,
+    name: "Novel",
+    symbol: "NOVEL",
+    decimals: "6",
+    balance: "5000.0",
+    holders: 5000,
+};
+
+// A transfer of 5,000 of a 6-decimal token to RECIPIENT.
+const TRANSFER_DATA = new Interface([
+    "function transfer(address to, uint256 amount)",
+]).encodeFunctionData("transfer", [RECIPIENT, 5000000000n]);
+
+// An EIP-2612 permit letting RECIPIENT take 5,000 of TOKEN.
+const PERMIT = {
+    types: {
+        EIP712Domain: [
+            { name: "name", type: "string" },
+            { name: "chainId", type: "uint256" },
+            { name: "verifyingContract", type: "address" },
+        ],
+        Permit: [
+            { name: "owner", type: "address" },
+            { name: "spender", type: "address" },
+            { name: "value", type: "uint256" },
+            { name: "nonce", type: "uint256" },
+            { name: "deadline", type: "uint256" },
+        ],
+    },
+    primaryType: "Permit",
+    domain: { name: "Novel", chainId: 1, verifyingContract: TOKEN },
+    message: {
+        owner: signer.address,
+        spender: RECIPIENT,
+        value: "5000000000",
+        nonce: "0",
+        deadline: "1790000000",
+    },
+};
+
+// The stored profile: the user's one address holds `tokenBalances`.
+function profile(useBlockscout, tokenBalances, extra) {
+    return unversionedValidProfile({
+        useBlockscout,
+        wallets: [
+            {
+                type: "key",
+                name: "Wallet 1",
+                encryptedSecret: "encrypted-key",
+                addresses: [
+                    {
+                        address: signer.address,
+                        balance: "1.0",
+                        tokenBalances,
+                    },
+                ],
+            },
+        ],
+        activeAddress: signer.address,
+        allowedSites: { [signer.address]: [ORIGIN] },
+        ...extra,
+    });
+}
+
+// The approval window for the site's request: a transfer sent to `token`, or
+// with `signParams`, a signature. The background answers the signed
+// transaction with `txResponse`.
+function bootApproval(stored, { token = TOKEN, signParams, txResponse } = {}) {
+    return bootPopup(stored, {
+        search: "?approval=approval-1",
+        runtime: {
+            connect: () => ({ postMessage: () => {} }),
+            sendMessage: (msg, reply) => {
+                if (msg.type === "AUTISTMASK_GET_APPROVAL") {
+                    reply({
+                        type: signParams ? "sign" : "tx",
+                        origin: ORIGIN,
+                        isPhishingDomain: false,
+                        approvedFrom: signer.address,
+                        signParams,
+                        approvedTx: {
+                            type: 2,
+                            from: signer.address,
+                            chainId: "0x1",
+                            nonce: "0x7",
+                            gasLimit: "0x30d40",
+                            maxPriorityFeePerGas: "0x3b9aca00",
+                            maxFeePerGas: "0x77359400",
+                            to: token,
+                            value: "0x0",
+                            data: TRANSFER_DATA,
+                            accessList: [],
+                        },
+                    });
+                } else if (msg.type === "AUTISTMASK_TX_RESPONSE") {
+                    reply(txResponse);
+                } else {
+                    reply(undefined);
+                }
+            },
+        },
+    });
+}
+
+beforeEach(() => {
+    // The page logs its failed RPC reads; the stub node in popupBoot.js
+    // answers none.
+    jest.spyOn(console, "error").mockImplementation(() => {});
+});
+
+afterEach(() => {
+    cleanupPopup();
+    jest.restoreAllMocks();
+});
+
+describe("TxApproval", () => {
+    test("says a token it cannot name was not looked up on Blockscout while Use Blockscout is off", async () => {
+        const page = await bootApproval(profile(false, []));
+        const details = page.node("approve-tx-decoded-details").innerHTML;
+        expect(details).toContain("Unknown token");
+        expect(details).toContain(LINE);
+        expect(details).toContain("5000000000 base units (decimals unknown)");
+        cleanupPopup();
+
+        // The bundled list names USDC, so there is nothing to say.
+        const bundled = await bootApproval(profile(false, []), {
+            token: USDC,
+        });
+        expect(
+            bundled.node("approve-tx-decoded-details").innerHTML,
+        ).not.toContain(LINE);
+        cleanupPopup();
+
+        const on = await bootApproval(profile(true, [TOKEN_ROW]));
+        const named = on.node("approve-tx-decoded-details").innerHTML;
+        expect(named).toContain("5000.0000 NOVEL");
+        expect(named).not.toContain(LINE);
+    });
+
+    test("names nothing from a Blockscout entry still in the balances while Use Blockscout is off", async () => {
+        const page = await bootApproval(profile(false, [TOKEN_ROW]));
+        const details = page.node("approve-tx-decoded-details").innerHTML;
+        expect(details).not.toContain("NOVEL");
+        expect(details).toContain("Unknown token");
+        expect(details).toContain(LINE);
+    });
+
+    test.each([
+        ["WaitTx", { txHash: TX_HASH }, "wait-tx"],
+        [
+            "ErrorTx",
+            { error: "The transaction could not be sent.", retryable: false },
+            "error-tx",
+        ],
+    ])(
+        "%s after it says so under the amount while Use Blockscout is off",
+        async (_name, txResponse, view) => {
+            const page = await bootApproval(profile(false, []), {
+                txResponse,
+            });
+            const { decryptWithPassword } = require("../src/shared/vault");
+            decryptWithPassword.mockResolvedValue(SIGNER_KEY);
+            page.node("approve-tx-password").value = "any password";
+            await page.click("btn-approve-tx");
+            expect(page.visibleViews()).toEqual([view]);
+            expect(page.node(view + "-token-note").innerHTML).toBe(
+                `<div class="text-xs text-muted">${LINE}</div>`,
+            );
+        },
+    );
+});
+
+test("SuccessTx says so under the decoded token while Use Blockscout is off", async () => {
+    const page = await bootPopup(
+        profile(false, [], {
+            currentView: "success-tx",
+            viewStack: ["main"],
+            viewData: {
+                amount: "5000000000 base units (decimals unknown)",
+                symbol: "?",
+                to: RECIPIENT,
+                hash: TX_HASH,
+                blockNumber: 21000000,
+                chainId: "0x1",
+                decoded: {
+                    name: "Token Transfer",
+                    description: "Transfer ERC-20 token",
+                    details: [
+                        {
+                            label: "Token",
+                            value: TOKEN,
+                            address: TOKEN,
+                            isToken: true,
+                        },
+                    ],
+                },
+            },
+        }),
+    );
+    expect(page.visibleViews()).toEqual(["success-tx"]);
+    const decoded = page.node("success-tx-decoded").innerHTML;
+    expect(decoded).toContain("Unknown token");
+    expect(decoded).toContain(LINE);
+});
+
+test("SignApproval says so under a permit's token while Use Blockscout is off", async () => {
+    const signParams = {
+        method: "eth_signTypedData_v4",
+        typedData: JSON.stringify(PERMIT),
+        from: signer.address,
+    };
+    const page = await bootApproval(profile(false, []), { signParams });
+    const message = page.node("approve-sign-message").innerHTML;
+    expect(message).toContain("Unknown token");
+    expect(message).toContain(LINE);
+    cleanupPopup();
+
+    const on = await bootApproval(profile(true, [TOKEN_ROW]), { signParams });
+    const named = on.node("approve-sign-message").innerHTML;
+    expect(named).toContain("5000.0000 NOVEL");
+    expect(named).not.toContain(LINE);
+});

tests/fabricatedDecimals.test.js

@@ -168,6 +168,9 @@ beforeEach(() => {
     debugFetch.mockReset();
     state.trackedTokens = [];
     state.wallets = [];
+    // The approval screens read the explorer's report only while the page's
+    // "Use Blockscout" is on.
+    state.useBlockscout = true;
 });
 
 describe("what fetchTokenBalances stores for an absent scale", () => {

tests/uniswapUnknownDecimals.test.js

@@ -90,6 +90,9 @@ function swapDetail(data, label) {
 beforeEach(() => {
     state.trackedTokens = [];
     state.wallets = [];
+    // The approval screen reads the explorer's report only while "Use
+    // Blockscout" is on.
+    state.useBlockscout = true;
 });
 
 describe("a swap of a token outside the bundled list", () => {