fix: the balance list and the add-token screens apply the spoof rule to tracked tokens (closes #705)

The balance list gave a tracked token a zero row while "Show tracked
tokens with zero balance" was on, even when the spoof rule refuses the
token. balanceLinesForAddress() now asks isSpoofedSymbol() before it adds
that row.

AddToken and SettingsAddToken now refuse such a token after the contract
lookup, with a flash message that says why. The bundled-list buttons on
SettingsAddToken need no check, because the rule never refuses a bundled
token.

The README and docs/README.md now say that the balance list drops such a
token whatever the settings.

Model: opus-5-5

README.md

@@ -1474,10 +1474,10 @@ tracked.
 A tracked token is shown when its balance is nonzero, and any other ERC-20 when
 its balance is nonzero and it is in the bundled known-token list or has 1,000 or
 more holders. A token claiming a symbol from the bundled list from any other
-contract address is always dropped, tracked or not, and so is any token claiming
-a symbol that belongs to the native asset and therefore has no legitimate
-contract at all (`"ETH"`, and every network's `nativeCurrency`, such as
-`"SepoliaETH"`, on every network). That filter is unconditional — the "Hide
+contract address is always dropped, whatever the settings, and so is any token
+claiming a symbol that belongs to the native asset and therefore has no
+legitimate contract at all (`"ETH"`, and every network's `nativeCurrency`, such
+as `"SepoliaETH"`, on every network). 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. A token's holder count is
 unknown when the explorer reports none, or reports anything other than a whole
@@ -2239,6 +2239,9 @@ view would leave a wallet one click from deletion.
       **AddressDetail**
     - "Add" with a token already tracked, a scam-listed address, or a failed
       contract lookup → flash message, no screen change
+    - "Add" with a token that the spoof rule refuses → nothing is tracked; "This
+      is a fake token impersonating a known symbol, so it was not added." flash
+      message, no screen change
     - "Add", then the contract lookup answers while another screen shows, or
       after AddToken was opened again → tracks the token, no screen change
     - "Add", then a network switch in Settings before the contract lookup
@@ -2547,6 +2550,9 @@ view would leave a wallet one click from deletion.
       "Added SYMBOL" flash message (no screen change)
     - A duplicate, a scam-listed address, or a failed contract lookup → flash
       message, no screen change
+    - "Add" by contract address with a token that the spoof rule refuses →
+      nothing is tracked; "This is a fake token impersonating a known symbol, so
+      it was not added." flash message, no screen change
     - "Add" by contract address, then a network switch in Settings before the
       lookup answers → nothing is tracked; "The active network changed before
       the lookup finished, so the token was not added." flash message, no screen

docs/README.md

@@ -380,10 +380,8 @@ but comes from an unrecognized contract, it is identified as a spoof and hidden.
 In your transaction history this is the "Hide fake tokens impersonating a known
 symbol" setting, which you can switch off; doing so also stops new entries being
 added to the fraud contract blocklist below, since detecting a spoof is what
-fills it. The send token list always applies the check. Your balances apply it
-too, with one exception: a token claiming the symbol "ETH" is not filtered
-there, so a fake "ETH" token can still show up in your balance list even though
-it is hidden from your transaction history and from the send token list.
+fills it. The send token list always applies the check. Your balance list always
+applies the check too.
 
 **Low-holder token filtering.** Tokens with fewer than 1,000 holders are hidden
 from transaction history and the send token list, and are left out of your

src/popup/views/addToken.js

@@ -3,6 +3,7 @@ const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
 const { isScamAddress } = require("../../shared/scamlist");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { log } = require("../../shared/log");
 
 // Counts the times AddToken has opened. A contract lookup started before
@@ -77,6 +78,18 @@ function init(ctx) {
                 );
                 return;
             }
+            // The balance list never shows a token that the spoof rule
+            // refuses, so such a token is not tracked.
+            if (isSpoofedSymbol(info.symbol, contractAddr)) {
+                showFlash(
+                    "This is a fake token impersonating a known symbol," +
+                        " so it was not added.",
+                );
+                if (addTokenScreenOpenings !== opening) return;
+                infoEl.textContent = "";
+                infoEl.style.visibility = "hidden";
+                return;
+            }
             log.infof("Adding token", info.symbol, contractAddr);
             state.trackedTokens.push({
                 address: contractAddr,

src/popup/views/helpers.js

@@ -33,6 +33,7 @@ const { networkByChainId } = require("../../shared/networks");
 const { formatUsd, getPrice } = require("../../shared/prices");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { displaySymbol } = require("../../shared/symbolDisplay");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { walletHasRecoveryPhrase } = require("../../shared/wallet");
 const { markViewRendered } = require("../viewRouter");
 
@@ -447,6 +448,9 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
     if (showZero && trackedTokens) {
         for (const t of trackedTokens) {
             if (seen.has(t.address.toLowerCase())) continue;
+            // A token that the spoof rule refuses has no stored balance, and
+            // gets no zero row either.
+            if (isSpoofedSymbol(t.symbol, t.address)) continue;
             html += balanceLine(
                 t.symbol,
                 0,

src/popup/views/settingsAddToken.js

@@ -3,6 +3,7 @@ const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
 const { isScamAddress } = require("../../shared/scamlist");
+const { isSpoofedSymbol } = require("../../shared/symbolSpoof");
 const { log } = require("../../shared/log");
 
 let ctx;
@@ -155,6 +156,19 @@ function init(_ctx) {
                 );
                 return;
             }
+            // The balance list never shows a token that the spoof rule
+            // refuses, so such a token is not tracked. The rule never refuses
+            // a bundled token, so the "Top tokens:" buttons and the top 100
+            // dropdown need no such check.
+            if (isSpoofedSymbol(info.symbol, addr)) {
+                showFlash(
+                    "This is a fake token impersonating a known symbol," +
+                        " so it was not added.",
+                );
+                infoEl.textContent = "";
+                infoEl.style.visibility = "hidden";
+                return;
+            }
             log.infof("Adding token", info.symbol, addr);
             state.trackedTokens.push({
                 address: addr,

tests/spoofedTrackedToken.test.js

@@ -0,0 +1,92 @@
+// A token that the spoof rule refuses never shows in the balance list, even
+// tracked at zero balance with "Show tracked tokens with zero balance" on, and
+// the two add-token screens refuse to track one
+// (https://git.eeqj.de/sneak/AutistMask/issues/705). Driven through the real
+// popup over a stored profile.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+    TOKEN_ADDRESS,
+} = require("./support/popupBoot");
+
+// Claims the symbol of the bundled USDT from another contract.
+const FAKE_USDT = {
+    address: TOKEN_ADDRESS,
+    symbol: "USDT",
+    decimals: 6,
+    name: "Tether USD",
+};
+// A symbol the bundled list does not have, so the spoof rule passes it.
+const TEST_TOKEN = {
+    address: "0xBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB",
+    symbol: "TST",
+    decimals: 18,
+    name: "Test Token",
+};
+const REFUSED_FLASH =
+    "This is a fake token impersonating a known symbol, so it was not added.";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+test("a fake token tracked at zero balance is not listed while zero balances are shown", async () => {
+    const boot = await bootPopup(
+        unversionedValidProfile({
+            currentView: "address",
+            selectedWallet: 0,
+            selectedAddress: 0,
+            trackedTokens: [FAKE_USDT, TEST_TOKEN],
+            showZeroBalanceTokens: true,
+        }),
+    );
+    const rows = boot.node("address-balances").innerHTML;
+    expect(rows).toContain(`data-token="${TEST_TOKEN.address.toLowerCase()}"`);
+    expect(rows).not.toContain(
+        `data-token="${FAKE_USDT.address.toLowerCase()}"`,
+    );
+});
+
+// Each screen is opened from AddressDetail by the buttons named, in order.
+describe.each([
+    [
+        "AddToken",
+        ["btn-add-token"],
+        "add-token",
+        "add-token-address",
+        "btn-add-token-confirm",
+    ],
+    [
+        "SettingsAddToken",
+        ["btn-settings", "btn-settings-add-token"],
+        "settings-addtoken",
+        "settings-addtoken-address",
+        "btn-settings-addtoken-manual",
+    ],
+])("%s", (_, opening, view, field, button) => {
+    test("refuses a fake token by contract address", async () => {
+        const boot = await bootPopup(
+            unversionedValidProfile({
+                currentView: "address",
+                selectedWallet: 0,
+                selectedAddress: 0,
+            }),
+        );
+        for (const id of opening) await boot.click(id);
+        expect(boot.visibleViews()).toEqual([view]);
+        const { lookupTokenInfo } = require("../src/shared/balances");
+        lookupTokenInfo.mockResolvedValueOnce({
+            symbol: FAKE_USDT.symbol,
+            decimals: FAKE_USDT.decimals,
+            name: FAKE_USDT.name,
+        });
+        boot.node(field).value = FAKE_USDT.address;
+
+        await boot.click(button);
+        expect(boot.text("flash-msg")).toBe(REFUSED_FLASH);
+        expect(boot.visibleViews()).toEqual([view]);
+        expect(boot.storage.read("autistmask").trackedTokens).toEqual([]);
+    });
+});