fix: the swap decoder names where a WRAP_ETH pays and counts the router's ETH in a V4 settle (closes #665)

A WRAP_ETH that sets the input side and pays its WETH to anyone but
the router now names that recipient on its Moved to line, or reads
The sender for address(1).

V4Router pays ETH from the router's own ETH, whoever a SETTLE names as
payer. ETH the router already holds now pays first for the ETH a V4
step would take from the user, and only the rest is moved from the
sender. An UNWRAP_WETH into the router keeps a known WETH amount as
the ETH the router then holds.

Model: opus-5-5

README.md

@@ -3412,48 +3412,47 @@ Currently supported:
   as a swap paid in ETH does, but only when that amount is not
   `CONTRACT_BALANCE` and the router held no WETH from an earlier step when the
   `WRAP_ETH` ran: after two `WRAP_ETH`s of 0.5 ETH into the router, a swap of 1
-  WETH from it reads as leaving the WETH there. A V2 or V3 exact-out step paid
+  WETH from it reads as leaving the WETH there. An `UNWRAP_WETH` into the router
-  from the router spends an amount the calldata does not state, at most its
+  turns all the router's WETH into as much ETH. The decoder then knows how much
-  `amountInMax`. The decoder then no longer knows how much of the step's input
+  ETH the router holds only when it knew the WETH's amount and the router held
-  token the router holds. A V4 `SETTLE` from the router has the same effect when
+  no ETH before. A V4 `SETTLE` of ETH spends the ETH the router holds, whoever
-  the decoder does not know what that `SETTLE` pays (see below). An
+  pays it (see below). A V2 or V3 exact-out step paid from the router spends an
-  `UNWRAP_WETH` into the router turns all the router's WETH into the same amount
+  amount the calldata does not state, at most its `amountInMax`, so the decoder
-  of ETH. The decoder knows how much ETH that is only when it knew how much WETH
+  counts it as spending nothing the router holds. A `SETTLE` of `OPEN_DELTA`
-  the router held and the router held no ETH before. A V4 `SETTLE` of ETH always
+  (zero), and a `SETTLE_ALL`, pay only what the step still owes of their token
-  spends the router's own ETH, whichever payer it names (see below). A `SETTLE`
+  when they run. The decoder takes that to be the amounts the step's swap
-  of `OPEN_DELTA` (zero), and a `SETTLE_ALL`, pay only what the step still owes
+  actions state they spend of that token only when every action in the step
-  of their token when they run. The decoder takes that to be the amounts the
+  could be read, every swap action names the token it spends and the token it
-  step's swap actions state they spend of that token only when every action in
+  buys (a swap action with an empty path swaps nothing), the `SETTLE` or
-  the step could be read, every swap action names the token it spends and the
+  `SETTLE_ALL` is the step's only `SETTLE` or `SETTLE_ALL` of that token and
-  token it buys (a swap action with an empty path swaps nothing), the `SETTLE`
-  or `SETTLE_ALL` is the step's only `SETTLE` or `SETTLE_ALL` of that token and
   comes after every swap action, no swap action buys that token, no `TAKE`,
   `TAKE_ALL` or `TAKE_PORTION` in the step takes it (a `TAKE` of a stated amount
   adds to what the step owes), and the swap actions that spend it state a
-  quantity together; otherwise it does not know the amount. So the rest of a V4
+  quantity together; otherwise it does not know the amount, and such a `SETTLE`
-  `SETTLE` of more than its swap spends, taken to the router, the WETH of a
+  from the router counts as spending nothing. So the rest of a V4 `SETTLE` of
-  `WRAP_ETH`, and a token a swap pays the router on the way to the output, each
+  more than its swap spends, taken to the router, the WETH of a `WRAP_ETH`, and
-  stays in the router when later steps do not spend all of it, where anyone can
+  a token a swap pays the router on the way to the output, each stays in the
-  take it in a later transaction. The router sends ETH as written, so a
+  router when later steps do not spend all of it, where anyone can take it in a
-  `TRANSFER` of `CONTRACT_BALANCE` of ETH always reverts and pays out nothing. A
+  later transaction. The router sends ETH as written, so a `TRANSFER` of
-  step paying a token to the V2 pair that the very next step spends, as a V2
+  `CONTRACT_BALANCE` of ETH always reverts and pays out nothing. A step paying a
-  exact-in of that token whose `amountIn` is `ALREADY_PAID` (zero) or
+  token to the V2 pair that the very next step spends, as a V2 exact-in of that
-  `CONTRACT_BALANCE`, is a hop, not a payout: Uniswap's mixed routes pay the
+  token whose `amountIn` is `ALREADY_PAID` (zero) or `CONTRACT_BALANCE`, is a
-  next V2 pair directly, and the router enforces that swap's own minimum. The
+  hop, not a payout: Uniswap's mixed routes pay the next V2 pair directly, and
-  decoder checks that the address paid is that pair, deriving it from the V2
+  the router enforces that swap's own minimum. The decoder checks that the
-  factory and pair init code hash the network's routers were deployed with and
+  address paid is that pair, deriving it from the V2 factory and pair init code
-  the first two tokens of that step's path; a payment to any other address is
+  hash the network's routers were deployed with and the first two tokens of that
-  named. (Sepolia's `UniversalRouterV1_2_V2Support` was deployed with
+  step's path; a payment to any other address is named. (Sepolia's
-  placeholders for both values, so no V2 swap step can succeed on that router.)
+  `UniversalRouterV1_2_V2Support` was deployed with placeholders for both
-  Every other payment counts, in whichever step and of whatever token, a share
+  values, so no V2 swap step can succeed on that router.) Every other payment
-  of the output included: an interface fee paid to another address by
+  counts, in whichever step and of whatever token, a share of the output
-  `PAY_PORTION`, `TRANSFER` or `TAKE_PORTION` is named, and the minimum reads
+  included: an interface fee paid to another address by `PAY_PORTION`,
-  `Min. paid out`, because the swap's minimum includes the fee. The minimum
+  `TRANSFER` or `TAKE_PORTION` is named, and the minimum reads `Min. paid out`,
-  reads `Min. received` only when some step pays the transaction's sender (the
+  because the swap's minimum includes the fee. The minimum reads `Min. received`
-  From address on TxApproval, the sender the explorer reports on
+  only when some step pays the transaction's sender (the From address on
-  TransactionDetail), no `Paid to` line is shown, and no permit or batch grants
+  TxApproval, the sender the explorer reports on TransactionDetail), no
-  an allowance to a spender other than the router (see below). `Paid to` lines
+  `Paid to` line is shown, and no permit or batch grants an allowance to a
-  after `Token Out` name each other address paid; one reads
+  spender other than the router (see below). `Paid to` lines after `Token Out`
+  name each other address paid; one reads
   `The bridge, which pays the deposit's recipient on another network` for a
   bridge deposit; one reads, for example,
   `The router, 2000.0000 USDT from the sender (later steps may not spend all of it)`
@@ -3486,66 +3485,65 @@ Currently supported:
   router's own ETH, whoever a `SETTLE` names as payer. So when a V4 step would
   take ETH from the user's wallet, ETH the router already holds pays first. The
   wallet pays only the rest. For example, an `UNWRAP_WETH` into the router
-  leaves ETH there. The decoder knows what the wallet pays only when it knows
+  leaves ETH there. When the decoder does not know how much ETH the router
-  how much ETH the router holds and how much the step would take. Otherwise that
+  holds, or how much the step would take, it counts the router as paying all of
-  payment reads as unknown, like any amount the decoder does not know. A later
+  that ETH. A later step paid from the router spends what the router holds and
-  step paid from the router spends what the router holds and takes nothing, and
+  takes nothing, and so does a V2 exact-in whose `amountIn` is `ALREADY_PAID`. A
-  so does a V2 exact-in whose `amountIn` is `ALREADY_PAID`. A later take of
+  later take of `Token In` is added to the total while both are quantities: a V3
-  `Token In` is added to the total while both are quantities: a V3 exact-in of
+  exact-in of 600 USDT and a V2 exact-in of 400 USDT, both paid by the user,
-  600 USDT and a V2 exact-in of 400 USDT, both paid by the user, read
+  read `1000.0000 USDT`. When the decoder does not know a take's amount, the
-  `1000.0000 USDT`. When the decoder does not know a take's amount, the total is
+  total is not known and there is no `Amount` line. A `PERMIT2_PERMIT` names
-  not known and there is no `Amount` line. A `PERMIT2_PERMIT` names `Token In`
+  `Token In` only when its amount, `Unlimited` included, stands as the `Amount`
-  only when its amount, `Unlimited` included, stands as the `Amount` figure in
+  figure in place of the total, which it does only in the plain shape of
-  place of the total, which it does only in the plain shape of Uniswap's own
+  Uniswap's own routes: it comes before the step that sets the input side, it is
-  routes: it comes before the step that sets the input side, it is the only
+  the only `PERMIT2_PERMIT` in the transaction and there is no
-  `PERMIT2_PERMIT` in the transaction and there is no `PERMIT2_PERMIT_BATCH`,
+  `PERMIT2_PERMIT_BATCH`, its spender is the router, the router may not let it
-  its spender is the router, the router may not let it fail, no step before it
+  fail, no step before it takes its token, a `PERMIT2_TRANSFER_FROM` of it
-  takes its token, a `PERMIT2_TRANSFER_FROM` of it included, or a token the
+  included, or a token the decoder does not know, and the decoder reads every
-  decoder does not know, and the decoder reads every step after it in full.
+  step after it in full. Permit2 then lets the router take no more of the token
-  Permit2 then lets the router take no more of the token than that amount, so
+  than that amount, so the permit covers every take of it. A step before the
-  the permit covers every take of it. A step before the permit takes under
+  permit takes under whatever allowance the router already had, so it may take
-  whatever allowance the router already had, so it may take more than the
+  more than the permit's amount, which would then read lower than what leaves
-  permit's amount, which would then read lower than what leaves the user's
+  the user's wallet: a `PERMIT2_TRANSFER_FROM` of 2,000 USDT into the router,
-  wallet: a `PERMIT2_TRANSFER_FROM` of 2,000 USDT into the router, then a permit
+  then a permit of 600 USDT to the router and a V3 exact-in of 2,000 USDT paid
-  of 600 USDT to the router and a V3 exact-in of 2,000 USDT paid from the
+  from the router, read `Amount 2000.0000 USDT`. A later permit or batch may
-  router, read `Amount 2000.0000 USDT`. A later permit or batch may raise what
+  raise what Permit2 lets the router take, and so may a step the decoder does
-  Permit2 lets the router take, and so may a step the decoder does not read in
+  not read in full: a command the decoder does not read (listed at the end of
-  full: a command the decoder does not read (listed at the end of this section),
+  this section), a step whose input it cannot read, in whole or in part, and a
-  a step whose input it cannot read, in whole or in part, and a step it fails
+  step it fails on. Every other `PERMIT2_PERMIT`, before the step that sets the
-  on. Every other `PERMIT2_PERMIT`, before the step that sets the input side or
+  input side or after it, leaves `Token In` and the `Amount` line as they read
-  after it, leaves `Token In` and the `Amount` line as they read with no permit,
+  with no permit, unless it lets a spender other than the router take `Token In`
-  unless it lets a spender other than the router take `Token In` (see below): a
+  (see below): a permit of 5,000 DAI to another address and then a V3 exact-in
-  permit of 5,000 DAI to another address and then a V3 exact-in of 600 USDT read
+  of 600 USDT read `Swap USDT → USDC` with `Amount 600.0000 USDT`, and so do
-  `Swap USDT → USDC` with `Amount 600.0000 USDT`, and so do that exact-in and
+  that exact-in and then a permit of 5,000 DAI to the router. When a permit's
-  then a permit of 5,000 DAI to the router. When a permit's amount stands and
+  amount stands and the step that sets the input side spends a token other than
-  the step that sets the input side spends a token other than the permit's, or
+  the permit's, or one the decoder does not know, that step's amount gets lines
-  one the decoder does not know, that step's amount gets lines of its own,
+  of its own, unless it states no amount and the user pays it none of its input
-  unless it states no amount and the user pays it none of its input token. Each
+  token. Each take the total does not count gives three lines after the `Amount`
-  take the total does not count gives three lines after the `Amount` line (after
+  line (after `Token In` when there is none): one of a token other than
-  `Token In` when there is none): one of a token other than `Token In`; one of
+  `Token In`; one of `Token In` after an amount that is not a quantity (a V4
-  `Token In` after an amount that is not a quantity (a V4 open delta,
+  open delta, `ALREADY_PAID`, which keep their wording on the `Amount` line, or
-  `ALREADY_PAID`, which keep their wording on the `Amount` line, or no stated
+  no stated amount, as of a V4 exact-out step); and one whose amount the decoder
-  amount, as of a V4 exact-out step); and one whose amount the decoder does not
+  does not know. When there is no `Amount` line, each take the total counts gets
-  know. When there is no `Amount` line, each take the total counts gets them
+  them too, so that every amount the decoder reads is shown: the amount the step
-  too, so that every amount the decoder reads is shown: the amount the step that
+  that sets the input side states, when it is a quantity and the user pays that
-  sets the input side states, when it is a quantity and the user pays that step
+  step (a V2 or V3 step whose `payerIsUser` is true, a V4 step the user pays
-  (a V2 or V3 step whose `payerIsUser` is true, a V4 step the user pays some of
+  some of its input token, or a `WRAP_ETH`, whose ETH comes from the
-  its input token, or a `WRAP_ETH`, whose ETH comes from the transaction's
+  transaction's value), and each later take of `Token In` added to it. A step
-  value), and each later take of `Token In` added to it. A step that sets the
+  that sets the input side and is paid from the router takes nothing from the
-  input side and is paid from the router takes nothing from the user's wallet
+  user's wallet and gets none. A `PERMIT2_PERMIT` the decoder cannot read, then
-  and gets none. A `PERMIT2_PERMIT` the decoder cannot read, then V3 exact-ins
+  V3 exact-ins of 600 USDT and 400 DAI paid by the user, give lines for both
-  of 600 USDT and 400 DAI paid by the user, give lines for both amounts. When
+  amounts. When the step that sets the input side states no amount, the user
-  the step that sets the input side states no amount, the user pays it some of
+  pays it some of its input token, and there is no `Amount` line, that step gets
-  its input token, and there is no `Amount` line, that step gets them too
+  them too whenever another take's lines give a figure, or a
-  whenever another take's lines give a figure, or a `PERMIT2_TRANSFER_FROM` of
+  `PERMIT2_TRANSFER_FROM` of its token gives one, on the lines below or, into
-  its token gives one, on the lines below or, into the router, on its `Paid to`
+  the router, on its `Paid to` line, so that figure cannot read as all that
-  line, so that figure cannot read as all that leaves. When it states no amount
+  leaves. When it states no amount and the user pays it none of its input token,
-  and the user pays it none of its input token, as when the router pays it, that
+  as when the router pays it, that step takes none of that token from the user's
-  step takes none of that token from the user's wallet and never gets them, with
+  wallet and never gets them, with a permit or without. They come in step order,
-  a permit or without. They come in step order, except that the step that sets
+  except that the step that sets the input side comes first when it has them,
-  the input side comes first when it has them, followed, when there is no
+  followed, when there is no `Amount` line, by the other takes the total counts:
-  `Amount` line, by the other takes the total counts: `Moved from the sender`,
+  `Moved from the sender`, its amount, worded as the `Amount` line words one, or
-  its amount, worded as the `Amount` line words one, or
   `Unknown (could not be decoded)` when the decoder does not know it;
   `Token moved`, giving the token's address as the `Token In` line does; and
   `Moved to`, which reads `The swap step that spends it`. For a `WRAP_ETH` that

src/shared/uniswap.js

@@ -1406,10 +1406,8 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // from the router (see spendFromRouter()). A V4 SETTLE of ETH paid by
         // the user spends the router's ETH too (see the V4_SWAP branch). The
         // value is the amount the router holds, in base units, when a
-        // WRAP_ETH stated it, otherwise null. A step that spends an unstated
+        // WRAP_ETH stated it, otherwise null. An UNWRAP_WETH into the router
-        // amount of the token from the router makes the value null. An
+        // turns that amount of WETH into the same amount of ETH.
-        // UNWRAP_WETH into the router turns that amount of WETH into the same
-        // amount of ETH.
         const heldByRouter = new Map();
         const isRouter = (recipient) => {
             const r = recipient.toLowerCase();
@@ -1419,17 +1417,15 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // own balance. CONTRACT_BALANCE pays all of it. Any other quantity
         // counts against a known amount the router holds, and the steps pay
         // all of it once their amounts reach that one: a swap paid in ETH wraps
-        // what its swap steps then spend. A null amount is one the calldata
+        // what its swap steps then spend. An amount that is not a quantity,
-        // does not state, as for a V2 or V3 exact-out or a SETTLE whose
+        // such as the null decodeV4Swap() gives a SETTLE whose payment it
-        // payment decodeV4Swap() cannot tell. A null amount makes the
+        // cannot tell, or one of a token whose amount is not known, pays out
-        // router's amount of the token unknown. ALREADY_PAID spends nothing.
+        // nothing this decoder can see.
         const spendFromRouter = (token, amount) => {
             const t = token.toLowerCase();
             const held = heldByRouter.get(t);
             if (amount === CONTRACT_BALANCE) {
                 heldByRouter.delete(t);
-            } else if (amount === null) {
-                if (heldByRouter.has(t)) heldByRouter.set(t, null);
             } else if (typeof held === "bigint" && typeof amount === "bigint") {
                 if (amount >= held) {
                     heldByRouter.delete(t);
@@ -1685,7 +1681,8 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                 ) {
                     // Buys exactly amountOut and spends at most amountInMax.
                     // Paid from the router, it spends an amount the calldata
-                    // does not state (see spendFromRouter()).
+                    // does not state, so it spends nothing spendFromRouter()
+                    // could count.
                     hasV2OrV3ExactOut = true;
                     const s =
                         command === "V2_SWAP_EXACT_OUT"
@@ -1699,9 +1696,6 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                             addUserPaid(s.tokenIn, s.amountInMax);
                         }
                         setOutput(i, s.tokenOut, s.amountOut, [s.recipient]);
-                        if (!s.payerIsUser) {
-                            spendFromRouter(s.tokenIn, null);
-                        }
                         if (!isHop(i, s.tokenOut, s.recipient)) {
                             addPayee(s.recipient, s.tokenOut);
                         }
@@ -1844,9 +1838,9 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                         // whoever a SETTLE names as payer. So ETH the router
                         // holds from an earlier step pays first for the ETH
                         // the user would pay the step. The user pays only the
-                        // rest. This decoder knows the rest only when it knows
+                        // rest. When this decoder does not know how much ETH
-                        // how much ETH the router holds and how much the user
+                        // the router holds, or how much the user would pay,
-                        // would pay. Otherwise the rest is unknown.
+                        // it counts the router as paying all of that ETH.
                         for (const p of v4.paidByUser) {
                             if (
                                 p.currency !==
@@ -1858,14 +1852,10 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
                             }
                             const held = heldByRouter.get(p.currency);
                             if (
-                                typeof held !== "bigint" ||
+                                typeof held === "bigint" &&
-                                typeof p.amount !== "bigint"
+                                typeof p.amount === "bigint" &&
+                                p.amount > held
                             ) {
-                                paidByUser.push({
-                                    currency: p.currency,
-                                    amount: null,
-                                });
-                            } else if (p.amount > held) {
                                 paidByUser.push({
                                     currency: p.currency,
                                     amount: p.amount - held,
@@ -2330,8 +2320,8 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
         // of the lines below for a PERMIT2_TRANSFER_FROM. An amount this
         // decoder does not know is said so, and a step it did not read gets
         // that one line alone. A take with no recipient goes to the swap step
-        // that spends it. A take with a recipient goes to that recipient;
+        // that spends it. A take with a recipient goes there, and MSG_SENDER
-        // `MSG_SENDER` means the sender.
+        // there is the sender.
         for (const s of spentFromSender) {
             details.push({
                 label: "Moved from the sender",

tests/uniswap.test.js

@@ -2474,8 +2474,8 @@ describe("uniswap decoder", () => {
         // from the router's own ETH, whoever a SETTLE names as payer. ETH the
         // router holds from an UNWRAP_WETH into it pays first, so the sender
         // pays only the ETH beyond it. On next each row also took the V4
-        // step's whole ETH from the sender: 1 ETH more in the first, and 1.5
+        // step's whole ETH from the sender: 1 ETH more in the first two, and
-        // ETH in the last.
+        // 1.5 ETH in the last.
         const unwrapIntoRouter = encodeWrapEth(ROUTER_ADDR, 0n); // UNWRAP_WETH, same encoding
         // A V4 step swapping `amount` of ETH for USDC, with a SETTLE of
         // OPEN_DELTA by the user.
@@ -2493,6 +2493,19 @@ describe("uniswap decoder", () => {
                 ],
             );
         test.each([
+            {
+                kind: "a V3 exact-in of 600 USDT for WETH paid to the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
+                commands: [0x00, 0x0c, 0x10],
+                inputs: [
+                    encodeV3SwapExactIn(ROUTER_ADDR, USDT_600, 1n, [
+                        USDT_ADDR,
+                        WETH_ADDR,
+                    ]),
+                    unwrapIntoRouter,
+                    v4EthForUsdc(ONE_ETH),
+                ],
+                lines: [["Amount", "600.0000 USDT"]],
+            },
             {
                 kind: "a WRAP_ETH of 1 ETH into the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
                 commands: [0x0b, 0x0c, 0x10],
@@ -2518,156 +2531,6 @@ describe("uniswap decoder", () => {
             expect(linesBetweenTokens(result)).toEqual(lines);
         });
 
-        // The lines for ETH the sender pays a V4 step, of an amount this
-        // decoder does not know.
-        const unknownEthLines = [
-            ["Moved from the sender", UNDECODED],
-            ["Token moved", "ETH"],
-            ["Moved to", "The swap step that spends it"],
-        ];
-
-        // https://git.eeqj.de/sneak/AutistMask/issues/665 — this decoder may
-        // not know how much ETH the router holds, or how much ETH the user
-        // pays a V4 step. The ETH the sender pays that step then reads as
-        // unknown. Counting the router as paying all of it would hide ETH
-        // that can leave the wallet.
-        test.each([
-            {
-                kind: "a V3 exact-in of 600 USDT for WETH paid to the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
-                commands: [0x00, 0x0c, 0x10],
-                inputs: [
-                    encodeV3SwapExactIn(ROUTER_ADDR, USDT_600, 1n, [
-                        USDT_ADDR,
-                        WETH_ADDR,
-                    ]),
-                    unwrapIntoRouter,
-                    v4EthForUsdc(ONE_ETH),
-                ],
-                lines: [["Amount", "600.0000 USDT"], ...unknownEthLines],
-            },
-            {
-                kind: "a V4 swap of 600 USDT that takes ETH into the router, then a V4 swap of 5 ETH that the user settles",
-                commands: [0x10, 0x10],
-                inputs: [
-                    encodeV4Swap(
-                        new Uint8Array([
-                            V4_SWAP_EXACT_IN_SINGLE_ID,
-                            V4_SETTLE_ID,
-                            V4_TAKE_ID,
-                        ]),
-                        [
-                            encodeV4ExactInSingle(
-                                USDT_ADDR,
-                                ZERO_ADDR,
-                                USDT_600,
-                                1n,
-                            ),
-                            settle(USDT_ADDR, 0n, true),
-                            take(ZERO_ADDR, ROUTER_ADDR, 0n),
-                        ],
-                    ),
-                    v4EthForUsdc(5n * ONE_ETH),
-                ],
-                lines: [["Amount", "600.0000 USDT"], ...unknownEthLines],
-            },
-            {
-                kind: "a WRAP_ETH of 1 ETH into the router, an UNWRAP_WETH into the router, then a V4 exact-out paid in ETH with a SETTLE_ALL of at most 3 ETH",
-                commands: [0x0b, 0x0c, 0x10],
-                inputs: [
-                    encodeWrapEth(ROUTER_ADDR, ONE_ETH),
-                    unwrapIntoRouter,
-                    encodeV4Swap(
-                        new Uint8Array([
-                            V4_SWAP_EXACT_OUT_SINGLE_ID,
-                            V4_SETTLE_ALL_ID,
-                            V4_TAKE_ALL_ID,
-                        ]),
-                        [
-                            encodeV4ExactOutSingle(
-                                ZERO_ADDR,
-                                USDC_ADDR,
-                                390000000n,
-                                3n * ONE_ETH,
-                            ),
-                            encodeV4SettleAll(ZERO_ADDR, 3n * ONE_ETH),
-                            encodeV4TakeAll(USDC_ADDR, 0n),
-                        ],
-                    ),
-                ],
-                lines: [
-                    ...wrapLines("The swap step that spends it"),
-                    ...unknownEthLines,
-                ],
-            },
-        ])("$kind", ({ commands, inputs, lines }) => {
-            const result = decodeSteps(commands, inputs);
-            expect(linesBetweenTokens(result)).toEqual(lines);
-        });
-
-        // https://git.eeqj.de/sneak/AutistMask/issues/665 — a step that spends
-        // an unstated amount of a token from the router makes the router's
-        // amount of that token unknown. In each row such a step spends the
-        // WETH of a WRAP_ETH of 1 ETH into the router. The UNWRAP_WETH then
-        // leaves an unknown amount of ETH there, so the ETH the sender pays
-        // the last step reads as unknown.
-        test.each([
-            {
-                kind: "a WRAP_ETH of 1 ETH into the router, a V3 exact-out of at most 1 WETH paid from the router, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
-                commands: [0x0b, 0x01, 0x0c, 0x10],
-                inputs: [
-                    encodeWrapEth(ROUTER_ADDR, ONE_ETH),
-                    encodeV3SwapExactOut(
-                        USER_ADDR,
-                        390000000n,
-                        ONE_ETH,
-                        [USDC_ADDR, WETH_ADDR],
-                        false,
-                    ),
-                    unwrapIntoRouter,
-                    v4EthForUsdc(ONE_ETH),
-                ],
-                lines: [
-                    ["Moved from the sender", "Up to 1.0000 ETH"],
-                    ["Token moved", "ETH"],
-                    ["Moved to", "The swap step that spends it"],
-                    ...unknownEthLines,
-                ],
-            },
-            {
-                kind: "a WRAP_ETH of 1 ETH into the router, a V4 exact-out paid from the router's WETH, an UNWRAP_WETH into the router, then a V4 swap of 1 ETH that the user settles",
-                commands: [0x0b, 0x10, 0x0c, 0x10],
-                inputs: [
-                    encodeWrapEth(ROUTER_ADDR, ONE_ETH),
-                    encodeV4Swap(
-                        new Uint8Array([
-                            V4_SWAP_EXACT_OUT_SINGLE_ID,
-                            V4_SETTLE_ID,
-                            V4_TAKE_ALL_ID,
-                        ]),
-                        [
-                            encodeV4ExactOutSingle(
-                                WETH_ADDR,
-                                USDC_ADDR,
-                                390000000n,
-                                ONE_ETH,
-                            ),
-                            settle(WETH_ADDR, 0n, false),
-                            encodeV4TakeAll(USDC_ADDR, 0n),
-                        ],
-                    ),
-                    unwrapIntoRouter,
-                    v4EthForUsdc(ONE_ETH),
-                ],
-                lines: [
-                    ...wrapLines("The swap step that spends it"),
-                    ...unknownEthLines,
-                ],
-            },
-        ])("$kind", ({ commands, inputs, lines }) => {
-            const result = decodeSteps(commands, inputs);
-            expect(linesBetweenTokens(result)).toEqual(lines);
-        });
-
         // A V3_SWAP_EXACT_OUT the user pays for, of at most `amountInMax`
         // USDT for USDC.
         const v3ExactOut = (amountInMax) =>