In `@src/common/abis/orderbook.ts`:
- Line 124: RouteLeg is missing an "as const" assertion so its literal ABI
string widens to string and breaks type inference when used with
parseAbiParameters (e.g., parseAbiParameters(_v6.RouteLeg)). Fix by adding the
as const assertion to the RouteLeg export (the exported constant named RouteLeg)
so it preserves the literal type; ensure any other occurrences in the _v6 ABI
group follow the same pattern to keep parseAbiParameters strongly typed.
- Around line 150-154: The ABI for Arb.arb4 changed to require four args
(orderBook, startTakeOrders[], exchangeData, task); update all call sites that
invoke arb4 (notably in the router and inter simulate functions) to pass the new
exchangeData parameter between startTakeOrders and task, e.g., modify the calls
in simulate.ts where arb4 is invoked to include an appropriate bytes
exchangeData value (or an empty bytes if no data) as the third argument; also
update any unit/integration tests that invoke arb4 to reflect the new
four-argument signature and adjust expected behavior accordingly.

In `@src/core/modes/index.test.ts`:
- Around line 23-29: Remove the leftover commented-out balancer mock in
index.test.ts (the vi.mock call for "./balancer" and findBestBalancerTrade);
either delete those three commented lines entirely or replace them with a brief
inline comment explaining why balancer support is omitted (e.g., removed/handled
in another PR) so future readers aren’t confused—locate the commented block near
the existing vi.mock("./raindex") mock to edit.
- Line 674: The test title string in the it(...) block "should return only
inter-orderbook trade when orderbook is in raindex router set" is misleading;
change that description to accurately reference the raindex router (for example:
"should return only trades routed via raindex router when orderbook is in
raindex router set") so the test name matches the behavior being asserted in the
test case (modify the it(...) title in src/core/modes/index.test.ts).
- Around line 323-328: The test has a copy-paste bug: the raindexResult constant
is created with type: "interOrderbook" instead of the correct "raindex"; update
the object literal in raindexResult (the Result.ok call named raindexResult) to
set type: "raindex" so the test validates raindex results using the correct type
field.

In `@src/core/modes/raindex/index.test.ts`:
- Line 937: The test case name in the it(...) call currently reads "should
return corrrect profit when order max input is lower counterparty max output"
(note the function symbol is the it(...) in
src/core/modes/raindex/index.test.ts) — fix the typo by renaming the test string
to "should return correct profit when order max input is lower counterparty max
output" so the test description is spelled correctly.
- Around line 23-32: The mocked Token class in the vi.mock for "sushi/currency"
returns a plain object from its constructor (return { ...args }), which violates
the noConstructorReturn rule and can break instanceof checks; change the mock to
either use a factory function that returns a proper Token-like object or mutate
the instance instead (e.g., in the Token constructor use Object.assign(this,
args) or populate properties on this) so the constructor returns the instance
rather than a new plain object, keeping the mock defined under
vi.mock("sushi/currency") and preserving the Token symbol.
- Around line 129-133: Replace incorrect assertions that use
.not.toHaveBeenCalledWith() with no arguments — which only checks for a call
with zero args — with .not.toHaveBeenCalled() to assert the mock was never
invoked; update the occurrences that reference
solver.state.contracts.getAddressesForTrade,
solver.orderManager.getCounterpartyOrdersAgainstBaseTokens, and
solver.state.router.sushi!.tryQuote (and the other similar spots in the same
test file) so each uses .not.toHaveBeenCalled() instead of
.not.toHaveBeenCalledWith().

In `@src/core/modes/raindex/index.ts`:
- Around line 28-38: Update the JSDoc comment in src/core/modes/raindex/index.ts
for the RainSolver method that begins "Tries to find the best raindex routed
trade..." and correct the typo "swaped" to "swapped" so the sentence reads
"...swapped through sushi RP"; ensure the change is applied in the JSDoc block
associated with the RainSolver/raindex function signature.
- Around line 196-204: The shared spanAttributes object is being mutated inside
the .map() callback (see Pair.isV4OrderbookV6 and spanAttributes usage) which
can overwrite or leak error context across counterparties; instead create a
local per-counterparty attributes object (e.g., let localSpanAttrs = {
...spanAttributes } or a new object) inside the map/callback and set
localSpanAttrs["error"] when Pair.isV4OrderbookV6(counterpartyOrderDetails)
fails, then return Result.err({... , spanAttributes: localSpanAttrs, ...}) as
SimulationResult so each error carries its own isolated attributes and the outer
spanAttributes remains unchanged for success paths.

In `@src/core/modes/raindex/simulation.ts`:
- Line 19: Update the top doc comment in src/core/modes/raindex/simulation.ts by
replacing the phrase "inter-orderbook trade" with "raindex router trade" so the
comment accurately describes the arguments for simulating a raindex router
trade; locate the comment that currently reads "Arguments for simulating
inter-orderbook trade" and change only the wording to "Arguments for simulating
raindex router trade".
- Around line 59-66: Edit the JSDoc above the RaindexRouterTradeSimulator class
(which extends TradeSimulatorBase) to fix typos and grammar: change "wwith" to
"with", "a external" to "an external", and ensure the phrase reads "Simulates a
trade between two orders with different IO through an external route" (also
correct "two order" → "two orders" if present); update any other small
grammatical issues in that block so the description is clear and consistent.

In `@src/core/modes/raindex/utils.test.ts`:
- Around line 9-141: Tests for calcCounterpartyInputProfit only use
buyTokenDecimals: 18 so scaleTo18 logic is untested; add a new unit test in
src/core/modes/raindex/utils.test.ts that uses a counterparty with
buyTokenDecimals: 6 (or another non-18 value) and a quote where
amountOut/maxOutput are scaled accordingly, then assert both
counterpartyInputProfit and counterpartyMaxOutput reflect the decimal scaling
(reference calcCounterpartyInputProfit and scaleTo18 to craft expected values).

In `@src/core/modes/raindex/utils.ts`:
- Around line 51-58: The function calcCounterpartyInputToEthPrice can divide by
quote.price which may be 0n; add a guard at the start of
calcCounterpartyInputToEthPrice to return 0n when quote.price === 0n (similar to
the check in calcCounterpartyInputProfit), so parsing outputToEthPrice and the
division (outputEthPrice * ONE18) / quote.price only run when quote.price is
non-zero; reference the function name calcCounterpartyInputToEthPrice and the
symbol quote.price when adding the early-return check.
- Line 17: Rename the misspelled variable counterpatryMaxInput to
counterpartyMaxInput everywhere in this file and update all references (the
declaration and uses at the occurrences you noted) so the identifier matches;
search for counterpatryMaxInput and replace with counterpartyMaxInput to avoid
runtime/reference errors and keep naming consistent with related variables like
maxSushiOutput.

In `@src/order/index.test.ts`:
- Around line 22-26: Tests mutate the mocked config object
BASES_TO_CHECK_TRADES_AGAINST created via vi.mock, and vi.clearAllMocks() does
not revert object property changes, so add a reset in beforeEach to restore the
mock state (e.g., call vi.resetModules() or explicitly reassign
BASES_TO_CHECK_TRADES_AGAINST[1] = [] before each test). Update the beforeEach
in src/order/index.test.ts (where vi.clearAllMocks() is used) to either call
vi.resetModules() and re-import the mock or directly reset the
BASES_TO_CHECK_TRADES_AGAINST[1] property so each test starts with a clean
array.

In `@src/order/index.ts`:
- Around line 531-538: The guard checking tokens can throw if
BASES_TO_CHECK_TRADES_AGAINST[this.state.chainConfig.id] is undefined; update
the condition in the loop that references tkn and sellToken so the .every() call
uses a null-coalescing default (e.g.,
BASES_TO_CHECK_TRADES_AGAINST[this.state.chainConfig.id] ?? []) before calling
.every(), ensuring the expression safely falls back to an empty array when the
chain id is not present.

In `@src/order/pair.test.ts`:
- Around line 463-665: The test title for the case validating identical inputs
with differing outputs is misleading; update the it() description string that
currently reads "should handle edge case where all pairs have same input and
output" (the test using createPair hashes hash1/hash2/hash3 and calling
getOptimalSortedList) to something clearer like "should handle edge case where
all pairs have same input but different outputs" so the test name matches the
assertions against getOptimalSortedList.

In `@src/order/pair.ts`:
- Line 82: The JSDoc for getSortedPairList mentions a non-existent parameter
"sortBy"; remove or update that line so the doc matches the function signature:
either delete the `@param sortBy` entry or replace it with descriptions of the
actual parameters accepted by getSortedPairList (use the exact function name
getSortedPairList to locate the comment) and ensure parameter names/types in the
JSDoc match the current signature.
- Around line 166-200: getOptimalSortedList currently mutates the caller's array
and also filters out pairs with maxOutput === 0n due to a truthiness check; fix
by sorting a shallow copy of the input (e.g., use [...options] before calling
.sort) so callers aren't surprised, and change the filter condition in the
pareto selection to explicitly check for undefined/null (e.g.,
opt.takeOrder.quote?.maxOutput !== undefined && opt.takeOrder.quote.maxOutput >=
0n) or at least opt.takeOrder.quote != null to include 0n results if desired;
also add a short inline comment near the filter to explain that 0n outputs are
intentionally excluded or included per the chosen behavior.

In `@src/state/contracts.test.ts`:
- Line 868: Fix the typo in the test description string inside the it(...) block
named "should return undefined for Raindex tradeType when raindexRab is not
available" by changing "raindexRab" to "raindexArb" so the description reads
"should return undefined for Raindex tradeType when raindexArb is not
available"; locate the it(...) in the tests (symbol: the it(...) with that
description) and update the string only—no logic changes.