fix(sdk): promote three bug-catching lint rules to error and fix the fallout

[alex-connolly]

Follow-up to #2944.

Why

#2944 shipped because the rule that would have caught it was set to warn, so nothing failed CI. This promotes three rules that catch runtime defects rather than style preferences, and clears the codebase so the gate stays green.

Rule	Was	Now	Catches
typescript/no-non-null-asserted-optional-chain	warn	error	a?.b! — undefined at runtime, typed as present
typescript/no-base-to-string	warn	error	"[object Object]" in error messages and analytics
eslint/preserve-caught-error	—	error	rethrow without cause, discarding the original stack

Two real defects surfaced

1. Bridge fee validation has been dead code. tokenBridge.getFee passed an uninvoked async function to Promise.all, so it resolved the function object and validateChainIds never ran:

-      async () => {
+      (async () => {
         if (req.action !== BridgeFeeActions.FINALISE_WITHDRAWAL) {
           await validateChainIds(req.sourceChainId, req.destinationChainId, this.config);
         }
-      },
+      })(),

⚠️ Behaviour change: this restores validation that has not been running. Callers passing mismatched chain ids will now get the intended error instead of silently proceeding. Worth a look from someone who knows the bridge callers.

2. Sale failure analytics reported nothing. PayWithCoins called error.toString() on a SignOrderError ({ type, data }, not an Error), so every checkoutPrimarySalePaymentMethods_FailEventFailed event carried the literal string "[object Object]". Now sends error.type.

Also fixed

• An undefined provider could reach NetworkSwitchDrawer via from?.browserProvider! — the same component fix(checkout-widgets): parse hex chain ids so the bridge stops demanding a network switch #2944 hardens
• OrderSummary dereferenced a possibly-missing smartCheckoutResult
• SaleWidget built block-explorer links containing undefined
• fundingBalanceFees pushed fees with a missing required token

On oxlint --fix

Not used. It is not safe on this repo. A trial run produced:

• .sort() → .toSorted() in 11 places — ES2023 array methods (Chrome 110 / Safari 16.4 / Node 20), shipped unpolyfilled. Note this is worse than a compile error: widgets-lib sets "lib": ["dom", "dom.iterable", "esnext"], so toSorted type-checks there and would have shipped silently. It only fails to compile in packages that inherit target: ES2022 from tsconfig.base.json (orderbook, wallet, checkout/sdk, …). Verified both ways.
• Dropped entries from React dependency arrays (×2) — silent behaviour change
• Dead whitespace throughout cancellablePromise.ts

Which is the same failure mode as #2944: an autofix applied without review. Every change here is hand-written.

Deferred, with counts

Rule	Count	Why not here
no-floating-promises	230	Closest to #2944's root cause, but needs per-site judgment — void for genuine fire-and-forget, real handling for user-triggered actions. Blanket-voiding would silence the signal rather than fix it. Own PR.
no-unsafe-enum-comparison	93	Needs a canonical type chosen per comparison — a refactor, not a lint fix
react-hooks/exhaustive-deps	235	Every fix changes render behaviour and can cause infinite loops

Do not enable the radix rule. It is currently off (style category), and its autofix is what caused #2944.

Testing

• pnpm typecheck clean across widgets-lib, orderbook, wallet, bridge-sdk, dex-sdk
• widgets-lib: 39 suites / 265 tests pass
• bridge-sdk + dex-sdk: 297 tests pass
• oxlint packages/ reports 0 errors

🤖 Generated with Claude Code

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 06508eb

Command	Status	Duration	Result
nx run-many -p @imtbl/sdk,@imtbl/checkout-widge...	✅ Succeeded	58s	View ↗
nx affected -t build,test	✅ Succeeded	1m 56s	View ↗

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☁️ Nx Cloud last updated this comment at 2026-08-07 08:36:46 UTC