fix(common-utils): forward original arguments in debounce

[Kropiunig]

Summary

debounce in libs/common-utils/src/misc.ts invokes the wrapped function with the collected arguments array as a single first parameter (func(args), line 48) instead of spreading it (func(...args)). Every argument-taking callback wrapped by this util receives an array as its first parameter and undefined for the rest:

const debounced = debounce((path?: string, params?: string[], title?: string) => { ... }, 1000)
debounced('/swap', ['param'], 'CoW Swap')
// after 1s the callback receives:
//   path   = ['/swap', ['param'], 'CoW Swap']   <- the whole args array
//   params = undefined
//   title  = undefined

The production consumer, debouncedPageView in libs/analytics/src/gtm/CowAnalyticsGtm.ts:109, declares exactly this 3-parameter callback. Consequences for every page_view pushed to the GTM data layer:

• page_path is an array (e.g. ['/swap']) instead of a string, so any GTM variable/trigger doing type-sensitive matching on it misbehaves
• any params/title passed to the public sendPageView(path, params, title) API are silently dropped: they end up folded into the page_path array while page_title/page_params become undefined and are stripped by sanitizeRecord

The fix spreads the arguments (func(...args)), which matches the declared generic type F extends (...args: any) => any and standard debounce semantics.

Regression tests added in libs/common-utils/src/misc.test.ts:

• "forwards the original arguments to the wrapped function" — fails on develop (received [['/swap?chain=mainnet', ['param'], 'CoW Swap']]), passes with the fix
• "invokes the wrapped function only once with the latest arguments" — also fails on develop (received [['second']]), passes with the fix
• "does not invoke the wrapped function before the wait time elapses"

To Test

1. Run npx nx test common-utils

• All suites pass; reverting the one-line change in misc.ts makes the two new debounce assertions fail

2. Run npx nx test analytics

• Passes

3. In the app, set window.enableGaLogging = true and navigate between pages

• The logged page_view data-layer push contains page_path as a string (e.g. "/swap"), not an array

Background

usePageViewTracking currently passes only path, so the most visible damage today is the wrong type for page_path in the data layer. But sendPageView accepts params and title as part of the CowAnalytics interface, and debounce is exported from @cowprotocol/common-utils, so any consumer passing arguments hits the same mangling.

Summary by CodeRabbit

• Bug Fixes
  • Fixed debounced callbacks to forward multiple arguments correctly (instead of passing a single argument array), ensuring analytics calls receive the expected (field, amount) values.
  • Updated advanced and limit order input handlers to invoke debounced trade amount analytics with separate parameters.
• Tests
  • Added Jest coverage for debounce argument forwarding, ensuring execution is delayed appropriately and that rapid repeated calls use only the latest arguments.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: c53059f2-d32d-48a9-a305-c20bdb99bd7d

📥 Commits

Reviewing files that changed from the base of the PR and between cbf8e4f and d35db40.

📒 Files selected for processing (3)

• apps/cowswap-frontend/src/modules/advancedOrders/hooks/useAdvancedOrdersActions.ts
• apps/cowswap-frontend/src/modules/limitOrders/containers/LimitOrdersWidget/hooks/useLimitOrdersWidgetActions.ts
• apps/cowswap-frontend/src/modules/trade/utils/analytics.ts

---

Walkthrough

The debounce utility now forwards arguments individually. Trade analytics callers use the corrected convention, and Jest tests cover forwarding, latest-argument behavior, and delayed invocation.

Changes

Debounce argument convention

Layer / File(s)	Summary
Forward debounced arguments and validate timing libs/common-utils/src/misc.ts, libs/common-utils/src/misc.test.ts	debounce invokes callbacks with spread arguments, with tests covering forwarding, latest arguments, and delay timing.
Update trade analytics callers apps/cowswap-frontend/src/modules/trade/utils/analytics.ts, apps/cowswap-frontend/src/modules/advancedOrders/hooks/useAdvancedOrdersActions.ts, apps/cowswap-frontend/src/modules/limitOrders/containers/LimitOrdersWidget/hooks/useLimitOrdersWidgetActions.ts	Trade analytics callbacks and their advanced- and limit-order callers now pass field and amount as separate arguments.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: kernelwhisperer

Poem

A rabbit tapped the timer’s drum,
“Send each carrot one by one!”
The latest bunch now leads the way,
No nibble comes before delay.
Hop, debounce, the fix is done!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: fixing debounce to forward arguments correctly.
Description check	✅ Passed	The description covers Summary, To Test, and Background with concrete behavior and verification steps.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Fix failing CI checks

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[shoom3301]

Thank you!
The change looks valid. I would kindly ask to check the places where the function is in use. I see two places:

• debouncedTradeAmountAnalytics([field, Number(typedValue)])
• this.debouncedPageView(path, params, title)

It looks like with this PR changes debouncedTradeAmountAnalytics call can be simplified.

[Kropiunig]

Good catch, thanks! Simplified the debouncedTradeAmountAnalytics call sites to pass (field, value) directly and changed the handler to take the two arguments naturally instead of a tuple. Verified debouncedPageView(path, params, title) already forwards correctly with the fixed debounce, so it needed no change. Updated in d35db40.

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Project	Deployment	Actions	Updated (UTC)
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