fix(perps): update drag value in tap handler

[michalconsensys]

Description

Fixed a bug in the leverage slider where tapping or long pressing on the slider track did not trigger the onDragEnd callback, causing inconsistent state management between tap and drag interactions.

Changelog

CHANGELOG entry: Fixed leverage slider tap and long press gesture not finalizing state updates correctly

Related issues

Fixes: https://consensyssoftware.atlassian.net/browse/TAT-1826

Manual testing steps

Feature: Leverage Slider Tap Gesture

  Scenario: user taps on leverage slider track
    Given user is on the perps market details screen
    And user taps "Long" or "Short" button
    And leverage adjustment modal is displayed

    When user taps anywhere on the leverage slider track
    Then the leverage value updates immediately
    And the dragging state resets to false
    And the liquidation price recalculates

  Scenario: user holds the slider for a long time
    Given user is on the leverage adjustment modal
    
    When user holds the slider
    Then releasing the slider properly finalizes the leverage value
    And the liquidation price updates when user releases the slider
    And no stale state remains between taps

Screenshots/Recordings

Before

Simulator.Screen.Recording.-.iPhone.16e.-.2025-10-27.at.07.12.51.mov

After

Simulator.Screen.Recording.-.iPhone.16e.-.2025-10-27.at.07.09.55.mov

Pre-merge author checklist

• I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

---

Note

Ensures tap and long-press finalize leverage changes, adds comprehensive gesture tests, and introduces a non-flickering skeleton state for liquidation data.

• PerpsLeverageBottomSheet:
  • Gesture handling:
    • Make onDragStart/onDragEnd required and invoke unconditionally during pan end/begin.
    • Add handleHoldEnd and wire to Gesture.Tap and Gesture.LongPress; compose with Pan via Gesture.Simultaneous.
    • Add testID leverage-slider-track for gesture/layout targeting.
  • Loading/Skeleton:
    • Introduce shouldShowSkeleton to control liquidation UI and prevent flicker; reset on close and when value unchanged.
    • Use Number.parseFloat; set dynamicLiquidationPrice to 0 while isCalculating.
    • Trigger skeleton on slider drag updates and on quick-select changes.
• Tests (PerpsLeverageBottomSheet.test.tsx):
  • Add gesture utilities/mocks (fireGestureHandler, LongPress, haptics) and extensive tests for pan/tap/long-press flows, state updates, and haptic integration.
  • Add coverage for quick-select behavior, risk styling, liquidation formatting, skeleton visibility, and layout+gesture sequences.

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[github-actions]

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.15%. Comparing base (a00ab1a) to head (81c7525).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...psLeverageBottomSheet/PerpsLeverageBottomSheet.tsx	66.66%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #21608   +/-   ##
=======================================
  Coverage   77.15%   77.15%           
=======================================
  Files        3720     3720           
  Lines       93544    93548    +4     
  Branches    17947    17949    +2     
=======================================
+ Hits        72171    72179    +8     
- Misses      16475    16476    +1     
+ Partials     4898     4893    -5     

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[gambinish]

Pulled down the branch, and this is the behavior that I am seeing:

Screen.Recording.2025-10-27.at.8.50.59.AM.mov

It seems like the Liquidation Price briefly gets computed with the "estimated" value before entering into the loading state for the computed value.

I think this is partly what we are trying to solve in this bugfix. I wonder if we can trigger the loading skeleton onDrag to avoid rendering the theoretical value entirely. I think that MSO is aligned with omitting the this estimated value entirely since it can be confusing for the user

[abretonc7s]

This seems like a very large amount of tests added, could they be grouped with better assertions?

[michalconsensys]

@abretonc7s @gambinish I've updated the tests and made it to display a loading indicator when the user starts dragging the slider, however can't quite get the coverage above 80%. Could you please have a look again? Thanks!

[sonarqubecloud]

Quality Gate failed

Failed conditions
78.8% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud