fix(perps): use current price to compute PnL

[michalconsensys]

Description

Fixes PnL calculation when closing positions. Previously the UI used ref which did not trigger a recalculation of the PnL. To solve the issue we refer to the variable without using ref.

Changelog

CHANGELOG entry: Fixed PnL calculation to use current price

Related issues

Fixes: https://consensyssoftware.atlassian.net/browse/TAT-2035

Manual testing steps

Feature: Close position

  Scenario: User closes a position 
    Given I have an open long position for BTC
    And the current market price is $50,000
    And my entry price was $45,000
    When I click on close position
    Then the P&L shown should be calculated using the current price

Screenshots/Recordings

Before

After

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

Use currentPrice directly (not a ref) for close-position positionValue and PnL, updating memo dependencies to reflect live price.

• Perps Close Position View (PerpsClosePositionView.tsx):
  • Calculations:
    • Replace ref-based price with direct currentPrice for positionValue and P&L computations.
    • Update useMemo dependencies to include currentPrice for live recalculation.
  • Cleanup:
    • Remove unused useRef for current price and related comments.

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[github-actions]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
1 Security Hotspot
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[nickewansmith]

Hey @michalconsensys thanks for jumping on this. I think #22229 will address it as well and may make this unnecessary.