[pull] main from MetaMask:main

app/components/UI/Perps/Perps.testIds.ts

@@ -759,3 +759,13 @@ export const PerpsTransactionsViewSelectorsIDs = {
   TAB_FUNDING: 'perps-transactions-tab-funding',
   TAB_DEPOSITS: 'perps-transactions-tab-deposits',
 } as const;
+
+// ========================================
+// PERPS FLIP POSITION CONFIRM SHEET SELECTORS
+// ========================================
+
+export const PerpsFlipPositionConfirmSheetSelectorsIDs = {
+  SHEET: 'perps-flip-position-confirm-sheet',
+  CANCEL_BUTTON: 'perps-flip-position-cancel-button',
+  FLIP_BUTTON: 'perps-flip-position-flip-button',
+} as const;

app/components/UI/Perps/components/PerpsFlipPositionConfirmSheet/PerpsFlipPositionConfirmSheet.test.tsx

@@ -7,6 +7,7 @@ import {
 } from '@testing-library/react-native';
 import PerpsFlipPositionConfirmSheet from './PerpsFlipPositionConfirmSheet';
 import { type Position } from '@metamask/perps-controller';
+import { usePerpsOrderFees } from '../../hooks';
 
 const mockHandleFlipPosition = jest.fn();
 let mockIsFlipping = false;
@@ -52,12 +53,12 @@ jest.mock('../../../../../../locales/i18n', () => ({
 }));
 
 jest.mock('../../hooks', () => ({
-  usePerpsOrderFees: () => ({
+  usePerpsOrderFees: jest.fn(() => ({
     totalFee: 0.5,
     makerFee: 0.2,
     takerFee: 0.3,
     isLoadingMetamaskFee: false,
-  }),
+  })),
   usePerpsRewards: () => ({
     shouldShowRewardsRow: false,
     estimatedPoints: undefined,
@@ -270,6 +271,12 @@ describe('PerpsFlipPositionConfirmSheet', () => {
   beforeEach(() => {
     jest.clearAllMocks();
     mockIsFlipping = false;
+    (usePerpsOrderFees as jest.Mock).mockReturnValue({
+      totalFee: 0.5,
+      makerFee: 0.2,
+      takerFee: 0.3,
+      isLoadingMetamaskFee: false,
+    });
   });
 
   it('renders the flip position title', () => {
@@ -366,4 +373,13 @@ describe('PerpsFlipPositionConfirmSheet', () => {
     // Math.abs(-2.5) = 2.5
     expect(screen.getByText('2.5 ETH')).toBeOnTheScreen();
   });
+
+  it('passes 2x position notional to usePerpsOrderFees for accurate fee estimate', () => {
+    render(<PerpsFlipPositionConfirmSheet position={mockLongPosition} />);
+
+    // ETH position: size=2.5, markPrice=2502 → 2x notional = 2.5 * 2 * 2502 = 12510
+    expect(usePerpsOrderFees).toHaveBeenCalledWith(
+      expect.objectContaining({ amount: '12510' }),
+    );
+  });
 });

app/components/UI/Perps/components/PerpsFlipPositionConfirmSheet/PerpsFlipPositionConfirmSheet.tsx

@@ -1,6 +1,7 @@
 import React, { useCallback, useMemo, useRef } from 'react';
 import { View, ActivityIndicator } from 'react-native';
 import { strings } from '../../../../../../locales/i18n';
+import { PerpsFlipPositionConfirmSheetSelectorsIDs } from '../../Perps.testIds';
 import BottomSheet, {
   BottomSheetRef,
 } from '../../../../../component-library/components/BottomSheets/BottomSheet';
@@ -67,9 +68,11 @@ const PerpsFlipPositionConfirmSheet: React.FC<
   const price = parseFloat(currentPrice?.price || '0');
   const markPrice = parseFloat(currentPrice?.markPrice || '0');
 
-  // Calculate USD amount for fee estimation
+  // Calculate USD amount for fee estimation.
+  // A flip places one order of 2x position size (1x to close current, 1x to open opposite).
+  // Fee is charged on the full 2x notional, so multiply by 2 for an accurate estimate.
   const usdAmount = useMemo(
-    () => (positionSize * (markPrice || price)).toString(),
+    () => (positionSize * 2 * (markPrice || price)).toString(),
     [positionSize, markPrice, price],
   );
 
@@ -140,6 +143,7 @@ const PerpsFlipPositionConfirmSheet: React.FC<
         variant: ButtonVariants.Secondary,
         size: ButtonSize.Lg,
         disabled: isFlipping,
+        testID: PerpsFlipPositionConfirmSheetSelectorsIDs.CANCEL_BUTTON,
       },
       {
         label: isFlipping
@@ -150,6 +154,7 @@ const PerpsFlipPositionConfirmSheet: React.FC<
         size: ButtonSize.Lg,
         disabled: isFlipping || !hasValidAmount,
         danger: true,
+        testID: PerpsFlipPositionConfirmSheetSelectorsIDs.FLIP_BUTTON,
       },
     ],
     [handleCloseInternal, handleReverse, isFlipping, hasValidAmount],
@@ -160,6 +165,7 @@ const PerpsFlipPositionConfirmSheet: React.FC<
       ref={sheetRef}
       shouldNavigateBack={!externalSheetRef}
       onClose={externalSheetRef ? onClose : undefined}
+      testID={PerpsFlipPositionConfirmSheetSelectorsIDs.SHEET}
     >
       <BottomSheetHeader onClose={handleCloseInternal}>
         <Text variant={TextVariant.HeadingMD}>

app/controllers/perps/services/TradingService.test.ts

@@ -2070,6 +2070,31 @@ describe('TradingService', () => {
       ).rejects.toThrow(/Insufficient balance for flip fees/);
     });
 
+    it('allows flip when balance covers 1x notional fee estimate', async () => {
+      // position: size=0.5, entryPrice=50000
+      // estimatedFees = positionSize * entryPrice * ESTIMATED_FEE_RATE
+      //               = 0.5 * 50000 * 0.0009 = $22.50 (1x notional, correct)
+      // pre-fix would compute 2x: 1.0 * 50000 * 0.0009 = $45 → would block this user
+      mockProvider.getAccountState = jest.fn().mockResolvedValue({
+        ...mockAccountState,
+        availableBalance: '30', // $30 > $22.50, sufficient with 1x
+      });
+      mockProvider.placeOrder.mockResolvedValue({
+        success: true,
+        orderId: 'flip-balance-fixed',
+        filledSize: '1.0',
+        averagePrice: '50000',
+      });
+
+      const result = await tradingService.flipPosition({
+        provider: mockProvider,
+        position: mockPosition,
+        context: mockContext,
+      });
+
+      expect(result.success).toBe(true);
+    });
+
     it('throws error when account state cannot be retrieved', async () => {
       mockProvider.getAccountState = jest.fn().mockResolvedValue(null);
 

app/controllers/perps/services/TradingService.ts

@@ -1951,11 +1951,12 @@ export class TradingService {
 
       const availableBalance = parseFloat(accountState.availableBalance);
 
-      // Estimate fees (close + open, approximately 0.09% of notional)
-      // Flip requires 2x position size (1x to close, 1x to open opposite)
+      // Estimate fees: ESTIMATED_FEE_RATE (0.09%) already accounts for both legs
+      // (close at 0.045% + open at 0.045% = 0.09% of position notional).
+      // Apply to 1x notional (positionSize * entryPrice), not 2x (flipSize * entryPrice).
       const entryPrice = parseFloat(position.entryPrice);
       const flipSize = positionSize * 2;
-      const notionalValue = flipSize * entryPrice;
+      const notionalValue = positionSize * entryPrice;
       const estimatedFees = notionalValue * ESTIMATED_FEE_RATE;
 
       if (estimatedFees > availableBalance) {