feat: reserve network fees from native Relay Max (CONF-2006)

packages/transaction-pay-controller/CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Reserve source-network fees from native-token Relay Max quotes when the paying account does not support EIP-7702 ([#10237](https://github.com/MetaMask/core/pull/10237))
 - Detect nested `perpsDepositAndOrder` and `predictDepositAndOrder` transactions when selecting `EXACT_OUTPUT` Relay quotes ([#10222](https://github.com/MetaMask/core/pull/10222))
 
 ## [28.0.2]

packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.test.ts

@@ -5,6 +5,7 @@ import type {
 import type { Hex } from '@metamask/utils';
 
 import { getDefaultRemoteFeatureFlagControllerState } from '../../../../remote-feature-flag-controller/src/remote-feature-flag-controller.js';
+import { CHAIN_ID_POLYGON, NATIVE_TOKEN_ADDRESS } from '../../constants.js';
 import { TransactionPayStrategy } from '../../index.js';
 import { getMessengerMock } from '../../tests/messenger-mock.js';
 import type {
@@ -224,6 +225,123 @@ describe('relay-max-gas-station', () => {
     expect(result).toBe(phase1Quote);
   });
 
+  it('reserves network fees when max source token is native and account does not support EIP-7702', async () => {
+    const phase1Quote = makeQuote({
+      sourceAmountRaw: '100000',
+      sourceNetworkGasRaw: '100',
+    });
+    const phase2Quote = makeQuote({
+      sourceAmountRaw: '99900',
+      sourceNetworkGasRaw: '100',
+    });
+    const getSingleQuote = jest
+      .fn()
+      .mockResolvedValueOnce(phase1Quote)
+      .mockResolvedValueOnce(phase2Quote);
+    getTokenBalanceMock.mockReturnValue('100000');
+    const nativeToken = getNativeTokenMock();
+    const request = {
+      ...BASE_REQUEST,
+      sourceTokenAddress: nativeToken,
+      sourceTokenAmount: '100000',
+    };
+
+    const result = await getRelayMaxGasStationQuote(
+      request,
+      makeFullRequest(messenger, request),
+      getSingleQuote,
+    );
+
+    expect(getSingleQuote).toHaveBeenCalledTimes(2);
+    expect(getSingleQuote).toHaveBeenNthCalledWith(
+      2,
+      expect.objectContaining({ sourceTokenAmount: '99900' }),
+      expect.any(Object),
+    );
+    expect(result).toBe(phase2Quote);
+  });
+
+  it('reserves network fees when Polygon native Max uses the Relay address', async () => {
+    const phase1Quote = makeQuote({
+      sourceAmountRaw: '100000',
+      sourceNetworkGasRaw: '100',
+    });
+    const phase2Quote = makeQuote({
+      sourceAmountRaw: '99900',
+      sourceNetworkGasRaw: '100',
+    });
+    const getSingleQuote = jest
+      .fn()
+      .mockResolvedValueOnce(phase1Quote)
+      .mockResolvedValueOnce(phase2Quote);
+    const request = {
+      ...BASE_REQUEST,
+      sourceChainId: CHAIN_ID_POLYGON,
+      sourceTokenAddress: NATIVE_TOKEN_ADDRESS,
+      sourceTokenAmount: '100000',
+    };
+
+    const result = await getRelayMaxGasStationQuote(
+      request,
+      makeFullRequest(messenger, request),
+      getSingleQuote,
+    );
+
+    expect(getSingleQuote).toHaveBeenNthCalledWith(
+      2,
+      expect.objectContaining({ sourceTokenAmount: '99900' }),
+      expect.any(Object),
+    );
+    expect(result).toBe(phase2Quote);
+  });
+
+  it('returns phase-1 quote when the adjusted native Max quote fails', async () => {
+    const phase1Quote = makeQuote({
+      sourceAmountRaw: '100000',
+      sourceNetworkGasRaw: '100',
+    });
+    const getSingleQuote = jest
+      .fn()
+      .mockResolvedValueOnce(phase1Quote)
+      .mockRejectedValueOnce(new Error('adjusted quote failed'));
+    const request = {
+      ...BASE_REQUEST,
+      sourceTokenAddress: getNativeTokenMock(),
+      sourceTokenAmount: '100000',
+    };
+
+    const result = await getRelayMaxGasStationQuote(
+      request,
+      makeFullRequest(messenger, request),
+      getSingleQuote,
+    );
+
+    expect(getSingleQuote).toHaveBeenCalledTimes(2);
+    expect(result).toBe(phase1Quote);
+  });
+
+  it('returns phase-1 quote when native network fees consume the Max amount', async () => {
+    const phase1Quote = makeQuote({
+      sourceAmountRaw: '100',
+      sourceNetworkGasRaw: '100',
+    });
+    const getSingleQuote = jest.fn().mockResolvedValue(phase1Quote);
+    const request = {
+      ...BASE_REQUEST,
+      sourceTokenAddress: getNativeTokenMock(),
+      sourceTokenAmount: '100',
+    };
+
+    const result = await getRelayMaxGasStationQuote(
+      request,
+      makeFullRequest(messenger, request),
+      getSingleQuote,
+    );
+
+    expect(getSingleQuote).toHaveBeenCalledTimes(1);
+    expect(result).toBe(phase1Quote);
+  });
+
   it('returns phase-1 quote when source chain is not gas-station eligible', async () => {
     const phase1Quote = makeQuote();
     const getSingleQuote = jest.fn().mockResolvedValue(phase1Quote);

packages/transaction-pay-controller/src/strategy/relay/relay-max-gas-station.ts

@@ -1,6 +1,7 @@
 import { createModuleLogger } from '@metamask/utils';
 import { BigNumber } from 'bignumber.js';
 
+import { NATIVE_TOKEN_ADDRESS } from '../../constants.js';
 import { projectLogger } from '../../logger.js';
 import type {
   PayStrategyGetQuotesRequest,
@@ -88,6 +89,14 @@ export async function getRelayMaxGasStationQuote(
     return phase1Quote;
   }
 
+  if (!fullRequest.accountSupports7702 && isNativeSourceToken(request)) {
+    return getNativeMaxQuoteWithReservedFees(
+      phase1Quote,
+      new BigNumber(sourceTokenAmount),
+      context,
+    );
+  }
+
   const nativeBalanceCheck = checkEnoughNativeBalanceIfSourceGasFeeTokenNotUsed(
     phase1Quote,
     messenger,
@@ -218,6 +227,46 @@ export async function getRelayMaxGasStationQuote(
   return phase2Quote;
 }
 
+function isNativeSourceToken(request: QuoteRequest): boolean {
+  const sourceTokenAddress = request.sourceTokenAddress.toLowerCase();
+
+  return (
+    sourceTokenAddress ===
+      getNativeToken(request.sourceChainId).toLowerCase() ||
+    sourceTokenAddress === NATIVE_TOKEN_ADDRESS.toLowerCase()
+  );
+}
+
+async function getNativeMaxQuoteWithReservedFees(
+  phase1Quote: TransactionPayQuote<RelayQuote>,
+  sourceAmount: BigNumber,
+  context: MaxAmountQuoteContext,
+): Promise<TransactionPayQuote<RelayQuote>> {
+  const networkFee = new BigNumber(phase1Quote.fees.sourceNetwork.max.raw);
+  const adjustedSourceAmount = getAdjustedSourceAmount(
+    sourceAmount,
+    networkFee,
+  );
+
+  if (!networkFee.isGreaterThan(0) || !adjustedSourceAmount.isGreaterThan(0)) {
+    return fallbackToPhase1(
+      phase1Quote,
+      'Unable to reserve native network fees',
+    );
+  }
+
+  const adjustedQuote = await getAdjustedPhase2Quote(
+    adjustedSourceAmount,
+    {
+      amount: networkFee,
+      source: GasCostEstimateSource.Quote,
+    },
+    context,
+  );
+
+  return adjustedQuote ?? phase1Quote;
+}
+
 function checkEnoughNativeBalanceIfSourceGasFeeTokenNotUsed(
   quote: TransactionPayQuote<RelayQuote>,
   messenger: TransactionPayControllerMessenger,