Subtract gas cost

Add gas fee token fee.

Author: matthewwalsh0

packages/transaction-controller/CHANGELOG.md

@@ -27,6 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Include gas limit and gas fees in simulation requests ([#5754](https://github.com/MetaMask/core/pull/5754))
+  - Add optional `fee` property to `GasFeeToken`.
 
 ### Fixed
 

packages/transaction-controller/src/api/simulation-api.ts

@@ -173,6 +173,9 @@ export type SimulationResponseTokenFee = {
   /** Conversation rate of 1 token to native WEI. */
   rateWei: Hex;
 
+  /** Portion of `balanceNeededToken` that is the fee paid to MetaMask. */
+  serviceFee?: Hex;
+
   /** Estimated gas limit required for fee transfer. */
   transferEstimate: Hex;
 };
@@ -200,6 +203,12 @@ export type SimulationResponseTransaction = {
     tokenFees: SimulationResponseTokenFee[];
   }[];
 
+  /**
+   * Estimated total gas cost of the transaction.
+   * Included in the stateDiff if `withGas` is true.
+   */
+  gasCost?: number;
+
   /** Required `gasLimit` for the transaction. */
   gasLimit?: Hex;
 

packages/transaction-controller/src/types.ts

@@ -1753,6 +1753,9 @@ export type GasFeeToken = {
   /** Decimals of the token. */
   decimals: number;
 
+  /** Portion of the amount that is the fee paid to MetaMask. */
+  fee?: Hex;
+
   /** Estimated gas limit required for original transaction. */
   gas: Hex;
 

packages/transaction-controller/src/utils/balance-changes.test.ts

@@ -182,17 +182,20 @@ function createEventResponseMock(
  *
  * @param previousBalance - The previous balance.
  * @param newBalance - The new balance.
+ * @param gasCost - Gas cost of the transaction.
  * @returns Mock API response.
  */
 function createNativeBalanceResponse(
   previousBalance: string,
   newBalance: string,
+  gasCost: number = 0,
 ) {
   return {
     transactions: [
       {
         ...defaultResponseTx,
         return: encodeTo32ByteHex(previousBalance),
+        gasCost,
         stateDiff: {
           pre: {
             [USER_ADDRESS_MOCK]: { balance: previousBalance },
@@ -317,6 +320,24 @@ describe('Simulation Utils', () => {
           tokenBalanceChanges: [],
         });
       });
+
+      it('ignoring gas cost', async () => {
+        simulateTransactionsMock.mockResolvedValueOnce(
+          createNativeBalanceResponse('0x3', '0x8', 2),
+        );
+
+        const result = await getBalanceChanges(REQUEST_MOCK);
+
+        expect(result).toStrictEqual({
+          nativeBalanceChange: {
+            difference: '0x7',
+            isDecrease: false,
+            newBalance: '0xa',
+            previousBalance: '0x3',
+          },
+          tokenBalanceChanges: [],
+        });
+      });
     });
 
     describe('returns token balance changes', () => {

packages/transaction-controller/src/utils/balance-changes.ts

@@ -195,7 +195,11 @@ function getNativeBalanceChange(
     return undefined;
   }
 
-  return getSimulationBalanceChange(previousBalance, newBalance);
+  return getSimulationBalanceChange(
+    previousBalance,
+    newBalance,
+    transactionResponse.gasCost,
+  );
 }
 
 /**
@@ -622,13 +626,17 @@ function extractLogs(
  *
  * @param previousBalance - The previous balance.
  * @param newBalance - The new balance.
+ * @param offset - Optional offset to apply to the new balance.
  * @returns The balance change data or undefined if unchanged.
  */
 function getSimulationBalanceChange(
   previousBalance: Hex,
   newBalance: Hex,
+  offset: number = 0,
 ): SimulationBalanceChange | undefined {
-  const differenceBN = hexToBN(newBalance).sub(hexToBN(previousBalance));
+  const newBalanceBN = hexToBN(newBalance).add(new BN(offset));
+  const previousBalanceBN = hexToBN(previousBalance);
+  const differenceBN = newBalanceBN.sub(previousBalanceBN);
   const isDecrease = differenceBN.isNeg();
   const difference = toHex(differenceBN.abs());
 
@@ -639,7 +647,7 @@ function getSimulationBalanceChange(
 
   return {
     previousBalance,
-    newBalance,
+    newBalance: toHex(newBalanceBN),
     difference,
     isDecrease,
   };

packages/transaction-controller/src/utils/gas-fee-tokens.test.ts

@@ -69,6 +69,7 @@ describe('Gas Fee Tokens Utils', () => {
                     feeRecipient: '0x6',
                     rateWei: '0x7',
                     transferEstimate: '0x7a',
+                    serviceFee: '0x7b',
                   },
                   {
                     token: {
@@ -81,6 +82,7 @@ describe('Gas Fee Tokens Utils', () => {
                     feeRecipient: '0xa',
                     rateWei: '0xb',
                     transferEstimate: '0xba',
+                    serviceFee: '0xbb',
                   },
                 ],
               },
@@ -97,6 +99,7 @@ describe('Gas Fee Tokens Utils', () => {
           amount: '0x4',
           balance: '0x5',
           decimals: 3,
+          fee: '0x7b',
           gas: '0x1',
           gasTransfer: '0x7a',
           maxFeePerGas: '0x2',
@@ -110,6 +113,7 @@ describe('Gas Fee Tokens Utils', () => {
           amount: '0x8',
           balance: '0x9',
           decimals: 4,
+          fee: '0xbb',
           gas: '0x1',
           gasTransfer: '0xba',
           maxFeePerGas: '0x2',
@@ -143,6 +147,7 @@ describe('Gas Fee Tokens Utils', () => {
                     feeRecipient: '0x6',
                     rateWei: '0x7',
                     transferEstimate: '0x7a',
+                    serviceFee: '0x7b',
                   },
                 ],
               },
@@ -162,6 +167,7 @@ describe('Gas Fee Tokens Utils', () => {
                     feeRecipient: '0xd',
                     rateWei: '0xe',
                     transferEstimate: '0xee',
+                    serviceFee: '0xef',
                   },
                 ],
               },
@@ -178,6 +184,7 @@ describe('Gas Fee Tokens Utils', () => {
           amount: '0x4',
           balance: '0x5',
           decimals: 3,
+          fee: '0x7b',
           gas: '0x1',
           gasTransfer: '0x7a',
           maxFeePerGas: '0x2',

packages/transaction-controller/src/utils/gas-fee-tokens.ts

@@ -126,6 +126,7 @@ function parseGasFeeTokens(response: SimulationResponse): GasFeeToken[] {
     amount: tokenFee.balanceNeededToken,
     balance: tokenFee.currentBalanceToken,
     decimals: tokenFee.token.decimals,
+    fee: tokenFee.serviceFee,
     gas: feeLevel.gas,
     gasTransfer: tokenFee.transferEstimate,
     maxFeePerGas: feeLevel.maxFeePerGas,