TD1453 Make sure maker/taker fee amounts are divisible by quantity of…

… order (#1828) Signed-off-by: Frank Li <[email protected]> Co-authored-by: mdymalla <[email protected]>
immutable · May 28, 2024 · 717babf · 717babf
1 parent 7290675
commit 717babf
Show file tree

Hide file tree

Showing 4 changed files with 36 additions and 6 deletions.
diff --git a/packages/checkout/sdk/src/smartCheckout/buy/buy.ts b/packages/checkout/sdk/src/smartCheckout/buy/buy.ts
@@ -166,7 +166,9 @@ export const buy = async (
 
   let fees: FeeValue[] = [];
   if (takerFees && takerFees.length > 0) {
-    fees = calculateFees(takerFees, buyToken.amount, decimals);
+    // eslint-disable-next-line max-len
+    const tokenQuantity = order.result.sell[0].type === ItemType.ERC721 ? BigNumber.from(1) : BigNumber.from(order.result.sell[0].amount);
+    fees = calculateFees(takerFees, buyToken.amount, decimals, tokenQuantity);
   }
 
   let unsignedApprovalTransactions: TransactionRequest[] = [];

diff --git a/packages/checkout/sdk/src/smartCheckout/fees/fees.test.ts b/packages/checkout/sdk/src/smartCheckout/fees/fees.test.ts
@@ -1,4 +1,4 @@
-import { utils } from 'ethers';
+import { BigNumber, utils } from 'ethers';
 import { calculateFees } from './fees';
 import { BuyToken, ItemType } from '../../types';
 import { CheckoutErrorType } from '../../errors';
@@ -94,6 +94,22 @@ describe('orderbook fees', () => {
     }]);
   });
 
+  it('TD-1453 sell token quantity > 1 and non divisible fee amount', async () => {
+    const decimals = 18;
+    const amount = utils.parseUnits('40.32258064516129033', 18).toString();
+    const makerFees = [{
+      amount: { percentageDecimal: 0.01 },
+      recipient: '0x222',
+    }];
+
+    const result = calculateFees(makerFees, amount, decimals, BigNumber.from(10));
+
+    expect(result).toEqual([{
+      amount: '403225806451612900',
+      recipientAddress: '0x222',
+    }]);
+  });
+
   it('should calculate the fees with multiple percentageDecimals', async () => {
     const decimals = 18;
     const amount = utils.parseUnits('10', 18).toString();

diff --git a/packages/checkout/sdk/src/smartCheckout/fees/fees.ts b/packages/checkout/sdk/src/smartCheckout/fees/fees.ts
@@ -9,6 +9,7 @@ export const MAX_FEE_DECIMAL_PLACES = 6; // will allow 0.000001 (0.0001%) as the
 const calculateFeesPercent = (
   orderFee:OrderFee,
   amountBn: BigNumber,
+  tokenQuantity: BigNumber = BigNumber.from(1),
 ): BigNumber => {
   const feePercentage = orderFee.amount as FeePercentage;
 
@@ -19,7 +20,8 @@ const calculateFeesPercent = (
     .mul(BigNumber.from(feePercentageMultiplier))
     .div(10 ** MAX_FEE_DECIMAL_PLACES);
 
-  return bnFeeAmount;
+  // always round down to have a fee amount divisible by the token quantity
+  return bnFeeAmount.sub(bnFeeAmount.mod(tokenQuantity));
 };
 
 const calculateFeesToken = (
@@ -35,6 +37,7 @@ export const calculateFees = (
   orderFees: Array<OrderFee>,
   weiAmount: string,
   decimals: number = 18,
+  tokenQuantity: BigNumber = BigNumber.from(1),
 ):Array<FeeValue> => {
   let totalTokenFees: BigNumber = BigNumber.from(0);
 
@@ -45,12 +48,13 @@ export const calculateFees = (
     .mul(MAX_FEE_PERCENTAGE_DECIMAL * (10 ** MAX_FEE_DECIMAL_PLACES))
     .div(10 ** MAX_FEE_DECIMAL_PLACES);
 
-  const calculateFeesResult:Array<FeeValue> = [];
+  const calculateFeesResult: Array<FeeValue> = [];
 
   for (const orderFee of orderFees) {
     let currentFeeBn = BigNumber.from(0);
     if (Object.hasOwn(orderFee.amount, 'percentageDecimal')) {
-      currentFeeBn = calculateFeesPercent(orderFee, amountBn);
+      currentFeeBn = calculateFeesPercent(orderFee, amountBn, tokenQuantity);
+
       totalTokenFees = totalTokenFees.add(currentFeeBn);
     } else if (Object.hasOwn(orderFee.amount, 'token')) {
       currentFeeBn = calculateFeesToken(orderFee, decimals);

diff --git a/packages/checkout/sdk/src/smartCheckout/sell/sell.ts b/packages/checkout/sdk/src/smartCheckout/sell/sell.ts
@@ -250,7 +250,15 @@ export const sell = async (
     };
 
     if (makerFees !== undefined) {
-      const orderBookFees = calculateFees(makerFees, buyTokenOrNative.amount, decimals);
+      let tokenQuantity = BigNumber.from(1);
+
+      // if type exists in sellToken then it is valid ERC721 or ERC1155 and not deprecated type
+      if ('type' in sellToken) {
+        const erc1155Token = sellToken as unknown as ERC1155Item | ERC721Item;
+        if (erc1155Token.type === ItemType.ERC1155) tokenQuantity = BigNumber.from(erc1155Token.amount);
+      }
+
+      const orderBookFees = calculateFees(makerFees, buyTokenOrNative.amount, decimals, tokenQuantity);
       if (orderBookFees.length !== makerFees.length) {
         throw new CheckoutError(
           'One of the fees is too small, must be greater than 0.000001',