Merge pull request #181 from 0xProject/feature/order-validation-zrx

Fees validations when one of the tokens is ZRX

1 files changed, 13 insertions, 2 deletions

diff --git a/src/utils/order_validation_utils.ts b/src/utils/order_validation_utils.ts
index 6f7522c41..0450d26a6 100644
--- a/src/utils/order_validation_utils.ts
+++ b/src/utils/order_validation_utils.ts
@@ -121,7 +121,11 @@ export class OrderValidationUtils {
         }
 
         if (!isMakerTokenZRX) {
-            const makerZRXBalance = await this.tokenWrapper.getBalanceAsync(zrxTokenAddress, signedOrder.maker);
+            let makerZRXBalance = await this.tokenWrapper.getBalanceAsync(zrxTokenAddress, signedOrder.maker);
+            const isTakerTokenZRX = signedOrder.takerTokenAddress === zrxTokenAddress;
+            if (isTakerTokenZRX) {
+                makerZRXBalance = makerZRXBalance.plus(fillTakerAmount);
+            }
             const makerZRXAllowance = await this.tokenWrapper.getProxyAllowanceAsync(
                 zrxTokenAddress, signedOrder.maker);
 
@@ -141,6 +145,9 @@ export class OrderValidationUtils {
             signedOrder.takerTokenAddress, senderAddress);
 
         const isTakerTokenZRX = signedOrder.takerTokenAddress === zrxTokenAddress;
+        // exchangeRate is the price of one maker token denominated in taker tokens
+        const exchangeRate = signedOrder.takerTokenAmount.div(signedOrder.makerTokenAmount);
+        const fillMakerAmount = fillTakerAmount.div(exchangeRate);
 
         const requiredTakerAmount = isTakerTokenZRX ? fillTakerAmount.plus(signedOrder.takerFee) : fillTakerAmount;
         if (requiredTakerAmount.greaterThan(takerBalance)) {
@@ -151,7 +158,11 @@ export class OrderValidationUtils {
         }
 
         if (!isTakerTokenZRX) {
-            const takerZRXBalance = await this.tokenWrapper.getBalanceAsync(zrxTokenAddress, senderAddress);
+            const isMakerTokenZRX = signedOrder.makerTokenAddress === zrxTokenAddress;
+            let takerZRXBalance = await this.tokenWrapper.getBalanceAsync(zrxTokenAddress, senderAddress);
+            if (isMakerTokenZRX) {
+                takerZRXBalance = takerZRXBalance.plus(fillMakerAmount);
+            }
             const takerZRXAllowance = await this.tokenWrapper.getProxyAllowanceAsync(zrxTokenAddress, senderAddress);
 
             if (signedOrder.takerFee.greaterThan(takerZRXBalance)) {