Update BuyQuote interface

2 files changed, 24 insertions, 13 deletions

diff --git a/packages/asset-buyer/src/utils/assert.ts b/packages/asset-buyer/src/utils/assert.ts
index 04f425237..d43b71fee 100644
--- a/packages/asset-buyer/src/utils/assert.ts
+++ b/packages/asset-buyer/src/utils/assert.ts
@@ -3,7 +3,7 @@ import { schemas } from '@0xproject/json-schemas';
 import { SignedOrder } from '@0xproject/types';
 import * as _ from 'lodash';
 
-import { BuyQuote, OrderProvider, OrderProviderRequest } from '../types';
+import { BuyQuote, BuyQuoteInfo, OrderProvider, OrderProviderRequest } from '../types';
 
 export const assert = {
     ...sharedAssert,
@@ -11,13 +11,18 @@ export const assert = {
         sharedAssert.isHexString(`${variableName}.assetData`, buyQuote.assetData);
         sharedAssert.doesConformToSchema(`${variableName}.orders`, buyQuote.orders, schemas.signedOrdersSchema);
         sharedAssert.doesConformToSchema(`${variableName}.feeOrders`, buyQuote.feeOrders, schemas.signedOrdersSchema);
-        sharedAssert.isBigNumber(`${variableName}.minRate`, buyQuote.minRate);
-        sharedAssert.isBigNumber(`${variableName}.maxRate`, buyQuote.maxRate);
+        assert.isValidBuyQuoteInfo(`${variableName}.bestCaseQuoteInfo`, buyQuote.bestCaseQuoteInfo);
+        assert.isValidBuyQuoteInfo(`${variableName}.worstCaseQuoteInfo`, buyQuote.worstCaseQuoteInfo);
         sharedAssert.isBigNumber(`${variableName}.assetBuyAmount`, buyQuote.assetBuyAmount);
         if (!_.isUndefined(buyQuote.feePercentage)) {
             sharedAssert.isNumber(`${variableName}.feePercentage`, buyQuote.feePercentage);
         }
     },
+    isValidBuyQuoteInfo(variableName: string, buyQuoteInfo: BuyQuoteInfo): void {
+        sharedAssert.isBigNumber(`${variableName}.ethPerAssetPrice`, buyQuoteInfo.ethPerAssetPrice);
+        sharedAssert.isBigNumber(`${variableName}.feeEthAmount`, buyQuoteInfo.feeEthAmount);
+        sharedAssert.isBigNumber(`${variableName}.totalEthAmount`, buyQuoteInfo.totalEthAmount);
+    },
     isValidOrderProvider(variableName: string, orderFetcher: OrderProvider): void {
         sharedAssert.isFunction(`${variableName}.getOrdersAsync`, orderFetcher.getOrdersAsync);
     },
diff --git a/packages/asset-buyer/src/utils/buy_quote_calculator.ts b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
index 78666356c..cb0fd128c 100644
--- a/packages/asset-buyer/src/utils/buy_quote_calculator.ts
+++ b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
@@ -3,7 +3,7 @@ import { BigNumber } from '@0xproject/utils';
 import * as _ from 'lodash';
 
 import { constants } from '../constants';
-import { AssetBuyerError, BuyQuote, OrdersAndFillableAmounts } from '../types';
+import { AssetBuyerError, BuyQuote, BuyQuoteInfo, OrdersAndFillableAmounts } from '../types';
 
 // Calculates a buy quote for orders that have WETH as the takerAsset
 export const buyQuoteCalculator = {
@@ -59,37 +59,38 @@ export const buyQuoteCalculator = {
             orders: resultFeeOrders,
             remainingFillableMakerAssetAmounts: feeOrdersRemainingFillableMakerAssetAmounts,
         };
-        const minRate = calculateRate(
+        const bestCaseQuoteInfo = calculateQuoteInfo(
             trimmedOrdersAndFillableAmounts,
             trimmedFeeOrdersAndFillableAmounts,
             assetBuyAmount,
             feePercentage,
         );
         // in order to calculate the maxRate, reverse the ordersAndFillableAmounts such that they are sorted from worst rate to best rate
-        const maxRate = calculateRate(
+        const worstCaseQuoteInfo = calculateQuoteInfo(
             reverseOrdersAndFillableAmounts(trimmedOrdersAndFillableAmounts),
             reverseOrdersAndFillableAmounts(trimmedFeeOrdersAndFillableAmounts),
             assetBuyAmount,
             feePercentage,
         );
+
         return {
             assetData,
             orders: resultOrders,
             feeOrders: resultFeeOrders,
-            minRate,
-            maxRate,
+            bestCaseQuoteInfo,
+            worstCaseQuoteInfo,
             assetBuyAmount,
             feePercentage,
         };
     },
 };
 
-function calculateRate(
+function calculateQuoteInfo(
     ordersAndFillableAmounts: OrdersAndFillableAmounts,
     feeOrdersAndFillableAmounts: OrdersAndFillableAmounts,
     assetBuyAmount: BigNumber,
     feePercentage: number,
-): BigNumber {
+): BuyQuoteInfo {
     // find the total eth and zrx needed to buy assetAmount from the resultOrders from left to right
     const [ethAmountToBuyAsset, zrxAmountToBuyAsset] = findEthAndZrxAmountNeededToBuyAsset(
         ordersAndFillableAmounts,
@@ -97,10 +98,15 @@ function calculateRate(
     );
     // find the total eth needed to buy fees
     const ethAmountToBuyFees = findEthAmountNeededToBuyFees(feeOrdersAndFillableAmounts, zrxAmountToBuyAsset);
-    const ethAmount = ethAmountToBuyAsset.plus(ethAmountToBuyFees).mul(feePercentage + 1);
+    const ethAmountBeforeAffiliateFee = ethAmountToBuyAsset.plus(ethAmountToBuyFees);
+    const totalEthAmount = ethAmountBeforeAffiliateFee.mul(feePercentage + 1);
     // divide into the assetBuyAmount in order to find rate of makerAsset / WETH
-    const result = assetBuyAmount.div(ethAmount);
-    return result;
+    const ethPerAssetPrice = ethAmountBeforeAffiliateFee.div(assetBuyAmount);
+    return {
+        totalEthAmount,
+        feeEthAmount: totalEthAmount.minus(ethAmountBeforeAffiliateFee),
+        ethPerAssetPrice,
+    };
 }
 
 // given an OrdersAndFillableAmounts, reverse the orders and remainingFillableMakerAssetAmounts properties