fix(asset-buyer): fix default values being overriden and incorrect fee rounding

3 files changed, 32 insertions, 13 deletions

diff --git a/packages/asset-buyer/CHANGELOG.json b/packages/asset-buyer/CHANGELOG.json
index 6ba2a0fd9..0d71bb84d 100644
--- a/packages/asset-buyer/CHANGELOG.json
+++ b/packages/asset-buyer/CHANGELOG.json
@@ -14,6 +14,16 @@
             {
                 "note": "No longer require that provided orders all have the same maker and taker asset data",
                 "pr": 1197
+            },
+            {
+                "note":
+                    "Fix bug where `BuyQuoteInfo` objects could return `totalEthAmount` and `feeEthAmount` that were not whole numbers",
+                "pr": 1207
+            },
+            {
+                "note":
+                    "Fix bug where default values for `AssetBuyer` public facing methods could get overriden by `undefined` values",
+                "pr": 1207
             }
         ]
     },
diff --git a/packages/asset-buyer/src/asset_buyer.ts b/packages/asset-buyer/src/asset_buyer.ts
index 49743404f..934410c55 100644
--- a/packages/asset-buyer/src/asset_buyer.ts
+++ b/packages/asset-buyer/src/asset_buyer.ts
@@ -90,10 +90,11 @@ export class AssetBuyer {
      * @return  An instance of AssetBuyer
      */
     constructor(provider: Provider, orderProvider: OrderProvider, options: Partial<AssetBuyerOpts> = {}) {
-        const { networkId, orderRefreshIntervalMs, expiryBufferSeconds } = {
-            ...constants.DEFAULT_ASSET_BUYER_OPTS,
-            ...options,
-        };
+        const { networkId, orderRefreshIntervalMs, expiryBufferSeconds } = _.merge(
+            {},
+            constants.DEFAULT_ASSET_BUYER_OPTS,
+            options,
+        );
         assert.isWeb3Provider('provider', provider);
         assert.isValidOrderProvider('orderProvider', orderProvider);
         assert.isNumber('networkId', networkId);
@@ -122,10 +123,11 @@ export class AssetBuyer {
         assetBuyAmount: BigNumber,
         options: Partial<BuyQuoteRequestOpts> = {},
     ): Promise<BuyQuote> {
-        const { feePercentage, shouldForceOrderRefresh, slippagePercentage } = {
-            ...constants.DEFAULT_BUY_QUOTE_REQUEST_OPTS,
-            ...options,
-        };
+        const { feePercentage, shouldForceOrderRefresh, slippagePercentage } = _.merge(
+            {},
+            constants.DEFAULT_BUY_QUOTE_REQUEST_OPTS,
+            options,
+        );
         assert.isString('assetData', assetData);
         assert.isBigNumber('assetBuyAmount', assetBuyAmount);
         assert.isValidPercentage('feePercentage', feePercentage);
@@ -186,10 +188,11 @@ export class AssetBuyer {
         buyQuote: BuyQuote,
         options: Partial<BuyQuoteExecutionOpts> = {},
     ): Promise<string> {
-        const { ethAmount, takerAddress, feeRecipient, gasLimit, gasPrice } = {
-            ...constants.DEFAULT_BUY_QUOTE_EXECUTION_OPTS,
-            ...options,
-        };
+        const { ethAmount, takerAddress, feeRecipient, gasLimit, gasPrice } = _.merge(
+            {},
+            constants.DEFAULT_BUY_QUOTE_EXECUTION_OPTS,
+            options,
+        );
         assert.isValidBuyQuote('buyQuote', buyQuote);
         if (!_.isUndefined(ethAmount)) {
             assert.isBigNumber('ethAmount', ethAmount);
@@ -198,6 +201,12 @@ export class AssetBuyer {
             assert.isETHAddressHex('takerAddress', takerAddress);
         }
         assert.isETHAddressHex('feeRecipient', feeRecipient);
+        if (!_.isUndefined(gasLimit)) {
+            assert.isNumber('gasLimit', gasLimit);
+        }
+        if (!_.isUndefined(gasPrice)) {
+            assert.isBigNumber('gasPrice', gasPrice);
+        }
         const { orders, feeOrders, feePercentage, assetBuyAmount, worstCaseQuoteInfo } = buyQuote;
         // if no takerAddress is provided, try to get one from the provider
         let finalTakerAddress;
diff --git a/packages/asset-buyer/src/utils/buy_quote_calculator.ts b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
index f94ab3fa4..6a67ed1ed 100644
--- a/packages/asset-buyer/src/utils/buy_quote_calculator.ts
+++ b/packages/asset-buyer/src/utils/buy_quote_calculator.ts
@@ -119,7 +119,7 @@ function calculateQuoteInfo(
         ethAmountToBuyZrx = findEthAmountNeededToBuyZrx(feeOrdersAndFillableAmounts, zrxAmountToBuyAsset);
     }
     /// find the eth amount needed to buy the affiliate fee
-    const ethAmountToBuyAffiliateFee = ethAmountToBuyAsset.mul(feePercentage);
+    const ethAmountToBuyAffiliateFee = ethAmountToBuyAsset.mul(feePercentage).ceil();
     const totalEthAmountWithoutAffiliateFee = ethAmountToBuyAsset.plus(ethAmountToBuyZrx);
     const ethAmountTotal = totalEthAmountWithoutAffiliateFee.plus(ethAmountToBuyAffiliateFee);
     // divide into the assetBuyAmount in order to find rate of makerAsset / WETH