Merge pull request #1988 from 0xProject/feature/asset-swapper/optimized-market-sell-output

Added optimization utils for asset-swapper exchange consumer

packages/asset-swapper/src/constants.ts

@@ -10,6 +10,7 @@ import {
     SwapQuoterOpts,
 } from './types';
 
+const NULL_BYTES = '0x';
 const NULL_ADDRESS = '0x0000000000000000000000000000000000000000';
 const MAINNET_NETWORK_ID = 1;
 const ONE_SECOND_MS = 1000;
@@ -44,6 +45,7 @@ const DEFAULT_LIQUIDITY_REQUEST_OPTS: LiquidityRequestOpts = {
 };
 
 export const constants = {
+    NULL_BYTES,
     ZERO_AMOUNT: new BigNumber(0),
     NULL_ADDRESS,
     MAINNET_NETWORK_ID,

packages/asset-swapper/src/quote_consumers/exchange_swap_quote_consumer.ts

@@ -77,6 +77,8 @@ export class ExchangeSwapQuoteConsumer implements SwapQuoteConsumerBase<Exchange
 
         const signatures = _.map(orders, o => o.signature);
 
+        const optimizedOrders = swapQuoteConsumerUtils.optimizeOrdersForMarketExchangeOperation(orders, quote.type);
+
         let params: ExchangeSmartContractParams;
         let methodName: string;
 
@@ -84,7 +86,7 @@ export class ExchangeSwapQuoteConsumer implements SwapQuoteConsumerBase<Exchange
             const { makerAssetFillAmount } = quote;
 
             params = {
-                orders,
+                orders: optimizedOrders,
                 signatures,
                 makerAssetFillAmount,
                 type: MarketOperation.Buy,
@@ -95,7 +97,7 @@ export class ExchangeSwapQuoteConsumer implements SwapQuoteConsumerBase<Exchange
             const { takerAssetFillAmount } = quote;
 
             params = {
-                orders,
+                orders: optimizedOrders,
                 signatures,
                 takerAssetFillAmount,
                 type: MarketOperation.Sell,

packages/asset-swapper/src/utils/assert.ts

@@ -12,6 +12,12 @@ export const assert = {
         sharedAssert.isHexString(`${variableName}.makerAssetData`, swapQuote.makerAssetData);
         sharedAssert.doesConformToSchema(`${variableName}.orders`, swapQuote.orders, schemas.signedOrdersSchema);
         sharedAssert.doesConformToSchema(`${variableName}.feeOrders`, swapQuote.feeOrders, schemas.signedOrdersSchema);
+        assert.isValidOrdersForSwapQuote(
+            `${variableName}.orders`,
+            swapQuote.orders,
+            swapQuote.makerAssetData,
+            swapQuote.takerAssetData,
+        );
         assert.isValidSwapQuoteInfo(`${variableName}.bestCaseQuoteInfo`, swapQuote.bestCaseQuoteInfo);
         assert.isValidSwapQuoteInfo(`${variableName}.worstCaseQuoteInfo`, swapQuote.worstCaseQuoteInfo);
         if (swapQuote.type === MarketOperation.Buy) {
@@ -20,6 +26,23 @@ export const assert = {
             sharedAssert.isBigNumber(`${variableName}.takerAssetFillAmount`, swapQuote.takerAssetFillAmount);
         }
     },
+    isValidOrdersForSwapQuote(
+        variableName: string,
+        orders: SignedOrder[],
+        makerAssetData: string,
+        takerAssetData: string,
+    ): void {
+        _.every(orders, (order: SignedOrder, index: number) => {
+            assert.assert(
+                order.takerAssetData === takerAssetData,
+                `Expected ${variableName}[${index}].takerAssetData to be ${takerAssetData}`,
+            );
+            assert.assert(
+                order.makerAssetData === makerAssetData,
+                `Expected ${variableName}[${index}].makerAssetData to be ${makerAssetData}`,
+            );
+        });
+    },
     isValidForwarderSwapQuote(variableName: string, swapQuote: SwapQuote, wethAssetData: string): void {
         assert.isValidSwapQuote(variableName, swapQuote);
         assert.isValidForwarderSignedOrders(`${variableName}.orders`, swapQuote.orders, wethAssetData);

packages/asset-swapper/src/utils/swap_quote_consumer_utils.ts

@@ -1,5 +1,5 @@
 import { ContractWrappers } from '@0x/contract-wrappers';
-import { SignedOrder } from '@0x/types';
+import { MarketOperation, SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { SupportedProvider, Web3Wrapper } from '@0x/web3-wrapper';
 import { Provider } from 'ethereum-types';
@@ -72,6 +72,17 @@ export const swapQuoteConsumerUtils = {
     isValidForwarderSignedOrder(order: SignedOrder, wethAssetData: string): boolean {
         return order.takerAssetData === wethAssetData;
     },
+    optimizeOrdersForMarketExchangeOperation(orders: SignedOrder[], operation: MarketOperation): SignedOrder[] {
+        return _.map(orders, (order: SignedOrder, index: number) => {
+            const optimizedOrder = _.clone(order);
+            if (operation === MarketOperation.Sell && index !== 0) {
+                optimizedOrder.takerAssetData = constants.NULL_BYTES;
+            } else if (index !== 0) {
+                optimizedOrder.makerAssetData = constants.NULL_BYTES;
+            }
+            return optimizedOrder;
+        });
+    },
     async getConsumerForSwapQuoteAsync(
         quote: SwapQuote,
         contractWrappers: ContractWrappers,