Dutch Auction Contract Wrapper

5 files changed, 158 insertions, 137 deletions

diff --git a/contracts/extensions/CHANGELOG.json b/contracts/extensions/CHANGELOG.json
index 083ad33fb..40e25565e 100644
--- a/contracts/extensions/CHANGELOG.json
+++ b/contracts/extensions/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "1.2.0",
+        "changes": [
+            {
+                "note": "Added Dutch Auction Wrapper",
+                "pr": 1465
+            }
+        ]
+    },
+    {
         "version": "1.1.0",
         "changes": [
             {
diff --git a/contracts/extensions/test/extensions/dutch_auction.ts b/contracts/extensions/test/extensions/dutch_auction.ts
index 6c3b2f0f3..7a1a546e7 100644
--- a/contracts/extensions/test/extensions/dutch_auction.ts
+++ b/contracts/extensions/test/extensions/dutch_auction.ts
@@ -29,13 +29,13 @@ import { RevertReason, SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
-import ethAbi = require('ethereumjs-abi');
-import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
 import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
 import { artifacts } from '../../src/artifacts';
 
+import { DutchAuctionWrapper } from '../utils/dutch_auction_wrapper';
+
 chaiSetup.configure();
 const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
@@ -68,19 +68,9 @@ describe(ContractName.DutchAuction, () => {
     let erc721MakerAssetIds: BigNumber[];
     const tenMinutesInSeconds = 10 * 60;
 
-    function extendMakerAssetData(makerAssetData: string, beginTimeSeconds: BigNumber, beginAmount: BigNumber): string {
-        return ethUtil.bufferToHex(
-            Buffer.concat([
-                ethUtil.toBuffer(makerAssetData),
-                ethUtil.toBuffer(
-                    (ethAbi as any).rawEncode(
-                        ['uint256', 'uint256'],
-                        [beginTimeSeconds.toString(), beginAmount.toString()],
-                    ),
-                ),
-            ]),
-        );
-    }
+    let dutchAuctionInstance: DutchAuctionContract;
+    let dutchAuctionWrapper: DutchAuctionWrapper;
+    let defaultMakerAssetData: string;
 
     before(async () => {
         await blockchainLifecycle.startAsync();
@@ -136,6 +126,7 @@ describe(ContractName.DutchAuction, () => {
             dutchAuctionInstance.address,
             provider,
         );
+        dutchAuctionWrapper = new DutchAuctionWrapper(dutchAuctionInstance, provider);
 
         defaultMakerAssetAddress = erc20TokenA.address;
         const defaultTakerAssetAddress = wethContract.address;
@@ -174,7 +165,7 @@ describe(ContractName.DutchAuction, () => {
             feeRecipientAddress,
             // taker address or sender address should be set to the ducth auction contract
             takerAddress: dutchAuctionContract.address,
-            makerAssetData: extendMakerAssetData(
+            makerAssetData: assetDataUtils.encodeDutchAuctionAssetData(
                 assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
                 auctionBeginTimeSeconds,
                 auctionBeginAmount,
@@ -199,6 +190,7 @@ describe(ContractName.DutchAuction, () => {
         const takerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(takerAddress)];
         sellerOrderFactory = new OrderFactory(makerPrivateKey, sellerDefaultOrderParams);
         buyerOrderFactory = new OrderFactory(takerPrivateKey, buyerDefaultOrderParams);
+        defaultMakerAssetData = assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress);
     });
     after(async () => {
         await blockchainLifecycle.revertAsync();
@@ -215,49 +207,41 @@ describe(ContractName.DutchAuction, () => {
     describe('matchOrders', () => {
         it('should be worth the begin price at the begining of the auction', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp + 2);
-            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
-            });
-            const auctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const makerAssetData = assetDataUtils.encodeDutchAuctionAssetData(
+                defaultMakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({ makerAssetData });
+            const auctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.lte(auctionBeginTimeSeconds);
             expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionBeginAmount);
             expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
         });
         it('should be be worth the end price at the end of the auction', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
             auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = assetDataUtils.encodeDutchAuctionAssetData(
+                defaultMakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
                 expirationTimeSeconds: auctionEndTimeSeconds,
             });
-            const auctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const auctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.gte(auctionEndTimeSeconds);
             expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionEndAmount);
             expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
         });
         it('should match orders at current amount and send excess to buyer', async () => {
-            const beforeAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const beforeAuctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
             buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                 makerAssetAmount: beforeAuctionDetails.currentAmount.times(2),
             });
-            await web3Wrapper.awaitTransactionSuccessAsync(
-                await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
-            );
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            await dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
             const newBalances = await erc20Wrapper.getBalancesAsync();
             expect(newBalances[dutchAuctionContract.address][wethContract.address]).to.be.bignumber.equal(
                 constants.ZERO_AMOUNT,
@@ -276,17 +260,8 @@ describe(ContractName.DutchAuction, () => {
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 makerFee: new BigNumber(1),
             });
-            const txHash = await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                buyOrder,
-                sellOrder,
-                buyOrder.signature,
-                sellOrder.signature,
-                {
-                    from: takerAddress,
-                },
-            );
-            await web3Wrapper.awaitTransactionSuccessAsync(txHash);
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            await dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
             const newBalances = await erc20Wrapper.getBalancesAsync();
             expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
                 erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
@@ -299,18 +274,9 @@ describe(ContractName.DutchAuction, () => {
             buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                 makerFee: new BigNumber(1),
             });
-            const txHash = await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                buyOrder,
-                sellOrder,
-                buyOrder.signature,
-                sellOrder.signature,
-                {
-                    from: takerAddress,
-                },
-            );
-            await web3Wrapper.awaitTransactionSuccessAsync(txHash);
+            await dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
             const newBalances = await erc20Wrapper.getBalancesAsync();
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const afterAuctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
             expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
                 erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
             );
@@ -321,24 +287,17 @@ describe(ContractName.DutchAuction, () => {
         it('should revert when auction expires', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
             auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = assetDataUtils.encodeDutchAuctionAssetData(
+                defaultMakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 expirationTimeSeconds: auctionEndTimeSeconds,
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionExpired,
             );
         });
@@ -347,15 +306,7 @@ describe(ContractName.DutchAuction, () => {
                 makerAssetAmount: sellOrder.takerAssetAmount,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidAmount,
             );
         });
@@ -364,38 +315,23 @@ describe(ContractName.DutchAuction, () => {
                 takerAssetAmount: auctionBeginAmount.plus(1),
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidAmount,
             );
         });
         it('begin time is less than end time', async () => {
             auctionBeginTimeSeconds = new BigNumber(auctionEndTimeSeconds).plus(tenMinutesInSeconds);
+            const makerAssetData = assetDataUtils.encodeDutchAuctionAssetData(
+                defaultMakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 expirationTimeSeconds: auctionEndTimeSeconds,
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidBeginTime,
             );
         });
@@ -404,45 +340,30 @@ describe(ContractName.DutchAuction, () => {
                 makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.InvalidAssetData,
             );
         });
+
         describe('ERC721', () => {
             it('should match orders when ERC721', async () => {
                 const makerAssetId = erc721MakerAssetIds[0];
+                const erc721MakerAssetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, makerAssetId);
+                const makerAssetData = assetDataUtils.encodeDutchAuctionAssetData(
+                    erc721MakerAssetData,
+                    auctionBeginTimeSeconds,
+                    auctionBeginAmount,
+                );
                 sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                     makerAssetAmount: new BigNumber(1),
-                    makerAssetData: extendMakerAssetData(
-                        assetDataUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
-                        auctionBeginTimeSeconds,
-                        auctionBeginAmount,
-                    ),
+                    makerAssetData,
                 });
                 buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                     takerAssetAmount: new BigNumber(1),
                     takerAssetData: sellOrder.makerAssetData,
                 });
-                await web3Wrapper.awaitTransactionSuccessAsync(
-                    await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                        buyOrder,
-                        sellOrder,
-                        buyOrder.signature,
-                        sellOrder.signature,
-                        {
-                            from: takerAddress,
-                        },
-                    ),
-                );
-                const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+                await dutchAuctionWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+                const afterAuctionDetails = await dutchAuctionWrapper.getAuctionDetailsAsync(sellOrder);
                 const newBalances = await erc20Wrapper.getBalancesAsync();
                 // HACK gte used here due to a bug in ganache where the timestamp can change
                 // between multiple calls to the same block. Which can move the amount in our case
diff --git a/contracts/extensions/test/utils/dutch_auction_wrapper.ts b/contracts/extensions/test/utils/dutch_auction_wrapper.ts
new file mode 100644
index 000000000..138b40ca9
--- /dev/null
+++ b/contracts/extensions/test/utils/dutch_auction_wrapper.ts
@@ -0,0 +1,62 @@
+import { artifacts as protocolArtifacts } from '@0x/contracts-protocol';
+import { LogDecoder } from '@0x/contracts-test-utils';
+import { artifacts as tokensArtifacts } from '@0x/contracts-tokens';
+import { DutchAuctionDetails, SignedOrder } from '@0x/types';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
+import { artifacts } from '../../src/artifacts';
+
+export class DutchAuctionWrapper {
+    private readonly _dutchAuctionContract: DutchAuctionContract;
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _logDecoder: LogDecoder;
+
+    constructor(contractInstance: DutchAuctionContract, provider: Provider) {
+        this._dutchAuctionContract = contractInstance;
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, {
+            ...artifacts,
+            ...tokensArtifacts,
+            ...protocolArtifacts,
+        });
+    }
+    /**
+     * Matches the buy and sell orders at an amount given the following: the current block time, the auction
+     * start time and the auction begin amount. The sell order is a an order at the lowest amount
+     * at the end of the auction. Excess from the match is transferred to the seller.
+     * Over time the price moves from beginAmount to endAmount given the current block.timestamp.
+     * @param buyOrder The Buyer's order. This order is for the current expected price of the auction.
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @param from Address the transaction is being sent from.
+     * @return Transaction receipt with decoded logs.
+     */
+    public async matchOrdersAsync(
+        buyOrder: SignedOrder,
+        sellOrder: SignedOrder,
+        from: string,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const txHash = await this._dutchAuctionContract.matchOrders.sendTransactionAsync(
+            buyOrder,
+            sellOrder,
+            buyOrder.signature,
+            sellOrder.signature,
+            {
+                from,
+            },
+        );
+        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return tx;
+    }
+    /**
+     * Calculates the Auction Details for the given order
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @return The dutch auction details.
+     */
+    public async getAuctionDetailsAsync(sellOrder: SignedOrder): Promise<DutchAuctionDetails> {
+        const afterAuctionDetails = await this._dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+        return afterAuctionDetails;
+    }
+}
diff --git a/packages/order-utils/src/asset_data_utils.ts b/packages/order-utils/src/asset_data_utils.ts
index f314891e2..0fc166969 100644
--- a/packages/order-utils/src/asset_data_utils.ts
+++ b/packages/order-utils/src/asset_data_utils.ts
@@ -305,4 +305,24 @@ export const assetDataUtils = {
                 throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
         }
     },
+    /**
+     * Dutch auction details are encoded with the asset data for a 0x order. This function produces a hex
+     * encoded assetData string, containing information both about the asset being traded and the
+     * dutch auction; which is usable in the makerAssetData or takerAssetData fields in a 0x order.
+     * @param assetData Hex encoded assetData string for the asset being auctioned.
+     * @param beginTimeSeconds Begin time of the dutch auction.
+     * @param beginAmount Starting amount being sold in the dutch auction.
+     * @return The hex encoded assetData string.
+     */
+    encodeDutchAuctionAssetData(assetData: string, beginTimeSeconds: BigNumber, beginAmount: BigNumber): string {
+        const assetDataBuffer = ethUtil.toBuffer(assetData);
+        const abiEncodedAuctionData = (ethAbi as any).rawEncode(
+            ['uint256', 'uint256'],
+            [beginTimeSeconds.toString(), beginAmount.toString()],
+        );
+        const abiEncodedAuctionDataBuffer = ethUtil.toBuffer(abiEncodedAuctionData);
+        const dutchAuctionDataBuffer = Buffer.concat([assetDataBuffer, abiEncodedAuctionDataBuffer]);
+        const dutchAuctionData = ethUtil.bufferToHex(dutchAuctionDataBuffer);
+        return dutchAuctionData;
+    },
 };
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index 472b56dc2..49f788fb0 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -676,3 +676,12 @@ export interface SimpleEvmOutput {
 export interface SimpleEvmBytecodeOutput {
     object: string;
 }
+
+export interface DutchAuctionDetails {
+    beginTimeSeconds: BigNumber;
+    endTimeSeconds: BigNumber;
+    beginAmount: BigNumber;
+    endAmount: BigNumber;
+    currentAmount: BigNumber;
+    currentTimeSeconds: BigNumber;
+}