Update AssetProxyUtils

1 files changed, 41 insertions, 90 deletions

diff --git a/packages/order-utils/src/asset_proxy_utils.ts b/packages/order-utils/src/asset_proxy_utils.ts
index fe91a3525..aad14d687 100644
--- a/packages/order-utils/src/asset_proxy_utils.ts
+++ b/packages/order-utils/src/asset_proxy_utils.ts
@@ -1,8 +1,7 @@
 import { AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0xproject/types';
-import { BigNumber, NULL_BYTES } from '@0xproject/utils';
+import { BigNumber } from '@0xproject/utils';
 import BN = require('bn.js');
 import ethUtil = require('ethereumjs-util');
-import * as _ from 'lodash';
 
 const ERC20_ASSET_DATA_BYTE_LENGTH = 36;
 const ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH = 53;
@@ -11,6 +10,13 @@ const ERC721_ASSET_DATA_TOKEN_ID_OFFSET = 20;
 const ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET = 52;
 const ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET = 84;
 
+// TODO: Push upstream to DefinitelyTyped
+interface EthAbi {
+    simpleEncode(signature: string, ...args: any[]): Buffer;
+    rawDecode(signature: string[], data: Buffer): any[];
+}
+const ethAbi = require('ethereumjs-abi') as EthAbi;
+
 export const assetProxyUtils = {
     encodeAssetProxyId(assetProxyId: AssetProxyId): Buffer {
         return ethUtil.toBuffer(assetProxyId);
@@ -55,123 +61,68 @@ export const assetProxyUtils = {
         return value;
     },
     encodeERC20AssetData(tokenAddress: string): string {
-        const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC20);
-        const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
-        const encodedAssetData = Buffer.concat([encodedAssetProxyId, encodedAddress]);
-        const encodedAssetDataHex = ethUtil.bufferToHex(encodedAssetData);
-        return encodedAssetDataHex;
+        return ethUtil.bufferToHex(ethAbi.simpleEncode(
+            'ERC20Token(address)',
+            tokenAddress,
+        ));
     },
-    decodeERC20AssetData(proxyData: string): ERC20AssetData {
-        const encodedAssetData = ethUtil.toBuffer(proxyData);
-        if (encodedAssetData.byteLength !== ERC20_ASSET_DATA_BYTE_LENGTH) {
+    decodeERC20AssetData(assetData: string): ERC20AssetData {
+        const data = ethUtil.toBuffer(assetData);
+        if (data.byteLength < ERC20_ASSET_DATA_BYTE_LENGTH) {
             throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be ${ERC20_ASSET_DATA_BYTE_LENGTH}. Got ${
-                    encodedAssetData.byteLength
-                }`,
+                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${ERC20_ASSET_DATA_BYTE_LENGTH}. Got ${data.byteLength}`,
             );
         }
-        const encodedAssetProxyId = encodedAssetData.slice(0, 4);
-        const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
+        const assetProxyId = ethUtil.bufferToHex(data.slice(0, 4));
         if (assetProxyId !== AssetProxyId.ERC20) {
             throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
-                    AssetProxyId.ERC20
-                }), but got ${assetProxyId}`,
+                `Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${AssetProxyId.ERC20}), but got ${assetProxyId}`,
             );
         }
-        const encodedTokenAddress = encodedAssetData.slice(16, 20);
-        const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
-        const erc20AssetData = {
+        const [tokenAddress] = ethAbi.rawDecode(['address'], data.slice(4));
+        return {
             assetProxyId,
-            tokenAddress,
+            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
         };
-        return erc20AssetData;
     },
     encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber, receiverData?: string): string {
-        const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC721);
-        const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
-        const encodedTokenId = assetProxyUtils.encodeUint256(tokenId);
-        let encodedAssetData = Buffer.concat([encodedAddress, encodedTokenId]);
-        if (!_.isUndefined(receiverData)) {
-            const encodedReceiverData = ethUtil.toBuffer(receiverData);
-            const receiverDataLength = new BigNumber(encodedReceiverData.byteLength);
-            const encodedReceiverDataLength = assetProxyUtils.encodeUint256(receiverDataLength);
-            encodedAssetData = Buffer.concat([encodedAssetData, encodedReceiverDataLength, encodedReceiverData]);
-        }
-        encodedAssetData = Buffer.concat([encodedAssetProxyId, encodedAssetData]);
-        const encodedAssetDataHex = ethUtil.bufferToHex(encodedAssetData);
-        return encodedAssetDataHex;
+        // TODO: Pass `tokendId` as a BigNumber.
+        return ethUtil.bufferToHex(ethAbi.simpleEncode(
+            'ERC721Token(address,uint256,bytes)',
+            tokenAddress,
+            tokenId.toString(16),
+            ethUtil.toBuffer(receiverData || '0x'),
+        ));
     },
     decodeERC721AssetData(assetData: string): ERC721AssetData {
-
-        const encodedAssetData = ethUtil.toBuffer(assetData);
-        if (encodedAssetData.byteLength < ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
+        const data = ethUtil.toBuffer(assetData);
+        if (data.byteLength < ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
             throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH}. Got ${
-                    encodedAssetData.byteLength
-                }`,
+                `Could not decode ERC721 Asset Data. Expected length of encoded data to be at least ${ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH}. Got ${data.byteLength}`,
             );
         }
-
-        console.log(rawDecode);
-        //const result = ethAbi.rawDecode(['address', 'uint256', 'bytes'], encodedAssetData.slice(4));
-        //console.log(result);
-
-        const encodedTokenAddress = encodedAssetData.slice(
-            ASSET_DATA_ADDRESS_OFFSET,
-            ERC721_ASSET_DATA_TOKEN_ID_OFFSET,
-        );
-        const encodedAssetProxyId = encodedAssetData.slice(0, 4);
-        const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
+        const assetProxyId = ethUtil.bufferToHex(data.slice(0, 4));
         if (assetProxyId !== AssetProxyId.ERC721) {
             throw new Error(
-                `Could not decode ERC721 Proxy Data. Expected Asset Proxy Id to be ERC721 (${
-                    AssetProxyId.ERC721
-                }), but got ${assetProxyId}`,
+                `Could not decode ERC721 Asset Data. Expected Asset Proxy Id to be ERC721 (${AssetProxyId.ERC721}), but got ${assetProxyId}`,
             );
         }
-        const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
-        const encodedTokenId = encodedAssetData.slice(
-            ERC721_ASSET_DATA_TOKEN_ID_OFFSET,
-            ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET,
+        const [tokenAddress, tokenId, receiverData] = ethAbi.rawDecode(
+            ['address', 'uint256', 'bytes'],
+            data.slice(4),
         );
-        const tokenId = assetProxyUtils.decodeUint256(encodedTokenId);
-        let receiverData = NULL_BYTES;
-        const lengthUpToReceiverDataLength = ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET + 1;
-        if (encodedAssetData.byteLength > lengthUpToReceiverDataLength) {
-            const encodedReceiverDataLength = encodedAssetData.slice(
-                ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET,
-                ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET,
-            );
-            const receiverDataLength = assetProxyUtils.decodeUint256(encodedReceiverDataLength);
-            const lengthUpToReceiverData = ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET + 1;
-            const expectedReceiverDataLength = new BigNumber(encodedAssetData.byteLength - lengthUpToReceiverData);
-            if (!receiverDataLength.equals(expectedReceiverDataLength)) {
-                throw new Error(
-                    `Data length (${receiverDataLength}) does not match actual length of data (${expectedReceiverDataLength})`,
-                );
-            }
-            const encodedReceiverData = encodedAssetData.slice(
-                ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET,
-                receiverDataLength.add(ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET).toNumber(),
-            );
-            receiverData = ethUtil.bufferToHex(encodedReceiverData);
-        }
-        const erc721AssetData: ERC721AssetData = {
+        return {
             assetProxyId,
-            tokenAddress,
-            tokenId,
-            receiverData,
+            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
+            tokenId: new BigNumber(tokenId.toString()),
+            receiverData: ethUtil.bufferToHex(receiverData),
         };
-        return erc721AssetData;
     },
     decodeAssetDataId(assetData: string): AssetProxyId {
         const encodedAssetData = ethUtil.toBuffer(assetData);
         if (encodedAssetData.byteLength < 4) {
             throw new Error(
-                `Could not decode Proxy Data. Expected length of encoded data to be at least 4. Got ${
-                    encodedAssetData.byteLength
-                }`,
+                `Could not decode Proxy Data. Expected length of encoded data to be at least 4. Got ${encodedAssetData.byteLength}`,
             );
         }
         const encodedAssetProxyId = encodedAssetData.slice(0, 4);