Use new AbiEncoder, add logic for encoding/decoding MultiAsset assetData

4 files changed, 217 insertions, 72 deletions

diff --git a/packages/order-utils/package.json b/packages/order-utils/package.json
index 400c9b66f..8a5150a48 100644
--- a/packages/order-utils/package.json
+++ b/packages/order-utils/package.json
@@ -13,12 +13,14 @@
         "test": "yarn run_mocha",
         "rebuild_and_test": "run-s build test",
         "test:circleci": "yarn test:coverage",
-        "run_mocha": "mocha --require source-map-support/register --require make-promises-safe lib/test/**/*_test.js --bail --exit",
+        "run_mocha":
+            "mocha --require source-map-support/register --require make-promises-safe lib/test/**/*_test.js --bail --exit",
         "test:coverage": "nyc npm run test --all && yarn coverage:report:lcov",
         "coverage:report:lcov": "nyc report --reporter=text-lcov > coverage/lcov.info",
         "clean": "shx rm -rf lib generated_docs",
         "lint": "tslint --format stylish --project .",
-        "docs:json": "typedoc --excludePrivate --excludeExternals --target ES5 --tsconfig typedoc-tsconfig.json --json $JSON_FILE_PATH $PROJECT_FILES"
+        "docs:json":
+            "typedoc --excludePrivate --excludeExternals --target ES5 --tsconfig typedoc-tsconfig.json --json $JSON_FILE_PATH $PROJECT_FILES"
     },
     "config": {
         "postpublish": {
diff --git a/packages/order-utils/src/asset_data_utils.ts b/packages/order-utils/src/asset_data_utils.ts
index 9bbef3a23..b5cfe698e 100644
--- a/packages/order-utils/src/asset_data_utils.ts
+++ b/packages/order-utils/src/asset_data_utils.ts
@@ -1,10 +1,13 @@
-import { AssetData, AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0x/types';
-import { BigNumber } from '@0x/utils';
-import ethAbi = require('ethereumjs-abi');
-import ethUtil = require('ethereumjs-util');
+import { AssetData, AssetProxyId, ERC20AssetData, ERC721AssetData, MultiAssetData } from '@0x/types';
+import { AbiEncoder, BigNumber } from '@0x/utils';
+import { MethodAbi } from 'ethereum-types';
+import * as _ from 'lodash';
 
 import { constants } from './constants';
 
+const encodingRules: AbiEncoder.EncodingRules = { optimize: true };
+const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+
 export const assetDataUtils = {
     /**
      * Encodes an ERC20 token address into a hex encoded assetData string, usable in the makerAssetData or
@@ -13,7 +16,10 @@ export const assetDataUtils = {
      * @return The hex encoded assetData string
      */
     encodeERC20AssetData(tokenAddress: string): string {
-        return ethUtil.bufferToHex(ethAbi.simpleEncode('ERC20Token(address)', tokenAddress));
+        const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI as MethodAbi);
+        const args = [tokenAddress];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
     },
     /**
      * Decodes an ERC20 assetData hex string into it's corresponding ERC20 tokenAddress & assetProxyId
@@ -21,26 +27,13 @@ export const assetDataUtils = {
      * @return An object containing the decoded tokenAddress & assetProxyId
      */
     decodeERC20AssetData(assetData: string): ERC20AssetData {
-        const data = ethUtil.toBuffer(assetData);
-        if (data.byteLength < constants.ERC20_ASSET_DATA_BYTE_LENGTH) {
-            throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
-                    constants.ERC20_ASSET_DATA_BYTE_LENGTH
-                }. Got ${data.byteLength}`,
-            );
-        }
-        const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
-        if (assetProxyId !== AssetProxyId.ERC20) {
-            throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
-                    AssetProxyId.ERC20
-                }), but got ${assetProxyId}`,
-            );
-        }
-        const [tokenAddress] = ethAbi.rawDecode(['address'], data.slice(constants.SELECTOR_LENGTH));
+        assetDataUtils.validateERC20AssetDataThrow(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI as MethodAbi);
+        const [tokenAddress] = abiEncoder.decode(assetData, decodingRules);
         return {
             assetProxyId,
-            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
+            tokenAddress,
         };
     },
     /**
@@ -51,14 +44,10 @@ export const assetDataUtils = {
      * @return The hex encoded assetData string
      */
     encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber): string {
-        // TODO: Pass `tokendId` as a BigNumber.
-        return ethUtil.bufferToHex(
-            ethAbi.simpleEncode(
-                'ERC721Token(address,uint256)',
-                tokenAddress,
-                `0x${tokenId.toString(constants.BASE_16)}`,
-            ),
-        );
+        const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI as MethodAbi);
+        const args = [tokenAddress, tokenId];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
     },
     /**
      * Decodes an ERC721 assetData hex string into it's corresponding ERC721 tokenAddress, tokenId & assetProxyId
@@ -66,27 +55,51 @@ export const assetDataUtils = {
      * @return An object containing the decoded tokenAddress, tokenId & assetProxyId
      */
     decodeERC721AssetData(assetData: string): ERC721AssetData {
-        const data = ethUtil.toBuffer(assetData);
-        if (data.byteLength < constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
-            throw new Error(
-                `Could not decode ERC721 Asset Data. Expected length of encoded data to be at least ${
-                    constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH
-                }. Got ${data.byteLength}`,
-            );
-        }
-        const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
-        if (assetProxyId !== AssetProxyId.ERC721) {
+        assetDataUtils.validateERC721AssetDataOrThrow(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI as MethodAbi);
+        const [tokenAddress, tokenId] = abiEncoder.decode(assetData, decodingRules);
+        return {
+            assetProxyId,
+            tokenAddress,
+            tokenId,
+        };
+    },
+    /**
+     * Encodes assetData for multiple AssetProxies into a single hex encoded assetData string, usable in the makerAssetData or
+     * takerAssetData fields in a 0x order.
+     * @param amounts Amounts of each asset that correspond to a ginle unit within an order.
+     * @param nestedAssetData assetData strings that correspond to a valid assetProxyId.
+     * @return The hex encoded assetData string
+     */
+    encodeMultiAssetData(amounts: BigNumber[], nestedAssetData: string[]): string {
+        _.forEach(nestedAssetData, assetDataElement => assetDataUtils.validateAssetDataOrThrow(assetDataElement));
+        const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI as MethodAbi);
+        const args = [amounts, nestedAssetData];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
+    },
+    /**
+     * Decodes a MultiAsset assetData hex string into it's corresponding amounts and nestedAssetData
+     * @param assetData Hex encoded assetData string to decode
+     * @return An object containing the decoded amounts and nestedAssetData
+     */
+    decodeMultiAssetData(assetData: string): MultiAssetData {
+        assetDataUtils.validateMultiAssetDataOrThrow(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI as MethodAbi);
+        const [amounts, nestedAssetData] = abiEncoder.decode(assetData, decodingRules);
+        if (amounts.length !== nestedAssetData.length) {
             throw new Error(
-                `Could not decode ERC721 Asset Data. Expected Asset Proxy Id to be ERC721 (${
-                    AssetProxyId.ERC721
-                }), but got ${assetProxyId}`,
+                `Invalid MultiAsset assetData. Expected length of 'amounts' (${
+                    amounts.length
+                }) to equal length of 'nestedAssetData' (${nestedAssetData.length})`,
             );
         }
-        const [tokenAddress, tokenId] = ethAbi.rawDecode(['address', 'uint256'], data.slice(constants.SELECTOR_LENGTH));
         return {
             assetProxyId,
-            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
-            tokenId: new BigNumber(tokenId.toString()),
+            amounts,
+            nestedAssetData,
         };
     },
     /**
@@ -95,19 +108,107 @@ export const assetDataUtils = {
      * @return The assetProxyId
      */
     decodeAssetProxyId(assetData: string): AssetProxyId {
-        const encodedAssetData = ethUtil.toBuffer(assetData);
-        if (encodedAssetData.byteLength < constants.SELECTOR_LENGTH) {
+        if (assetData.length < constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX) {
             throw new Error(
-                `Could not decode assetData. Expected length of encoded data to be at least 4. Got ${
-                    encodedAssetData.byteLength
+                `Could not decode assetData. Expected length of encoded data to be at least 10. Got ${
+                    assetData.length
                 }`,
             );
         }
-        const encodedAssetProxyId = encodedAssetData.slice(0, constants.SELECTOR_LENGTH);
-        const assetProxyId = decodeAssetProxyId(encodedAssetProxyId);
+        const assetProxyId = assetData.slice(0, constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX);
+        if (
+            assetProxyId !== AssetProxyId.ERC20 &&
+            assetProxyId !== AssetProxyId.ERC721 &&
+            assetProxyId !== AssetProxyId.MultiAsset
+        ) {
+            throw new Error(`Invalid assetProxyId: ${assetProxyId}`);
+        }
         return assetProxyId;
     },
     /**
+     * Throws if the length or assetProxyId are invalid for the ERC20Proxy.
+     * @param assetData Hex encoded assetData string
+     */
+    validateERC20AssetDataThrow(assetData: string): void {
+        if (assetData.length < constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
+                    constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.ERC20) {
+            throw new Error(
+                `Could not decode ERC20 assetData. Expected assetProxyId to be ERC20 (${
+                    AssetProxyId.ERC20
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the ERC721Proxy.
+     * @param assetData Hex encoded assetData string
+     */
+    validateERC721AssetDataOrThrow(assetData: string): void {
+        if (assetData.length < constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode ERC721 assetData. Expected length of encoded data to be at least ${
+                    constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.ERC721) {
+            throw new Error(
+                `Could not decode ERC721 assetData. Expected assetProxyId to be ERC721 (${
+                    AssetProxyId.ERC721
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the MultiAssetProxy.
+     * @param assetData Hex encoded assetData string
+     */
+    validateMultiAssetDataOrThrow(assetData: string): void {
+        if (assetData.length < constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode MultiAsset assetData. Expected length of encoded data to be at least ${
+                    constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.MultiAsset) {
+            throw new Error(
+                `Could not decode MultiAsset assetData. Expected assetProxyId to be MultiAsset (${
+                    AssetProxyId.MultiAsset
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the corresponding AssetProxy.
+     * @param assetData Hex encoded assetData string
+     */
+    validateAssetDataOrThrow(assetData: string): void {
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+                assetDataUtils.validateERC20AssetDataThrow(assetData);
+                break;
+            case AssetProxyId.ERC721:
+                assetDataUtils.validateERC721AssetDataOrThrow(assetData);
+                break;
+            case AssetProxyId.MultiAsset:
+                assetDataUtils.validateMultiAssetDataOrThrow(assetData);
+                break;
+            default:
+                throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
+        }
+    },
+    /**
      * Decode any assetData into it's corresponding assetData object
      * @param assetData Hex encoded assetData string to decode
      * @return Either a ERC20 or ERC721 assetData object
@@ -121,19 +222,11 @@ export const assetDataUtils = {
             case AssetProxyId.ERC721:
                 const erc721AssetData = assetDataUtils.decodeERC721AssetData(assetData);
                 return erc721AssetData;
+            case AssetProxyId.MultiAsset:
+                const multiAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+                return multiAssetData;
             default:
                 throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
         }
     },
 };
-
-function decodeAssetProxyId(encodedAssetProxyId: Buffer): AssetProxyId {
-    const hexString = ethUtil.bufferToHex(encodedAssetProxyId);
-    if (hexString === AssetProxyId.ERC20) {
-        return AssetProxyId.ERC20;
-    }
-    if (hexString === AssetProxyId.ERC721) {
-        return AssetProxyId.ERC721;
-    }
-    throw new Error(`Invalid ProxyId: ${hexString}`);
-}
diff --git a/packages/order-utils/src/constants.ts b/packages/order-utils/src/constants.ts
index 10029dcc3..be7f3a885 100644
--- a/packages/order-utils/src/constants.ts
+++ b/packages/order-utils/src/constants.ts
@@ -7,10 +7,10 @@ export const constants = {
     UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
     TESTRPC_NETWORK_ID: 50,
     ADDRESS_LENGTH: 20,
-    ERC20_ASSET_DATA_BYTE_LENGTH: 36,
-    ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH: 53,
-    SELECTOR_LENGTH: 4,
-    BASE_16: 16,
+    ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 74,
+    ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 136,
+    MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 266,
+    SELECTOR_CHAR_LENGTH_WITH_PREFIX: 10,
     INFINITE_TIMESTAMP_SEC: new BigNumber(2524604400), // Close to infinite
     ZERO_AMOUNT: new BigNumber(0),
     EIP712_DOMAIN_NAME: '0x Protocol',
@@ -48,4 +48,54 @@ export const constants = {
             { name: 'data', type: 'bytes' },
         ],
     },
+    ERC20_METHOD_ABI: {
+        constant: false,
+        inputs: [
+            {
+                name: 'tokenContract',
+                type: 'address',
+            },
+        ],
+        name: 'ERC20Token',
+        outputs: [],
+        payable: false,
+        stateMutability: 'nonpayable',
+        type: 'function',
+    },
+    ERC721_METHOD_ABI: {
+        constant: false,
+        inputs: [
+            {
+                name: 'tokenContract',
+                type: 'address',
+            },
+            {
+                name: 'tokenId',
+                type: 'uint256',
+            },
+        ],
+        name: 'ERC721Token',
+        outputs: [],
+        payable: false,
+        stateMutability: 'nonpayable',
+        type: 'function',
+    },
+    MULTI_ASSET_METHOD_ABI: {
+        constant: false,
+        inputs: [
+            {
+                name: 'amounts',
+                type: 'uint256[]',
+            },
+            {
+                name: 'nestedAssetData',
+                type: 'bytes[]',
+            },
+        ],
+        name: 'MultiAsset',
+        outputs: [],
+        payable: false,
+        stateMutability: 'nonpayable',
+        type: 'function',
+    },
 };
diff --git a/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts b/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
index f42a76d0c..0bbaa844a 100644
--- a/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
+++ b/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
@@ -119,10 +119,10 @@ export class BalanceAndProxyAllowanceLazyStore implements AbstractBalanceAndProx
     public deleteAllERC721ProxyAllowance(tokenAddress: string, userAddress: string): void {
         for (const assetData in this._proxyAllowance) {
             if (this._proxyAllowance.hasOwnProperty(assetData)) {
-                const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+                const decodedAssetData = assetDataUtils.decodeERC721AssetData(assetData);
                 if (
                     decodedAssetData.assetProxyId === AssetProxyId.ERC721 &&
-                    decodedAssetData.tokenAddress === tokenAddress &&
+                    !_.isUndefined(decodedAssetData.tokenAddress) &&
                     !_.isUndefined(this._proxyAllowance[assetData][userAddress])
                 ) {
                     delete this._proxyAllowance[assetData][userAddress];