Merge branch 'master' into implementFirstExchangeMethod

# Conflicts:
#	package.json
#	src/ts/0x.js.ts
#	src/ts/globals.d.ts
#	src/ts/types.ts

6 files changed, 110 insertions, 1 deletions

diff --git a/package.json b/package.json
index a55f7bfa2..3f27a8d2e 100644
--- a/package.json
+++ b/package.json
@@ -59,6 +59,7 @@
   "dependencies": {
     "bignumber.js": "^4.0.2",
     "es6-promisify": "^5.0.0",
+    "ethereumjs-abi": "^0.6.4",
     "ethereumjs-util": "^5.1.1",
     "jsonschema": "^1.1.1",
     "lodash": "^4.17.4",
diff --git a/src/ts/0x.js.ts b/src/ts/0x.js.ts
index cc3c43e79..7c6557b5b 100644
--- a/src/ts/0x.js.ts
+++ b/src/ts/0x.js.ts
@@ -1,12 +1,16 @@
 import * as BigNumber from 'bignumber.js';
+import * as BN from 'bn.js';
 import * as ethUtil from 'ethereumjs-util';
 import * as Web3 from 'web3';
+import * as ethABI from 'ethereumjs-abi';
+import * as _ from 'lodash';
+import {constants} from './utils/constants';
 import {assert} from './utils/assert';
 import {Web3Wrapper} from './web3_wrapper';
 import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper';
 import contract = require('truffle-contract');
 import {ECSignatureSchema} from './schemas/ec_signature_schema';
-import {ECSignature} from './types';
+import {SolidityTypes, ECSignature} from './types';
 
 const MAX_DIGITS_IN_UNSIGNED_256_INT = 78;
 
@@ -14,6 +18,48 @@ export class ZeroEx {
     public web3Wrapper: Web3Wrapper;
     public exchange: ExchangeWrapper;
     /**
+     * Computes the orderHash given the order parameters and returns it as a hex encoded string.
+     */
+    public static getOrderHashHex(exchangeContractAddr: string, makerAddr: string, takerAddr: string,
+                                  tokenMAddress: string, tokenTAddress: string, feeRecipient: string,
+                                  valueM: BigNumber.BigNumber, valueT: BigNumber.BigNumber,
+                                  makerFee: BigNumber.BigNumber, takerFee: BigNumber.BigNumber,
+                                  expiration: BigNumber.BigNumber, salt: BigNumber.BigNumber): string {
+        takerAddr = _.isEmpty(takerAddr) ? constants.NULL_ADDRESS : takerAddr ;
+        assert.isETHAddressHex('exchangeContractAddr', exchangeContractAddr);
+        assert.isETHAddressHex('makerAddr', makerAddr);
+        assert.isETHAddressHex('takerAddr', takerAddr);
+        assert.isETHAddressHex('tokenMAddress', tokenMAddress);
+        assert.isETHAddressHex('tokenTAddress', tokenTAddress);
+        assert.isETHAddressHex('feeRecipient', feeRecipient);
+        assert.isBigNumber('valueM', valueM);
+        assert.isBigNumber('valueT', valueT);
+        assert.isBigNumber('makerFee', makerFee);
+        assert.isBigNumber('takerFee', takerFee);
+        assert.isBigNumber('expiration', expiration);
+        assert.isBigNumber('salt', salt);
+
+        const orderParts = [
+            {value: exchangeContractAddr, type: SolidityTypes.address},
+            {value: makerAddr, type: SolidityTypes.address},
+            {value: takerAddr, type: SolidityTypes.address},
+            {value: tokenMAddress, type: SolidityTypes.address},
+            {value: tokenTAddress, type: SolidityTypes.address},
+            {value: feeRecipient, type: SolidityTypes.address},
+            {value: this.bigNumberToBN(valueM), type: SolidityTypes.uint256},
+            {value: this.bigNumberToBN(valueT), type: SolidityTypes.uint256},
+            {value: this.bigNumberToBN(makerFee), type: SolidityTypes.uint256},
+            {value: this.bigNumberToBN(takerFee), type: SolidityTypes.uint256},
+            {value: this.bigNumberToBN(expiration), type: SolidityTypes.uint256},
+            {value: this.bigNumberToBN(salt), type: SolidityTypes.uint256},
+        ];
+        const types = _.map(orderParts, o => o.type);
+        const values = _.map(orderParts, o => o.value);
+        const hashBuff = ethABI.soliditySHA3(types, values);
+        const hashHex = ethUtil.bufferToHex(hashBuff);
+        return hashHex;
+    }
+    /**
      * Verifies that the elliptic curve signature `signature` was generated
      * by signing `data` with the private key corresponding to the `signerAddressHex` address.
      */
@@ -80,6 +126,15 @@ export class ZeroEx {
         const baseUnitAmount = amount.times(unit);
         return baseUnitAmount;
     }
+    /**
+     * Converts BigNumber instance to BN
+     * The only we convert to BN is to remain compatible with `ethABI. soliditySHA3 ` that
+     * expects values of Solidity type `uint` to be of type `BN`.
+     * We do not use BN anywhere else in the codebase.
+     */
+    private static bigNumberToBN(value: BigNumber.BigNumber) {
+        return new BN(value.toString(), 10);
+    }
     constructor(web3: Web3) {
         this.web3Wrapper = new Web3Wrapper(web3);
         this.exchange = new ExchangeWrapper(this.web3Wrapper);
diff --git a/src/ts/globals.d.ts b/src/ts/globals.d.ts
index 04328509a..30225d0d8 100644
--- a/src/ts/globals.d.ts
+++ b/src/ts/globals.d.ts
@@ -1,4 +1,5 @@
 declare module 'chai-bignumber';
+declare module 'bn.js';
 
 declare interface Schema {
     id: string;
@@ -51,3 +52,7 @@ declare function promisify(original: any, settings?: any): ((...arg: any[]) => P
 declare module 'es6-promisify' {
     export = promisify;
 }
+
+declare module 'ethereumjs-abi' {
+    const soliditySHA3: (argTypes: string[], args: any[]) => Buffer;
+}
diff --git a/src/ts/types.ts b/src/ts/types.ts
index 01380af02..04123782e 100644
--- a/src/ts/types.ts
+++ b/src/ts/types.ts
@@ -1,4 +1,5 @@
 import * as _ from 'lodash';
+import * as BigNumber from 'bignumber.js';
 
 // Utility function to create a K:V from a list of strings
 // Adapted from: https://basarat.gitbooks.io/typescript/content/docs/types/literal-types.html
@@ -28,3 +29,9 @@ export interface ECSignature {
 export interface ExchangeContract {
     isValidSignature: any;
 }
+
+export const SolidityTypes = strEnum([
+    'address',
+    'uint256',
+]);
+export type SolidityTypes = keyof typeof SolidityTypes;
diff --git a/src/ts/utils/constants.ts b/src/ts/utils/constants.ts
new file mode 100644
index 000000000..60af7b674
--- /dev/null
+++ b/src/ts/utils/constants.ts
@@ -0,0 +1,3 @@
+export const constants = {
+    NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
+}
diff --git a/test/0x.js.ts b/test/0x.js.ts
index a913fd6b5..d5b2015fb 100644
--- a/test/0x.js.ts
+++ b/test/0x.js.ts
@@ -3,12 +3,50 @@ import * as chai from 'chai';
 import 'mocha';
 import * as BigNumber from 'bignumber.js';
 import ChaiBigNumber = require('chai-bignumber');
+import {constants} from '../src/ts/utils/constants';
 
 // Use BigNumber chai add-on
 chai.use(ChaiBigNumber());
 const expect = chai.expect;
 
 describe('ZeroEx library', () => {
+    describe('#getOrderHash', () => {
+        const ORDER_HASH = '0x103a5e97dab5dbeb8f385636f86a7d1e458a7ccbe1bd194727f0b2f85ab116c7';
+        it('defaults takerAddress to NULL address', () => {
+            const orderHash = ZeroEx.getOrderHashHex(
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                '',
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+            );
+            expect(orderHash).to.be.equal(ORDER_HASH);
+        });
+        it('calculates the order hash', () => {
+            const orderHash = ZeroEx.getOrderHashHex(
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                constants.NULL_ADDRESS,
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+                new BigNumber(0),
+            );
+            expect(orderHash).to.be.equal(ORDER_HASH);
+        });
+    });
     describe('#isValidSignature', () => {
         // This test data was borrowed from the JSON RPC documentation
         // Source: https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign