Switch over to Lerna + Yarn Workspaces setup for a mono-repo approach

23 files changed, 3258 insertions, 0 deletions

diff --git a/packages/0x.js/test/0x.js_test.ts b/packages/0x.js/test/0x.js_test.ts
new file mode 100644
index 000000000..d56acc38b
--- /dev/null
+++ b/packages/0x.js/test/0x.js_test.ts
@@ -0,0 +1,259 @@
+import * as _ from 'lodash';
+import * as chai from 'chai';
+import {chaiSetup} from './utils/chai_setup';
+import 'mocha';
+import BigNumber from 'bignumber.js';
+import * as Sinon from 'sinon';
+import {ZeroEx, Order, ZeroExError, LogWithDecodedArgs, ApprovalContractEventArgs, TokenEvents} from '../src';
+import {constants} from './utils/constants';
+import {TokenUtils} from './utils/token_utils';
+import {web3Factory} from './utils/web3_factory';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+
+const blockchainLifecycle = new BlockchainLifecycle();
+chaiSetup.configure();
+const expect = chai.expect;
+
+describe('ZeroEx library', () => {
+    const web3 = web3Factory.create();
+    const zeroEx = new ZeroEx(web3.currentProvider);
+    describe('#setProvider', () => {
+        it('overrides provider in nested web3s and invalidates contractInstances', async () => {
+            // Instantiate the contract instances with the current provider
+            await (zeroEx.exchange as any)._getExchangeContractAsync();
+            await (zeroEx.tokenRegistry as any)._getTokenRegistryContractAsync();
+            expect((zeroEx.exchange as any)._exchangeContractIfExists).to.not.be.undefined();
+            expect((zeroEx.tokenRegistry as any)._tokenRegistryContractIfExists).to.not.be.undefined();
+
+            const newProvider = web3Factory.getRpcProvider();
+            // Add property to newProvider so that we can differentiate it from old provider
+            (newProvider as any).zeroExTestId = 1;
+            await zeroEx.setProviderAsync(newProvider);
+
+            // Check that contractInstances with old provider are removed after provider update
+            expect((zeroEx.exchange as any)._exchangeContractIfExists).to.be.undefined();
+            expect((zeroEx.tokenRegistry as any)._tokenRegistryContractIfExists).to.be.undefined();
+
+            // Check that all nested web3 wrapper instances return the updated provider
+            const nestedWeb3WrapperProvider = (zeroEx as any)._web3Wrapper.getCurrentProvider();
+            expect((nestedWeb3WrapperProvider as any).zeroExTestId).to.be.a('number');
+            const exchangeWeb3WrapperProvider = (zeroEx.exchange as any)._web3Wrapper.getCurrentProvider();
+            expect((exchangeWeb3WrapperProvider as any).zeroExTestId).to.be.a('number');
+            const tokenRegistryWeb3WrapperProvider = (zeroEx.tokenRegistry as any)._web3Wrapper.getCurrentProvider();
+            expect((tokenRegistryWeb3WrapperProvider as any).zeroExTestId).to.be.a('number');
+        });
+    });
+    describe('#isValidSignature', () => {
+        // The Exchange smart contract `isValidSignature` method only validates orderHashes and assumes
+        // the length of the data is exactly 32 bytes. Thus for these tests, we use data of this size.
+        const dataHex = '0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222b0';
+        const signature = {
+            v: 27,
+            r: '0x61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc33',
+            s: '0x40349190569279751135161d22529dc25add4f6069af05be04cacbda2ace2254',
+        };
+        const address = '0x5409ed021d9299bf6814279a6a1411a7e866a631';
+        it('should return false if the data doesn\'t pertain to the signature & address', async () => {
+            expect(ZeroEx.isValidSignature('0x0', signature, address)).to.be.false();
+            return expect(
+                (zeroEx.exchange as any)._isValidSignatureUsingContractCallAsync('0x0', signature, address),
+            ).to.become(false);
+        });
+        it('should return false if the address doesn\'t pertain to the signature & data', async () => {
+            const validUnrelatedAddress = '0x8b0292b11a196601ed2ce54b665cafeca0347d42';
+            expect(ZeroEx.isValidSignature(dataHex, signature, validUnrelatedAddress)).to.be.false();
+            return expect(
+                (zeroEx.exchange as any)._isValidSignatureUsingContractCallAsync(dataHex, signature,
+                                                                                validUnrelatedAddress),
+            ).to.become(false);
+        });
+        it('should return false if the signature doesn\'t pertain to the dataHex & address', async () => {
+            const wrongSignature = _.assign({}, signature, {v: 28});
+            expect(ZeroEx.isValidSignature(dataHex, wrongSignature, address)).to.be.false();
+            return expect(
+                (zeroEx.exchange as any)._isValidSignatureUsingContractCallAsync(dataHex, wrongSignature, address),
+            ).to.become(false);
+        });
+        it('should return true if the signature does pertain to the dataHex & address', async () => {
+            const isValidSignatureLocal = ZeroEx.isValidSignature(dataHex, signature, address);
+            expect(isValidSignatureLocal).to.be.true();
+            const isValidSignatureOnContract = await (zeroEx.exchange as any)
+                ._isValidSignatureUsingContractCallAsync(dataHex, signature, address);
+            return expect(isValidSignatureOnContract).to.be.true();
+        });
+    });
+    describe('#generateSalt', () => {
+        it('generates different salts', () => {
+            const equal = ZeroEx.generatePseudoRandomSalt().eq(ZeroEx.generatePseudoRandomSalt());
+            expect(equal).to.be.false();
+        });
+        it('generates salt in range [0..2^256)', () => {
+            const salt = ZeroEx.generatePseudoRandomSalt();
+            expect(salt.greaterThanOrEqualTo(0)).to.be.true();
+            const twoPow256 = new BigNumber(2).pow(256);
+            expect(salt.lessThan(twoPow256)).to.be.true();
+        });
+    });
+    describe('#isValidOrderHash', () => {
+        it('returns false if the value is not a hex string', () => {
+            const isValid = ZeroEx.isValidOrderHash('not a hex');
+            expect(isValid).to.be.false();
+        });
+        it('returns false if the length is wrong', () => {
+            const isValid = ZeroEx.isValidOrderHash('0xdeadbeef');
+            expect(isValid).to.be.false();
+        });
+        it('returns true if order hash is correct', () => {
+            const isValid = ZeroEx.isValidOrderHash('0x' + Array(65).join('0'));
+            expect(isValid).to.be.true();
+        });
+    });
+    describe('#toUnitAmount', () => {
+        it('Should return the expected unit amount for the decimals passed in', () => {
+            const baseUnitAmount = new BigNumber(1000000000);
+            const decimals = 6;
+            const unitAmount = ZeroEx.toUnitAmount(baseUnitAmount, decimals);
+            const expectedUnitAmount = new BigNumber(1000);
+            expect(unitAmount).to.be.bignumber.equal(expectedUnitAmount);
+        });
+    });
+    describe('#toBaseUnitAmount', () => {
+        it('Should return the expected base unit amount for the decimals passed in', () => {
+            const unitAmount = new BigNumber(1000);
+            const decimals = 6;
+            const baseUnitAmount = ZeroEx.toBaseUnitAmount(unitAmount, decimals);
+            const expectedUnitAmount = new BigNumber(1000000000);
+            expect(baseUnitAmount).to.be.bignumber.equal(expectedUnitAmount);
+        });
+    });
+    describe('#getOrderHashHex', () => {
+        const expectedOrderHash = '0x39da987067a3c9e5f1617694f1301326ba8c8b0498ebef5df4863bed394e3c83';
+        const fakeExchangeContractAddress = '0xb69e673309512a9d726f87304c6984054f87a93b';
+        const order: Order = {
+            maker: constants.NULL_ADDRESS,
+            taker: constants.NULL_ADDRESS,
+            feeRecipient: constants.NULL_ADDRESS,
+            makerTokenAddress: constants.NULL_ADDRESS,
+            takerTokenAddress: constants.NULL_ADDRESS,
+            exchangeContractAddress: fakeExchangeContractAddress,
+            salt: new BigNumber(0),
+            makerFee: new BigNumber(0),
+            takerFee: new BigNumber(0),
+            makerTokenAmount: new BigNumber(0),
+            takerTokenAmount: new BigNumber(0),
+            expirationUnixTimestampSec: new BigNumber(0),
+        };
+        it('calculates the order hash', async () => {
+            const orderHash = ZeroEx.getOrderHashHex(order);
+            expect(orderHash).to.be.equal(expectedOrderHash);
+        });
+    });
+    describe('#signOrderHashAsync', () => {
+        let stubs: Sinon.SinonStub[] = [];
+        let makerAddress: string;
+        before(async () => {
+            const availableAddreses = await zeroEx.getAvailableAddressesAsync();
+            makerAddress = availableAddreses[0];
+        });
+        afterEach(() => {
+            // clean up any stubs after the test has completed
+            _.each(stubs, s => s.restore());
+            stubs = [];
+        });
+        it('Should return the correct ECSignature', async () => {
+            const orderHash = '0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222b0';
+            const expectedECSignature = {
+                v: 27,
+                r: '0x61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc33',
+                s: '0x40349190569279751135161d22529dc25add4f6069af05be04cacbda2ace2254',
+            };
+            const ecSignature = await zeroEx.signOrderHashAsync(orderHash, makerAddress);
+            expect(ecSignature).to.deep.equal(expectedECSignature);
+        });
+        it('should return the correct ECSignature for signatureHex concatenated as R + S + V', async () => {
+            const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
+            // tslint:disable-next-line: max-line-length
+            const signature = '0x22109d11d79cb8bf96ed88625e1cd9558800c4073332a9a02857499883ee5ce3050aa3cc1f2c435e67e114cdce54b9527b4f50548342401bc5d2b77adbdacb021b';
+            const expectedECSignature = {
+                v: 27,
+                r: '0x22109d11d79cb8bf96ed88625e1cd9558800c4073332a9a02857499883ee5ce3',
+                s: '0x050aa3cc1f2c435e67e114cdce54b9527b4f50548342401bc5d2b77adbdacb02',
+            };
+            stubs = [
+                Sinon.stub((zeroEx as any)._web3Wrapper, 'signTransactionAsync')
+                    .returns(Promise.resolve(signature)),
+                Sinon.stub(ZeroEx, 'isValidSignature').returns(true),
+            ];
+
+            const ecSignature = await zeroEx.signOrderHashAsync(orderHash, makerAddress);
+            expect(ecSignature).to.deep.equal(expectedECSignature);
+        });
+        it('should return the correct ECSignature for signatureHex concatenated as V + R + S', async () => {
+            const orderHash = '0xc793e33ffded933b76f2f48d9aa3339fc090399d5e7f5dec8d3660f5480793f7';
+            // tslint:disable-next-line: max-line-length
+            const signature = '0x1bc80bedc6756722672753413efdd749b5adbd4fd552595f59c13427407ee9aee02dea66f25a608bbae457e020fb6decb763deb8b7192abab624997242da248960';
+            const expectedECSignature = {
+                v: 27,
+                r: '0xc80bedc6756722672753413efdd749b5adbd4fd552595f59c13427407ee9aee0',
+                s: '0x2dea66f25a608bbae457e020fb6decb763deb8b7192abab624997242da248960',
+            };
+            stubs = [
+                Sinon.stub((zeroEx as any)._web3Wrapper, 'signTransactionAsync')
+                    .returns(Promise.resolve(signature)),
+                Sinon.stub(ZeroEx, 'isValidSignature').returns(true),
+            ];
+
+            const ecSignature = await zeroEx.signOrderHashAsync(orderHash, makerAddress);
+            expect(ecSignature).to.deep.equal(expectedECSignature);
+        });
+    });
+    describe('#awaitTransactionMinedAsync', () => {
+        beforeEach(async () => {
+            await blockchainLifecycle.startAsync();
+        });
+        afterEach(async () => {
+            await blockchainLifecycle.revertAsync();
+        });
+        it('returns transaction receipt with decoded logs', async () => {
+            const availableAddresses = await zeroEx.getAvailableAddressesAsync();
+            const coinbase = availableAddresses[0];
+            const tokens = await zeroEx.tokenRegistry.getTokensAsync();
+            const tokenUtils = new TokenUtils(tokens);
+            const zrxTokenAddress = tokenUtils.getProtocolTokenOrThrow().address;
+            const proxyAddress = await zeroEx.proxy.getContractAddressAsync();
+            const txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(zrxTokenAddress, coinbase);
+            const txReceiptWithDecodedLogs = await zeroEx.awaitTransactionMinedAsync(txHash);
+            const log = txReceiptWithDecodedLogs.logs[0] as LogWithDecodedArgs<ApprovalContractEventArgs>;
+            expect(log.event).to.be.equal(TokenEvents.Approval);
+            expect(log.args._owner).to.be.equal(coinbase);
+            expect(log.args._spender).to.be.equal(proxyAddress);
+            expect(log.args._value).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
+        });
+    });
+    describe('#config', () => {
+        it('allows to specify exchange contract address', async () => {
+            const config = {
+                exchangeContractAddress: ZeroEx.NULL_ADDRESS,
+            };
+            const zeroExWithWrongExchangeAddress = new ZeroEx(web3.currentProvider, config);
+            return expect(zeroExWithWrongExchangeAddress.exchange.getContractAddressAsync())
+                .to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+        });
+        it('allows to specify ether token contract address', async () => {
+            const config = {
+                etherTokenContractAddress: ZeroEx.NULL_ADDRESS,
+            };
+            const zeroExWithWrongEtherTokenAddress = new ZeroEx(web3.currentProvider, config);
+            return expect(zeroExWithWrongEtherTokenAddress.etherToken.getContractAddressAsync())
+                .to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+        });
+        it('allows to specify token registry token contract address', async () => {
+            const config = {
+                tokenRegistryContractAddress: ZeroEx.NULL_ADDRESS,
+            };
+            const zeroExWithWrongTokenRegistryAddress = new ZeroEx(web3.currentProvider, config);
+            return expect(zeroExWithWrongTokenRegistryAddress.tokenRegistry.getContractAddressAsync())
+                .to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+        });
+    });
+});
diff --git a/packages/0x.js/test/artifacts_test.ts b/packages/0x.js/test/artifacts_test.ts
new file mode 100644
index 000000000..b2866a1d6
--- /dev/null
+++ b/packages/0x.js/test/artifacts_test.ts
@@ -0,0 +1,49 @@
+import * as fs from 'fs';
+import * as chai from 'chai';
+import {chaiSetup} from './utils/chai_setup';
+import HDWalletProvider = require('truffle-hdwallet-provider');
+import {ZeroEx} from '../src';
+import {constants} from './utils/constants';
+
+chaiSetup.configure();
+const expect = chai.expect;
+
+// Those tests are slower cause they're talking to a remote node
+const TIMEOUT = 10000;
+
+describe('Artifacts', () => {
+    describe('contracts are deployed on kovan', () => {
+        const kovanRpcUrl = constants.KOVAN_RPC_URL;
+        const packageJSONContent = fs.readFileSync('package.json', 'utf-8');
+        const packageJSON = JSON.parse(packageJSONContent);
+        const mnemonic = packageJSON.config.mnemonic;
+        const web3Provider = new HDWalletProvider(mnemonic, kovanRpcUrl);
+        const zeroEx = new ZeroEx(web3Provider);
+        it('token registry contract is deployed', async () => {
+            await (zeroEx.tokenRegistry as any)._getTokenRegistryContractAsync();
+        }).timeout(TIMEOUT);
+        it('proxy contract is deployed', async () => {
+            await (zeroEx.token as any)._getTokenTransferProxyAddressAsync();
+        }).timeout(TIMEOUT);
+        it('exchange contract is deployed', async () => {
+            await zeroEx.exchange.getContractAddressAsync();
+        }).timeout(TIMEOUT);
+    });
+    describe('contracts are deployed on ropsten', () => {
+        const ropstenRpcUrl = constants.ROPSTEN_RPC_URL;
+        const packageJSONContent = fs.readFileSync('package.json', 'utf-8');
+        const packageJSON = JSON.parse(packageJSONContent);
+        const mnemonic = packageJSON.config.mnemonic;
+        const web3Provider = new HDWalletProvider(mnemonic, ropstenRpcUrl);
+        const zeroEx = new ZeroEx(web3Provider);
+        it('token registry contract is deployed', async () => {
+            await (zeroEx.tokenRegistry as any)._getTokenRegistryContractAsync();
+        }).timeout(TIMEOUT);
+        it('proxy contract is deployed', async () => {
+            await (zeroEx.token as any)._getTokenTransferProxyAddressAsync();
+        }).timeout(TIMEOUT);
+        it('exchange contract is deployed', async () => {
+            await zeroEx.exchange.getContractAddressAsync();
+        }).timeout(TIMEOUT);
+    });
+});
diff --git a/packages/0x.js/test/assert_test.ts b/packages/0x.js/test/assert_test.ts
new file mode 100644
index 000000000..bfca95d9c
--- /dev/null
+++ b/packages/0x.js/test/assert_test.ts
@@ -0,0 +1,34 @@
+import * as chai from 'chai';
+import 'mocha';
+import {ZeroEx} from '../src';
+import {assert} from '../src/utils/assert';
+import {web3Factory} from './utils/web3_factory';
+
+const expect = chai.expect;
+
+describe('Assertion library', () => {
+    const web3 = web3Factory.create();
+    const zeroEx = new ZeroEx(web3.currentProvider);
+    describe('#isSenderAddressHexAsync', () => {
+        it('throws when address is invalid', async () => {
+            const address = '0xdeadbeef';
+            const varName = 'address';
+            return expect(assert.isSenderAddressAsync(varName, address, (zeroEx as any)._web3Wrapper))
+                .to.be.rejectedWith(`Expected ${varName} to be of type ETHAddressHex, encountered: ${address}`);
+        });
+        it('throws when address is unavailable', async () => {
+            const validUnrelatedAddress = '0x8b0292b11a196601eddce54b665cafeca0347d42';
+            const varName = 'address';
+            return expect(assert.isSenderAddressAsync(varName, validUnrelatedAddress, (zeroEx as any)._web3Wrapper))
+                .to.be.rejectedWith(
+                    `Specified ${varName} ${validUnrelatedAddress} isn't available through the supplied web3 provider`,
+                );
+        });
+        it('doesn\'t throw if address is available', async () => {
+            const availableAddress = (await zeroEx.getAvailableAddressesAsync())[0];
+            const varName = 'address';
+            return expect(assert.isSenderAddressAsync(varName, availableAddress, (zeroEx as any)._web3Wrapper))
+                .to.become(undefined);
+        });
+    });
+});
diff --git a/packages/0x.js/test/ether_token_wrapper_test.ts b/packages/0x.js/test/ether_token_wrapper_test.ts
new file mode 100644
index 000000000..ba679d1a1
--- /dev/null
+++ b/packages/0x.js/test/ether_token_wrapper_test.ts
@@ -0,0 +1,111 @@
+import 'mocha';
+import * as chai from 'chai';
+import {chaiSetup} from './utils/chai_setup';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx, ZeroExError} from '../src';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+// Since the address depositing/withdrawing ETH/WETH also needs to pay gas costs for the transaction,
+// a small amount of ETH will be used to pay this gas cost. We therefore check that the difference between
+// the expected balance and actual balance (given the amount of ETH deposited), only deviates by the amount
+// required to pay gas costs.
+const MAX_REASONABLE_GAS_COST_IN_WEI = 62237;
+
+describe('EtherTokenWrapper', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let userAddresses: string[];
+    let addressWithETH: string;
+    let wethContractAddress: string;
+    let depositWeiAmount: BigNumber;
+    let decimalPlaces: number;
+    const gasPrice = new BigNumber(1);
+    const zeroExConfig = {
+        gasPrice,
+    };
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        addressWithETH = userAddresses[0];
+        wethContractAddress = await zeroEx.etherToken.getContractAddressAsync();
+        depositWeiAmount = (zeroEx as any)._web3Wrapper.toWei(new BigNumber(5));
+        decimalPlaces = 7;
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('#depositAsync', () => {
+        it('should successfully deposit ETH and issue Wrapped ETH tokens', async () => {
+            const preETHBalance = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+            const preWETHBalance = await zeroEx.token.getBalanceAsync(wethContractAddress, addressWithETH);
+            expect(preETHBalance).to.be.bignumber.gt(0);
+            expect(preWETHBalance).to.be.bignumber.equal(0);
+
+            const txHash = await zeroEx.etherToken.depositAsync(depositWeiAmount, addressWithETH);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+
+            const postETHBalanceInWei = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+            const postWETHBalanceInBaseUnits = await zeroEx.token.getBalanceAsync(wethContractAddress, addressWithETH);
+
+            expect(postWETHBalanceInBaseUnits).to.be.bignumber.equal(depositWeiAmount);
+            const remainingETHInWei = preETHBalance.minus(depositWeiAmount);
+            const gasCost = remainingETHInWei.minus(postETHBalanceInWei);
+            expect(gasCost).to.be.bignumber.lte(MAX_REASONABLE_GAS_COST_IN_WEI);
+        });
+        it('should throw if user has insufficient ETH balance for deposit', async () => {
+            const preETHBalance = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+
+            const extraETHBalance = (zeroEx as any)._web3Wrapper.toWei(5, 'ether');
+            const overETHBalanceinWei = preETHBalance.add(extraETHBalance);
+
+            return expect(
+                zeroEx.etherToken.depositAsync(overETHBalanceinWei, addressWithETH),
+            ).to.be.rejectedWith(ZeroExError.InsufficientEthBalanceForDeposit);
+        });
+    });
+    describe('#withdrawAsync', () => {
+        it('should successfully withdraw ETH in return for Wrapped ETH tokens', async () => {
+            const ETHBalanceInWei = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+
+            await zeroEx.etherToken.depositAsync(depositWeiAmount, addressWithETH);
+
+            const expectedPreETHBalance = ETHBalanceInWei.minus(depositWeiAmount);
+            const preETHBalance = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+            const preWETHBalance = await zeroEx.token.getBalanceAsync(wethContractAddress, addressWithETH);
+            let gasCost = expectedPreETHBalance.minus(preETHBalance);
+            expect(gasCost).to.be.bignumber.lte(MAX_REASONABLE_GAS_COST_IN_WEI);
+            expect(preWETHBalance).to.be.bignumber.equal(depositWeiAmount);
+
+            const txHash = await zeroEx.etherToken.withdrawAsync(depositWeiAmount, addressWithETH);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+
+            const postETHBalance = await (zeroEx as any)._web3Wrapper.getBalanceInWeiAsync(addressWithETH);
+            const postWETHBalanceInBaseUnits = await zeroEx.token.getBalanceAsync(wethContractAddress, addressWithETH);
+
+            expect(postWETHBalanceInBaseUnits).to.be.bignumber.equal(0);
+            const expectedETHBalance = preETHBalance.add(depositWeiAmount).round(decimalPlaces);
+            gasCost = expectedETHBalance.minus(postETHBalance);
+            expect(gasCost).to.be.bignumber.lte(MAX_REASONABLE_GAS_COST_IN_WEI);
+        });
+        it('should throw if user has insufficient WETH balance for withdrawl', async () => {
+            const preWETHBalance = await zeroEx.token.getBalanceAsync(wethContractAddress, addressWithETH);
+            expect(preWETHBalance).to.be.bignumber.equal(0);
+
+            const overWETHBalance = preWETHBalance.add(999999999);
+
+            return expect(
+                zeroEx.etherToken.withdrawAsync(overWETHBalance, addressWithETH),
+            ).to.be.rejectedWith(ZeroExError.InsufficientWEthBalanceForWithdrawal);
+        });
+    });
+});
diff --git a/packages/0x.js/test/event_watcher_test.ts b/packages/0x.js/test/event_watcher_test.ts
new file mode 100644
index 000000000..b4164fe63
--- /dev/null
+++ b/packages/0x.js/test/event_watcher_test.ts
@@ -0,0 +1,127 @@
+import 'mocha';
+import * as chai from 'chai';
+import * as _ from 'lodash';
+import * as Sinon from 'sinon';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {Web3Wrapper} from '../src/web3_wrapper';
+import {EventWatcher} from '../src/order_watcher/event_watcher';
+import {
+    ZeroEx,
+    LogEvent,
+    DecodedLogEvent,
+} from '../src';
+import {DoneCallback} from '../src/types';
+
+chaiSetup.configure();
+const expect = chai.expect;
+
+describe('EventWatcher', () => {
+    let web3: Web3;
+    let stubs: Sinon.SinonStub[] = [];
+    let eventWatcher: EventWatcher;
+    let web3Wrapper: Web3Wrapper;
+    const numConfirmations = 0;
+    const logA: Web3.LogEntry = {
+        address: '0x71d271f8b14adef568f8f28f1587ce7271ac4ca5',
+        blockHash: null,
+        blockNumber: null,
+        data: '',
+        logIndex: null,
+        topics: [],
+        transactionHash: '0x004881d38cd4a8f72f1a0d68c8b9b8124504706041ff37019c1d1ed6bfda8e17',
+        transactionIndex: 0,
+    };
+    const logB: Web3.LogEntry = {
+        address: '0x8d12a197cb00d4747a1fe03395095ce2a5cc6819',
+        blockHash: null,
+        blockNumber: null,
+        data: '',
+        logIndex: null,
+        topics: [ '0xf341246adaac6f497bc2a656f546ab9e182111d630394f0c57c710a59a2cb567' ],
+        transactionHash: '0x01ef3c048b18d9b09ea195b4ed94cf8dd5f3d857a1905ff886b152cfb1166f25',
+        transactionIndex: 0,
+    };
+    const logC: Web3.LogEntry = {
+        address: '0x1d271f8b174adef58f1587ce68f8f27271ac4ca5',
+        blockHash: null,
+        blockNumber: null,
+        data: '',
+        logIndex: null,
+        topics: [ '0xf341246adaac6f497bc2a656f546ab9e182111d630394f0c57c710a59a2cb567' ],
+        transactionHash: '0x01ef3c048b18d9b09ea195b4ed94cf8dd5f3d857a1905ff886b152cfb1166f25',
+        transactionIndex: 0,
+    };
+    before(async () => {
+        web3 = web3Factory.create();
+        const pollingIntervalMs = 10;
+        web3Wrapper = new Web3Wrapper(web3.currentProvider);
+        eventWatcher = new EventWatcher(web3Wrapper, pollingIntervalMs);
+    });
+    afterEach(() => {
+        // clean up any stubs after the test has completed
+        _.each(stubs, s => s.restore());
+        stubs = [];
+        eventWatcher.unsubscribe();
+    });
+    it('correctly emits initial log events', (done: DoneCallback) => {
+        const logs: Web3.LogEntry[] = [logA, logB];
+        const expectedLogEvents = [
+            {
+                removed: false,
+                ...logA,
+            },
+            {
+                removed: false,
+                ...logB,
+            },
+        ];
+        const getLogsStub = Sinon.stub(web3Wrapper, 'getLogsAsync');
+        getLogsStub.onCall(0).returns(logs);
+        stubs.push(getLogsStub);
+        const callback = (event: LogEvent) => {
+            const expectedLogEvent = expectedLogEvents.shift();
+            expect(event).to.be.deep.equal(expectedLogEvent);
+            if (_.isEmpty(expectedLogEvents)) {
+                done();
+            }
+        };
+        eventWatcher.subscribe(callback);
+    });
+    it('correctly computes the difference and emits only changes', (done: DoneCallback) => {
+        const initialLogs: Web3.LogEntry[] = [logA, logB];
+        const changedLogs: Web3.LogEntry[] = [logA, logC];
+        const expectedLogEvents = [
+            {
+                removed: false,
+                ...logA,
+            },
+            {
+                removed: false,
+                ...logB,
+            },
+            {
+                removed: true,
+                ...logB,
+            },
+            {
+                removed: false,
+                ...logC,
+            },
+        ];
+        const getLogsStub = Sinon.stub(web3Wrapper, 'getLogsAsync');
+        getLogsStub.onCall(0).returns(initialLogs);
+        getLogsStub.onCall(1).returns(changedLogs);
+        stubs.push(getLogsStub);
+        const callback = (event: LogEvent) => {
+            const expectedLogEvent = expectedLogEvents.shift();
+            expect(event).to.be.deep.equal(expectedLogEvent);
+            if (_.isEmpty(expectedLogEvents)) {
+                done();
+            }
+        };
+        eventWatcher.subscribe(callback);
+    });
+});
diff --git a/packages/0x.js/test/exchange_transfer_simulator_test.ts b/packages/0x.js/test/exchange_transfer_simulator_test.ts
new file mode 100644
index 000000000..99cb7fb4f
--- /dev/null
+++ b/packages/0x.js/test/exchange_transfer_simulator_test.ts
@@ -0,0 +1,87 @@
+import * as chai from 'chai';
+import BigNumber from 'bignumber.js';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx, ExchangeContractErrs, Token} from '../src';
+import {TradeSide, TransferType} from '../src/types';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {ExchangeTransferSimulator} from '../src/utils/exchange_transfer_simulator';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+describe('ExchangeTransferSimulator', () => {
+    const web3 = web3Factory.create();
+    const zeroEx = new ZeroEx(web3.currentProvider);
+    const transferAmount = new BigNumber(5);
+    let userAddresses: string[];
+    let tokens: Token[];
+    let coinbase: string;
+    let sender: string;
+    let recipient: string;
+    let exampleTokenAddress: string;
+    let exchangeTransferSimulator: ExchangeTransferSimulator;
+    let txHash: string;
+    before(async () => {
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        [coinbase, sender, recipient] = userAddresses;
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        exampleTokenAddress = tokens[0].address;
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('#transferFromAsync', () => {
+        beforeEach(() => {
+            exchangeTransferSimulator = new ExchangeTransferSimulator(zeroEx.token);
+        });
+        it('throws if the user doesn\'t have enough allowance', async () => {
+            return expect(exchangeTransferSimulator.transferFromAsync(
+                exampleTokenAddress, sender, recipient, transferAmount, TradeSide.Taker, TransferType.Trade,
+            )).to.be.rejectedWith(ExchangeContractErrs.InsufficientTakerAllowance);
+        });
+        it('throws if the user doesn\'t have enough balance', async () => {
+            txHash = await zeroEx.token.setProxyAllowanceAsync(exampleTokenAddress, sender, transferAmount);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            return expect(exchangeTransferSimulator.transferFromAsync(
+                exampleTokenAddress, sender, recipient, transferAmount, TradeSide.Maker, TransferType.Trade,
+            )).to.be.rejectedWith(ExchangeContractErrs.InsufficientMakerBalance);
+        });
+        it('updates balances and proxyAllowance after transfer', async () => {
+            txHash = await zeroEx.token.transferAsync(exampleTokenAddress, coinbase, sender, transferAmount);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            txHash = await zeroEx.token.setProxyAllowanceAsync(exampleTokenAddress, sender, transferAmount);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            await exchangeTransferSimulator.transferFromAsync(
+                exampleTokenAddress, sender, recipient, transferAmount, TradeSide.Taker, TransferType.Trade,
+            );
+            const store = (exchangeTransferSimulator as any).store;
+            const senderBalance = await store.getBalanceAsync(exampleTokenAddress, sender);
+            const recipientBalance = await store.getBalanceAsync(exampleTokenAddress, recipient);
+            const senderProxyAllowance = await store.getProxyAllowanceAsync(exampleTokenAddress, sender);
+            expect(senderBalance).to.be.bignumber.equal(0);
+            expect(recipientBalance).to.be.bignumber.equal(transferAmount);
+            expect(senderProxyAllowance).to.be.bignumber.equal(0);
+        });
+        it('doesn\'t update proxyAllowance after transfer if unlimited', async () => {
+            txHash = await zeroEx.token.transferAsync(exampleTokenAddress, coinbase, sender, transferAmount);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(exampleTokenAddress, sender);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            await exchangeTransferSimulator.transferFromAsync(
+                exampleTokenAddress, sender, recipient, transferAmount, TradeSide.Taker, TransferType.Trade,
+            );
+            const store = (exchangeTransferSimulator as any).store;
+            const senderBalance = await store.getBalanceAsync(exampleTokenAddress, sender);
+            const recipientBalance = await store.getBalanceAsync(exampleTokenAddress, recipient);
+            const senderProxyAllowance = await store.getProxyAllowanceAsync(exampleTokenAddress, sender);
+            expect(senderBalance).to.be.bignumber.equal(0);
+            expect(recipientBalance).to.be.bignumber.equal(transferAmount);
+            expect(senderProxyAllowance).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
+        });
+    });
+});
diff --git a/packages/0x.js/test/exchange_wrapper_test.ts b/packages/0x.js/test/exchange_wrapper_test.ts
new file mode 100644
index 000000000..26b8c1e0e
--- /dev/null
+++ b/packages/0x.js/test/exchange_wrapper_test.ts
@@ -0,0 +1,824 @@
+import 'mocha';
+import * as chai from 'chai';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {
+    ZeroEx,
+    Token,
+    SignedOrder,
+    SubscriptionOpts,
+    ExchangeEvents,
+    ExchangeContractErrs,
+    OrderCancellationRequest,
+    OrderFillRequest,
+    LogFillContractEventArgs,
+    LogCancelContractEventArgs,
+    LogEvent,
+    DecodedLogEvent,
+} from '../src';
+import {DoneCallback, BlockParamLiteral} from '../src/types';
+import {FillScenarios} from './utils/fill_scenarios';
+import {TokenUtils} from './utils/token_utils';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+const NON_EXISTENT_ORDER_HASH = '0x79370342234e7acd6bbeac335bd3bb1d368383294b64b8160a00f4060e4d3777';
+
+describe('ExchangeWrapper', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let tokenUtils: TokenUtils;
+    let tokens: Token[];
+    let userAddresses: string[];
+    let zrxTokenAddress: string;
+    let fillScenarios: FillScenarios;
+    let exchangeContractAddress: string;
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        exchangeContractAddress = await zeroEx.exchange.getContractAddressAsync();
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
+        zrxTokenAddress = tokenUtils.getProtocolTokenOrThrow().address;
+        fillScenarios = new FillScenarios(zeroEx, userAddresses, tokens, zrxTokenAddress, exchangeContractAddress);
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('fillOrKill order(s)', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let coinbase: string;
+        let makerAddress: string;
+        let takerAddress: string;
+        let feeRecipient: string;
+        const takerTokenFillAmount = new BigNumber(5);
+        before(async () => {
+            [coinbase, makerAddress, takerAddress, feeRecipient] = userAddresses;
+            tokens = await zeroEx.tokenRegistry.getTokensAsync();
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        describe('#batchFillOrKillAsync', () => {
+            it('successfully batch fillOrKill', async () => {
+                const fillableAmount = new BigNumber(5);
+                const partialFillTakerAmount = new BigNumber(2);
+                const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                const anotherSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                const orderFillRequests = [
+                    {
+                        signedOrder,
+                        takerTokenFillAmount: partialFillTakerAmount,
+                    },
+                    {
+                        signedOrder: anotherSignedOrder,
+                        takerTokenFillAmount: partialFillTakerAmount,
+                    },
+                ];
+                await zeroEx.exchange.batchFillOrKillAsync(orderFillRequests, takerAddress);
+            });
+            describe('order transaction options', () => {
+                let signedOrder: SignedOrder;
+                let orderFillRequests: OrderFillRequest[];
+                const fillableAmount = new BigNumber(5);
+                beforeEach(async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                    );
+                    orderFillRequests = [
+                        {
+                            signedOrder,
+                            takerTokenFillAmount: new BigNumber(0),
+                        },
+                    ];
+                });
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.batchFillOrKillAsync(orderFillRequests, takerAddress))
+                        .to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.batchFillOrKillAsync(orderFillRequests, takerAddress, {
+                        shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.batchFillOrKillAsync(orderFillRequests, takerAddress, {
+                        shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+            });
+        });
+        describe('#fillOrKillOrderAsync', () => {
+            let signedOrder: SignedOrder;
+            const fillableAmount = new BigNumber(5);
+            beforeEach(async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+            });
+            describe('successful fills', () => {
+                it('should fill a valid order', async () => {
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(0);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(0);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount);
+                    await zeroEx.exchange.fillOrKillOrderAsync(signedOrder, takerTokenFillAmount, takerAddress);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(takerTokenFillAmount));
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(takerTokenFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(takerTokenFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(takerTokenFillAmount));
+                });
+                it('should partially fill a valid order', async () => {
+                    const partialFillAmount = new BigNumber(3);
+                    await zeroEx.exchange.fillOrKillOrderAsync(signedOrder, partialFillAmount, takerAddress);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(partialFillAmount));
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(partialFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(partialFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(partialFillAmount));
+                });
+            });
+            describe('order transaction options', () => {
+                const emptyFillableAmount = new BigNumber(0);
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.fillOrKillOrderAsync(signedOrder, emptyFillableAmount, takerAddress))
+                        .to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrKillOrderAsync(signedOrder, emptyFillableAmount, takerAddress, {
+                        shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrKillOrderAsync(signedOrder, emptyFillableAmount, takerAddress, {
+                        shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+            });
+        });
+    });
+    describe('fill order(s)', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let coinbase: string;
+        let makerAddress: string;
+        let takerAddress: string;
+        let feeRecipient: string;
+        const fillableAmount = new BigNumber(5);
+        const takerTokenFillAmount = new BigNumber(5);
+        const shouldThrowOnInsufficientBalanceOrAllowance = true;
+        before(async () => {
+            [coinbase, makerAddress, takerAddress, feeRecipient] = userAddresses;
+            tokens = await zeroEx.tokenRegistry.getTokensAsync();
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        describe('#fillOrderAsync', () => {
+            describe('successful fills', () => {
+                it('should fill a valid order', async () => {
+                    const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                    );
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(0);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(0);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount);
+                    const txHash = await zeroEx.exchange.fillOrderAsync(
+                        signedOrder, takerTokenFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress);
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(takerTokenFillAmount));
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(takerTokenFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(takerTokenFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(takerTokenFillAmount));
+                });
+                it('should partially fill the valid order', async () => {
+                    const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                    );
+                    const partialFillAmount = new BigNumber(3);
+                    const txHash = await zeroEx.exchange.fillOrderAsync(
+                        signedOrder, partialFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress);
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(partialFillAmount));
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, makerAddress))
+                        .to.be.bignumber.equal(partialFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(makerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(partialFillAmount);
+                    expect(await zeroEx.token.getBalanceAsync(takerTokenAddress, takerAddress))
+                        .to.be.bignumber.equal(fillableAmount.minus(partialFillAmount));
+                });
+                it('should fill the valid orders with fees', async () => {
+                    const makerFee = new BigNumber(1);
+                    const takerFee = new BigNumber(2);
+                    const signedOrder = await fillScenarios.createFillableSignedOrderWithFeesAsync(
+                        makerTokenAddress, takerTokenAddress, makerFee, takerFee,
+                        makerAddress, takerAddress, fillableAmount, feeRecipient,
+                    );
+                    const txHash = await zeroEx.exchange.fillOrderAsync(
+                        signedOrder, takerTokenFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress);
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    expect(await zeroEx.token.getBalanceAsync(zrxTokenAddress, feeRecipient))
+                        .to.be.bignumber.equal(makerFee.plus(takerFee));
+                });
+            });
+            describe('order transaction options', () => {
+                let signedOrder: SignedOrder;
+                const emptyFillTakerAmount = new BigNumber(0);
+                beforeEach(async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                    );
+                });
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.fillOrderAsync(
+                        signedOrder, emptyFillTakerAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+                    )).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrderAsync(
+                        signedOrder, emptyFillTakerAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrderAsync(
+                        signedOrder, emptyFillTakerAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+            });
+        });
+        describe('#batchFillOrdersAsync', () => {
+            let signedOrder: SignedOrder;
+            let signedOrderHashHex: string;
+            let anotherSignedOrder: SignedOrder;
+            let anotherOrderHashHex: string;
+            let orderFillBatch: OrderFillRequest[];
+            beforeEach(async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                signedOrderHashHex = ZeroEx.getOrderHashHex(signedOrder);
+                anotherSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                anotherOrderHashHex = ZeroEx.getOrderHashHex(anotherSignedOrder);
+            });
+            describe('successful batch fills', () => {
+                beforeEach(() => {
+                    orderFillBatch = [
+                        {
+                            signedOrder,
+                            takerTokenFillAmount,
+                        },
+                        {
+                            signedOrder: anotherSignedOrder,
+                            takerTokenFillAmount,
+                        },
+                    ];
+                });
+                it('should throw if a batch is empty', async () => {
+                    return expect(zeroEx.exchange.batchFillOrdersAsync(
+                        [], shouldThrowOnInsufficientBalanceOrAllowance, takerAddress),
+                    ).to.be.rejectedWith(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
+                });
+                it('should successfully fill multiple orders', async () => {
+                    const txHash = await zeroEx.exchange.batchFillOrdersAsync(
+                        orderFillBatch, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress);
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    const filledAmount = await zeroEx.exchange.getFilledTakerAmountAsync(signedOrderHashHex);
+                    const anotherFilledAmount = await zeroEx.exchange.getFilledTakerAmountAsync(anotherOrderHashHex);
+                    expect(filledAmount).to.be.bignumber.equal(takerTokenFillAmount);
+                    expect(anotherFilledAmount).to.be.bignumber.equal(takerTokenFillAmount);
+                });
+            });
+            describe('order transaction options', () => {
+                beforeEach(async () => {
+                    const emptyFillTakerAmount = new BigNumber(0);
+                    orderFillBatch = [
+                        {
+                            signedOrder,
+                            takerTokenFillAmount: emptyFillTakerAmount,
+                        },
+                        {
+                            signedOrder: anotherSignedOrder,
+                            takerTokenFillAmount: emptyFillTakerAmount,
+                        },
+                    ];
+                });
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.batchFillOrdersAsync(
+                        orderFillBatch, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress),
+                    ).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.batchFillOrdersAsync(
+                        orderFillBatch, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.batchFillOrdersAsync(
+                        orderFillBatch, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+            });
+        });
+        describe('#fillOrdersUpTo', () => {
+            let signedOrder: SignedOrder;
+            let signedOrderHashHex: string;
+            let anotherSignedOrder: SignedOrder;
+            let anotherOrderHashHex: string;
+            let signedOrders: SignedOrder[];
+            const fillUpToAmount = fillableAmount.plus(fillableAmount).minus(1);
+            beforeEach(async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                signedOrderHashHex = ZeroEx.getOrderHashHex(signedOrder);
+                anotherSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                anotherOrderHashHex = ZeroEx.getOrderHashHex(anotherSignedOrder);
+                signedOrders = [signedOrder, anotherSignedOrder];
+            });
+            describe('successful batch fills', () => {
+                it('should throw if a batch is empty', async () => {
+                    return expect(zeroEx.exchange.fillOrdersUpToAsync(
+                        [], fillUpToAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress),
+                    ).to.be.rejectedWith(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
+                });
+                it('should successfully fill up to specified amount', async () => {
+                    const txHash = await zeroEx.exchange.fillOrdersUpToAsync(
+                        signedOrders, fillUpToAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+                    );
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    const filledAmount = await zeroEx.exchange.getFilledTakerAmountAsync(signedOrderHashHex);
+                    const anotherFilledAmount = await zeroEx.exchange.getFilledTakerAmountAsync(anotherOrderHashHex);
+                    expect(filledAmount).to.be.bignumber.equal(fillableAmount);
+                    const remainingFillAmount = fillableAmount.minus(1);
+                    expect(anotherFilledAmount).to.be.bignumber.equal(remainingFillAmount);
+                });
+            });
+            describe('order transaction options', () => {
+                const emptyFillUpToAmount = new BigNumber(0);
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.fillOrdersUpToAsync(
+                        signedOrders, emptyFillUpToAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+                    )).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrdersUpToAsync(
+                        signedOrders, emptyFillUpToAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.fillOrdersUpToAsync(
+                        signedOrders, emptyFillUpToAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress, {
+                            shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+                });
+            });
+        });
+    });
+    describe('cancel order(s)', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let coinbase: string;
+        let makerAddress: string;
+        let takerAddress: string;
+        const fillableAmount = new BigNumber(5);
+        let signedOrder: SignedOrder;
+        let orderHashHex: string;
+        const cancelAmount = new BigNumber(3);
+        beforeEach(async () => {
+            [coinbase, makerAddress, takerAddress] = userAddresses;
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+            signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            orderHashHex = ZeroEx.getOrderHashHex(signedOrder);
+        });
+        describe('#cancelOrderAsync', () => {
+            describe('successful cancels', () => {
+                it('should cancel an order', async () => {
+                    const txHash = await zeroEx.exchange.cancelOrderAsync(signedOrder, cancelAmount);
+                    await zeroEx.awaitTransactionMinedAsync(txHash);
+                    const cancelledAmount = await zeroEx.exchange.getCanceledTakerAmountAsync(orderHashHex);
+                    expect(cancelledAmount).to.be.bignumber.equal(cancelAmount);
+                });
+            });
+            describe('order transaction options', () => {
+                const emptyCancelTakerTokenAmount = new BigNumber(0);
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.cancelOrderAsync(signedOrder, emptyCancelTakerTokenAmount))
+                        .to.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.cancelOrderAsync(signedOrder, emptyCancelTakerTokenAmount, {
+                        shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.cancelOrderAsync(signedOrder, emptyCancelTakerTokenAmount, {
+                        shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+            });
+        });
+        describe('#batchCancelOrdersAsync', () => {
+            let anotherSignedOrder: SignedOrder;
+            let anotherOrderHashHex: string;
+            let cancelBatch: OrderCancellationRequest[];
+            beforeEach(async () => {
+                anotherSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+                );
+                anotherOrderHashHex = ZeroEx.getOrderHashHex(anotherSignedOrder);
+                cancelBatch = [
+                    {
+                        order: signedOrder,
+                        takerTokenCancelAmount: cancelAmount,
+                    },
+                    {
+                        order: anotherSignedOrder,
+                        takerTokenCancelAmount: cancelAmount,
+                    },
+                ];
+            });
+            describe('failed batch cancels', () => {
+                it('should throw when orders have different makers', async () => {
+                    const signedOrderWithDifferentMaker = await fillScenarios.createFillableSignedOrderAsync(
+                        makerTokenAddress, takerTokenAddress, takerAddress, takerAddress, fillableAmount,
+                    );
+                    return expect(zeroEx.exchange.batchCancelOrdersAsync([
+                        cancelBatch[0],
+                        {
+                            order: signedOrderWithDifferentMaker,
+                            takerTokenCancelAmount: cancelAmount,
+                        },
+                    ])).to.be.rejectedWith(ExchangeContractErrs.MultipleMakersInSingleCancelBatchDisallowed);
+                });
+            });
+            describe('successful batch cancels', () => {
+                it('should cancel a batch of orders', async () => {
+                    await zeroEx.exchange.batchCancelOrdersAsync(cancelBatch);
+                    const cancelledAmount = await zeroEx.exchange.getCanceledTakerAmountAsync(orderHashHex);
+                    const anotherCancelledAmount = await zeroEx.exchange.getCanceledTakerAmountAsync(
+                        anotherOrderHashHex,
+                    );
+                    expect(cancelledAmount).to.be.bignumber.equal(cancelAmount);
+                    expect(anotherCancelledAmount).to.be.bignumber.equal(cancelAmount);
+                });
+            });
+            describe('order transaction options', () => {
+                beforeEach(async () => {
+                    const emptyTakerTokenCancelAmount = new BigNumber(0);
+                    cancelBatch = [
+                        {
+                            order: signedOrder,
+                            takerTokenCancelAmount: emptyTakerTokenCancelAmount,
+                        },
+                        {
+                            order: anotherSignedOrder,
+                            takerTokenCancelAmount: emptyTakerTokenCancelAmount,
+                        },
+                    ];
+                });
+                it('should validate when orderTransactionOptions are not present', async () => {
+                    return expect(zeroEx.exchange.batchCancelOrdersAsync(cancelBatch))
+                        .to.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+                it('should validate when orderTransactionOptions specify to validate', async () => {
+                    return expect(zeroEx.exchange.batchCancelOrdersAsync(cancelBatch, {
+                        shouldValidate: true,
+                    })).to.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+                it('should not validate when orderTransactionOptions specify not to validate', async () => {
+                    return expect(zeroEx.exchange.batchCancelOrdersAsync(cancelBatch, {
+                        shouldValidate: false,
+                    })).to.not.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+                });
+            });
+        });
+    });
+    describe('tests that require partially filled order', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let takerAddress: string;
+        let fillableAmount: BigNumber;
+        let partialFillAmount: BigNumber;
+        let signedOrder: SignedOrder;
+        let orderHash: string;
+        before(() => {
+            takerAddress = userAddresses[1];
+            const [makerToken, takerToken] = tokens;
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        beforeEach(async () => {
+            fillableAmount = new BigNumber(5);
+            partialFillAmount = new BigNumber(2);
+            signedOrder = await fillScenarios.createPartiallyFilledSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, takerAddress, fillableAmount, partialFillAmount,
+            );
+            orderHash = ZeroEx.getOrderHashHex(signedOrder);
+        });
+        describe('#getUnavailableTakerAmountAsync', () => {
+            it('should throw if passed an invalid orderHash', async () => {
+                const invalidOrderHashHex = '0x123';
+                return expect(zeroEx.exchange.getUnavailableTakerAmountAsync(invalidOrderHashHex)).to.be.rejected();
+            });
+            it('should return zero if passed a valid but non-existent orderHash', async () => {
+                const unavailableValueT = await zeroEx.exchange.getUnavailableTakerAmountAsync(NON_EXISTENT_ORDER_HASH);
+                expect(unavailableValueT).to.be.bignumber.equal(0);
+            });
+            it('should return the unavailableValueT for a valid and partially filled orderHash', async () => {
+                const unavailableValueT = await zeroEx.exchange.getUnavailableTakerAmountAsync(orderHash);
+                expect(unavailableValueT).to.be.bignumber.equal(partialFillAmount);
+            });
+        });
+        describe('#getFilledTakerAmountAsync', () => {
+            it('should throw if passed an invalid orderHash', async () => {
+                const invalidOrderHashHex = '0x123';
+                return expect(zeroEx.exchange.getFilledTakerAmountAsync(invalidOrderHashHex)).to.be.rejected();
+            });
+            it('should return zero if passed a valid but non-existent orderHash', async () => {
+                const filledValueT = await zeroEx.exchange.getFilledTakerAmountAsync(NON_EXISTENT_ORDER_HASH,
+                );
+                expect(filledValueT).to.be.bignumber.equal(0);
+            });
+            it('should return the filledValueT for a valid and partially filled orderHash', async () => {
+                const filledValueT = await zeroEx.exchange.getFilledTakerAmountAsync(orderHash);
+                expect(filledValueT).to.be.bignumber.equal(partialFillAmount);
+            });
+        });
+        describe('#getCanceledTakerAmountAsync', () => {
+            it('should throw if passed an invalid orderHash', async () => {
+                const invalidOrderHashHex = '0x123';
+                return expect(zeroEx.exchange.getCanceledTakerAmountAsync(invalidOrderHashHex)).to.be.rejected();
+            });
+            it('should return zero if passed a valid but non-existent orderHash', async () => {
+                const cancelledValueT = await zeroEx.exchange.getCanceledTakerAmountAsync(NON_EXISTENT_ORDER_HASH);
+                expect(cancelledValueT).to.be.bignumber.equal(0);
+            });
+            it('should return the cancelledValueT for a valid and partially filled orderHash', async () => {
+                const cancelledValueT = await zeroEx.exchange.getCanceledTakerAmountAsync(orderHash);
+                expect(cancelledValueT).to.be.bignumber.equal(0);
+            });
+            it('should return the cancelledValueT for a valid and cancelled orderHash', async () => {
+                const cancelAmount = fillableAmount.minus(partialFillAmount);
+                await zeroEx.exchange.cancelOrderAsync(signedOrder, cancelAmount);
+                const cancelledValueT = await zeroEx.exchange.getCanceledTakerAmountAsync(orderHash);
+                expect(cancelledValueT).to.be.bignumber.equal(cancelAmount);
+            });
+        });
+    });
+    describe('#subscribeAsync', () => {
+        const indexFilterValues = {};
+        const shouldThrowOnInsufficientBalanceOrAllowance = true;
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let coinbase: string;
+        let takerAddress: string;
+        let makerAddress: string;
+        let fillableAmount: BigNumber;
+        let signedOrder: SignedOrder;
+        const takerTokenFillAmountInBaseUnits = new BigNumber(1);
+        const cancelTakerAmountInBaseUnits = new BigNumber(1);
+        before(() => {
+            [coinbase, makerAddress, takerAddress] = userAddresses;
+            const [makerToken, takerToken] = tokens;
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        beforeEach(async () => {
+            fillableAmount = new BigNumber(5);
+            signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+        });
+        afterEach(async () => {
+            zeroEx.exchange.unsubscribeAll();
+        });
+        // Hack: Mocha does not allow a test to be both async and have a `done` callback
+        // Since we need to await the receipt of the event in the `subscribe` callback,
+        // we do need both. A hack is to make the top-level a sync fn w/ a done callback and then
+        // wrap the rest of the test in an async block
+        // Source: https://github.com/mochajs/mocha/issues/2407
+        it('Should receive the LogFill event when an order is filled', (done: DoneCallback) => {
+            (async () => {
+
+                const callback = (err: Error, logEvent: DecodedLogEvent<LogFillContractEventArgs>) => {
+                    expect(logEvent.event).to.be.equal(ExchangeEvents.LogFill);
+                    done();
+                };
+                await zeroEx.exchange.subscribeAsync(
+                    ExchangeEvents.LogFill, indexFilterValues, callback,
+                );
+                await zeroEx.exchange.fillOrderAsync(
+                    signedOrder, takerTokenFillAmountInBaseUnits, shouldThrowOnInsufficientBalanceOrAllowance,
+                    takerAddress,
+                );
+            })().catch(done);
+        });
+        it('Should receive the LogCancel event when an order is cancelled', (done: DoneCallback) => {
+            (async () => {
+
+                const callback = (err: Error, logEvent: DecodedLogEvent<LogCancelContractEventArgs>) => {
+                    expect(logEvent.event).to.be.equal(ExchangeEvents.LogCancel);
+                    done();
+                };
+                await zeroEx.exchange.subscribeAsync(
+                    ExchangeEvents.LogCancel, indexFilterValues, callback,
+                );
+                await zeroEx.exchange.cancelOrderAsync(signedOrder, cancelTakerAmountInBaseUnits);
+            })().catch(done);
+        });
+        it('Outstanding subscriptions are cancelled when zeroEx.setProviderAsync called', (done: DoneCallback) => {
+            (async () => {
+
+                const callbackNeverToBeCalled = (err: Error, logEvent: DecodedLogEvent<LogFillContractEventArgs>) => {
+                    done(new Error('Expected this subscription to have been cancelled'));
+                };
+                await zeroEx.exchange.subscribeAsync(
+                    ExchangeEvents.LogFill, indexFilterValues, callbackNeverToBeCalled,
+                );
+
+                const newProvider = web3Factory.getRpcProvider();
+                await zeroEx.setProviderAsync(newProvider);
+
+                const callback = (err: Error, logEvent: DecodedLogEvent<LogFillContractEventArgs>) => {
+                    expect(logEvent.event).to.be.equal(ExchangeEvents.LogFill);
+                    done();
+                };
+                await zeroEx.exchange.subscribeAsync(
+                    ExchangeEvents.LogFill, indexFilterValues, callback,
+                );
+                await zeroEx.exchange.fillOrderAsync(
+                    signedOrder, takerTokenFillAmountInBaseUnits, shouldThrowOnInsufficientBalanceOrAllowance,
+                    takerAddress,
+                );
+            })().catch(done);
+        });
+        it('Should cancel subscription when unsubscribe called', (done: DoneCallback) => {
+            (async () => {
+                const callbackNeverToBeCalled = (err: Error, logEvent: DecodedLogEvent<LogFillContractEventArgs>) => {
+                    done(new Error('Expected this subscription to have been cancelled'));
+                };
+                const subscriptionToken = await zeroEx.exchange.subscribeAsync(
+                    ExchangeEvents.LogFill, indexFilterValues, callbackNeverToBeCalled,
+                );
+                zeroEx.exchange.unsubscribe(subscriptionToken);
+                await zeroEx.exchange.fillOrderAsync(
+                    signedOrder, takerTokenFillAmountInBaseUnits, shouldThrowOnInsufficientBalanceOrAllowance,
+                    takerAddress,
+                );
+                done();
+            })().catch(done);
+        });
+    });
+    describe('#getOrderHashHexUsingContractCallAsync', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let makerAddress: string;
+        let takerAddress: string;
+        const fillableAmount = new BigNumber(5);
+        before(async () => {
+            [, makerAddress, takerAddress] = userAddresses;
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        it('get\'s the same hash as the local function', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+            const orderHashFromContract = await (zeroEx.exchange as any)
+                ._getOrderHashHexUsingContractCallAsync(signedOrder);
+            expect(orderHash).to.equal(orderHashFromContract);
+        });
+    });
+    describe('#getZRXTokenAddressAsync', () => {
+        it('gets the same token as is in token registry', async () => {
+            const zrxAddress = await zeroEx.exchange.getZRXTokenAddressAsync();
+            const zrxToken = tokenUtils.getProtocolTokenOrThrow();
+            expect(zrxAddress).to.equal(zrxToken.address);
+        });
+    });
+    describe('#getLogsAsync', () => {
+        let makerTokenAddress: string;
+        let takerTokenAddress: string;
+        let makerAddress: string;
+        let takerAddress: string;
+        const fillableAmount = new BigNumber(5);
+        const shouldThrowOnInsufficientBalanceOrAllowance = true;
+        const subscriptionOpts: SubscriptionOpts = {
+            fromBlock: BlockParamLiteral.Earliest,
+            toBlock: BlockParamLiteral.Latest,
+        };
+        let txHash: string;
+        before(async () => {
+            [, makerAddress, takerAddress] = userAddresses;
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+        });
+        it('should get logs with decoded args emitted by LogFill', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            txHash = await zeroEx.exchange.fillOrderAsync(
+                signedOrder, fillableAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+            );
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            const eventName = ExchangeEvents.LogFill;
+            const indexFilterValues = {};
+            const logs = await zeroEx.exchange.getLogsAsync(eventName, subscriptionOpts, indexFilterValues);
+            expect(logs).to.have.length(1);
+            expect(logs[0].event).to.be.equal(eventName);
+        });
+        it('should only get the logs with the correct event name', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            txHash = await zeroEx.exchange.fillOrderAsync(
+                signedOrder, fillableAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+            );
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            const differentEventName = ExchangeEvents.LogCancel;
+            const indexFilterValues = {};
+            const logs = await zeroEx.exchange.getLogsAsync(differentEventName, subscriptionOpts, indexFilterValues);
+            expect(logs).to.have.length(0);
+        });
+        it('should only get the logs with the correct indexed fields', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            txHash = await zeroEx.exchange.fillOrderAsync(
+                signedOrder, fillableAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+            );
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+
+            const differentMakerAddress = userAddresses[2];
+            const anotherSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, differentMakerAddress, takerAddress, fillableAmount,
+            );
+            txHash = await zeroEx.exchange.fillOrderAsync(
+                anotherSignedOrder, fillableAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+            );
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+
+            const eventName = ExchangeEvents.LogFill;
+            const indexFilterValues = {
+                maker: differentMakerAddress,
+            };
+            const logs = await zeroEx.exchange.getLogsAsync<LogFillContractEventArgs>(
+                eventName, subscriptionOpts, indexFilterValues,
+            );
+            expect(logs).to.have.length(1);
+            const args = logs[0].args;
+            expect(args.maker).to.be.equal(differentMakerAddress);
+        });
+    });
+});
diff --git a/packages/0x.js/test/order_state_watcher_test.ts b/packages/0x.js/test/order_state_watcher_test.ts
new file mode 100644
index 000000000..c8a4a8064
--- /dev/null
+++ b/packages/0x.js/test/order_state_watcher_test.ts
@@ -0,0 +1,356 @@
+import 'mocha';
+import * as chai from 'chai';
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import { chaiSetup } from './utils/chai_setup';
+import { web3Factory } from './utils/web3_factory';
+import { Web3Wrapper } from '../src/web3_wrapper';
+import { OrderStateWatcher } from '../src/order_watcher/order_state_watcher';
+import {
+    Token,
+    ZeroEx,
+    LogEvent,
+    DecodedLogEvent,
+    ZeroExConfig,
+    OrderState,
+    SignedOrder,
+    ZeroExError,
+    OrderStateValid,
+    OrderStateInvalid,
+    ExchangeContractErrs,
+} from '../src';
+import { TokenUtils } from './utils/token_utils';
+import { FillScenarios } from './utils/fill_scenarios';
+import { DoneCallback } from '../src/types';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {reportCallbackErrors} from './utils/report_callback_errors';
+
+const TIMEOUT_MS = 150;
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+describe('OrderStateWatcher', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let tokens: Token[];
+    let tokenUtils: TokenUtils;
+    let fillScenarios: FillScenarios;
+    let userAddresses: string[];
+    let zrxTokenAddress: string;
+    let exchangeContractAddress: string;
+    let makerToken: Token;
+    let takerToken: Token;
+    let maker: string;
+    let taker: string;
+    let web3Wrapper: Web3Wrapper;
+    let signedOrder: SignedOrder;
+    const fillableAmount = new BigNumber(5);
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        exchangeContractAddress = await zeroEx.exchange.getContractAddressAsync();
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        [, maker, taker] = userAddresses;
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
+        zrxTokenAddress = tokenUtils.getProtocolTokenOrThrow().address;
+        fillScenarios = new FillScenarios(zeroEx, userAddresses, tokens, zrxTokenAddress, exchangeContractAddress);
+        [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+        web3Wrapper = (zeroEx as any)._web3Wrapper;
+    });
+    describe('#removeOrder', async () => {
+        it('should successfully remove existing order', async () => {
+            signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerToken.address, takerToken.address, maker, taker, fillableAmount,
+            );
+            const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+            zeroEx.orderStateWatcher.addOrder(signedOrder);
+            expect((zeroEx.orderStateWatcher as any)._orderByOrderHash).to.include({
+                [orderHash]: signedOrder,
+            });
+            let dependentOrderHashes = (zeroEx.orderStateWatcher as any)._dependentOrderHashes;
+            expect(dependentOrderHashes[signedOrder.maker][signedOrder.makerTokenAddress]).to.have.keys(orderHash);
+            zeroEx.orderStateWatcher.removeOrder(orderHash);
+            expect((zeroEx.orderStateWatcher as any)._orderByOrderHash).to.not.include({
+                [orderHash]: signedOrder,
+            });
+            dependentOrderHashes = (zeroEx.orderStateWatcher as any)._dependentOrderHashes;
+            expect(dependentOrderHashes[signedOrder.maker]).to.be.undefined();
+        });
+        it('should no-op when removing a non-existing order', async () => {
+            signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerToken.address, takerToken.address, maker, taker, fillableAmount,
+            );
+            const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+            const nonExistentOrderHash = `0x${orderHash.substr(2).split('').reverse().join('')}`;
+            zeroEx.orderStateWatcher.removeOrder(nonExistentOrderHash);
+        });
+    });
+    describe('#subscribe', async () => {
+        afterEach(async () => {
+            zeroEx.orderStateWatcher.unsubscribe();
+        });
+        it('should fail when trying to subscribe twice', async () => {
+            zeroEx.orderStateWatcher.subscribe(_.noop);
+            expect(() => zeroEx.orderStateWatcher.subscribe(_.noop))
+                .to.throw(ZeroExError.SubscriptionAlreadyPresent);
+        });
+    });
+    describe('tests with cleanup', async () => {
+        afterEach(async () => {
+            zeroEx.orderStateWatcher.unsubscribe();
+            const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+            zeroEx.orderStateWatcher.removeOrder(orderHash);
+        });
+        it('should emit orderStateInvalid when maker allowance set to 0 for watched order', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    expect(orderState.isValid).to.be.false();
+                    const invalidOrderState = orderState as OrderStateInvalid;
+                    expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                    expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerAllowance);
+                    done();
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+                await zeroEx.token.setProxyAllowanceAsync(makerToken.address, maker, new BigNumber(0));
+            })().catch(done);
+        });
+        it('should not emit an orderState event when irrelevant Transfer event received', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    throw new Error('OrderState callback fired for irrelevant order');
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+                const notTheMaker = userAddresses[0];
+                const anyRecipient = taker;
+                const transferAmount = new BigNumber(2);
+                const notTheMakerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, notTheMaker);
+                await zeroEx.token.transferAsync(makerToken.address, notTheMaker, anyRecipient, transferAmount);
+                setTimeout(() => {
+                    done();
+                }, TIMEOUT_MS);
+            })().catch(done);
+        });
+        it('should emit orderStateInvalid when maker moves balance backing watched order', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    expect(orderState.isValid).to.be.false();
+                    const invalidOrderState = orderState as OrderStateInvalid;
+                    expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                    expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerBalance);
+                    done();
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+                const anyRecipient = taker;
+                const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+                await zeroEx.token.transferAsync(makerToken.address, maker, anyRecipient, makerBalance);
+            })().catch(done);
+        });
+        it('should emit orderStateInvalid when watched order fully filled', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                let eventCount = 0;
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    eventCount++;
+                    expect(orderState.isValid).to.be.false();
+                    const invalidOrderState = orderState as OrderStateInvalid;
+                    expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                    expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.OrderRemainingFillAmountZero);
+                    if (eventCount === 2) {
+                        done();
+                    }
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+
+                const shouldThrowOnInsufficientBalanceOrAllowance = true;
+                await zeroEx.exchange.fillOrderAsync(
+                    signedOrder, fillableAmount, shouldThrowOnInsufficientBalanceOrAllowance, taker,
+                );
+            })().catch(done);
+        });
+        it('should emit orderStateValid when watched order partially filled', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+
+                const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+                const takerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, taker);
+
+                const fillAmountInBaseUnits = new BigNumber(2);
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                let eventCount = 0;
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    eventCount++;
+                    expect(orderState.isValid).to.be.true();
+                    const validOrderState = orderState as OrderStateValid;
+                    expect(validOrderState.orderHash).to.be.equal(orderHash);
+                    const orderRelevantState = validOrderState.orderRelevantState;
+                    const remainingMakerBalance = makerBalance.sub(fillAmountInBaseUnits);
+                    const remainingFillable = fillableAmount.minus(fillAmountInBaseUnits);
+                    expect(orderRelevantState.remainingFillableMakerTokenAmount).to.be.bignumber.equal(
+                        remainingFillable);
+                    expect(orderRelevantState.makerBalance).to.be.bignumber.equal(remainingMakerBalance);
+                    if (eventCount === 2) {
+                        done();
+                    }
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+                const shouldThrowOnInsufficientBalanceOrAllowance = true;
+                await zeroEx.exchange.fillOrderAsync(
+                    signedOrder, fillAmountInBaseUnits, shouldThrowOnInsufficientBalanceOrAllowance, taker,
+                );
+            })().catch(done);
+        });
+        describe('remainingFillableMakerTokenAmount', () => {
+          it('should calculate correct remaining fillable', (done: DoneCallback) => {
+              (async () => {
+                  const takerFillableAmount = new BigNumber(10);
+                  const makerFillableAmount = new BigNumber(20);
+                  signedOrder = await fillScenarios.createAsymmetricFillableSignedOrderAsync(
+                      makerToken.address, takerToken.address, maker, taker, makerFillableAmount, takerFillableAmount);
+                  const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+                  const takerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, taker);
+                  const fillAmountInBaseUnits = new BigNumber(2);
+                  const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                  zeroEx.orderStateWatcher.addOrder(signedOrder);
+                  let eventCount = 0;
+                  const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                      eventCount++;
+                      expect(orderState.isValid).to.be.true();
+                      const validOrderState = orderState as OrderStateValid;
+                      expect(validOrderState.orderHash).to.be.equal(orderHash);
+                      const orderRelevantState = validOrderState.orderRelevantState;
+                      expect(orderRelevantState.remainingFillableMakerTokenAmount).to.be.bignumber.equal(
+                          new BigNumber(16));
+                      if (eventCount === 2) {
+                          done();
+                      }
+                  });
+                  zeroEx.orderStateWatcher.subscribe(callback);
+                  const shouldThrowOnInsufficientBalanceOrAllowance = true;
+                  await zeroEx.exchange.fillOrderAsync(
+                      signedOrder, fillAmountInBaseUnits, shouldThrowOnInsufficientBalanceOrAllowance, taker,
+                  );
+              })().catch(done);
+          });
+          it('should equal approved amount when approved amount is lowest', (done: DoneCallback) => {
+              (async () => {
+                  signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                      makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                  );
+
+                  const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+
+                  const changedMakerApprovalAmount = new BigNumber(3);
+                  zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                  const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                      const validOrderState = orderState as OrderStateValid;
+                      const orderRelevantState = validOrderState.orderRelevantState;
+                      expect(orderRelevantState.remainingFillableMakerTokenAmount).to.be.bignumber.equal(
+                          changedMakerApprovalAmount);
+                      done();
+                  });
+                  zeroEx.orderStateWatcher.subscribe(callback);
+                  await zeroEx.token.setProxyAllowanceAsync(makerToken.address, maker, changedMakerApprovalAmount);
+              })().catch(done);
+          });
+          it('should equal balance amount when balance amount is lowest', (done: DoneCallback) => {
+              (async () => {
+                  signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                      makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                  );
+
+                  const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+
+                  const remainingAmount = new BigNumber(1);
+                  const transferAmount = makerBalance.sub(remainingAmount);
+                  zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                  const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                      const validOrderState = orderState as OrderStateValid;
+                      const orderRelevantState = validOrderState.orderRelevantState;
+                      expect(orderRelevantState.remainingFillableMakerTokenAmount).to.be.bignumber.equal(
+                          remainingAmount);
+                      done();
+                  });
+                  zeroEx.orderStateWatcher.subscribe(callback);
+                  await zeroEx.token.transferAsync(
+                      makerToken.address, maker, ZeroEx.NULL_ADDRESS, transferAmount);
+              })().catch(done);
+          });
+        });
+        it('should emit orderStateInvalid when watched order cancelled', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    expect(orderState.isValid).to.be.false();
+                    const invalidOrderState = orderState as OrderStateInvalid;
+                    expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                    expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.OrderRemainingFillAmountZero);
+                    done();
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+
+                const shouldThrowOnInsufficientBalanceOrAllowance = true;
+                await zeroEx.exchange.cancelOrderAsync(signedOrder, fillableAmount);
+            })().catch(done);
+        });
+        it('should emit orderStateValid when watched order partially cancelled', (done: DoneCallback) => {
+            (async () => {
+                signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                    makerToken.address, takerToken.address, maker, taker, fillableAmount,
+                );
+
+                const makerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, maker);
+                const takerBalance = await zeroEx.token.getBalanceAsync(makerToken.address, taker);
+
+                const cancelAmountInBaseUnits = new BigNumber(2);
+                const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+                zeroEx.orderStateWatcher.addOrder(signedOrder);
+
+                const callback = reportCallbackErrors(done)((orderState: OrderState) => {
+                    expect(orderState.isValid).to.be.true();
+                    const validOrderState = orderState as OrderStateValid;
+                    expect(validOrderState.orderHash).to.be.equal(orderHash);
+                    const orderRelevantState = validOrderState.orderRelevantState;
+                    expect(orderRelevantState.canceledTakerTokenAmount).to.be.bignumber.equal(cancelAmountInBaseUnits);
+                    done();
+                });
+                zeroEx.orderStateWatcher.subscribe(callback);
+                await zeroEx.exchange.cancelOrderAsync(signedOrder, cancelAmountInBaseUnits);
+            })().catch(done);
+        });
+    });
+});
diff --git a/packages/0x.js/test/order_validation_test.ts b/packages/0x.js/test/order_validation_test.ts
new file mode 100644
index 000000000..4f18742d3
--- /dev/null
+++ b/packages/0x.js/test/order_validation_test.ts
@@ -0,0 +1,327 @@
+import * as chai from 'chai';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import * as Sinon from 'sinon';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx, SignedOrder, Token, ExchangeContractErrs, ZeroExError} from '../src';
+import {TradeSide, TransferType} from '../src/types';
+import {TokenUtils} from './utils/token_utils';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {FillScenarios} from './utils/fill_scenarios';
+import {OrderValidationUtils} from '../src/utils/order_validation_utils';
+import {ExchangeTransferSimulator} from '../src/utils/exchange_transfer_simulator';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+describe('OrderValidation', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let userAddresses: string[];
+    let tokens: Token[];
+    let tokenUtils: TokenUtils;
+    let exchangeContractAddress: string;
+    let zrxTokenAddress: string;
+    let fillScenarios: FillScenarios;
+    let makerTokenAddress: string;
+    let takerTokenAddress: string;
+    let coinbase: string;
+    let makerAddress: string;
+    let takerAddress: string;
+    let feeRecipient: string;
+    let orderValidationUtils: OrderValidationUtils;
+    const fillableAmount = new BigNumber(5);
+    const fillTakerAmount = new BigNumber(5);
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        exchangeContractAddress = await zeroEx.exchange.getContractAddressAsync();
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        [coinbase, makerAddress, takerAddress, feeRecipient] = userAddresses;
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
+        zrxTokenAddress = tokenUtils.getProtocolTokenOrThrow().address;
+        fillScenarios = new FillScenarios(zeroEx, userAddresses, tokens, zrxTokenAddress, exchangeContractAddress);
+        const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+        makerTokenAddress = makerToken.address;
+        takerTokenAddress = takerToken.address;
+        orderValidationUtils = new OrderValidationUtils(zeroEx.token, zeroEx.exchange);
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('validateOrderFillableOrThrowAsync', () => {
+        it('should succeed if the order is fillable', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            await zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            );
+        });
+        it('should succeed if the order is asymmetric and fillable', async () => {
+            const makerFillableAmount = fillableAmount;
+            const takerFillableAmount = fillableAmount.minus(4);
+            const signedOrder = await fillScenarios.createAsymmetricFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                makerFillableAmount, takerFillableAmount,
+            );
+            await zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            );
+        });
+        it('should throw when the order is fully filled or cancelled', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            await zeroEx.exchange.cancelOrderAsync(signedOrder, fillableAmount);
+            return expect(zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderRemainingFillAmountZero);
+        });
+        it('should throw when order is expired', async () => {
+            const expirationInPast = new BigNumber(1496826058); // 7th Jun 2017
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                fillableAmount, expirationInPast,
+            );
+            return expect(zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderFillExpired);
+        });
+    });
+    describe('validateFillOrderAndThrowIfInvalidAsync', () => {
+        it('should throw when the fill amount is zero', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            const zeroFillAmount = new BigNumber(0);
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, zeroFillAmount, takerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderFillAmountZero);
+        });
+        it('should throw when the signature is invalid', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            // 27 <--> 28
+            signedOrder.ecSignature.v = 27 + (28 - signedOrder.ecSignature.v);
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, fillableAmount, takerAddress,
+            )).to.be.rejectedWith(ZeroExError.InvalidSignature);
+        });
+        it('should throw when the order is fully filled or cancelled', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            await zeroEx.exchange.cancelOrderAsync(signedOrder, fillableAmount);
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, fillableAmount, takerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderRemainingFillAmountZero);
+        });
+        it('should throw when sender is not a taker', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            const nonTakerAddress = userAddresses[6];
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, fillTakerAmount, nonTakerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.TransactionSenderIsNotFillOrderTaker);
+        });
+        it('should throw when order is expired', async () => {
+            const expirationInPast = new BigNumber(1496826058); // 7th Jun 2017
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                fillableAmount, expirationInPast,
+            );
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, fillTakerAmount, takerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderFillExpired);
+        });
+        it('should throw when there a rounding error would have occurred', async () => {
+            const makerAmount = new BigNumber(3);
+            const takerAmount = new BigNumber(5);
+            const signedOrder = await fillScenarios.createAsymmetricFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                makerAmount, takerAmount,
+            );
+            const fillTakerAmountThatCausesRoundingError = new BigNumber(3);
+            return expect(zeroEx.exchange.validateFillOrderThrowIfInvalidAsync(
+                signedOrder, fillTakerAmountThatCausesRoundingError, takerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderFillRoundingError);
+        });
+    });
+    describe('#validateFillOrKillOrderAndThrowIfInvalidAsync', () => {
+        it('should throw if remaining fillAmount is less then the desired fillAmount', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            const tooLargeFillAmount = new BigNumber(7);
+            const fillAmountDifference = tooLargeFillAmount.minus(fillableAmount);
+            await zeroEx.token.transferAsync(takerTokenAddress, coinbase, takerAddress, fillAmountDifference);
+            await zeroEx.token.setProxyAllowanceAsync(takerTokenAddress, takerAddress, tooLargeFillAmount);
+            await zeroEx.token.transferAsync(makerTokenAddress, coinbase, makerAddress, fillAmountDifference);
+            await zeroEx.token.setProxyAllowanceAsync(makerTokenAddress, makerAddress, tooLargeFillAmount);
+
+            return expect(zeroEx.exchange.validateFillOrKillOrderThrowIfInvalidAsync(
+                signedOrder, tooLargeFillAmount, takerAddress,
+            )).to.be.rejectedWith(ExchangeContractErrs.InsufficientRemainingFillAmount);
+        });
+    });
+    describe('validateCancelOrderAndThrowIfInvalidAsync', () => {
+        let signedOrder: SignedOrder;
+        let orderHashHex: string;
+        const cancelAmount = new BigNumber(3);
+        beforeEach(async () => {
+            [coinbase, makerAddress, takerAddress] = userAddresses;
+            const [makerToken, takerToken] = tokenUtils.getNonProtocolTokens();
+            makerTokenAddress = makerToken.address;
+            takerTokenAddress = takerToken.address;
+            signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            orderHashHex = ZeroEx.getOrderHashHex(signedOrder);
+        });
+        it('should throw when cancel amount is zero', async () => {
+            const zeroCancelAmount = new BigNumber(0);
+            return expect(zeroEx.exchange.validateCancelOrderThrowIfInvalidAsync(signedOrder, zeroCancelAmount))
+                .to.be.rejectedWith(ExchangeContractErrs.OrderCancelAmountZero);
+        });
+        it('should throw when order is expired', async () => {
+            const expirationInPast = new BigNumber(1496826058); // 7th Jun 2017
+            const expiredSignedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                fillableAmount, expirationInPast,
+            );
+            orderHashHex = ZeroEx.getOrderHashHex(expiredSignedOrder);
+            return expect(zeroEx.exchange.validateCancelOrderThrowIfInvalidAsync(expiredSignedOrder, cancelAmount))
+                .to.be.rejectedWith(ExchangeContractErrs.OrderCancelExpired);
+        });
+        it('should throw when order is already cancelled or filled', async () => {
+            await zeroEx.exchange.cancelOrderAsync(signedOrder, fillableAmount);
+            return expect(zeroEx.exchange.validateCancelOrderThrowIfInvalidAsync(signedOrder, fillableAmount))
+                .to.be.rejectedWith(ExchangeContractErrs.OrderAlreadyCancelledOrFilled);
+        });
+    });
+    describe('#validateFillOrderBalancesAllowancesThrowIfInvalidAsync', () => {
+        let exchangeTransferSimulator: ExchangeTransferSimulator;
+        let transferFromAsync: Sinon.SinonSpy;
+        const bigNumberMatch = (expected: BigNumber) => {
+            return Sinon.match((value: BigNumber) => value.eq(expected));
+        };
+        beforeEach('create exchangeTransferSimulator', async () => {
+            exchangeTransferSimulator = new ExchangeTransferSimulator(zeroEx.token);
+            transferFromAsync = Sinon.spy();
+            exchangeTransferSimulator.transferFromAsync = transferFromAsync as any;
+        });
+        it('should call exchangeTransferSimulator.transferFrom in a correct order', async () => {
+            const makerFee = new BigNumber(2);
+            const takerFee = new BigNumber(2);
+            const signedOrder = await fillScenarios.createFillableSignedOrderWithFeesAsync(
+                makerTokenAddress, takerTokenAddress, makerFee, takerFee,
+                makerAddress, takerAddress, fillableAmount, feeRecipient,
+            );
+            await orderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
+                exchangeTransferSimulator, signedOrder, fillableAmount, takerAddress, zrxTokenAddress,
+            );
+            expect(transferFromAsync.callCount).to.be.equal(4);
+            expect(
+                transferFromAsync.getCall(0).calledWith(
+                    makerTokenAddress, makerAddress, takerAddress, bigNumberMatch(fillableAmount),
+                    TradeSide.Maker, TransferType.Trade,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(1).calledWith(
+                    takerTokenAddress, takerAddress, makerAddress, bigNumberMatch(fillableAmount),
+                    TradeSide.Taker, TransferType.Trade,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(2).calledWith(
+                    zrxTokenAddress, makerAddress, feeRecipient, bigNumberMatch(makerFee),
+                    TradeSide.Maker, TransferType.Fee,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(3).calledWith(
+                    zrxTokenAddress, takerAddress, feeRecipient, bigNumberMatch(takerFee),
+                    TradeSide.Taker, TransferType.Fee,
+                ),
+            ).to.be.true();
+        });
+        it('should call exchangeTransferSimulator.transferFrom with correct values for an open order', async () => {
+            const makerFee = new BigNumber(2);
+            const takerFee = new BigNumber(2);
+            const signedOrder = await fillScenarios.createFillableSignedOrderWithFeesAsync(
+                makerTokenAddress, takerTokenAddress, makerFee, takerFee,
+                makerAddress, ZeroEx.NULL_ADDRESS, fillableAmount, feeRecipient,
+            );
+            await orderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
+                exchangeTransferSimulator, signedOrder, fillableAmount, takerAddress, zrxTokenAddress,
+            );
+            expect(transferFromAsync.callCount).to.be.equal(4);
+            expect(
+                transferFromAsync.getCall(0).calledWith(
+                    makerTokenAddress, makerAddress, takerAddress, bigNumberMatch(fillableAmount),
+                    TradeSide.Maker, TransferType.Trade,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(1).calledWith(
+                    takerTokenAddress, takerAddress, makerAddress, bigNumberMatch(fillableAmount),
+                    TradeSide.Taker, TransferType.Trade,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(2).calledWith(
+                    zrxTokenAddress, makerAddress, feeRecipient, bigNumberMatch(makerFee),
+                    TradeSide.Maker, TransferType.Fee,
+                ),
+            ).to.be.true();
+            expect(
+                transferFromAsync.getCall(3).calledWith(
+                    zrxTokenAddress, takerAddress, feeRecipient, bigNumberMatch(takerFee),
+                    TradeSide.Taker, TransferType.Fee,
+                ),
+            ).to.be.true();
+        });
+        it('should correctly round the fillMakerTokenAmount', async () => {
+            const makerTokenAmount = new BigNumber(3);
+            const takerTokenAmount = new BigNumber(1);
+            const signedOrder = await fillScenarios.createAsymmetricFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, makerTokenAmount, takerTokenAmount,
+            );
+            await orderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
+                exchangeTransferSimulator, signedOrder, takerTokenAmount, takerAddress, zrxTokenAddress,
+            );
+            expect(transferFromAsync.callCount).to.be.equal(4);
+            const makerFillAmount = transferFromAsync.getCall(0).args[3];
+            expect(makerFillAmount).to.be.bignumber.equal(makerTokenAmount);
+        });
+        it('should correctly round the makerFeeAmount', async () => {
+            const makerFee = new BigNumber(2);
+            const takerFee = new BigNumber(4);
+            const signedOrder = await fillScenarios.createFillableSignedOrderWithFeesAsync(
+                makerTokenAddress, takerTokenAddress, makerFee, takerFee, makerAddress, takerAddress,
+                fillableAmount, ZeroEx.NULL_ADDRESS,
+            );
+            const fillTakerTokenAmount = fillableAmount.div(2).round(0);
+            await orderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
+                exchangeTransferSimulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress,
+            );
+            const makerPartialFee = makerFee.div(2);
+            const takerPartialFee = takerFee.div(2);
+            expect(transferFromAsync.callCount).to.be.equal(4);
+            const partialMakerFee = transferFromAsync.getCall(2).args[3];
+            expect(partialMakerFee).to.be.bignumber.equal(makerPartialFee);
+            const partialTakerFee = transferFromAsync.getCall(3).args[3];
+            expect(partialTakerFee).to.be.bignumber.equal(takerPartialFee);
+        });
+    });
+});
diff --git a/packages/0x.js/test/subscription_test.ts b/packages/0x.js/test/subscription_test.ts
new file mode 100644
index 000000000..985fdc1d6
--- /dev/null
+++ b/packages/0x.js/test/subscription_test.ts
@@ -0,0 +1,95 @@
+import 'mocha';
+import * as _ from 'lodash';
+import * as chai from 'chai';
+import * as Sinon from 'sinon';
+import {chaiSetup} from './utils/chai_setup';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import promisify = require('es6-promisify');
+import {web3Factory} from './utils/web3_factory';
+import {
+    ZeroEx,
+    ZeroExError,
+    Token,
+    ApprovalContractEventArgs,
+    TokenEvents,
+    LogEvent,
+} from '../src';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {TokenUtils} from './utils/token_utils';
+import {DoneCallback, BlockParamLiteral} from '../src/types';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+describe('SubscriptionTest', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let userAddresses: string[];
+    let tokens: Token[];
+    let tokenUtils: TokenUtils;
+    let coinbase: string;
+    let addressWithoutFunds: string;
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
+        coinbase = userAddresses[0];
+        addressWithoutFunds = userAddresses[1];
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('#subscribe', () => {
+        const indexFilterValues = {};
+        const shouldThrowOnInsufficientBalanceOrAllowance = true;
+        let tokenAddress: string;
+        const transferAmount = new BigNumber(42);
+        const allowanceAmount = new BigNumber(42);
+        let stubs: Sinon.SinonStub[] = [];
+        before(() => {
+            const token = tokens[0];
+            tokenAddress = token.address;
+        });
+        afterEach(() => {
+            zeroEx.token.unsubscribeAll();
+            _.each(stubs, s => s.restore());
+            stubs = [];
+        });
+        it('Should receive the Error when an error occurs', (done: DoneCallback) => {
+            (async () => {
+                const callback = (err: Error, logEvent: LogEvent<ApprovalContractEventArgs>) => {
+                    expect(err).to.not.be.null();
+                    expect(logEvent).to.be.undefined();
+                    done();
+                };
+                stubs = [
+                  Sinon.stub((zeroEx as any)._web3Wrapper, 'getBlockAsync')
+                   .throws("JSON RPC error")
+                ]
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Approval, indexFilterValues, callback);
+                await zeroEx.token.setAllowanceAsync(tokenAddress, coinbase, addressWithoutFunds, allowanceAmount);
+            })().catch(done);
+         });
+        it('Should allow unsubscribeAll to be called successfully after an error', (done: DoneCallback) => {
+            (async () => {
+                const callback = (err: Error, logEvent: LogEvent<ApprovalContractEventArgs>) => { };
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Approval, indexFilterValues, callback);
+                stubs = [
+                  Sinon.stub((zeroEx as any)._web3Wrapper, 'getBlockAsync')
+                   .throws("JSON RPC error")
+                ]
+                zeroEx.token.unsubscribeAll();
+                done();
+            })().catch(done);
+         });
+    })
+  })
\ No newline at end of file
diff --git a/packages/0x.js/test/token_registry_wrapper_test.ts b/packages/0x.js/test/token_registry_wrapper_test.ts
new file mode 100644
index 000000000..6b5dd517e
--- /dev/null
+++ b/packages/0x.js/test/token_registry_wrapper_test.ts
@@ -0,0 +1,123 @@
+import * as _ from 'lodash';
+import 'mocha';
+import * as chai from 'chai';
+import {SchemaValidator, schemas} from '0x-json-schemas';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx, Token} from '../src';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+const TOKEN_REGISTRY_SIZE_AFTER_MIGRATION = 7;
+
+describe('TokenRegistryWrapper', () => {
+    let zeroEx: ZeroEx;
+    let tokens: Token[];
+    const tokenAddressBySymbol: {[symbol: string]: string} = {};
+    const tokenAddressByName: {[symbol: string]: string} = {};
+    const tokenBySymbol: {[symbol: string]: Token} = {};
+    const tokenByName: {[symbol: string]: Token} = {};
+    const registeredSymbol = 'ZRX';
+    const registeredName = '0x Protocol Token';
+    const unregisteredSymbol = 'MAL';
+    const unregisteredName = 'Malicious Token';
+    before(async () => {
+        const web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        _.map(tokens, token => {
+            tokenAddressBySymbol[token.symbol] = token.address;
+            tokenAddressByName[token.name] = token.address;
+            tokenBySymbol[token.symbol] = token;
+            tokenByName[token.name] = token;
+        });
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('#getTokensAsync', () => {
+        it('should return all the tokens added to the tokenRegistry during the migration', async () => {
+            expect(tokens).to.have.lengthOf(TOKEN_REGISTRY_SIZE_AFTER_MIGRATION);
+
+            const schemaValidator = new SchemaValidator();
+            _.each(tokens, token => {
+                const validationResult = schemaValidator.validate(token, schemas.tokenSchema);
+                expect(validationResult.errors).to.have.lengthOf(0);
+            });
+        });
+    });
+    describe('#getTokenAddressesAsync', () => {
+        it('should return all the token addresses added to the tokenRegistry during the migration', async () => {
+            const tokenAddresses = await zeroEx.tokenRegistry.getTokenAddressesAsync();
+            expect(tokenAddresses).to.have.lengthOf(TOKEN_REGISTRY_SIZE_AFTER_MIGRATION);
+
+            const schemaValidator = new SchemaValidator();
+            _.each(tokenAddresses, tokenAddress => {
+                const validationResult = schemaValidator.validate(tokenAddress, schemas.addressSchema);
+                expect(validationResult.errors).to.have.lengthOf(0);
+                expect(tokenAddress).to.not.be.equal(ZeroEx.NULL_ADDRESS);
+            });
+        });
+    });
+    describe('#getTokenAddressBySymbol', () => {
+        it('should return correct address for a token in the registry', async () => {
+            const tokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(registeredSymbol);
+            expect(tokenAddress).to.be.equal(tokenAddressBySymbol[registeredSymbol]);
+        });
+        it('should return undefined for a token out of registry', async () => {
+            const tokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(unregisteredSymbol);
+            expect(tokenAddress).to.be.undefined();
+        });
+    });
+    describe('#getTokenAddressByName', () => {
+        it('should return correct address for a token in the registry', async () => {
+            const tokenAddress = await zeroEx.tokenRegistry.getTokenAddressByNameIfExistsAsync(registeredName);
+            expect(tokenAddress).to.be.equal(tokenAddressByName[registeredName]);
+        });
+        it('should return undefined for a token out of registry', async () => {
+            const tokenAddress = await zeroEx.tokenRegistry.getTokenAddressByNameIfExistsAsync(unregisteredName);
+            expect(tokenAddress).to.be.undefined();
+        });
+    });
+    describe('#getTokenBySymbol', () => {
+        it('should return correct token for a token in the registry', async () => {
+            const token = await zeroEx.tokenRegistry.getTokenBySymbolIfExistsAsync(registeredSymbol);
+            expect(token).to.be.deep.equal(tokenBySymbol[registeredSymbol]);
+        });
+        it('should return undefined for a token out of registry', async () => {
+            const token = await zeroEx.tokenRegistry.getTokenBySymbolIfExistsAsync(unregisteredSymbol);
+            expect(token).to.be.undefined();
+        });
+    });
+    describe('#getTokenByName', () => {
+        it('should return correct token for a token in the registry', async () => {
+            const token = await zeroEx.tokenRegistry.getTokenByNameIfExistsAsync(registeredName);
+            expect(token).to.be.deep.equal(tokenByName[registeredName]);
+        });
+        it('should return undefined for a token out of registry', async () => {
+            const token = await zeroEx.tokenRegistry.getTokenByNameIfExistsAsync(unregisteredName);
+            expect(token).to.be.undefined();
+        });
+    });
+    describe('#getTokenIfExistsAsync', () => {
+        it('should return the token added to the tokenRegistry during the migration', async () => {
+            const aToken = tokens[0];
+
+            const token = await zeroEx.tokenRegistry.getTokenIfExistsAsync(aToken.address);
+            const schemaValidator = new SchemaValidator();
+            const validationResult = schemaValidator.validate(token, schemas.tokenSchema);
+            expect(validationResult.errors).to.have.lengthOf(0);
+        });
+        it('should return return undefined when passed a token address not in the tokenRegistry', async () => {
+            const unregisteredTokenAddress = '0x5409ed021d9299bf6814279a6a1411a7e866a631';
+            const tokenIfExists = await zeroEx.tokenRegistry.getTokenIfExistsAsync(unregisteredTokenAddress);
+            expect(tokenIfExists).to.be.undefined();
+        });
+    });
+});
diff --git a/packages/0x.js/test/token_transfer_proxy_wrapper_test.ts b/packages/0x.js/test/token_transfer_proxy_wrapper_test.ts
new file mode 100644
index 000000000..8faef0b30
--- /dev/null
+++ b/packages/0x.js/test/token_transfer_proxy_wrapper_test.ts
@@ -0,0 +1,31 @@
+import * as chai from 'chai';
+import {chaiSetup} from './utils/chai_setup';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx} from '../src';
+import {TokenTransferProxyWrapper} from '../src/contract_wrappers/token_transfer_proxy_wrapper';
+
+chaiSetup.configure();
+const expect = chai.expect;
+
+describe('TokenTransferProxyWrapper', () => {
+    let zeroEx: ZeroEx;
+    before(async () => {
+        const web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+    });
+    describe('#isAuthorizedAsync', () => {
+        it('should return false if the address is not authorized', async () => {
+            const isAuthorized = await zeroEx.proxy.isAuthorizedAsync(ZeroEx.NULL_ADDRESS);
+            expect(isAuthorized).to.be.false();
+        });
+    });
+    describe('#getAuthorizedAddressesAsync', () => {
+        it('should return the list of authorized addresses', async () => {
+            const authorizedAddresses = await zeroEx.proxy.getAuthorizedAddressesAsync();
+            for (const authorizedAddress of authorizedAddresses) {
+                const isAuthorized = await zeroEx.proxy.isAuthorizedAsync(authorizedAddress);
+                expect(isAuthorized).to.be.true();
+            }
+        });
+    });
+});
diff --git a/packages/0x.js/test/token_wrapper_test.ts b/packages/0x.js/test/token_wrapper_test.ts
new file mode 100644
index 000000000..b30762e8c
--- /dev/null
+++ b/packages/0x.js/test/token_wrapper_test.ts
@@ -0,0 +1,477 @@
+import 'mocha';
+import * as chai from 'chai';
+import {chaiSetup} from './utils/chai_setup';
+import * as Web3 from 'web3';
+import BigNumber from 'bignumber.js';
+import promisify = require('es6-promisify');
+import {web3Factory} from './utils/web3_factory';
+import {
+    ZeroEx,
+    ZeroExError,
+    Token,
+    SubscriptionOpts,
+    TokenEvents,
+    ContractEvent,
+    TransferContractEventArgs,
+    ApprovalContractEventArgs,
+    TokenContractEventArgs,
+    LogWithDecodedArgs,
+    LogEvent,
+    DecodedLogEvent,
+} from '../src';
+import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {TokenUtils} from './utils/token_utils';
+import {DoneCallback, BlockParamLiteral} from '../src/types';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle();
+
+describe('TokenWrapper', () => {
+    let web3: Web3;
+    let zeroEx: ZeroEx;
+    let userAddresses: string[];
+    let tokens: Token[];
+    let tokenUtils: TokenUtils;
+    let coinbase: string;
+    let addressWithoutFunds: string;
+    before(async () => {
+        web3 = web3Factory.create();
+        zeroEx = new ZeroEx(web3.currentProvider);
+        userAddresses = await zeroEx.getAvailableAddressesAsync();
+        tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
+        coinbase = userAddresses[0];
+        addressWithoutFunds = userAddresses[1];
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('#transferAsync', () => {
+        let token: Token;
+        let transferAmount: BigNumber;
+        before(() => {
+            token = tokens[0];
+            transferAmount = new BigNumber(42);
+        });
+        it('should successfully transfer tokens', async () => {
+            const fromAddress = coinbase;
+            const toAddress = addressWithoutFunds;
+            const preBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            expect(preBalance).to.be.bignumber.equal(0);
+            const txHash = await zeroEx.token.transferAsync(token.address, fromAddress, toAddress, transferAmount);
+            const receipt = await zeroEx.awaitTransactionMinedAsync(txHash);
+            const postBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            return expect(postBalance).to.be.bignumber.equal(transferAmount);
+        });
+        it('should fail to transfer tokens if fromAddress has an insufficient balance', async () => {
+            const fromAddress = addressWithoutFunds;
+            const toAddress = coinbase;
+            return expect(zeroEx.token.transferAsync(
+                token.address, fromAddress, toAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.InsufficientBalanceForTransfer);
+        });
+        it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
+            const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
+            const fromAddress = coinbase;
+            const toAddress = coinbase;
+            return expect(zeroEx.token.transferAsync(
+                nonExistentTokenAddress, fromAddress, toAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+        });
+    });
+    describe('#transferFromAsync', () => {
+        let token: Token;
+        let toAddress: string;
+        let senderAddress: string;
+        before(async () => {
+            token = tokens[0];
+            toAddress = addressWithoutFunds;
+            senderAddress = userAddresses[2];
+        });
+        it('should fail to transfer tokens if fromAddress has insufficient allowance set', async () => {
+            const fromAddress = coinbase;
+            const transferAmount = new BigNumber(42);
+
+            const fromAddressBalance = await zeroEx.token.getBalanceAsync(token.address, fromAddress);
+            expect(fromAddressBalance).to.be.bignumber.greaterThan(transferAmount);
+
+            const fromAddressAllowance = await zeroEx.token.getAllowanceAsync(token.address, fromAddress,
+                                                                              toAddress);
+            expect(fromAddressAllowance).to.be.bignumber.equal(0);
+
+            return expect(zeroEx.token.transferFromAsync(
+                token.address, fromAddress, toAddress, senderAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.InsufficientAllowanceForTransfer);
+        });
+        it('[regression] should fail to transfer tokens if set allowance for toAddress instead of senderAddress',
+            async () => {
+            const fromAddress = coinbase;
+            const transferAmount = new BigNumber(42);
+
+            await zeroEx.token.setAllowanceAsync(token.address, fromAddress, toAddress, transferAmount);
+
+            return expect(zeroEx.token.transferFromAsync(
+                token.address, fromAddress, toAddress, senderAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.InsufficientAllowanceForTransfer);
+        });
+        it('should fail to transfer tokens if fromAddress has insufficient balance', async () => {
+            const fromAddress = addressWithoutFunds;
+            const transferAmount = new BigNumber(42);
+
+            const fromAddressBalance = await zeroEx.token.getBalanceAsync(token.address, fromAddress);
+            expect(fromAddressBalance).to.be.bignumber.equal(0);
+
+            await zeroEx.token.setAllowanceAsync(token.address, fromAddress, senderAddress, transferAmount);
+            const fromAddressAllowance = await zeroEx.token.getAllowanceAsync(token.address, fromAddress,
+                                                                              senderAddress);
+            expect(fromAddressAllowance).to.be.bignumber.equal(transferAmount);
+
+            return expect(zeroEx.token.transferFromAsync(
+                token.address, fromAddress, toAddress, senderAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.InsufficientBalanceForTransfer);
+        });
+        it('should successfully transfer tokens', async () => {
+            const fromAddress = coinbase;
+
+            const preBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            expect(preBalance).to.be.bignumber.equal(0);
+
+            const transferAmount = new BigNumber(42);
+            await zeroEx.token.setAllowanceAsync(token.address, fromAddress, senderAddress, transferAmount);
+
+            await zeroEx.token.transferFromAsync(token.address, fromAddress, toAddress, senderAddress,
+                                                 transferAmount);
+            const postBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            return expect(postBalance).to.be.bignumber.equal(transferAmount);
+        });
+        it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
+            const fromAddress = coinbase;
+            const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
+            return expect(zeroEx.token.transferFromAsync(
+                nonExistentTokenAddress, fromAddress, toAddress, senderAddress, new BigNumber(42),
+            )).to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+        });
+    });
+    describe('#getBalanceAsync', () => {
+        describe('With web3 provider with accounts', () => {
+            it('should return the balance for an existing ERC20 token', async () => {
+                const token = tokens[0];
+                const ownerAddress = coinbase;
+                const balance = await zeroEx.token.getBalanceAsync(token.address, ownerAddress);
+                const expectedBalance = new BigNumber('1000000000000000000000000000');
+                return expect(balance).to.be.bignumber.equal(expectedBalance);
+            });
+            it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
+                const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
+                const ownerAddress = coinbase;
+                return expect(zeroEx.token.getBalanceAsync(nonExistentTokenAddress, ownerAddress))
+                    .to.be.rejectedWith(ZeroExError.ContractDoesNotExist);
+            });
+            it('should return a balance of 0 for a non-existent owner address', async () => {
+                const token = tokens[0];
+                const nonExistentOwner = '0x198c6ad858f213fb31b6fe809e25040e6b964593';
+                const balance = await zeroEx.token.getBalanceAsync(token.address, nonExistentOwner);
+                const expectedBalance = new BigNumber(0);
+                return expect(balance).to.be.bignumber.equal(expectedBalance);
+            });
+        });
+        describe('With web3 provider without accounts', () => {
+            let zeroExWithoutAccounts: ZeroEx;
+            before(async () => {
+                const hasAddresses = false;
+                const web3WithoutAccounts = web3Factory.create(hasAddresses);
+                zeroExWithoutAccounts = new ZeroEx(web3WithoutAccounts.currentProvider);
+            });
+            it('should return balance even when called with Web3 provider instance without addresses', async () => {
+                    const token = tokens[0];
+                    const ownerAddress = coinbase;
+                    const balance = await zeroExWithoutAccounts.token.getBalanceAsync(token.address, ownerAddress);
+                    const expectedBalance = new BigNumber('1000000000000000000000000000');
+                    return expect(balance).to.be.bignumber.equal(expectedBalance);
+            });
+        });
+    });
+    describe('#setAllowanceAsync', () => {
+        it('should set the spender\'s allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+            const spenderAddress = addressWithoutFunds;
+
+            const allowanceBeforeSet = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress,
+                                                                            spenderAddress);
+            const expectedAllowanceBeforeAllowanceSet = new BigNumber(0);
+            expect(allowanceBeforeSet).to.be.bignumber.equal(expectedAllowanceBeforeAllowanceSet);
+
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setAllowanceAsync(token.address, ownerAddress, spenderAddress, amountInBaseUnits);
+
+            const allowanceAfterSet = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+            const expectedAllowanceAfterAllowanceSet = amountInBaseUnits;
+            return expect(allowanceAfterSet).to.be.bignumber.equal(expectedAllowanceAfterAllowanceSet);
+        });
+    });
+    describe('#setUnlimitedAllowanceAsync', () => {
+        it('should set the unlimited spender\'s allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+            const spenderAddress = addressWithoutFunds;
+
+            await zeroEx.token.setUnlimitedAllowanceAsync(token.address, ownerAddress, spenderAddress);
+            const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+            return expect(allowance).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
+        });
+        it('should reduce the gas cost for transfers including tokens with unlimited allowance support', async () => {
+            const transferAmount = new BigNumber(5);
+            const zrx = tokenUtils.getProtocolTokenOrThrow();
+            const [, userWithNormalAllowance, userWithUnlimitedAllowance] = userAddresses;
+            await zeroEx.token.setAllowanceAsync(zrx.address, coinbase, userWithNormalAllowance, transferAmount);
+            await zeroEx.token.setUnlimitedAllowanceAsync(zrx.address, coinbase, userWithUnlimitedAllowance);
+
+            const initBalanceWithNormalAllowance = await promisify(web3.eth.getBalance)(userWithNormalAllowance);
+            const initBalanceWithUnlimitedAllowance = await promisify(web3.eth.getBalance)(userWithUnlimitedAllowance);
+
+            await zeroEx.token.transferFromAsync(
+                zrx.address, coinbase, userWithNormalAllowance, userWithNormalAllowance, transferAmount,
+            );
+            await zeroEx.token.transferFromAsync(
+                zrx.address, coinbase, userWithUnlimitedAllowance, userWithUnlimitedAllowance, transferAmount,
+            );
+
+            const finalBalanceWithNormalAllowance = await promisify(web3.eth.getBalance)(userWithNormalAllowance);
+            const finalBalanceWithUnlimitedAllowance = await promisify(web3.eth.getBalance)(userWithUnlimitedAllowance);
+
+            const normalGasCost = initBalanceWithNormalAllowance.minus(finalBalanceWithNormalAllowance);
+            const unlimitedGasCost = initBalanceWithUnlimitedAllowance.minus(finalBalanceWithUnlimitedAllowance);
+
+            // In theory the gas cost with unlimited allowance should be smaller, but with testrpc it's actually bigger.
+            // This needs to be investigated in ethereumjs-vm. This test is essentially a repro.
+            // TODO: Make this test pass with inverted assertion.
+            expect(unlimitedGasCost.toNumber()).to.be.gt(normalGasCost.toNumber());
+        });
+    });
+    describe('#getAllowanceAsync', () => {
+        describe('With web3 provider with accounts', () => {
+            it('should get the proxy allowance', async () => {
+                const token = tokens[0];
+                const ownerAddress = coinbase;
+                const spenderAddress = addressWithoutFunds;
+
+                const amountInBaseUnits = new BigNumber(50);
+                await zeroEx.token.setAllowanceAsync(token.address, ownerAddress, spenderAddress, amountInBaseUnits);
+
+                const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+                const expectedAllowance = amountInBaseUnits;
+                return expect(allowance).to.be.bignumber.equal(expectedAllowance);
+            });
+            it('should return 0 if no allowance set yet', async () => {
+                const token = tokens[0];
+                const ownerAddress = coinbase;
+                const spenderAddress = addressWithoutFunds;
+                const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+                const expectedAllowance = new BigNumber(0);
+                return expect(allowance).to.be.bignumber.equal(expectedAllowance);
+            });
+        });
+        describe('With web3 provider without accounts', () => {
+            let zeroExWithoutAccounts: ZeroEx;
+            before(async () => {
+                const hasAddresses = false;
+                const web3WithoutAccounts = web3Factory.create(hasAddresses);
+                zeroExWithoutAccounts = new ZeroEx(web3WithoutAccounts.currentProvider);
+            });
+            it('should get the proxy allowance', async () => {
+                const token = tokens[0];
+                const ownerAddress = coinbase;
+                const spenderAddress = addressWithoutFunds;
+
+                const amountInBaseUnits = new BigNumber(50);
+                await zeroEx.token.setAllowanceAsync(token.address, ownerAddress, spenderAddress, amountInBaseUnits);
+
+                const allowance = await zeroExWithoutAccounts.token.getAllowanceAsync(
+                    token.address, ownerAddress, spenderAddress,
+                );
+                const expectedAllowance = amountInBaseUnits;
+                return expect(allowance).to.be.bignumber.equal(expectedAllowance);
+            });
+        });
+    });
+    describe('#getProxyAllowanceAsync', () => {
+        it('should get the proxy allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setProxyAllowanceAsync(token.address, ownerAddress, amountInBaseUnits);
+
+            const allowance = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
+            const expectedAllowance = amountInBaseUnits;
+            return expect(allowance).to.be.bignumber.equal(expectedAllowance);
+        });
+    });
+    describe('#setProxyAllowanceAsync', () => {
+        it('should set the proxy allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+
+            const allowanceBeforeSet = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
+            const expectedAllowanceBeforeAllowanceSet = new BigNumber(0);
+            expect(allowanceBeforeSet).to.be.bignumber.equal(expectedAllowanceBeforeAllowanceSet);
+
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setProxyAllowanceAsync(token.address, ownerAddress, amountInBaseUnits);
+
+            const allowanceAfterSet = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
+            const expectedAllowanceAfterAllowanceSet = amountInBaseUnits;
+            return expect(allowanceAfterSet).to.be.bignumber.equal(expectedAllowanceAfterAllowanceSet);
+        });
+    });
+    describe('#setUnlimitedProxyAllowanceAsync', () => {
+        it('should set the unlimited proxy allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+
+            await zeroEx.token.setUnlimitedProxyAllowanceAsync(token.address, ownerAddress);
+            const allowance = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
+            return expect(allowance).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
+        });
+    });
+    describe('#subscribe', () => {
+        const indexFilterValues = {};
+        const shouldThrowOnInsufficientBalanceOrAllowance = true;
+        let tokenAddress: string;
+        const transferAmount = new BigNumber(42);
+        const allowanceAmount = new BigNumber(42);
+        before(() => {
+            const token = tokens[0];
+            tokenAddress = token.address;
+        });
+        afterEach(() => {
+            zeroEx.token.unsubscribeAll();
+        });
+        // Hack: Mocha does not allow a test to be both async and have a `done` callback
+        // Since we need to await the receipt of the event in the `subscribe` callback,
+        // we do need both. A hack is to make the top-level a sync fn w/ a done callback and then
+        // wrap the rest of the test in an async block
+        // Source: https://github.com/mochajs/mocha/issues/2407
+        it('Should receive the Transfer event when tokens are transfered', (done: DoneCallback) => {
+            (async () => {
+                const callback = (err: Error, logEvent: DecodedLogEvent<TransferContractEventArgs>) => {
+                    expect(logEvent).to.not.be.undefined();
+                    const args = logEvent.args;
+                    expect(args._from).to.be.equal(coinbase);
+                    expect(args._to).to.be.equal(addressWithoutFunds);
+                    expect(args._value).to.be.bignumber.equal(transferAmount);
+                    done();
+                };
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Transfer, indexFilterValues, callback);
+                await zeroEx.token.transferAsync(tokenAddress, coinbase, addressWithoutFunds, transferAmount);
+            })().catch(done);
+        });
+        it('Should receive the Approval event when allowance is being set', (done: DoneCallback) => {
+            (async () => {
+                const callback = (err: Error, logEvent: DecodedLogEvent<ApprovalContractEventArgs>) => {
+                    expect(logEvent).to.not.be.undefined();
+                    const args = logEvent.args;
+                    expect(args._owner).to.be.equal(coinbase);
+                    expect(args._spender).to.be.equal(addressWithoutFunds);
+                    expect(args._value).to.be.bignumber.equal(allowanceAmount);
+                    done();
+                };
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Approval, indexFilterValues, callback);
+                await zeroEx.token.setAllowanceAsync(tokenAddress, coinbase, addressWithoutFunds, allowanceAmount);
+            })().catch(done);
+        });
+        it('Outstanding subscriptions are cancelled when zeroEx.setProviderAsync called', (done: DoneCallback) => {
+            (async () => {
+                const callbackNeverToBeCalled = (err: Error, logEvent: DecodedLogEvent<ApprovalContractEventArgs>) => {
+                    done(new Error('Expected this subscription to have been cancelled'));
+                };
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Transfer, indexFilterValues, callbackNeverToBeCalled,
+                );
+                const callbackToBeCalled = (err: Error, logEvent: DecodedLogEvent<ApprovalContractEventArgs>) => {
+                    done();
+                };
+                const newProvider = web3Factory.getRpcProvider();
+                await zeroEx.setProviderAsync(newProvider);
+                zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Transfer, indexFilterValues, callbackToBeCalled,
+                );
+                await zeroEx.token.transferAsync(tokenAddress, coinbase, addressWithoutFunds, transferAmount);
+            })().catch(done);
+        });
+        it('Should cancel subscription when unsubscribe called', (done: DoneCallback) => {
+            (async () => {
+                const callbackNeverToBeCalled = (err: Error, logEvent: DecodedLogEvent<ApprovalContractEventArgs>) => {
+                    done(new Error('Expected this subscription to have been cancelled'));
+                };
+                const subscriptionToken = zeroEx.token.subscribe(
+                    tokenAddress, TokenEvents.Transfer, indexFilterValues, callbackNeverToBeCalled);
+                zeroEx.token.unsubscribe(subscriptionToken);
+                await zeroEx.token.transferAsync(tokenAddress, coinbase, addressWithoutFunds, transferAmount);
+                done();
+            })().catch(done);
+        });
+    });
+    describe('#getLogsAsync', () => {
+        let tokenAddress: string;
+        let tokenTransferProxyAddress: string;
+        const subscriptionOpts: SubscriptionOpts = {
+            fromBlock: BlockParamLiteral.Earliest,
+            toBlock: BlockParamLiteral.Latest,
+        };
+        let txHash: string;
+        before(async () => {
+            const token = tokens[0];
+            tokenAddress = token.address;
+            tokenTransferProxyAddress = await zeroEx.proxy.getContractAddressAsync();
+        });
+        it('should get logs with decoded args emitted by Approval', async () => {
+            txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(tokenAddress, coinbase);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            const eventName = TokenEvents.Approval;
+            const indexFilterValues = {};
+            const logs = await zeroEx.token.getLogsAsync<ApprovalContractEventArgs>(
+                tokenAddress, eventName, subscriptionOpts, indexFilterValues,
+            );
+            expect(logs).to.have.length(1);
+            const args = logs[0].args;
+            expect(logs[0].event).to.be.equal(eventName);
+            expect(args._owner).to.be.equal(coinbase);
+            expect(args._spender).to.be.equal(tokenTransferProxyAddress);
+            expect(args._value).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
+        });
+        it('should only get the logs with the correct event name', async () => {
+            txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(tokenAddress, coinbase);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            const differentEventName = TokenEvents.Transfer;
+            const indexFilterValues = {};
+            const logs = await zeroEx.token.getLogsAsync(
+                tokenAddress, differentEventName, subscriptionOpts, indexFilterValues,
+            );
+            expect(logs).to.have.length(0);
+        });
+        it('should only get the logs with the correct indexed fields', async () => {
+            txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(tokenAddress, coinbase);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            txHash = await zeroEx.token.setUnlimitedProxyAllowanceAsync(tokenAddress, addressWithoutFunds);
+            await zeroEx.awaitTransactionMinedAsync(txHash);
+            const eventName = TokenEvents.Approval;
+            const indexFilterValues = {
+                _owner: coinbase,
+            };
+            const logs = await zeroEx.token.getLogsAsync<ApprovalContractEventArgs>(
+                tokenAddress, eventName, subscriptionOpts, indexFilterValues,
+            );
+            expect(logs).to.have.length(1);
+            const args = logs[0].args;
+            expect(args._owner).to.be.equal(coinbase);
+        });
+    });
+});
diff --git a/packages/0x.js/test/utils/blockchain_lifecycle.ts b/packages/0x.js/test/utils/blockchain_lifecycle.ts
new file mode 100644
index 000000000..9a44ccd6f
--- /dev/null
+++ b/packages/0x.js/test/utils/blockchain_lifecycle.ts
@@ -0,0 +1,26 @@
+import {RPC} from './rpc';
+
+export class BlockchainLifecycle {
+    private rpc: RPC;
+    private snapshotIdsStack: number[];
+    constructor() {
+        this.rpc = new RPC();
+        this.snapshotIdsStack = [];
+    }
+    // TODO: In order to run these tests on an actual node, we should check if we are running against
+    // TestRPC, if so, use snapshots, otherwise re-deploy contracts before every test
+    public async startAsync(): Promise<void> {
+        const snapshotId = await this.rpc.takeSnapshotAsync();
+        this.snapshotIdsStack.push(snapshotId);
+    }
+    public async revertAsync(): Promise<void> {
+        const snapshotId = this.snapshotIdsStack.pop() as number;
+        const didRevert = await this.rpc.revertSnapshotAsync(snapshotId);
+        if (!didRevert) {
+            throw new Error(`Snapshot with id #${snapshotId} failed to revert`);
+        }
+    }
+    public async mineABlock(): Promise<void> {
+        await this.rpc.mineBlockAsync();
+    }
+}
diff --git a/packages/0x.js/test/utils/chai_setup.ts b/packages/0x.js/test/utils/chai_setup.ts
new file mode 100644
index 000000000..c18988106
--- /dev/null
+++ b/packages/0x.js/test/utils/chai_setup.ts
@@ -0,0 +1,13 @@
+import * as chai from 'chai';
+import * as dirtyChai from 'dirty-chai';
+import ChaiBigNumber = require('chai-bignumber');
+import chaiAsPromised = require('chai-as-promised');
+
+export const chaiSetup = {
+    configure() {
+        chai.config.includeStack = true;
+        chai.use(ChaiBigNumber());
+        chai.use(dirtyChai);
+        chai.use(chaiAsPromised);
+    },
+};
diff --git a/packages/0x.js/test/utils/constants.ts b/packages/0x.js/test/utils/constants.ts
new file mode 100644
index 000000000..c7d3aebca
--- /dev/null
+++ b/packages/0x.js/test/utils/constants.ts
@@ -0,0 +1,8 @@
+export const constants = {
+    NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
+    RPC_HOST: 'localhost',
+    RPC_PORT: 8545,
+    TESTRPC_NETWORK_ID: 50,
+    KOVAN_RPC_URL: 'https://kovan.infura.io',
+    ROPSTEN_RPC_URL: 'https://ropsten.infura.io',
+};
diff --git a/packages/0x.js/test/utils/fill_scenarios.ts b/packages/0x.js/test/utils/fill_scenarios.ts
new file mode 100644
index 000000000..a0632b12c
--- /dev/null
+++ b/packages/0x.js/test/utils/fill_scenarios.ts
@@ -0,0 +1,114 @@
+import BigNumber from 'bignumber.js';
+import {ZeroEx, Token, SignedOrder} from '../../src';
+import {orderFactory} from '../utils/order_factory';
+import {constants} from './constants';
+
+export class FillScenarios {
+    private zeroEx: ZeroEx;
+    private userAddresses: string[];
+    private tokens: Token[];
+    private coinbase: string;
+    private zrxTokenAddress: string;
+    private exchangeContractAddress: string;
+    constructor(zeroEx: ZeroEx, userAddresses: string[],
+                tokens: Token[], zrxTokenAddress: string, exchangeContractAddress: string) {
+        this.zeroEx = zeroEx;
+        this.userAddresses = userAddresses;
+        this.tokens = tokens;
+        this.coinbase = userAddresses[0];
+        this.zrxTokenAddress = zrxTokenAddress;
+        this.exchangeContractAddress = exchangeContractAddress;
+    }
+    public async createFillableSignedOrderAsync(makerTokenAddress: string, takerTokenAddress: string,
+                                                makerAddress: string, takerAddress: string,
+                                                fillableAmount: BigNumber,
+                                                expirationUnixTimestampSec?: BigNumber):
+                                           Promise<SignedOrder> {
+        return this.createAsymmetricFillableSignedOrderAsync(
+            makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+            fillableAmount, fillableAmount, expirationUnixTimestampSec,
+        );
+    }
+    public async createFillableSignedOrderWithFeesAsync(
+        makerTokenAddress: string, takerTokenAddress: string,
+        makerFee: BigNumber, takerFee: BigNumber,
+        makerAddress: string, takerAddress: string,
+        fillableAmount: BigNumber,
+        feeRecepient: string, expirationUnixTimestampSec?: BigNumber,
+    ): Promise<SignedOrder> {
+        return this.createAsymmetricFillableSignedOrderWithFeesAsync(
+            makerTokenAddress, takerTokenAddress, makerFee, takerFee, makerAddress, takerAddress,
+            fillableAmount, fillableAmount, feeRecepient, expirationUnixTimestampSec,
+        );
+    }
+    public async createAsymmetricFillableSignedOrderAsync(
+        makerTokenAddress: string, takerTokenAddress: string, makerAddress: string, takerAddress: string,
+        makerFillableAmount: BigNumber, takerFillableAmount: BigNumber,
+        expirationUnixTimestampSec?: BigNumber): Promise<SignedOrder> {
+        const makerFee = new BigNumber(0);
+        const takerFee = new BigNumber(0);
+        const feeRecepient = constants.NULL_ADDRESS;
+        return this.createAsymmetricFillableSignedOrderWithFeesAsync(
+            makerTokenAddress, takerTokenAddress, makerFee, takerFee, makerAddress, takerAddress,
+            makerFillableAmount, takerFillableAmount, feeRecepient, expirationUnixTimestampSec,
+        );
+    }
+    public async createPartiallyFilledSignedOrderAsync(makerTokenAddress: string, takerTokenAddress: string,
+                                                       takerAddress: string, fillableAmount: BigNumber,
+                                                       partialFillAmount: BigNumber) {
+        const [makerAddress] = this.userAddresses;
+        const signedOrder = await this.createAsymmetricFillableSignedOrderAsync(
+            makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+            fillableAmount, fillableAmount,
+        );
+        const shouldThrowOnInsufficientBalanceOrAllowance = false;
+        await this.zeroEx.exchange.fillOrderAsync(
+            signedOrder, partialFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+        );
+        return signedOrder;
+    }
+    private async createAsymmetricFillableSignedOrderWithFeesAsync(
+        makerTokenAddress: string, takerTokenAddress: string,
+        makerFee: BigNumber, takerFee: BigNumber,
+        makerAddress: string, takerAddress: string,
+        makerFillableAmount: BigNumber, takerFillableAmount: BigNumber,
+        feeRecepient: string, expirationUnixTimestampSec?: BigNumber): Promise<SignedOrder> {
+
+        await Promise.all([
+            this.increaseBalanceAndAllowanceAsync(makerTokenAddress, makerAddress, makerFillableAmount),
+            this.increaseBalanceAndAllowanceAsync(takerTokenAddress, takerAddress, takerFillableAmount),
+        ]);
+        await Promise.all([
+            this.increaseBalanceAndAllowanceAsync(this.zrxTokenAddress, makerAddress, makerFee),
+            this.increaseBalanceAndAllowanceAsync(this.zrxTokenAddress, takerAddress, takerFee),
+        ]);
+
+        const signedOrder = await orderFactory.createSignedOrderAsync(this.zeroEx,
+            makerAddress, takerAddress, makerFee, takerFee,
+            makerFillableAmount, makerTokenAddress, takerFillableAmount, takerTokenAddress,
+            this.exchangeContractAddress, feeRecepient, expirationUnixTimestampSec);
+        return signedOrder;
+    }
+    private async increaseBalanceAndAllowanceAsync(
+        tokenAddress: string, address: string, amount: BigNumber): Promise<void> {
+        if (amount.isZero() || address === ZeroEx.NULL_ADDRESS) {
+            return; // noop
+        }
+        await Promise.all([
+            this.increaseBalanceAsync(tokenAddress, address, amount),
+            this.increaseAllowanceAsync(tokenAddress, address, amount),
+        ]);
+    }
+    private async increaseBalanceAsync(
+        tokenAddress: string, address: string, amount: BigNumber): Promise<void> {
+        await this.zeroEx.token.transferAsync(tokenAddress, this.coinbase, address, amount);
+    }
+    private async increaseAllowanceAsync(
+        tokenAddress: string, address: string, amount: BigNumber): Promise<void> {
+        const oldMakerAllowance = await this.zeroEx.token.getProxyAllowanceAsync(tokenAddress, address);
+        const newMakerAllowance = oldMakerAllowance.plus(amount);
+        await this.zeroEx.token.setProxyAllowanceAsync(
+            tokenAddress, address, newMakerAllowance,
+        );
+    }
+}
diff --git a/packages/0x.js/test/utils/order_factory.ts b/packages/0x.js/test/utils/order_factory.ts
new file mode 100644
index 000000000..6086e09f7
--- /dev/null
+++ b/packages/0x.js/test/utils/order_factory.ts
@@ -0,0 +1,42 @@
+import * as _ from 'lodash';
+import BigNumber from 'bignumber.js';
+import {ZeroEx, SignedOrder} from '../../src';
+
+export const orderFactory = {
+    async createSignedOrderAsync(
+        zeroEx: ZeroEx,
+        maker: string,
+        taker: string,
+        makerFee: BigNumber,
+        takerFee: BigNumber,
+        makerTokenAmount: BigNumber,
+        makerTokenAddress: string,
+        takerTokenAmount: BigNumber,
+        takerTokenAddress: string,
+        exchangeContractAddress: string,
+        feeRecipient: string,
+        expirationUnixTimestampSec?: BigNumber): Promise<SignedOrder> {
+        const defaultExpirationUnixTimestampSec = new BigNumber(2524604400); // Close to infinite
+        expirationUnixTimestampSec = _.isUndefined(expirationUnixTimestampSec) ?
+            defaultExpirationUnixTimestampSec :
+            expirationUnixTimestampSec;
+        const order = {
+            maker,
+            taker,
+            makerFee,
+            takerFee,
+            makerTokenAmount,
+            takerTokenAmount,
+            makerTokenAddress,
+            takerTokenAddress,
+            salt: ZeroEx.generatePseudoRandomSalt(),
+            exchangeContractAddress,
+            feeRecipient,
+            expirationUnixTimestampSec,
+        };
+        const orderHash = ZeroEx.getOrderHashHex(order);
+        const ecSignature = await zeroEx.signOrderHashAsync(orderHash, maker);
+        const signedOrder: SignedOrder = _.assign(order, {ecSignature});
+        return signedOrder;
+    },
+};
diff --git a/packages/0x.js/test/utils/report_callback_errors.ts b/packages/0x.js/test/utils/report_callback_errors.ts
new file mode 100644
index 000000000..d471b2af2
--- /dev/null
+++ b/packages/0x.js/test/utils/report_callback_errors.ts
@@ -0,0 +1,14 @@
+import { DoneCallback } from '../../src/types';
+
+export const reportCallbackErrors = (done: DoneCallback) => {
+    return (f: (...args: any[]) => void) => {
+        const wrapped = (...args: any[]) => {
+            try {
+                f(...args);
+            } catch (err) {
+                done(err);
+            }
+        };
+        return wrapped;
+    };
+};
diff --git a/packages/0x.js/test/utils/rpc.ts b/packages/0x.js/test/utils/rpc.ts
new file mode 100644
index 000000000..299e72e79
--- /dev/null
+++ b/packages/0x.js/test/utils/rpc.ts
@@ -0,0 +1,57 @@
+import * as ethUtil from 'ethereumjs-util';
+import * as request from 'request-promise-native';
+import {constants} from './constants';
+
+export class RPC {
+    private host: string;
+    private port: number;
+    private id: number;
+    constructor() {
+        this.host = constants.RPC_HOST;
+        this.port = constants.RPC_PORT;
+        this.id = 0;
+    }
+    public async takeSnapshotAsync(): Promise<number> {
+        const method = 'evm_snapshot';
+        const params: any[] = [];
+        const payload = this.toPayload(method, params);
+        const snapshotIdHex = await this.sendAsync(payload);
+        const snapshotId = ethUtil.bufferToInt(ethUtil.toBuffer(snapshotIdHex));
+        return snapshotId;
+    }
+    public async revertSnapshotAsync(snapshotId: number): Promise<boolean> {
+        const method = 'evm_revert';
+        const params = [snapshotId];
+        const payload = this.toPayload(method, params);
+        const didRevert = await this.sendAsync(payload);
+        return didRevert;
+    }
+    public async mineBlockAsync(): Promise<void> {
+        const method = 'evm_mine';
+        const params: any[] = [];
+        const payload = this.toPayload(method, params);
+        await this.sendAsync(payload);
+    }
+    private toPayload(method: string, params: any[] = []): string {
+        const payload = JSON.stringify({
+            id: this.id,
+            method,
+            params,
+        });
+        this.id += 1;
+        return payload;
+    }
+    private async sendAsync(payload: string): Promise<any> {
+        const opts = {
+            method: 'POST',
+            uri: `http://${this.host}:${this.port}`,
+            body: payload,
+            headers: {
+                'content-type': 'application/json',
+            },
+        };
+        const bodyString = await request(opts);
+        const body = JSON.parse(bodyString);
+        return body.result;
+    }
+}
diff --git a/packages/0x.js/test/utils/token_utils.ts b/packages/0x.js/test/utils/token_utils.ts
new file mode 100644
index 000000000..51cb9411c
--- /dev/null
+++ b/packages/0x.js/test/utils/token_utils.ts
@@ -0,0 +1,24 @@
+import * as _ from 'lodash';
+import {Token, InternalZeroExError} from '../../src/types';
+
+const PROTOCOL_TOKEN_SYMBOL = 'ZRX';
+
+export class TokenUtils {
+    private tokens: Token[];
+    constructor(tokens: Token[]) {
+        this.tokens = tokens;
+    }
+    public getProtocolTokenOrThrow(): Token {
+        const zrxToken = _.find(this.tokens, {symbol: PROTOCOL_TOKEN_SYMBOL});
+        if (_.isUndefined(zrxToken)) {
+            throw new Error(InternalZeroExError.ZrxNotInTokenRegistry);
+        }
+        return zrxToken;
+    }
+    public getNonProtocolTokens(): Token[] {
+        const nonProtocolTokens = _.filter(this.tokens, token => {
+            return token.symbol !== PROTOCOL_TOKEN_SYMBOL;
+        });
+        return nonProtocolTokens;
+    }
+}
diff --git a/packages/0x.js/test/utils/web3_factory.ts b/packages/0x.js/test/utils/web3_factory.ts
new file mode 100644
index 000000000..b20070c74
--- /dev/null
+++ b/packages/0x.js/test/utils/web3_factory.ts
@@ -0,0 +1,31 @@
+// HACK: web3 injects XMLHttpRequest into the global scope and ProviderEngine checks XMLHttpRequest
+// to know whether it is running in a browser or node environment. We need it to be undefined since
+// we are not running in a browser env.
+// Filed issue: https://github.com/ethereum/web3.js/issues/844
+(global as any).XMLHttpRequest = undefined;
+import ProviderEngine = require('web3-provider-engine');
+import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
+import * as Web3 from 'web3';
+import {constants} from './constants';
+import {EmptyWalletSubProvider} from '../../src/subproviders/empty_wallet_subprovider';
+
+export const web3Factory = {
+    create(hasAddresses: boolean = true): Web3 {
+        const provider = this.getRpcProvider(hasAddresses);
+        const web3 = new Web3();
+        web3.setProvider(provider);
+        return web3;
+    },
+    getRpcProvider(hasAddresses: boolean = true): Web3.Provider {
+        const provider = new ProviderEngine();
+        const rpcUrl = `http://${constants.RPC_HOST}:${constants.RPC_PORT}`;
+        if (!hasAddresses) {
+            provider.addProvider(new EmptyWalletSubProvider());
+        }
+        provider.addProvider(new RpcSubprovider({
+            rpcUrl,
+        }));
+        provider.start();
+        return provider;
+    },
+};
diff --git a/packages/0x.js/test/web3_wrapper_test.ts b/packages/0x.js/test/web3_wrapper_test.ts
new file mode 100644
index 000000000..d1c2e8e89
--- /dev/null
+++ b/packages/0x.js/test/web3_wrapper_test.ts
@@ -0,0 +1,29 @@
+import * as chai from 'chai';
+import {web3Factory} from './utils/web3_factory';
+import {ZeroEx} from '../src/';
+import {Web3Wrapper} from '../src/web3_wrapper';
+import {constants} from './utils/constants';
+
+chai.config.includeStack = true;
+const expect = chai.expect;
+
+describe('Web3Wrapper', () => {
+    const web3Provider = web3Factory.create().currentProvider;
+    describe('#getNetworkIdIfExistsAsync', () => {
+        it('caches network id requests', async () => {
+            const web3Wrapper = (new ZeroEx(web3Provider) as any)._web3Wrapper as Web3Wrapper;
+            expect((web3Wrapper as any).networkIdIfExists).to.be.undefined();
+            const networkIdIfExists = await web3Wrapper.getNetworkIdIfExistsAsync();
+            expect((web3Wrapper as any).networkIdIfExists).to.be.equal(constants.TESTRPC_NETWORK_ID);
+        });
+        it('invalidates network id cache on setProvider call', async () => {
+            const web3Wrapper = (new ZeroEx(web3Provider) as any)._web3Wrapper as Web3Wrapper;
+            expect((web3Wrapper as any).networkIdIfExists).to.be.undefined();
+            const networkIdIfExists = await web3Wrapper.getNetworkIdIfExistsAsync();
+            expect((web3Wrapper as any).networkIdIfExists).to.be.equal(constants.TESTRPC_NETWORK_ID);
+            const newProvider = web3Factory.create().currentProvider;
+            web3Wrapper.setProvider(newProvider);
+            expect((web3Wrapper as any).networkIdIfExists).to.be.undefined();
+        });
+    });
+});