Split 0x.js into contract-wrappers, order-watcher but keep 0x.js as a unifying library with the same interface

8 files changed, 0 insertions, 687 deletions

diff --git a/packages/0x.js/src/utils/assert.ts b/packages/0x.js/src/utils/assert.ts
deleted file mode 100644
index 2588a4d09..000000000
--- a/packages/0x.js/src/utils/assert.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import { assert as sharedAssert } from '@0xproject/assert';
-// We need those two unused imports because they're actually used by sharedAssert which gets injected here
-// tslint:disable-next-line:no-unused-variable
-import { Schema } from '@0xproject/json-schemas';
-// tslint:disable-next-line:no-unused-variable
-import { ECSignature } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as _ from 'lodash';
-
-import { isValidSignature } from '@0xproject/order-utils';
-
-export const assert = {
-    ...sharedAssert,
-    isValidSignature(orderHash: string, ecSignature: ECSignature, signerAddress: string) {
-        const isValid = isValidSignature(orderHash, ecSignature, signerAddress);
-        this.assert(isValid, `Expected order with hash '${orderHash}' to have a valid signature`);
-    },
-    async isSenderAddressAsync(
-        variableName: string,
-        senderAddressHex: string,
-        web3Wrapper: Web3Wrapper,
-    ): Promise<void> {
-        sharedAssert.isETHAddressHex(variableName, senderAddressHex);
-        const isSenderAddressAvailable = await web3Wrapper.isSenderAddressAvailableAsync(senderAddressHex);
-        sharedAssert.assert(
-            isSenderAddressAvailable,
-            `Specified ${variableName} ${senderAddressHex} isn't available through the supplied web3 provider`,
-        );
-    },
-};
diff --git a/packages/0x.js/src/utils/constants.ts b/packages/0x.js/src/utils/constants.ts
index 07da6745d..7cd5eb574 100644
--- a/packages/0x.js/src/utils/constants.ts
+++ b/packages/0x.js/src/utils/constants.ts
@@ -3,9 +3,4 @@ import { BigNumber } from '@0xproject/utils';
 export const constants = {
     NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
     TESTRPC_NETWORK_ID: 50,
-    INVALID_JUMP_PATTERN: 'invalid JUMP at',
-    OUT_OF_GAS_PATTERN: 'out of gas',
-    INVALID_TAKER_FORMAT: 'instance.taker is not of a type(s) string',
-    UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
-    DEFAULT_BLOCK_POLLING_INTERVAL: 1000,
 };
diff --git a/packages/0x.js/src/utils/decorators.ts b/packages/0x.js/src/utils/decorators.ts
deleted file mode 100644
index f774d734e..000000000
--- a/packages/0x.js/src/utils/decorators.ts
+++ /dev/null
@@ -1,91 +0,0 @@
-import * as _ from 'lodash';
-
-import { AsyncMethod, SyncMethod, ZeroExError } from '../types';
-
-import { constants } from './constants';
-
-type ErrorTransformer = (err: Error) => Error;
-
-const contractCallErrorTransformer = (error: Error) => {
-    if (_.includes(error.message, constants.INVALID_JUMP_PATTERN)) {
-        return new Error(ZeroExError.InvalidJump);
-    }
-    if (_.includes(error.message, constants.OUT_OF_GAS_PATTERN)) {
-        return new Error(ZeroExError.OutOfGas);
-    }
-    return error;
-};
-
-const schemaErrorTransformer = (error: Error) => {
-    if (_.includes(error.message, constants.INVALID_TAKER_FORMAT)) {
-        const errMsg =
-            'Order taker must be of type string. If you want anyone to be able to fill an order - pass ZeroEx.NULL_ADDRESS';
-        return new Error(errMsg);
-    }
-    return error;
-};
-
-/**
- * Source: https://stackoverflow.com/a/29837695/3546986
- */
-const asyncErrorHandlerFactory = (errorTransformer: ErrorTransformer) => {
-    const asyncErrorHandlingDecorator = (
-        target: object,
-        key: string | symbol,
-        descriptor: TypedPropertyDescriptor<AsyncMethod>,
-    ) => {
-        const originalMethod = descriptor.value as AsyncMethod;
-
-        // Do not use arrow syntax here. Use a function expression in
-        // order to use the correct value of `this` in this method
-        // tslint:disable-next-line:only-arrow-functions
-        descriptor.value = async function(...args: any[]) {
-            try {
-                const result = await originalMethod.apply(this, args);
-                return result;
-            } catch (error) {
-                const transformedError = errorTransformer(error);
-                throw transformedError;
-            }
-        };
-
-        return descriptor;
-    };
-
-    return asyncErrorHandlingDecorator;
-};
-
-const syncErrorHandlerFactory = (errorTransformer: ErrorTransformer) => {
-    const syncErrorHandlingDecorator = (
-        target: object,
-        key: string | symbol,
-        descriptor: TypedPropertyDescriptor<SyncMethod>,
-    ) => {
-        const originalMethod = descriptor.value as SyncMethod;
-
-        // Do not use arrow syntax here. Use a function expression in
-        // order to use the correct value of `this` in this method
-        // tslint:disable-next-line:only-arrow-functions
-        descriptor.value = function(...args: any[]) {
-            try {
-                const result = originalMethod.apply(this, args);
-                return result;
-            } catch (error) {
-                const transformedError = errorTransformer(error);
-                throw transformedError;
-            }
-        };
-
-        return descriptor;
-    };
-
-    return syncErrorHandlingDecorator;
-};
-
-// _.flow(f, g) = f ∘ g
-const zeroExErrorTransformer = _.flow(schemaErrorTransformer, contractCallErrorTransformer);
-
-export const decorators = {
-    asyncZeroExErrorHandler: asyncErrorHandlerFactory(zeroExErrorTransformer),
-    syncZeroExErrorHandler: syncErrorHandlerFactory(zeroExErrorTransformer),
-};
diff --git a/packages/0x.js/src/utils/exchange_transfer_simulator.ts b/packages/0x.js/src/utils/exchange_transfer_simulator.ts
deleted file mode 100644
index f8301f5c2..000000000
--- a/packages/0x.js/src/utils/exchange_transfer_simulator.ts
+++ /dev/null
@@ -1,115 +0,0 @@
-import { BlockParamLiteral } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import * as _ from 'lodash';
-
-import { TokenWrapper } from '../contract_wrappers/token_wrapper';
-import { BalanceAndProxyAllowanceLazyStore } from '../stores/balance_proxy_allowance_lazy_store';
-import { ExchangeContractErrs, TradeSide, TransferType } from '../types';
-import { constants } from '../utils/constants';
-
-enum FailureReason {
-    Balance = 'balance',
-    ProxyAllowance = 'proxyAllowance',
-}
-
-const ERR_MSG_MAPPING = {
-    [FailureReason.Balance]: {
-        [TradeSide.Maker]: {
-            [TransferType.Trade]: ExchangeContractErrs.InsufficientMakerBalance,
-            [TransferType.Fee]: ExchangeContractErrs.InsufficientMakerFeeBalance,
-        },
-        [TradeSide.Taker]: {
-            [TransferType.Trade]: ExchangeContractErrs.InsufficientTakerBalance,
-            [TransferType.Fee]: ExchangeContractErrs.InsufficientTakerFeeBalance,
-        },
-    },
-    [FailureReason.ProxyAllowance]: {
-        [TradeSide.Maker]: {
-            [TransferType.Trade]: ExchangeContractErrs.InsufficientMakerAllowance,
-            [TransferType.Fee]: ExchangeContractErrs.InsufficientMakerFeeAllowance,
-        },
-        [TradeSide.Taker]: {
-            [TransferType.Trade]: ExchangeContractErrs.InsufficientTakerAllowance,
-            [TransferType.Fee]: ExchangeContractErrs.InsufficientTakerFeeAllowance,
-        },
-    },
-};
-
-export class ExchangeTransferSimulator {
-    private _store: BalanceAndProxyAllowanceLazyStore;
-    private _UNLIMITED_ALLOWANCE_IN_BASE_UNITS: BigNumber;
-    private static _throwValidationError(
-        failureReason: FailureReason,
-        tradeSide: TradeSide,
-        transferType: TransferType,
-    ): never {
-        const errMsg = ERR_MSG_MAPPING[failureReason][tradeSide][transferType];
-        throw new Error(errMsg);
-    }
-    constructor(token: TokenWrapper, defaultBlock: BlockParamLiteral) {
-        this._store = new BalanceAndProxyAllowanceLazyStore(token, defaultBlock);
-        this._UNLIMITED_ALLOWANCE_IN_BASE_UNITS = token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
-    }
-    /**
-     * Simulates transferFrom call performed by a proxy
-     * @param  tokenAddress      Address of the token to be transferred
-     * @param  from              Owner of the transferred tokens
-     * @param  to                Recipient of the transferred tokens
-     * @param  amountInBaseUnits The amount of tokens being transferred
-     * @param  tradeSide         Is Maker/Taker transferring
-     * @param  transferType      Is it a fee payment or a value transfer
-     */
-    public async transferFromAsync(
-        tokenAddress: string,
-        from: string,
-        to: string,
-        amountInBaseUnits: BigNumber,
-        tradeSide: TradeSide,
-        transferType: TransferType,
-    ): Promise<void> {
-        // HACK: When simulating an open order (e.g taker is NULL_ADDRESS), we don't want to adjust balances/
-        // allowances for the taker. We do however, want to increase the balance of the maker since the maker
-        // might be relying on those funds to fill subsequent orders or pay the order's fees.
-        if (from === constants.NULL_ADDRESS && tradeSide === TradeSide.Taker) {
-            await this._increaseBalanceAsync(tokenAddress, to, amountInBaseUnits);
-            return;
-        }
-        const balance = await this._store.getBalanceAsync(tokenAddress, from);
-        const proxyAllowance = await this._store.getProxyAllowanceAsync(tokenAddress, from);
-        if (proxyAllowance.lessThan(amountInBaseUnits)) {
-            ExchangeTransferSimulator._throwValidationError(FailureReason.ProxyAllowance, tradeSide, transferType);
-        }
-        if (balance.lessThan(amountInBaseUnits)) {
-            ExchangeTransferSimulator._throwValidationError(FailureReason.Balance, tradeSide, transferType);
-        }
-        await this._decreaseProxyAllowanceAsync(tokenAddress, from, amountInBaseUnits);
-        await this._decreaseBalanceAsync(tokenAddress, from, amountInBaseUnits);
-        await this._increaseBalanceAsync(tokenAddress, to, amountInBaseUnits);
-    }
-    private async _decreaseProxyAllowanceAsync(
-        tokenAddress: string,
-        userAddress: string,
-        amountInBaseUnits: BigNumber,
-    ): Promise<void> {
-        const proxyAllowance = await this._store.getProxyAllowanceAsync(tokenAddress, userAddress);
-        if (!proxyAllowance.eq(this._UNLIMITED_ALLOWANCE_IN_BASE_UNITS)) {
-            this._store.setProxyAllowance(tokenAddress, userAddress, proxyAllowance.minus(amountInBaseUnits));
-        }
-    }
-    private async _increaseBalanceAsync(
-        tokenAddress: string,
-        userAddress: string,
-        amountInBaseUnits: BigNumber,
-    ): Promise<void> {
-        const balance = await this._store.getBalanceAsync(tokenAddress, userAddress);
-        this._store.setBalance(tokenAddress, userAddress, balance.plus(amountInBaseUnits));
-    }
-    private async _decreaseBalanceAsync(
-        tokenAddress: string,
-        userAddress: string,
-        amountInBaseUnits: BigNumber,
-    ): Promise<void> {
-        const balance = await this._store.getBalanceAsync(tokenAddress, userAddress);
-        this._store.setBalance(tokenAddress, userAddress, balance.minus(amountInBaseUnits));
-    }
-}
diff --git a/packages/0x.js/src/utils/filter_utils.ts b/packages/0x.js/src/utils/filter_utils.ts
deleted file mode 100644
index c5df7321e..000000000
--- a/packages/0x.js/src/utils/filter_utils.ts
+++ /dev/null
@@ -1,95 +0,0 @@
-import {
-    ConstructorAbi,
-    ContractAbi,
-    EventAbi,
-    FallbackAbi,
-    FilterObject,
-    LogEntry,
-    MethodAbi,
-} from '@0xproject/types';
-import * as ethUtil from 'ethereumjs-util';
-import * as jsSHA3 from 'js-sha3';
-import * as _ from 'lodash';
-import * as uuid from 'uuid/v4';
-
-import { BlockRange, ContractEvents, IndexedFilterValues } from '../types';
-
-const TOPIC_LENGTH = 32;
-
-export const filterUtils = {
-    generateUUID(): string {
-        return uuid();
-    },
-    getFilter(
-        address: string,
-        eventName: ContractEvents,
-        indexFilterValues: IndexedFilterValues,
-        abi: ContractAbi,
-        blockRange?: BlockRange,
-    ): FilterObject {
-        const eventAbi = _.find(abi, { name: eventName }) as EventAbi;
-        const eventSignature = filterUtils.getEventSignatureFromAbiByName(eventAbi, eventName);
-        const topicForEventSignature = ethUtil.addHexPrefix(jsSHA3.keccak256(eventSignature));
-        const topicsForIndexedArgs = filterUtils.getTopicsForIndexedArgs(eventAbi, indexFilterValues);
-        const topics = [topicForEventSignature, ...topicsForIndexedArgs];
-        let filter: FilterObject = {
-            address,
-            topics,
-        };
-        if (!_.isUndefined(blockRange)) {
-            filter = {
-                ...blockRange,
-                ...filter,
-            };
-        }
-        return filter;
-    },
-    getEventSignatureFromAbiByName(eventAbi: EventAbi, eventName: ContractEvents): string {
-        const types = _.map(eventAbi.inputs, 'type');
-        const signature = `${eventAbi.name}(${types.join(',')})`;
-        return signature;
-    },
-    getTopicsForIndexedArgs(abi: EventAbi, indexFilterValues: IndexedFilterValues): Array<string | null> {
-        const topics: Array<string | null> = [];
-        for (const eventInput of abi.inputs) {
-            if (!eventInput.indexed) {
-                continue;
-            }
-            if (_.isUndefined(indexFilterValues[eventInput.name])) {
-                // Null is a wildcard topic in a JSON-RPC call
-                topics.push(null);
-            } else {
-                const value = indexFilterValues[eventInput.name] as string;
-                const buffer = ethUtil.toBuffer(value);
-                const paddedBuffer = ethUtil.setLengthLeft(buffer, TOPIC_LENGTH);
-                const topic = ethUtil.bufferToHex(paddedBuffer);
-                topics.push(topic);
-            }
-        }
-        return topics;
-    },
-    matchesFilter(log: LogEntry, filter: FilterObject): boolean {
-        if (!_.isUndefined(filter.address) && log.address !== filter.address) {
-            return false;
-        }
-        if (!_.isUndefined(filter.topics)) {
-            return filterUtils.matchesTopics(log.topics, filter.topics);
-        }
-        return true;
-    },
-    matchesTopics(logTopics: string[], filterTopics: Array<string[] | string | null>): boolean {
-        const matchesTopic = _.zipWith(logTopics, filterTopics, filterUtils.matchesTopic.bind(filterUtils));
-        const matchesTopics = _.every(matchesTopic);
-        return matchesTopics;
-    },
-    matchesTopic(logTopic: string, filterTopic: string[] | string | null): boolean {
-        if (_.isArray(filterTopic)) {
-            return _.includes(filterTopic, logTopic);
-        }
-        if (_.isString(filterTopic)) {
-            return filterTopic === logTopic;
-        }
-        // null topic is a wildcard
-        return true;
-    },
-};
diff --git a/packages/0x.js/src/utils/order_state_utils.ts b/packages/0x.js/src/utils/order_state_utils.ts
deleted file mode 100644
index b0310d8a8..000000000
--- a/packages/0x.js/src/utils/order_state_utils.ts
+++ /dev/null
@@ -1,138 +0,0 @@
-import { SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import * as _ from 'lodash';
-
-import { ZeroEx } from '../0x';
-import { BalanceAndProxyAllowanceFetcher } from '../abstract/balance_and_proxy_allowance_fetcher';
-import { OrderFilledCancelledFetcher } from '../abstract/order_filled_cancelled_fetcher';
-import { ExchangeWrapper } from '../contract_wrappers/exchange_wrapper';
-import { RemainingFillableCalculator } from '../order_watcher/remaining_fillable_calculator';
-import { ExchangeContractErrs, OrderRelevantState, OrderState, OrderStateInvalid, OrderStateValid } from '../types';
-
-const ACCEPTABLE_RELATIVE_ROUNDING_ERROR = 0.0001;
-
-export class OrderStateUtils {
-    private _balanceAndProxyAllowanceFetcher: BalanceAndProxyAllowanceFetcher;
-    private _orderFilledCancelledFetcher: OrderFilledCancelledFetcher;
-    private static _validateIfOrderIsValid(signedOrder: SignedOrder, orderRelevantState: OrderRelevantState): void {
-        const unavailableTakerTokenAmount = orderRelevantState.cancelledTakerTokenAmount.add(
-            orderRelevantState.filledTakerTokenAmount,
-        );
-        const availableTakerTokenAmount = signedOrder.takerTokenAmount.minus(unavailableTakerTokenAmount);
-        if (availableTakerTokenAmount.eq(0)) {
-            throw new Error(ExchangeContractErrs.OrderRemainingFillAmountZero);
-        }
-
-        if (orderRelevantState.makerBalance.eq(0)) {
-            throw new Error(ExchangeContractErrs.InsufficientMakerBalance);
-        }
-        if (orderRelevantState.makerProxyAllowance.eq(0)) {
-            throw new Error(ExchangeContractErrs.InsufficientMakerAllowance);
-        }
-        if (!signedOrder.makerFee.eq(0)) {
-            if (orderRelevantState.makerFeeBalance.eq(0)) {
-                throw new Error(ExchangeContractErrs.InsufficientMakerFeeBalance);
-            }
-            if (orderRelevantState.makerFeeProxyAllowance.eq(0)) {
-                throw new Error(ExchangeContractErrs.InsufficientMakerFeeAllowance);
-            }
-        }
-        const minFillableTakerTokenAmountWithinNoRoundingErrorRange = signedOrder.takerTokenAmount
-            .dividedBy(ACCEPTABLE_RELATIVE_ROUNDING_ERROR)
-            .dividedBy(signedOrder.makerTokenAmount);
-        if (
-            orderRelevantState.remainingFillableTakerTokenAmount.lessThan(
-                minFillableTakerTokenAmountWithinNoRoundingErrorRange,
-            )
-        ) {
-            throw new Error(ExchangeContractErrs.OrderFillRoundingError);
-        }
-    }
-    constructor(
-        balanceAndProxyAllowanceFetcher: BalanceAndProxyAllowanceFetcher,
-        orderFilledCancelledFetcher: OrderFilledCancelledFetcher,
-    ) {
-        this._balanceAndProxyAllowanceFetcher = balanceAndProxyAllowanceFetcher;
-        this._orderFilledCancelledFetcher = orderFilledCancelledFetcher;
-    }
-    public async getOrderStateAsync(signedOrder: SignedOrder): Promise<OrderState> {
-        const orderRelevantState = await this.getOrderRelevantStateAsync(signedOrder);
-        const orderHash = ZeroEx.getOrderHashHex(signedOrder);
-        try {
-            OrderStateUtils._validateIfOrderIsValid(signedOrder, orderRelevantState);
-            const orderState: OrderStateValid = {
-                isValid: true,
-                orderHash,
-                orderRelevantState,
-            };
-            return orderState;
-        } catch (err) {
-            const orderState: OrderStateInvalid = {
-                isValid: false,
-                orderHash,
-                error: err.message,
-            };
-            return orderState;
-        }
-    }
-    public async getOrderRelevantStateAsync(signedOrder: SignedOrder): Promise<OrderRelevantState> {
-        // HACK: We access the private property here but otherwise the interface will be less nice.
-        // If we pass it from the instantiator - there is no opportunity to get it there
-        // because JS doesn't support async constructors.
-        // Moreover - it's cached under the hood so it's equivalent to an async constructor.
-        const exchange = (this._orderFilledCancelledFetcher as any)._exchangeWrapper as ExchangeWrapper;
-        const zrxTokenAddress = exchange.getZRXTokenAddress();
-        const orderHash = ZeroEx.getOrderHashHex(signedOrder);
-        const makerBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(
-            signedOrder.makerTokenAddress,
-            signedOrder.maker,
-        );
-        const makerProxyAllowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
-            signedOrder.makerTokenAddress,
-            signedOrder.maker,
-        );
-        const makerFeeBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(
-            zrxTokenAddress,
-            signedOrder.maker,
-        );
-        const makerFeeProxyAllowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
-            zrxTokenAddress,
-            signedOrder.maker,
-        );
-        const filledTakerTokenAmount = await this._orderFilledCancelledFetcher.getFilledTakerAmountAsync(orderHash);
-        const cancelledTakerTokenAmount = await this._orderFilledCancelledFetcher.getCancelledTakerAmountAsync(
-            orderHash,
-        );
-        const unavailableTakerTokenAmount = await exchange.getUnavailableTakerAmountAsync(orderHash);
-        const totalMakerTokenAmount = signedOrder.makerTokenAmount;
-        const totalTakerTokenAmount = signedOrder.takerTokenAmount;
-        const remainingTakerTokenAmount = totalTakerTokenAmount.minus(unavailableTakerTokenAmount);
-        const remainingMakerTokenAmount = remainingTakerTokenAmount
-            .times(totalMakerTokenAmount)
-            .dividedToIntegerBy(totalTakerTokenAmount);
-        const transferrableMakerTokenAmount = BigNumber.min([makerProxyAllowance, makerBalance]);
-        const transferrableFeeTokenAmount = BigNumber.min([makerFeeProxyAllowance, makerFeeBalance]);
-
-        const isMakerTokenZRX = signedOrder.makerTokenAddress === zrxTokenAddress;
-        const remainingFillableCalculator = new RemainingFillableCalculator(
-            signedOrder,
-            isMakerTokenZRX,
-            transferrableMakerTokenAmount,
-            transferrableFeeTokenAmount,
-            remainingMakerTokenAmount,
-        );
-        const remainingFillableMakerTokenAmount = remainingFillableCalculator.computeRemainingMakerFillable();
-        const remainingFillableTakerTokenAmount = remainingFillableCalculator.computeRemainingTakerFillable();
-        const orderRelevantState = {
-            makerBalance,
-            makerProxyAllowance,
-            makerFeeBalance,
-            makerFeeProxyAllowance,
-            filledTakerTokenAmount,
-            cancelledTakerTokenAmount,
-            remainingFillableMakerTokenAmount,
-            remainingFillableTakerTokenAmount,
-        };
-        return orderRelevantState;
-    }
-}
diff --git a/packages/0x.js/src/utils/order_validation_utils.ts b/packages/0x.js/src/utils/order_validation_utils.ts
deleted file mode 100644
index a13c3dc04..000000000
--- a/packages/0x.js/src/utils/order_validation_utils.ts
+++ /dev/null
@@ -1,199 +0,0 @@
-import { getOrderHashHex, OrderError } from '@0xproject/order-utils';
-import { Order, SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import * as _ from 'lodash';
-
-import { ZeroEx } from '../0x';
-import { ExchangeWrapper } from '../contract_wrappers/exchange_wrapper';
-import { ExchangeContractErrs, TradeSide, TransferType, ZeroExError } from '../types';
-import { constants } from '../utils/constants';
-import { utils } from '../utils/utils';
-
-import { ExchangeTransferSimulator } from './exchange_transfer_simulator';
-
-export class OrderValidationUtils {
-    private _exchangeWrapper: ExchangeWrapper;
-    public static validateCancelOrderThrowIfInvalid(
-        order: Order,
-        cancelTakerTokenAmount: BigNumber,
-        unavailableTakerTokenAmount: BigNumber,
-    ): void {
-        if (cancelTakerTokenAmount.eq(0)) {
-            throw new Error(ExchangeContractErrs.OrderCancelAmountZero);
-        }
-        if (order.takerTokenAmount.eq(unavailableTakerTokenAmount)) {
-            throw new Error(ExchangeContractErrs.OrderAlreadyCancelledOrFilled);
-        }
-        const currentUnixTimestampSec = utils.getCurrentUnixTimestampSec();
-        if (order.expirationUnixTimestampSec.lessThan(currentUnixTimestampSec)) {
-            throw new Error(ExchangeContractErrs.OrderCancelExpired);
-        }
-    }
-    public static async validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
-        exchangeTradeEmulator: ExchangeTransferSimulator,
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        senderAddress: string,
-        zrxTokenAddress: string,
-    ): Promise<void> {
-        const fillMakerTokenAmount = OrderValidationUtils._getPartialAmount(
-            fillTakerTokenAmount,
-            signedOrder.takerTokenAmount,
-            signedOrder.makerTokenAmount,
-        );
-        await exchangeTradeEmulator.transferFromAsync(
-            signedOrder.makerTokenAddress,
-            signedOrder.maker,
-            senderAddress,
-            fillMakerTokenAmount,
-            TradeSide.Maker,
-            TransferType.Trade,
-        );
-        await exchangeTradeEmulator.transferFromAsync(
-            signedOrder.takerTokenAddress,
-            senderAddress,
-            signedOrder.maker,
-            fillTakerTokenAmount,
-            TradeSide.Taker,
-            TransferType.Trade,
-        );
-        const makerFeeAmount = OrderValidationUtils._getPartialAmount(
-            fillTakerTokenAmount,
-            signedOrder.takerTokenAmount,
-            signedOrder.makerFee,
-        );
-        await exchangeTradeEmulator.transferFromAsync(
-            zrxTokenAddress,
-            signedOrder.maker,
-            signedOrder.feeRecipient,
-            makerFeeAmount,
-            TradeSide.Maker,
-            TransferType.Fee,
-        );
-        const takerFeeAmount = OrderValidationUtils._getPartialAmount(
-            fillTakerTokenAmount,
-            signedOrder.takerTokenAmount,
-            signedOrder.takerFee,
-        );
-        await exchangeTradeEmulator.transferFromAsync(
-            zrxTokenAddress,
-            senderAddress,
-            signedOrder.feeRecipient,
-            takerFeeAmount,
-            TradeSide.Taker,
-            TransferType.Fee,
-        );
-    }
-    private static _validateRemainingFillAmountNotZeroOrThrow(
-        takerTokenAmount: BigNumber,
-        unavailableTakerTokenAmount: BigNumber,
-    ) {
-        if (takerTokenAmount.eq(unavailableTakerTokenAmount)) {
-            throw new Error(ExchangeContractErrs.OrderRemainingFillAmountZero);
-        }
-    }
-    private static _validateOrderNotExpiredOrThrow(expirationUnixTimestampSec: BigNumber) {
-        const currentUnixTimestampSec = utils.getCurrentUnixTimestampSec();
-        if (expirationUnixTimestampSec.lessThan(currentUnixTimestampSec)) {
-            throw new Error(ExchangeContractErrs.OrderFillExpired);
-        }
-    }
-    private static _getPartialAmount(numerator: BigNumber, denominator: BigNumber, target: BigNumber): BigNumber {
-        const fillMakerTokenAmount = numerator
-            .mul(target)
-            .div(denominator)
-            .round(0);
-        return fillMakerTokenAmount;
-    }
-    constructor(exchangeWrapper: ExchangeWrapper) {
-        this._exchangeWrapper = exchangeWrapper;
-    }
-    public async validateOrderFillableOrThrowAsync(
-        exchangeTradeEmulator: ExchangeTransferSimulator,
-        signedOrder: SignedOrder,
-        zrxTokenAddress: string,
-        expectedFillTakerTokenAmount?: BigNumber,
-    ): Promise<void> {
-        const orderHash = getOrderHashHex(signedOrder);
-        const unavailableTakerTokenAmount = await this._exchangeWrapper.getUnavailableTakerAmountAsync(orderHash);
-        OrderValidationUtils._validateRemainingFillAmountNotZeroOrThrow(
-            signedOrder.takerTokenAmount,
-            unavailableTakerTokenAmount,
-        );
-        OrderValidationUtils._validateOrderNotExpiredOrThrow(signedOrder.expirationUnixTimestampSec);
-        let fillTakerTokenAmount = signedOrder.takerTokenAmount.minus(unavailableTakerTokenAmount);
-        if (!_.isUndefined(expectedFillTakerTokenAmount)) {
-            fillTakerTokenAmount = expectedFillTakerTokenAmount;
-        }
-        await OrderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            fillTakerTokenAmount,
-            signedOrder.taker,
-            zrxTokenAddress,
-        );
-    }
-    public async validateFillOrderThrowIfInvalidAsync(
-        exchangeTradeEmulator: ExchangeTransferSimulator,
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        takerAddress: string,
-        zrxTokenAddress: string,
-    ): Promise<BigNumber> {
-        if (fillTakerTokenAmount.eq(0)) {
-            throw new Error(ExchangeContractErrs.OrderFillAmountZero);
-        }
-        const orderHash = getOrderHashHex(signedOrder);
-        if (!ZeroEx.isValidSignature(orderHash, signedOrder.ecSignature, signedOrder.maker)) {
-            throw new Error(OrderError.InvalidSignature);
-        }
-        const unavailableTakerTokenAmount = await this._exchangeWrapper.getUnavailableTakerAmountAsync(orderHash);
-        OrderValidationUtils._validateRemainingFillAmountNotZeroOrThrow(
-            signedOrder.takerTokenAmount,
-            unavailableTakerTokenAmount,
-        );
-        if (signedOrder.taker !== constants.NULL_ADDRESS && signedOrder.taker !== takerAddress) {
-            throw new Error(ExchangeContractErrs.TransactionSenderIsNotFillOrderTaker);
-        }
-        OrderValidationUtils._validateOrderNotExpiredOrThrow(signedOrder.expirationUnixTimestampSec);
-        const remainingTakerTokenAmount = signedOrder.takerTokenAmount.minus(unavailableTakerTokenAmount);
-        const filledTakerTokenAmount = remainingTakerTokenAmount.lessThan(fillTakerTokenAmount)
-            ? remainingTakerTokenAmount
-            : fillTakerTokenAmount;
-        await OrderValidationUtils.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            filledTakerTokenAmount,
-            takerAddress,
-            zrxTokenAddress,
-        );
-
-        const wouldRoundingErrorOccur = await this._exchangeWrapper.isRoundingErrorAsync(
-            filledTakerTokenAmount,
-            signedOrder.takerTokenAmount,
-            signedOrder.makerTokenAmount,
-        );
-        if (wouldRoundingErrorOccur) {
-            throw new Error(ExchangeContractErrs.OrderFillRoundingError);
-        }
-        return filledTakerTokenAmount;
-    }
-    public async validateFillOrKillOrderThrowIfInvalidAsync(
-        exchangeTradeEmulator: ExchangeTransferSimulator,
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        takerAddress: string,
-        zrxTokenAddress: string,
-    ): Promise<void> {
-        const filledTakerTokenAmount = await this.validateFillOrderThrowIfInvalidAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            fillTakerTokenAmount,
-            takerAddress,
-            zrxTokenAddress,
-        );
-        if (filledTakerTokenAmount !== fillTakerTokenAmount) {
-            throw new Error(ExchangeContractErrs.InsufficientRemainingFillAmount);
-        }
-    }
-}
diff --git a/packages/0x.js/src/utils/utils.ts b/packages/0x.js/src/utils/utils.ts
deleted file mode 100644
index af1125632..000000000
--- a/packages/0x.js/src/utils/utils.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { BigNumber } from '@0xproject/utils';
-
-export const utils = {
-    spawnSwitchErr(name: string, value: any): Error {
-        return new Error(`Unexpected switch value: ${value} encountered for ${name}`);
-    },
-    getCurrentUnixTimestampSec(): BigNumber {
-        return new BigNumber(Date.now() / 1000).round();
-    },
-    getCurrentUnixTimestampMs(): BigNumber {
-        return new BigNumber(Date.now());
-    },
-};