How to use the 0x.js.BigNumber function in 0x

chainId: number;
}

interface ItemByChainId {
    [chainId: string]: T;
}

enum RequestedAssetType {
    ETH = 'ETH', // tslint:disable-line:enum-naming
    WETH = 'WETH', // tslint:disable-line:enum-naming
    ZRX = 'ZRX', // tslint:disable-line:enum-naming
}

const FIVE_DAYS_IN_MS = 4.32e8; // TODO: make this configurable
const NULL_ADDRESS = '0x0000000000000000000000000000000000000000';
const ZERO = new BigNumber(0);
const ASSET_AMOUNT = new BigNumber(0.1);

export class Handler {
    private readonly _chainConfigByChainId: ItemByChainId = {};
    private static _createProviderEngine(rpcUrl: string): Web3ProviderEngine {
        if (configs.DISPENSER_PRIVATE_KEY === undefined) {
            throw new Error('Dispenser Private key not found');
        }
        const engine = new Web3ProviderEngine();
        engine.addProvider(new NonceTrackerSubprovider());
        engine.addProvider(new PrivateKeyWalletSubprovider(configs.DISPENSER_PRIVATE_KEY));
        engine.addProvider(new RPCSubprovider(rpcUrl));
        engine.start();
        return engine;
    }
    constructor() {

const contractAddresses = getContractAddressesForChainOrThrow(chainConfig.chainId);
        const order: Order = {
            makerAddress: configs.DISPENSER_ADDRESS,
            takerAddress: req.params.recipient as string,
            makerFee: ZERO,
            takerFee: ZERO,
            makerAssetAmount,
            takerAssetAmount,
            makerAssetData,
            takerAssetData,
            salt: generatePseudoRandomSalt(),
            makerFeeAssetData: makerAssetData,
            takerFeeAssetData: takerAssetData,
            feeRecipientAddress: NULL_ADDRESS,
            senderAddress: NULL_ADDRESS,
            expirationTimeSeconds: new BigNumber(Date.now() + FIVE_DAYS_IN_MS)
                // tslint:disable-next-line:custom-no-magic-numbers
                .div(1000)
                .integerValue(BigNumber.ROUND_FLOOR),
            exchangeAddress: contractAddresses.exchange,
            chainId: chainConfig.chainId,
        };
        const orderHash = orderHashUtils.getOrderHashHex(order);
        const signature = await signatureUtils.ecSignHashAsync(
            chainConfig.web3Wrapper.getProvider(),
            orderHash,
            configs.DISPENSER_ADDRESS,
        );
        const signedOrder: SignedOrder = {
            ...order,
            signature,
        };

const etherTokenAddress = contractAddresses.etherToken;
    const dummyERC721TokenContract = dummyERC721TokenContracts[0];
    if (!dummyERC721TokenContract) {
        console.log('No Dummy ERC721 Tokens deployed on this network');
        return;
    }

    // Initialize the Web3Wrapper, this provides helper functions around fetching
    // account information, balances, general contract logs
    const web3Wrapper = new Web3Wrapper(providerEngine);
    const [maker, taker] = await web3Wrapper.getAvailableAddressesAsync();
    const printUtils = new PrintUtils(web3Wrapper, contractWrappers, { maker, taker }, { WETH: etherTokenAddress });
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset: 1 ERC721 Token
    const makerAssetAmount = new BigNumber(1);
    // the amount the maker is selling of maker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);
    const tokenId = generatePseudoRandomSalt();
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC721AssetData(dummyERC721TokenContract.address, tokenId);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    let txHash;

    // Mint a new ERC721 token for the maker
    const mintTxHash = await dummyERC721TokenContract.mint.sendTransactionAsync(maker, tokenId, { from: maker });
    await printUtils.awaitTransactionMinedSpinnerAsync('Mint ERC721 Token', mintTxHash);
    // Allow the 0x ERC721 Proxy to move ERC721 tokens on behalf of maker
    const isApproved = true;
    const makerERC721ApprovalTxHash = await dummyERC721TokenContract.setApprovalForAll.validateAndSendTransactionAsync(
        contractAddresses.erc721Proxy,
        isApproved,

const [maker, taker, sender] = await web3Wrapper.getAvailableAddressesAsync();
    const feeRecipientAddress = sender;
    const zrxTokenAddress = contractAddresses.zrxToken;
    const etherTokenAddress = contractAddresses.etherToken;
    const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker, sender },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset
    const makerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(5), DECIMALS);
    // the amount the maker wants of taker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);
    // the amount of fees the maker pays in ZRX
    const makerFee = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.01), DECIMALS);
    // the amount of fees the taker pays in ZRX
    const takerFee = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.01), DECIMALS);
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    let txHash;

    const zrxToken = new ERC20TokenContract(zrxTokenAddress, providerEngine);
    // Approve the ERC20 Proxy to move ZRX for maker
    const makerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(
        contractAddresses.erc20Proxy,
        UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
        { from: maker },
    );

// Initialize the Web3Wrapper, this provides helper functions around fetching
    // account information, balances, general contract logs
    const web3Wrapper = new Web3Wrapper(providerEngine);
    const [maker, taker] = await web3Wrapper.getAvailableAddressesAsync();
    const zrxTokenAddress = contractAddresses.zrxToken;
    const etherTokenAddress = contractAddresses.etherToken;
    const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset
    const makerAssetAmount = new BigNumber(100);
    // the amount the maker wants of taker asset
    const takerAssetAmount = new BigNumber(10);
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);

    // Set up the Order and fill it
    const randomExpiration = getRandomFutureDateInSeconds();
    const exchangeAddress = contractAddresses.exchange;

    // Rather than using a random salt, we use an incrementing salt value.
    // When combined with cancelOrdersUpTo, all lesser values of salt can be cancelled
    // This allows the maker to cancel many orders with one on-chain transaction

    // Create the order
    const order1: Order = {

const zrxTokenAddress = contractAddresses.zrxToken;
    const etherTokenAddress = contractAddresses.etherToken;
    const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    // the amount the maker is selling of maker asset
    const makerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(5), DECIMALS);
    // the amount the maker wants of taker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);

    let txHash;
    let txReceipt;

    const zrxToken = new ERC20TokenContract(zrxTokenAddress, providerEngine);
    // Allow the 0x ERC20 Proxy to move ZRX on behalf of makerAccount
    const makerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(
        contractAddresses.erc20Proxy,
        UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
        { from: maker },
    );
    await printUtils.awaitTransactionMinedSpinnerAsync('Maker ZRX Approval', makerZRXApprovalTxHash);

    // Allow the 0x ERC20 Proxy to move ZRX on behalf of takerAccount
    const takerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(
        contractAddresses.erc20Proxy,

{ maker, taker },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset (1 set of ERC721 Token and ERC20 tokens)
    // when set to 1, this order cannot be partially filled.
    const makerAssetAmount = new BigNumber(1);
    // the amount the maker wants of taker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);
    // Generate a random token id
    const tokenId = generatePseudoRandomSalt();
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const erc721AssetData = assetDataUtils.encodeERC721AssetData(dummyERC721TokenContract.address, tokenId);
    const erc20AssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const erc20AssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.2), DECIMALS);
    // combine both the ERC721 asset data and the ERC20 asset data into multi asset data
    // the order is exchanging 1 ERC721 and 0.2 ZRX in exchange for 0.1 WETH
    const makerAssetData = assetDataUtils.encodeMultiAssetData(
        [makerAssetAmount, erc20AssetAmount],
        [erc721AssetData, erc20AssetData],
    );
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    let txHash;

    const zrxToken = new ERC20TokenContract(zrxTokenAddress, providerEngine);
    // Mint a new ERC721 token for the maker
    const mintTxHash = await dummyERC721TokenContract.mint.validateAndSendTransactionAsync(maker, tokenId, {
        from: maker,
    });
    await printUtils.awaitTransactionMinedSpinnerAsync('Mint ERC721 Token', mintTxHash);

const web3Wrapper = new Web3Wrapper(providerEngine);
    const [maker, taker] = await web3Wrapper.getAvailableAddressesAsync();
    const zrxTokenAddress = contractAddresses.zrxToken;
    const etherTokenAddress = contractAddresses.etherToken;
    const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset
    const makerAssetAmount = new BigNumber(100);
    // the amount the maker wants of taker asset
    const takerAssetAmount = new BigNumber(10);
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);

    // Set up the Order and fill it
    const randomExpiration = getRandomFutureDateInSeconds();
    const exchangeAddress = contractAddresses.exchange;

    // Rather than using a random salt, we use an incrementing salt value.
    // When combined with cancelOrdersUpTo, all lesser values of salt can be cancelled
    // This allows the maker to cancel many orders with one on-chain transaction

    // Create the order
    const order1: Order = {
        exchangeAddress,
        makerAddress: maker,

const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker, feeRecipient },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling in maker asset
    const makerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(5), DECIMALS);
    // the amount the maker wants of taker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);
    // the amount of fees the maker pays in ZRX
    const makerFee = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.01), DECIMALS);
    // the amount of fees the taker pays in ZRX
    const takerFee = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.01), DECIMALS);

    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    let txHash;
    let txReceipt;

    const zrxToken = new ERC20TokenContract(zrxTokenAddress, providerEngine);
    // Approve the ERC20 Proxy to move ZRX for maker and taker
    const makerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(
        contractAddresses.erc20Proxy,
        UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
        { from: maker },
    );
    await printUtils.awaitTransactionMinedSpinnerAsync('Maker ZRX Approval', makerZRXApprovalTxHash);
    const takerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(

const web3Wrapper = new Web3Wrapper(providerEngine);
    const [maker, taker] = await web3Wrapper.getAvailableAddressesAsync();
    const zrxTokenAddress = contractAddresses.zrxToken;
    const etherTokenAddress = contractAddresses.etherToken;
    const printUtils = new PrintUtils(
        web3Wrapper,
        contractWrappers,
        { maker, taker },
        { WETH: etherTokenAddress, ZRX: zrxTokenAddress },
    );
    printUtils.printAccounts();

    // the amount the maker is selling of maker asset
    const makerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(5), DECIMALS);
    // the amount the maker wants of taker asset
    const takerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS);
    // 0x v2 uses hex encoded asset data strings to encode all the information needed to identify an asset
    const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
    const takerAssetData = assetDataUtils.encodeERC20AssetData(etherTokenAddress);
    let txHash;
    let txReceipt;

    const zrxToken = new ERC20TokenContract(zrxTokenAddress, providerEngine);
    // Allow the 0x ERC20 Proxy to move ZRX on behalf of makerAccount
    const makerZRXApprovalTxHash = await zrxToken.approve.validateAndSendTransactionAsync(
        contractAddresses.erc20Proxy,
        UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
        { from: maker },
    );
    await printUtils.awaitTransactionMinedSpinnerAsync('Maker ZRX Approval', makerZRXApprovalTxHash);
    // With the Forwarding contract, the taker requires no set up
    PrintUtils.printData('Setup', [['Maker ZRX Approval', makerZRXApprovalTxHash]]);