How to use @0x/contract-wrappers - 10 common examples

export async function scenarioAsync(): Promise {
    await runMigrationsOnceIfRequiredAsync();
    let txHash;
    PrintUtils.printScenario('Create Staking Pool');
    // account information, balances, general contract logs
    const web3Wrapper = new Web3Wrapper(providerEngine);
    const [maker, otherMaker] = await web3Wrapper.getAvailableAddressesAsync();
    const contractWrappers = new ContractWrappers(providerEngine, { chainId: NETWORK_CONFIGS.chainId });
    const zrxTokenAddress = contractWrappers.contractAddresses.zrxToken;
    const printUtils = new PrintUtils(web3Wrapper, contractWrappers, { maker }, { ZRX: zrxTokenAddress });

    // Staking Proxy is a delegate contract. We initialize a Staking Contract (ABI) pointing to the delegate proxy
    // at stakingProxyContractAddress
    const stakingContract = new StakingContract(contractWrappers.contractAddresses.stakingProxy, providerEngine, {
        from: maker,
    });

    // A small share is kept for the operator, note 1,000,000 represents all rebates
    // going to the operator
    const operatorSharePpm = new BigNumber(900000); // 90 %
    const stakingPoolReceipt = await stakingContract
        .createStakingPool(operatorSharePpm, true)
        .awaitTransactionSuccessAsync({
            from: maker,

});

    // A small share is kept for the operator, note 1,000,000 represents all rebates
    // going to the operator
    const operatorSharePpm = new BigNumber(900000); // 90 %
    const stakingPoolReceipt = await stakingContract
        .createStakingPool(operatorSharePpm, true)
        .awaitTransactionSuccessAsync({
            from: maker,
        });
    const createStakingPoolLog = stakingPoolReceipt.logs[0];
    const poolId = (createStakingPoolLog as any).args.poolId;
    await printUtils.awaitTransactionMinedSpinnerAsync(`Create Pool ${poolId}`, stakingPoolReceipt.transactionHash);

    // Approve the ZRX token for Staking using the ERC20Proxy
    const zrxTokenContract = new ERC20TokenContract(zrxTokenAddress, providerEngine, { from: maker });
    await zrxTokenContract
        .approve(contractWrappers.contractAddresses.erc20Proxy, UNLIMITED_ALLOWANCE_IN_BASE_UNITS)
        .sendTransactionAsync();

    // Stake 1000 ZRX
    const stakeAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(100), DECIMALS);
    // Transfer the ZRX to the Staking Contract
    txHash = await stakingContract.stake(stakeAmount).sendTransactionAsync({ from: maker });
    await printUtils.awaitTransactionMinedSpinnerAsync('Stake ZRX', txHash);
    // Move the staked ZRX to delegate the Staking Pool
    txHash = await stakingContract
        .moveStake(
            { status: StakeStatus.Undelegated, poolId: NIL_POOL_ID },
            { status: StakeStatus.Delegated, poolId },
            stakeAmount,
        )

private async _fetchHistoricalExchangeLogFillEventsAsync(indexFilterValues: IndexedFilterValues): Promise {
        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);

        const fromBlock = tradeHistoryStorage.getFillsLatestBlock(this._userAddressIfExists, this.networkId);
        const blockRange: BlockRange = {
            fromBlock,
            toBlock: 'latest' as BlockParam,
        };
        const decodedLogs = await this._contractWrappers.exchange.getLogsAsync(
            ExchangeEvents.Fill,
            blockRange,
            indexFilterValues,
        );
        for (const decodedLog of decodedLogs) {
            if (!this._doesLogEventInvolveUser(decodedLog)) {
                continue; // We aren't interested in the fill event
            }
            this._updateLatestFillsBlockIfNeeded(decodedLog.blockNumber);
            const fill = await this._convertDecodedLogToFillAsync(decodedLog);
            tradeHistoryStorage.addFillToUser(this._userAddressIfExists, this.networkId, fill);
        }
    }
    private async _convertDecodedLogToFillAsync(decodedLog: LogWithDecodedArgs): Promise {

break;
            }
            case WETH9Events.Withdrawal: {
                // Invalidate cache
                const args = decodedLog.args as WETH9WithdrawalEventArgs;
                const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
                this._deleteLazyStoreBalance(tokenAssetData, args._owner);
                // Revalidate orders
                const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                    args._owner,
                    tokenAssetData,
                );
                await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
                break;
            }
            case ExchangeEvents.Fill: {
                // Invalidate cache
                const args = decodedLog.args as ExchangeFillEventArgs;
                this._orderFilledCancelledLazyStore.deleteFilledTakerAmount(args.orderHash);
                // Revalidate orders
                const orderHash = args.orderHash;
                const isOrderWatched = this._orderByOrderHash[orderHash] !== undefined;
                if (isOrderWatched) {
                    await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
                }
                break;
            }
            case ExchangeEvents.Cancel: {
                // Invalidate cache
                const args = decodedLog.args as ExchangeCancelEventArgs;
                this._orderFilledCancelledLazyStore.deleteIsCancelled(args.orderHash);
                // Revalidate orders

private async _startListeningForExchangeLogFillEventsAsync(indexFilterValues: IndexedFilterValues): Promise {
        utils.assert(!_.isUndefined(this._contractWrappers), 'ContractWrappers must be instantiated.');
        utils.assert(this._doesUserAddressExist(), BlockchainCallErrs.UserHasNoAssociatedAddresses);

        // Fetch historical logs
        await this._fetchHistoricalExchangeLogFillEventsAsync(indexFilterValues);

        // Start a subscription for new logs
        this._contractWrappers.exchange.subscribe(
            ExchangeEvents.Fill,
            indexFilterValues,
            async (err: Error, decodedLogEvent: DecodedLogEvent) => {
                if (err) {
                    // Note: it's not entirely clear from the documentation which
                    // errors will be thrown by `watch`. For now, let's log the error
                    // to rollbar and stop watching when one occurs
                    errorReporter.report(err); // fire and forget
                    return;
                } else {
                    const decodedLog = decodedLogEvent.log;
                    if (!this._doesLogEventInvolveUser(decodedLog)) {
                        return; // We aren't interested in the fill event
                    }
                    this._updateLatestFillsBlockIfNeeded(decodedLog.blockNumber);
                    const fill = await this._convertDecodedLogToFillAsync(decodedLog);
                    if (decodedLogEvent.isRemoved) {

await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
                break;
            }
            case ExchangeEvents.Fill: {
                // Invalidate cache
                const args = decodedLog.args as ExchangeFillEventArgs;
                this._orderFilledCancelledLazyStore.deleteFilledTakerAmount(args.orderHash);
                // Revalidate orders
                const orderHash = args.orderHash;
                const isOrderWatched = this._orderByOrderHash[orderHash] !== undefined;
                if (isOrderWatched) {
                    await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
                }
                break;
            }
            case ExchangeEvents.Cancel: {
                // Invalidate cache
                const args = decodedLog.args as ExchangeCancelEventArgs;
                this._orderFilledCancelledLazyStore.deleteIsCancelled(args.orderHash);
                // Revalidate orders
                const orderHash = args.orderHash;
                const isOrderWatched = this._orderByOrderHash[orderHash] !== undefined;
                if (isOrderWatched) {
                    await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
                }
                break;
            }
            case ExchangeEvents.CancelUpTo: {
                // TODO(logvinov): Do it smarter and actually look at the salt and order epoch
                // Invalidate cache
                const args = decodedLog.args as ExchangeCancelUpToEventArgs;
                this._orderFilledCancelledLazyStore.deleteAllIsCancelled();

(accOrders, order, index) => {
            // get corresponding on-chain state for the order
            const { orderInfo, traderInfo } = ordersAndTradersInfo[index];
            // if the order IS NOT fillable, do not add anything to the accumulations and continue iterating
            if (orderInfo.orderStatus !== OrderStatus.Fillable) {
                return accOrders;
            }
            // if the order IS fillable, add the order and calculate the remaining fillable amount
            const transferrableAssetAmount = BigNumber.min(traderInfo.makerAllowance, traderInfo.makerBalance);
            const transferrableFeeAssetAmount = BigNumber.min(traderInfo.makerZrxAllowance, traderInfo.makerZrxBalance);
            const remainingTakerAssetAmount = order.takerAssetAmount.minus(orderInfo.orderTakerAssetFilledAmount);
            const remainingMakerAssetAmount = orderCalculationUtils.getMakerFillAmount(
                order,
                remainingTakerAssetAmount,
            );
            const remainingFillableCalculator = new RemainingFillableCalculator(
                order.makerFee,
                order.makerAssetAmount,
                isMakerAssetZrxToken,
                transferrableAssetAmount,
                transferrableFeeAssetAmount,

(accOrders, order, index) => {
            // get corresponding on-chain state for the order
            const { orderInfo, traderInfo } = ordersAndTradersInfo[index];
            // if the order IS NOT fillable, do not add anything to the accumulations and continue iterating
            if (orderInfo.orderStatus !== OrderStatus.Fillable) {
                return accOrders;
            }
            // if the order IS fillable, add the order and calculate the remaining fillable amount
            const transferrableAssetAmount = BigNumber.min(traderInfo.makerAllowance, traderInfo.makerBalance);
            const transferrableFeeAssetAmount = BigNumber.min(traderInfo.makerZrxAllowance, traderInfo.makerZrxBalance);
            const remainingTakerAssetAmount = order.takerAssetAmount.minus(orderInfo.orderTakerAssetFilledAmount);
            const remainingMakerAssetAmount = orderCalculationUtils.getMakerFillAmount(
                order,
                remainingTakerAssetAmount,
            );
            const remainingFillableCalculator = new RemainingFillableCalculator(
                order.makerFee,
                order.makerAssetAmount,
                isMakerAssetZrxToken,
                transferrableAssetAmount,
                transferrableFeeAssetAmount,

(accOrders, order, index) => {
            // get corresponding on-chain state for the order
            const { orderInfo, traderInfo } = ordersAndTradersInfo[index];
            // if the order IS NOT fillable, do not add anything to the accumulations and continue iterating
            if (orderInfo.orderStatus !== OrderStatus.Fillable) {
                return accOrders;
            }
            // if the order IS fillable, add the order and calculate the remaining fillable amount
            const transferrableAssetAmount = BigNumber.min(traderInfo.makerAllowance, traderInfo.makerBalance);
            const transferrableFeeAssetAmount = BigNumber.min(traderInfo.makerZrxAllowance, traderInfo.makerZrxBalance);
            const remainingTakerAssetAmount = order.takerAssetAmount.minus(orderInfo.orderTakerAssetFilledAmount);
            const remainingMakerAssetAmount = orderCalculationUtils.getMakerFillAmount(
                order,
                remainingTakerAssetAmount,
            );
            const remainingFillableCalculator = new RemainingFillableCalculator(
                order.makerFee,
                order.makerAssetAmount,
                isMakerAssetZrxToken,
                transferrableAssetAmount,
                transferrableFeeAssetAmount,

}
                break;
            }
            case ExchangeEvents.Cancel: {
                // Invalidate cache
                const args = decodedLog.args as ExchangeCancelEventArgs;
                this._orderFilledCancelledLazyStore.deleteIsCancelled(args.orderHash);
                // Revalidate orders
                const orderHash = args.orderHash;
                const isOrderWatched = this._orderByOrderHash[orderHash] !== undefined;
                if (isOrderWatched) {
                    await this._emitRevalidateOrdersAsync([orderHash], transactionHash);
                }
                break;
            }
            case ExchangeEvents.CancelUpTo: {
                // TODO(logvinov): Do it smarter and actually look at the salt and order epoch
                // Invalidate cache
                const args = decodedLog.args as ExchangeCancelUpToEventArgs;
                this._orderFilledCancelledLazyStore.deleteAllIsCancelled();
                // Revalidate orders
                const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByMaker(args.makerAddress);
                await this._emitRevalidateOrdersAsync(orderHashes, transactionHash);
                break;
            }

            default:
                throw errorUtils.spawnSwitchErr('decodedLog.event', decodedLog.event);
        }
    }
    private async _emitRevalidateOrdersAsync(orderHashes: string[], transactionHash?: string): Promise {