import * as _ from 'lodash'; import * as BigNumber from 'bignumber.js'; import {SchemaValidator, schemas} from '0x-json-schemas'; import {Web3Wrapper} from '../web3_wrapper'; import {assert} from '../utils/assert'; import {utils} from '../utils/utils'; import {eventUtils} from '../utils/event_utils'; import {constants} from '../utils/constants'; import {ContractWrapper} from './contract_wrapper'; import * as TokenArtifacts from '../artifacts/Token.json'; import * as TokenTransferProxyArtifacts from '../artifacts/TokenTransferProxy.json'; import { TokenContract, ZeroExError, TokenEvents, IndexedFilterValues, SubscriptionOpts, CreateContractEvent, ContractEventEmitter, ContractEventObj, } from '../types'; const ALLOWANCE_TO_ZERO_GAS_AMOUNT = 47155; /** * This class includes all the functionality related to interacting with ERC20 token contracts. * All ERC20 method calls are supported, along with some convenience methods for getting/setting allowances * to the 0x Proxy smart contract. */ export class TokenWrapper extends ContractWrapper { public UNLIMITED_ALLOWANCE_IN_BASE_UNITS = constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS; private _tokenContractsByAddress: {[address: string]: TokenContract}; private _tokenLogEventEmitters: ContractEventEmitter[]; constructor(web3Wrapper: Web3Wrapper, gasPrice?: BigNumber.BigNumber) { super(web3Wrapper, gasPrice); this._tokenContractsByAddress = {}; this._tokenLogEventEmitters = []; } /** * Retrieves an owner's ERC20 token balance. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address whose balance you would like to check. * @return The owner's ERC20 token balance in base units. */ public async getBalanceAsync(tokenAddress: string, ownerAddress: string): Promise { assert.isETHAddressHex('ownerAddress', ownerAddress); assert.isETHAddressHex('tokenAddress', tokenAddress); const tokenContract = await this._getTokenContractAsync(tokenAddress); let balance = await tokenContract.balanceOf.call(ownerAddress); // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber balance = new BigNumber(balance); return balance; } /** * Sets the spender's allowance to a specified number of baseUnits on behalf of the owner address. * Equivalent to the ERC20 spec method `approve`. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address who would like to set an allowance * for spenderAddress. * @param spenderAddress The hex encoded user Ethereum address who will be able to spend the set allowance. * @param amountInBaseUnits The allowance amount you would like to set. */ public async setAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string, amountInBaseUnits: BigNumber.BigNumber): Promise { await assert.isSenderAddressAsync('ownerAddress', ownerAddress, this._web3Wrapper); assert.isETHAddressHex('spenderAddress', spenderAddress); assert.isETHAddressHex('tokenAddress', tokenAddress); assert.isBigNumber('amountInBaseUnits', amountInBaseUnits); const tokenContract = await this._getTokenContractAsync(tokenAddress); // Hack: for some reason default estimated gas amount causes `base fee exceeds gas limit` exception // on testrpc. Probably related to https://github.com/ethereumjs/testrpc/issues/294 // TODO: Debug issue in testrpc and submit a PR, then remove this hack const networkIdIfExists = await this._web3Wrapper.getNetworkIdIfExistsAsync(); const gas = networkIdIfExists === constants.TESTRPC_NETWORK_ID ? ALLOWANCE_TO_ZERO_GAS_AMOUNT : undefined; await tokenContract.approve(spenderAddress, amountInBaseUnits, { from: ownerAddress, gas, }); } /** * Sets the spender's allowance to an unlimited number of baseUnits on behalf of the owner address. * Equivalent to the ERC20 spec method `approve`. * Setting an unlimited allowance will lower the gas cost for filling orders involving tokens that forego updating * allowances set to the max amount (e.g ZRX, WETH) * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address who would like to set an allowance * for spenderAddress. * @param spenderAddress The hex encoded user Ethereum address who will be able to spend the set allowance. */ public async setUnlimitedAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string): Promise { await this.setAllowanceAsync( tokenAddress, ownerAddress, spenderAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS, ); } /** * Retrieves the owners allowance in baseUnits set to the spender's address. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address whose allowance to spenderAddress * you would like to retrieve. * @param spenderAddress The hex encoded user Ethereum address who can spend the allowance you are fetching. */ public async getAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string) { assert.isETHAddressHex('ownerAddress', ownerAddress); assert.isETHAddressHex('tokenAddress', tokenAddress); const tokenContract = await this._getTokenContractAsync(tokenAddress); let allowanceInBaseUnits = await tokenContract.allowance.call(ownerAddress, spenderAddress); // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber allowanceInBaseUnits = new BigNumber(allowanceInBaseUnits); return allowanceInBaseUnits; } /** * Retrieves the owner's allowance in baseUnits set to the 0x proxy contract. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address whose proxy contract allowance we are retrieving. */ public async getProxyAllowanceAsync(tokenAddress: string, ownerAddress: string) { assert.isETHAddressHex('ownerAddress', ownerAddress); assert.isETHAddressHex('tokenAddress', tokenAddress); const proxyAddress = await this._getProxyAddressAsync(); const allowanceInBaseUnits = await this.getAllowanceAsync(tokenAddress, ownerAddress, proxyAddress); return allowanceInBaseUnits; } /** * Sets the 0x proxy contract's allowance to a specified number of a tokens' baseUnits on behalf * of an owner address. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address who is setting an allowance * for the Proxy contract. * @param amountInBaseUnits The allowance amount specified in baseUnits. */ public async setProxyAllowanceAsync(tokenAddress: string, ownerAddress: string, amountInBaseUnits: BigNumber.BigNumber): Promise { assert.isETHAddressHex('ownerAddress', ownerAddress); assert.isETHAddressHex('tokenAddress', tokenAddress); assert.isBigNumber('amountInBaseUnits', amountInBaseUnits); const proxyAddress = await this._getProxyAddressAsync(); await this.setAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, amountInBaseUnits); } /** * Sets the 0x proxy contract's allowance to a unlimited number of a tokens' baseUnits on behalf * of an owner address. * Setting an unlimited allowance will lower the gas cost for filling orders involving tokens that forego updating * allowances set to the max amount (e.g ZRX, WETH) * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param ownerAddress The hex encoded user Ethereum address who is setting an allowance * for the Proxy contract. */ public async setUnlimitedProxyAllowanceAsync(tokenAddress: string, ownerAddress: string): Promise { await this.setProxyAllowanceAsync(tokenAddress, ownerAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS); } /** * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param fromAddress The hex encoded user Ethereum address that will send the funds. * @param toAddress The hex encoded user Ethereum address that will receive the funds. * @param amountInBaseUnits The amount (specified in baseUnits) of the token to transfer. */ public async transferAsync(tokenAddress: string, fromAddress: string, toAddress: string, amountInBaseUnits: BigNumber.BigNumber): Promise { assert.isETHAddressHex('tokenAddress', tokenAddress); await assert.isSenderAddressAsync('fromAddress', fromAddress, this._web3Wrapper); assert.isETHAddressHex('toAddress', toAddress); assert.isBigNumber('amountInBaseUnits', amountInBaseUnits); const tokenContract = await this._getTokenContractAsync(tokenAddress); const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress); if (fromAddressBalance.lessThan(amountInBaseUnits)) { throw new Error(ZeroExError.InsufficientBalanceForTransfer); } await tokenContract.transfer(toAddress, amountInBaseUnits, { from: fromAddress, }); } /** * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`. * Requires the fromAddress to have sufficient funds and to have approved an allowance of * `amountInBaseUnits` to `senderAddress`. * @param tokenAddress The hex encoded contract Ethereum address where the ERC20 token is deployed. * @param fromAddress The hex encoded user Ethereum address whose funds are being sent. * @param toAddress The hex encoded user Ethereum address that will receive the funds. * @param senderAddress The hex encoded user Ethereum address whose initiates the fund transfer. The * `fromAddress` must have set an allowance to the `senderAddress` * before this call. * @param amountInBaseUnits The amount (specified in baseUnits) of the token to transfer. */ public async transferFromAsync(tokenAddress: string, fromAddress: string, toAddress: string, senderAddress: string, amountInBaseUnits: BigNumber.BigNumber): Promise { assert.isETHAddressHex('tokenAddress', tokenAddress); assert.isETHAddressHex('fromAddress', fromAddress); assert.isETHAddressHex('toAddress', toAddress); await assert.isSenderAddressAsync('senderAddress', senderAddress, this._web3Wrapper); assert.isBigNumber('amountInBaseUnits', amountInBaseUnits); const tokenContract = await this._getTokenContractAsync(tokenAddress); const fromAddressAllowance = await this.getAllowanceAsync(tokenAddress, fromAddress, senderAddress); if (fromAddressAllowance.lessThan(amountInBaseUnits)) { throw new Error(ZeroExError.InsufficientAllowanceForTransfer); } const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress); if (fromAddressBalance.lessThan(amountInBaseUnits)) { throw new Error(ZeroExError.InsufficientBalanceForTransfer); } await tokenContract.transferFrom(fromAddress, toAddress, amountInBaseUnits, { from: senderAddress, }); } /** * Subscribe to an event type emitted by the Token contract. * @param tokenAddress The hex encoded address where the ERC20 token is deployed. * @param eventName The token contract event you would like to subscribe to. * @param subscriptionOpts Subscriptions options that let you configure the subscription. * @param indexFilterValues An object where the keys are indexed args returned by the event and * the value is the value you are interested in. E.g `{maker: aUserAddressHex}` * @return ContractEventEmitter object */ public async subscribeAsync(tokenAddress: string, eventName: TokenEvents, subscriptionOpts: SubscriptionOpts, indexFilterValues: IndexedFilterValues): Promise { assert.isETHAddressHex('tokenAddress', tokenAddress); assert.doesBelongToStringEnum('eventName', eventName, TokenEvents); assert.doesConformToSchema('subscriptionOpts', subscriptionOpts, schemas.subscriptionOptsSchema); assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema); const tokenContract = await this._getTokenContractAsync(tokenAddress); let createLogEvent: CreateContractEvent; switch (eventName) { case TokenEvents.Approval: createLogEvent = tokenContract.Approval; break; case TokenEvents.Transfer: createLogEvent = tokenContract.Transfer; break; default: throw utils.spawnSwitchErr('TokenEvents', eventName); } const logEventObj: ContractEventObj = createLogEvent(indexFilterValues, subscriptionOpts); const eventEmitter = eventUtils.wrapEventEmitter(logEventObj); this._tokenLogEventEmitters.push(eventEmitter); return eventEmitter; } /** * Stops watching for all token events */ public async stopWatchingAllEventsAsync(): Promise { const stopWatchingPromises = _.map(this._tokenLogEventEmitters, logEventObj => logEventObj.stopWatchingAsync()); await Promise.all(stopWatchingPromises); this._tokenLogEventEmitters = []; } private async _invalidateContractInstancesAsync(): Promise { await this.stopWatchingAllEventsAsync(); this._tokenContractsByAddress = {}; } private async _getTokenContractAsync(tokenAddress: string): Promise { let tokenContract = this._tokenContractsByAddress[tokenAddress]; if (!_.isUndefined(tokenContract)) { return tokenContract; } const contractInstance = await this._instantiateContractIfExistsAsync((TokenArtifacts as any), tokenAddress); tokenContract = contractInstance as TokenContract; this._tokenContractsByAddress[tokenAddress] = tokenContract; return tokenContract; } private async _getProxyAddressAsync() { const networkIdIfExists = await this._web3Wrapper.getNetworkIdIfExistsAsync(); const proxyNetworkConfigsIfExists = _.isUndefined(networkIdIfExists) ? undefined : (TokenTransferProxyArtifacts as any).networks[networkIdIfExists]; if (_.isUndefined(proxyNetworkConfigsIfExists)) { throw new Error(ZeroExError.ContractNotDeployedOnNetwork); } const proxyAddress = proxyNetworkConfigsIfExists.address.toLowerCase(); return proxyAddress; } }