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 {artifacts} from '../artifacts';
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) {
super(web3Wrapper);
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<BigNumber.BigNumber> {
assert.isETHAddressHex('ownerAddress', ownerAddress);
assert.isETHAddressHex('tokenAddress', tokenAddress);
const tokenContract = await this._getTokenContractAsync(tokenAddress);
let balance = await tokenContract.balanceOf.callAsync(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.
* @return Transaction hash.
*/
public async setAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string,
amountInBaseUnits: BigNumber.BigNumber): Promise<string> {
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;
const txHash = await tokenContract.approve.sendTransactionAsync(spenderAddress, amountInBaseUnits, {
from: ownerAddress,
gas,
});
return txHash;
}
/**
* 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.
* @return Transaction hash.
*/
public async setUnlimitedAllowanceAsync(tokenAddress: string, ownerAddress: string,
spenderAddress: string): Promise<string> {
const txHash = await this.setAllowanceAsync(
tokenAddress, ownerAddress, spenderAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
);
return txHash;
}
/**
* 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): Promise<BigNumber.BigNumber> {
assert.isETHAddressHex('ownerAddress', ownerAddress);
assert.isETHAddressHex('tokenAddress', tokenAddress);
const tokenContract = await this._getTokenContractAsync(tokenAddress);
let allowanceInBaseUnits = await tokenContract.allowance.callAsync(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): Promise<BigNumber.BigNumber> {
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.
* @return Transaction hash.
*/
public async setProxyAllowanceAsync(tokenAddress: string, ownerAddress: string,
amountInBaseUnits: BigNumber.BigNumber): Promise<string> {
assert.isETHAddressHex('ownerAddress', ownerAddress);
assert.isETHAddressHex('tokenAddress', tokenAddress);
assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
const proxyAddress = await this._getProxyAddressAsync();
const txHash = await this.setAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, amountInBaseUnits);
return txHash;
}
/**
* 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.
* @return Transaction hash.
*/
public async setUnlimitedProxyAllowanceAsync(tokenAddress: string, ownerAddress: string): Promise<string> {
const txHash = await this.setProxyAllowanceAsync(
tokenAddress, ownerAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
);
return txHash;
}
/**
* 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.
* @return Transaction hash.
*/
public async transferAsync(tokenAddress: string, fromAddress: string, toAddress: string,
amountInBaseUnits: BigNumber.BigNumber): Promise<string> {
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);
}
const txHash = await tokenContract.transfer.sendTransactionAsync(toAddress, amountInBaseUnits, {
from: fromAddress,
});
return txHash;
}
/**
* 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.
* @return Transaction hash.
*/
public async transferFromAsync(tokenAddress: string, fromAddress: string, toAddress: string,
senderAddress: string, amountInBaseUnits: BigNumber.BigNumber):
Promise<string> {
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);
}
const txHash = await tokenContract.transferFrom.sendTransactionAsync(
fromAddress, toAddress, amountInBaseUnits,
{
from: senderAddress,
},
);
return txHash;
}
/**
* 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<ContractEventEmitter> {
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<void> {
const stopWatchingPromises = _.map(this._tokenLogEventEmitters,
logEventObj => logEventObj.stopWatchingAsync());
await Promise.all(stopWatchingPromises);
this._tokenLogEventEmitters = [];
}
private async _invalidateContractInstancesAsync(): Promise<void> {
await this.stopWatchingAllEventsAsync();
this._tokenContractsByAddress = {};
}
private async _getTokenContractAsync(tokenAddress: string): Promise<TokenContract> {
let tokenContract = this._tokenContractsByAddress[tokenAddress];
if (!_.isUndefined(tokenContract)) {
return tokenContract;
}
const contractInstance = await this._instantiateContractIfExistsAsync<TokenContract>(
artifacts.TokenArtifact, 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 :
artifacts.TokenTransferProxyArtifact.networks[networkIdIfExists];
if (_.isUndefined(proxyNetworkConfigsIfExists)) {
throw new Error(ZeroExError.ContractNotDeployedOnNetwork);
}
const proxyAddress = proxyNetworkConfigsIfExists.address.toLowerCase();
return proxyAddress;
}
}
