import {
BlockParam,
BlockWithoutTransactionData,
CallData,
ContractAbi,
FilterObject,
JSONRPCRequestPayload,
JSONRPCResponsePayload,
LogEntry,
Provider,
RawLogEntry,
TransactionReceipt,
TransactionReceiptWithDecodedLogs,
TxData,
} from '@0xproject/types';
import { AbiDecoder, addressUtils, BigNumber, intervalUtils, promisify } from '@0xproject/utils';
import * as _ from 'lodash';
import * as Web3 from 'web3';
import { Web3WrapperErrors } from './types';
/**
* A wrapper around the Web3.js 0.x library that provides a consistent, clean promise-based interface.
*/
export class Web3Wrapper {
/**
* Flag to check if this instance is of type Web3Wrapper
*/
public isZeroExWeb3Wrapper = true;
public abiDecoder: AbiDecoder;
private _web3: Web3;
private _defaults: Partial<TxData>;
private _jsonRpcRequestId: number;
/**
* Check if an address is a valid Ethereum address
* @param address Address to check
* @returns Whether the address is a valid Ethereum address
*/
public static isAddress(address: string): boolean {
return addressUtils.isAddress(address);
}
/**
* A unit amount is defined as the amount of a token above the specified decimal places (integer part).
* E.g: If a currency has 18 decimal places, 1e18 or one quintillion of the currency is equivalent
* to 1 unit.
* @param amount The amount in baseUnits that you would like converted to units.
* @param decimals The number of decimal places the unit amount has.
* @return The amount in units.
*/
public static toUnitAmount(amount: BigNumber, decimals: number): BigNumber {
const aUnit = new BigNumber(10).pow(decimals);
const unit = amount.div(aUnit);
return unit;
}
/**
* A baseUnit is defined as the smallest denomination of a token. An amount expressed in baseUnits
* is the amount expressed in the smallest denomination.
* E.g: 1 unit of a token with 18 decimal places is expressed in baseUnits as 1000000000000000000
* @param amount The amount of units that you would like converted to baseUnits.
* @param decimals The number of decimal places the unit amount has.
* @return The amount in baseUnits.
*/
public static toBaseUnitAmount(amount: BigNumber, decimals: number): BigNumber {
const unit = new BigNumber(10).pow(decimals);
const baseUnitAmount = amount.times(unit);
const hasDecimals = baseUnitAmount.decimalPlaces() !== 0;
if (hasDecimals) {
throw new Error(`Invalid unit amount: ${amount.toString()} - Too many decimal places`);
}
return baseUnitAmount;
}
/**
* Convert an Ether amount from ETH to Wei
* @param ethAmount Amount of Ether to convert to wei
* @returns Amount in wei
*/
public static toWei(ethAmount: BigNumber): BigNumber {
const ETH_DECIMALS = 18;
const balanceWei = Web3Wrapper.toBaseUnitAmount(ethAmount, ETH_DECIMALS);
return balanceWei;
}
/**
* Instantiates a new Web3Wrapper.
* @param provider The Web3 provider instance you would like the Web3Wrapper to use for interacting with
* the backing Ethereum node.
* @param defaults Override TxData defaults sent with RPC requests to the backing Ethereum node.
* @return An instance of the Web3Wrapper class.
*/
constructor(provider: Provider, defaults?: Partial<TxData>) {
if (_.isUndefined((provider as any).sendAsync)) {
// Web3@1.0 provider doesn't support synchronous http requests,
// so it only has an async `send` method, instead of a `send` and `sendAsync` in web3@0.x.x`
// We re-assign the send method so that Web3@1.0 providers work with @0xproject/web3-wrapper
(provider as any).sendAsync = (provider as any).send;
}
this.abiDecoder = new AbiDecoder([]);
this._web3 = new Web3();
this._web3.setProvider(provider);
this._defaults = defaults || {};
this._jsonRpcRequestId = 0;
}
/**
* Get the contract defaults set to the Web3Wrapper instance
* @return TxData defaults (e.g gas, gasPrice, nonce, etc...)
*/
public getContractDefaults(): Partial<TxData> {
return this._defaults;
}
/**
* Retrieve the Web3 provider
* @return Web3 provider instance
*/
public getProvider(): Provider {
return this._web3.currentProvider;
}
/**
* Update the used Web3 provider
* @param provider The new Web3 provider to be set
*/
public setProvider(provider: Provider) {
this._web3.setProvider(provider);
}
/**
* Check whether an address is available through the backing provider. This can be
* useful if you want to know whether a user can sign messages or transactions from
* a given Ethereum address.
* @param senderAddress Address to check availability for
* @returns Whether the address is available through the provider.
*/
public async isSenderAddressAvailableAsync(senderAddress: string): Promise<boolean> {
const addresses = await this.getAvailableAddressesAsync();
const normalizedAddress = senderAddress.toLowerCase();
return _.includes(addresses, normalizedAddress);
}
/**
* Fetch the backing Ethereum node's version string (e.g `MetaMask/v4.2.0`)
* @returns Ethereum node's version string
*/
public async getNodeVersionAsync(): Promise<string> {
const nodeVersion = await this._sendRawPayloadAsync<string>({ method: 'web3_clientVersion' });
return nodeVersion;
}
/**
* Fetches the networkId of the backing Ethereum node
* @returns The network id
*/
public async getNetworkIdAsync(): Promise<number> {
const networkIdStr = await this._sendRawPayloadAsync<string>({ method: 'net_version' });
const networkId = _.parseInt(networkIdStr);
return networkId;
}
/**
* Retrieves the transaction receipt for a given transaction hash
* @param txHash Transaction hash
* @returns The transaction receipt, including it's status (0: failed, 1: succeeded or undefined: not found)
*/
public async getTransactionReceiptAsync(txHash: string): Promise<TransactionReceipt> {
const transactionReceipt = await promisify<TransactionReceipt>(this._web3.eth.getTransactionReceipt)(txHash);
if (!_.isNull(transactionReceipt)) {
transactionReceipt.status = this._normalizeTxReceiptStatus(transactionReceipt.status);
}
return transactionReceipt;
}
/**
* Retrieves an accounts Ether balance in wei
* @param owner Account whose balance you wish to check
* @returns Balance in wei
*/
public async getBalanceInWeiAsync(owner: string): Promise<BigNumber> {
let balanceInWei = await promisify<BigNumber>(this._web3.eth.getBalance)(owner);
// Rewrap in a new BigNumber
balanceInWei = new BigNumber(balanceInWei);
return balanceInWei;
}
/**
* Check if a contract exists at a given address
* @param address Address to which to check
* @returns Whether or not contract code was found at the supplied address
*/
public async doesContractExistAtAddressAsync(address: string): Promise<boolean> {
const code = await promisify<string>(this._web3.eth.getCode)(address);
// Regex matches 0x0, 0x00, 0x in order to accommodate poorly implemented clients
const codeIsEmpty = /^0x0{0,40}$/i.test(code);
return !codeIsEmpty;
}
/**
* Sign a message with a specific address's private key (`eth_sign`)
* @param address Address of signer
* @param message Message to sign
* @returns Signature string (might be VRS or RSV depending on the Signer)
*/
public async signMessageAsync(address: string, message: string): Promise<string> {
const signData = await promisify<string>(this._web3.eth.sign)(address, message);
return signData;
}
/**
* Fetches the latest block number
* @returns Block number
*/
public async getBlockNumberAsync(): Promise<number> {
const blockNumber = await promisify<number>(this._web3.eth.getBlockNumber)();
return blockNumber;
}
/**
* Fetch a specific Ethereum block
* @param blockParam The block you wish to fetch (blockHash, blockNumber or blockLiteral)
* @returns The requested block without transaction data
*/
public async getBlockAsync(blockParam: string | BlockParam): Promise<BlockWithoutTransactionData> {
const block = await promisify<BlockWithoutTransactionData>(this._web3.eth.getBlock)(blockParam);
return block;
}
/**
* Fetch a block's timestamp
* @param blockParam The block you wish to fetch (blockHash, blockNumber or blockLiteral)
* @returns The block's timestamp
*/
public async getBlockTimestampAsync(blockParam: string | BlockParam): Promise<number> {
const { timestamp } = await this.getBlockAsync(blockParam);
return timestamp;
}
/**
* Retrieve the user addresses available through the backing provider
* @returns Available user addresses
*/
public async getAvailableAddressesAsync(): Promise<string[]> {
const addresses = await promisify<string[]>(this._web3.eth.getAccounts)();
const normalizedAddresses = _.map(addresses, address => address.toLowerCase());
return normalizedAddresses;
}
/**
* Take a snapshot of the blockchain state on a TestRPC/Ganache local node
* @returns The snapshot id. This can be used to revert to this snapshot
*/
public async takeSnapshotAsync(): Promise<number> {
const snapshotId = Number(await this._sendRawPayloadAsync<string>({ method: 'evm_snapshot', params: [] }));
return snapshotId;
}
/**
* Revert the blockchain state to a previous snapshot state on TestRPC/Ganache local node
* @param snapshotId snapshot id to revert to
* @returns Whether the revert was successful
*/
public async revertSnapshotAsync(snapshotId: number): Promise<boolean> {
const didRevert = await this._sendRawPayloadAsync<boolean>({ method: 'evm_revert', params: [snapshotId] });
return didRevert;
}
/**
* Mine a block on a TestRPC/Ganache local node
*/
public async mineBlockAsync(): Promise<void> {
await this._sendRawPayloadAsync<string>({ method: 'evm_mine', params: [] });
}
/**
* Increase the next blocks timestamp on TestRPC/Ganache local node
* @param timeDelta Amount of time to add in seconds
*/
public async increaseTimeAsync(timeDelta: number): Promise<void> {
await this._sendRawPayloadAsync<string>({ method: 'evm_increaseTime', params: [timeDelta] });
}
/**
* Retrieve smart contract logs for a given filter
* @param filter Parameters by which to filter which logs to retrieve
* @returns The corresponding log entries
*/
public async getLogsAsync(filter: FilterObject): Promise<LogEntry[]> {
let fromBlock = filter.fromBlock;
if (_.isNumber(fromBlock)) {
fromBlock = this._web3.toHex(fromBlock);
}
let toBlock = filter.toBlock;
if (_.isNumber(toBlock)) {
toBlock = this._web3.toHex(toBlock);
}
const serializedFilter = {
...filter,
fromBlock,
toBlock,
};
const payload = {
jsonrpc: '2.0',
id: this._jsonRpcRequestId++,
method: 'eth_getLogs',
params: [serializedFilter],
};
const rawLogs = await this._sendRawPayloadAsync<RawLogEntry[]>(payload);
const formattedLogs = _.map(rawLogs, this._formatLog.bind(this));
return formattedLogs;
}
/**
* Get a Web3 contract factory instance for a given ABI
* @param abi Smart contract ABI
* @returns Web3 contract factory which can create Web3 Contract instances from the supplied ABI
*/
public getContractFromAbi(abi: ContractAbi): Web3.Contract<any> {
const web3Contract = this._web3.eth.contract(abi);
return web3Contract;
}
/**
* Calculate the estimated gas cost for a given transaction
* @param txData Transaction data
* @returns Estimated gas cost
*/
public async estimateGasAsync(txData: Partial<TxData>): Promise<number> {
const gas = await promisify<number>(this._web3.eth.estimateGas)(txData);
return gas;
}
/**
* Call a smart contract method at a given block height
* @param callData Call data
* @param defaultBlock Block height at which to make the call. Defaults to `latest`
* @returns The raw call result
*/
public async callAsync(callData: CallData, defaultBlock?: BlockParam): Promise<string> {
const rawCallResult = await promisify<string>(this._web3.eth.call)(callData, defaultBlock);
return rawCallResult;
}
/**
* Send a transaction
* @param txData Transaction data
* @returns Transaction hash
*/
public async sendTransactionAsync(txData: TxData): Promise<string> {
const txHash = await promisify<string>(this._web3.eth.sendTransaction)(txData);
return txHash;
}
/**
* Waits for a transaction to be mined and returns the transaction receipt.
* @param txHash Transaction hash
* @param pollingIntervalMs How often (in ms) should we check if the transaction is mined.
* @param timeoutMs How long (in ms) to poll for transaction mined until aborting.
* @return Transaction receipt with decoded log args.
*/
public async awaitTransactionMinedAsync(
txHash: string,
pollingIntervalMs = 1000,
timeoutMs?: number,
): Promise<TransactionReceiptWithDecodedLogs> {
let timeoutExceeded = false;
if (timeoutMs) {
setTimeout(() => (timeoutExceeded = true), timeoutMs);
}
const txReceiptPromise = new Promise(
(resolve: (receipt: TransactionReceiptWithDecodedLogs) => void, reject) => {
const intervalId = intervalUtils.setAsyncExcludingInterval(
async () => {
if (timeoutExceeded) {
intervalUtils.clearAsyncExcludingInterval(intervalId);
return reject(Web3WrapperErrors.TransactionMiningTimeout);
}
const transactionReceipt = await this.getTransactionReceiptAsync(txHash);
if (!_.isNull(transactionReceipt)) {
intervalUtils.clearAsyncExcludingInterval(intervalId);
const logsWithDecodedArgs = _.map(
transactionReceipt.logs,
this.abiDecoder.tryToDecodeLogOrNoop.bind(this.abiDecoder),
);
const transactionReceiptWithDecodedLogArgs: TransactionReceiptWithDecodedLogs = {
...transactionReceipt,
logs: logsWithDecodedArgs,
};
resolve(transactionReceiptWithDecodedLogArgs);
}
},
pollingIntervalMs,
(err: Error) => {
intervalUtils.clearAsyncExcludingInterval(intervalId);
reject(err);
},
);
},
);
const txReceipt = await txReceiptPromise;
return txReceipt;
}
private async _sendRawPayloadAsync<A>(payload: Partial<JSONRPCRequestPayload>): Promise<A> {
const sendAsync = this._web3.currentProvider.sendAsync.bind(this._web3.currentProvider);
const response = await promisify<JSONRPCResponsePayload>(sendAsync)(payload);
const result = response.result;
return result;
}
private _normalizeTxReceiptStatus(status: undefined | null | string | 0 | 1): null | 0 | 1 {
// Transaction status might have four values
// undefined - Testrpc and other old clients
// null - New clients on old transactions
// number - Parity
// hex - Geth
if (_.isString(status)) {
return this._web3.toDecimal(status) as 0 | 1;
} else if (_.isUndefined(status)) {
return null;
} else {
return status;
}
}
private _formatLog(rawLog: RawLogEntry): LogEntry {
const formattedLog = {
...rawLog,
logIndex: this._hexToDecimal(rawLog.logIndex),
blockNumber: this._hexToDecimal(rawLog.blockNumber),
transactionIndex: this._hexToDecimal(rawLog.transactionIndex),
};
return formattedLog;
}
private _hexToDecimal(hex: string | null): number | null {
if (_.isNull(hex)) {
return null;
}
const decimal = this._web3.toDecimal(hex);
return decimal;
}
}
