import { RawLogEntry, TransactionReceipt, TxData } from '@0xproject/types'; import { BigNumber, promisify } from '@0xproject/utils'; import * as _ from 'lodash'; import * as Web3 from 'web3'; /** * 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; private _web3: Web3; private _defaults: Partial; private _jsonRpcRequestId: number; /** * 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: Web3.Provider, defaults?: Partial) { 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._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 { return this._defaults; } /** * Retrieve the Web3 provider * @return Web3 provider instance */ public getProvider(): Web3.Provider { return this._web3.currentProvider; } /** * Update the used Web3 provider * @param provider The new Web3 provider to be set */ public setProvider(provider: Web3.Provider) { this._web3.setProvider(provider); } /** * Check if an address is a valid Ethereum address * @param address Address to check * @returns Whether the address is a valid Ethereum address */ public isAddress(address: string): boolean { return this._web3.isAddress(address); } /** * 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 { 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 { const nodeVersion = await promisify(this._web3.version.getNode)(); return nodeVersion; } /** * Fetches the networkId of the backing Ethereum node * @returns The network id */ public async getNetworkIdAsync(): Promise { const networkIdStr = await promisify(this._web3.version.getNetwork)(); 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 { const transactionReceipt = await promisify(this._web3.eth.getTransactionReceipt)(txHash); if (!_.isNull(transactionReceipt)) { transactionReceipt.status = this._normalizeTxReceiptStatus(transactionReceipt.status); } return transactionReceipt; } /** * Convert an Ether amount from ETH to Wei * @param ethAmount Amount of Ether to convert to wei * @returns Amount in wei */ public toWei(ethAmount: BigNumber): BigNumber { const balanceWei = this._web3.toWei(ethAmount, 'ether'); return balanceWei; } /** * 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 { let balanceInWei = await promisify(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 { const code = await promisify(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 { const signData = await promisify(this._web3.eth.sign)(address, message); return signData; } /** * Fetches the latest block number * @returns Block number */ public async getBlockNumberAsync(): Promise { const blockNumber = await promisify(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 | Web3.BlockParam): Promise { const block = await promisify(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 | Web3.BlockParam): Promise { 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 { const addresses = await promisify(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 { const snapshotId = Number(await this._sendRawPayloadAsync({ 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 { const didRevert = await this._sendRawPayloadAsync({ method: 'evm_revert', params: [snapshotId] }); return didRevert; } /** * Mine a block on a TestRPC/Ganache local node */ public async mineBlockAsync(): Promise { await this._sendRawPayloadAsync({ 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 { await this._sendRawPayloadAsync({ 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: Web3.FilterObject): Promise { 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(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: Web3.ContractAbi): Web3.Contract { 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): Promise { const gas = await promisify(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: Web3.CallData, defaultBlock?: Web3.BlockParam): Promise { const rawCallResult = await promisify(this._web3.eth.call)(callData, defaultBlock); return rawCallResult; } /** * Send a transaction * @param txData Transaction data * @returns Transaction hash */ public async sendTransactionAsync(txData: Web3.TxData): Promise { const txHash = await promisify(this._web3.eth.sendTransaction)(txData); return txHash; } private async _sendRawPayloadAsync(payload: Partial): Promise { const sendAsync = this._web3.currentProvider.sendAsync.bind(this._web3.currentProvider); const response = await promisify(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): Web3.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; } }