import { ContractArtifact } from '@0xproject/sol-compiler'; import { AbiDecoder, BigNumber } from '@0xproject/utils'; import { Web3Wrapper } from '@0xproject/web3-wrapper'; import { AbiDefinition, DecodedLogArgs, LogEntry, LogWithDecodedArgs, RawLog, TransactionReceiptWithDecodedLogs, } from 'ethereum-types'; import * as _ from 'lodash'; import { artifacts } from './artifacts'; import { constants } from './constants'; export class LogDecoder { private _web3Wrapper: Web3Wrapper; private _contractAddress: string; private _abiDecoder: AbiDecoder; public static wrapLogBigNumbers(log: any): any { const argNames = _.keys(log.args); for (const argName of argNames) { const isWeb3BigNumber = _.startsWith(log.args[argName].constructor.toString(), 'function BigNumber('); if (isWeb3BigNumber) { log.args[argName] = new BigNumber(log.args[argName]); } } } constructor(web3Wrapper: Web3Wrapper, contractAddress: string) { this._web3Wrapper = web3Wrapper; this._contractAddress = contractAddress; const abiArrays: AbiDefinition[][] = []; _.forEach(artifacts, (artifact: ContractArtifact) => { const compilerOutput = artifact.compilerOutput; abiArrays.push(compilerOutput.abi); }); this._abiDecoder = new AbiDecoder(abiArrays); } public decodeLogOrThrow(log: LogEntry): LogWithDecodedArgs | RawLog { const logWithDecodedArgsOrLog = this._abiDecoder.tryToDecodeLogOrNoop(log); if (_.isUndefined((logWithDecodedArgsOrLog as LogWithDecodedArgs).args)) { throw new Error(`Unable to decode log: ${JSON.stringify(log)}`); } LogDecoder.wrapLogBigNumbers(logWithDecodedArgsOrLog); return logWithDecodedArgsOrLog; } public async getTxWithDecodedLogsAsync(txHash: string): Promise { const tx = await this._web3Wrapper.awaitTransactionSuccessAsync(txHash, constants.AWAIT_TRANSACTION_MINED_MS); tx.logs = _.filter(tx.logs, log => log.address === this._contractAddress); tx.logs = _.map(tx.logs, log => this.decodeLogOrThrow(log)); return tx; } }