import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0xproject/subproviders'; import { BlockParam, CallData, JSONRPCRequestPayload, TransactionTrace, TxData } from 'ethereum-types'; import * as _ from 'lodash'; import { Lock } from 'semaphore-async-await'; import { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter'; import { constants } from './constants'; import { CoverageManager } from './coverage_manager'; import { getTracesByContractAddress } from './trace'; import { BlockParamLiteral, TraceInfoExistingContract, TraceInfoNewContract } from './types'; interface MaybeFakeTxData extends TxData { isFakeTransaction?: boolean; } // Because there is no notion of a call trace in the Ethereum rpc - we collect them in a rather non-obvious/hacky way. // On each call - we create a snapshot, execute the call as a transaction, get the trace, revert the snapshot. // That allows us to avoid influencing test behaviour. /** * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface. * It collects traces of all transactions that were sent and all calls that were executed through JSON RPC. */ export class CoverageSubprovider extends Subprovider { // Lock is used to not accept normal transactions while doing call/snapshot magic because they'll be reverted later otherwise private _lock: Lock; private _coverageManager: CoverageManager; private _defaultFromAddress: string; /** * Instantiates a CoverageSubprovider instance * @param artifactAdapter Adapter for used artifacts format (0x, truffle, giveth, etc.) * @param defaultFromAddress default from address to use when sending transactions * @param isVerbose If true, we will log any unknown transactions. Otherwise we will ignore them */ constructor(artifactAdapter: AbstractArtifactAdapter, defaultFromAddress: string, isVerbose: boolean = true) { super(); this._lock = new Lock(); this._defaultFromAddress = defaultFromAddress; this._coverageManager = new CoverageManager(artifactAdapter, this._getContractCodeAsync.bind(this), isVerbose); } /** * Write the test coverage results to a file in Istanbul format. */ public async writeCoverageAsync(): Promise { await this._coverageManager.writeCoverageAsync(); } /** * This method conforms to the web3-provider-engine interface. * It is called internally by the ProviderEngine when it is this subproviders * turn to handle a JSON RPC request. * @param payload JSON RPC payload * @param next Callback to call if this subprovider decides not to handle the request * @param end Callback to call if subprovider handled the request and wants to pass back the request. */ // tslint:disable-next-line:prefer-function-over-method async-suffix public async handleRequest(payload: JSONRPCRequestPayload, next: NextCallback, end: ErrorCallback): Promise { switch (payload.method) { case 'eth_sendTransaction': const txData = payload.params[0]; next(this._onTransactionSentAsync.bind(this, txData)); return; case 'eth_call': const callData = payload.params[0]; const blockNumber = payload.params[1]; next(this._onCallExecutedAsync.bind(this, callData, blockNumber)); return; default: next(); return; } } private async _onTransactionSentAsync( txData: MaybeFakeTxData, err: Error | null, txHash: string | undefined, cb: Callback, ): Promise { if (!txData.isFakeTransaction) { // This transaction is a usual ttransaction. Not a call executed as one. // And we don't want it to be executed within a snapshotting period await this._lock.acquire(); } if (_.isNull(err)) { const toAddress = _.isUndefined(txData.to) || txData.to === '0x0' ? constants.NEW_CONTRACT : txData.to; await this._recordTxTraceAsync(toAddress, txData.data, txHash as string); } else { const payload = { method: 'eth_getBlockByNumber', params: [BlockParamLiteral.Latest, true], }; const jsonRPCResponsePayload = await this.emitPayloadAsync(payload); const transactions = jsonRPCResponsePayload.result.transactions; for (const transaction of transactions) { const toAddress = _.isUndefined(txData.to) || txData.to === '0x0' ? constants.NEW_CONTRACT : txData.to; await this._recordTxTraceAsync(toAddress, transaction.data, transaction.hash); } } if (!txData.isFakeTransaction) { // This transaction is a usual ttransaction. Not a call executed as one. // And we don't want it to be executed within a snapshotting period this._lock.release(); } cb(); } private async _onCallExecutedAsync( callData: Partial, blockNumber: BlockParam, err: Error | null, callResult: string, cb: Callback, ): Promise { await this._recordCallTraceAsync(callData, blockNumber); cb(); } private async _recordTxTraceAsync(address: string, data: string | undefined, txHash: string): Promise { let payload = { method: 'debug_traceTransaction', params: [txHash, { disableMemory: true, disableStack: false, disableStorage: true }], }; let jsonRPCResponsePayload = await this.emitPayloadAsync(payload); const trace: TransactionTrace = jsonRPCResponsePayload.result; const tracesByContractAddress = getTracesByContractAddress(trace.structLogs, address); const subcallAddresses = _.keys(tracesByContractAddress); if (address === constants.NEW_CONTRACT) { for (const subcallAddress of subcallAddresses) { let traceInfo: TraceInfoNewContract | TraceInfoExistingContract; if (subcallAddress === 'NEW_CONTRACT') { const traceForThatSubcall = tracesByContractAddress[subcallAddress]; const coveredPcs = _.map(traceForThatSubcall, log => log.pc); traceInfo = { coveredPcs, txHash, address: constants.NEW_CONTRACT, bytecode: data as string, }; } else { payload = { method: 'eth_getCode', params: [subcallAddress, BlockParamLiteral.Latest] }; jsonRPCResponsePayload = await this.emitPayloadAsync(payload); const runtimeBytecode = jsonRPCResponsePayload.result; const traceForThatSubcall = tracesByContractAddress[subcallAddress]; const coveredPcs = _.map(traceForThatSubcall, log => log.pc); traceInfo = { coveredPcs, txHash, address: subcallAddress, runtimeBytecode, }; } this._coverageManager.appendTraceInfo(traceInfo); } } else { for (const subcallAddress of subcallAddresses) { payload = { method: 'eth_getCode', params: [subcallAddress, BlockParamLiteral.Latest] }; jsonRPCResponsePayload = await this.emitPayloadAsync(payload); const runtimeBytecode = jsonRPCResponsePayload.result; const traceForThatSubcall = tracesByContractAddress[subcallAddress]; const coveredPcs = _.map(traceForThatSubcall, log => log.pc); const traceInfo: TraceInfoExistingContract = { coveredPcs, txHash, address: subcallAddress, runtimeBytecode, }; this._coverageManager.appendTraceInfo(traceInfo); } } } private async _recordCallTraceAsync(callData: Partial, blockNumber: BlockParam): Promise { // We don't want other transactions to be exeucted during snashotting period, that's why we lock the // transaction execution for all transactions except our fake ones. await this._lock.acquire(); const snapshotId = Number((await this.emitPayloadAsync({ method: 'evm_snapshot' })).result); const fakeTxData: MaybeFakeTxData = { isFakeTransaction: true, // This transaction (and only it) is allowed to come through when the lock is locked ...callData, from: callData.from || this._defaultFromAddress, }; try { await this.emitPayloadAsync({ method: 'eth_sendTransaction', params: [fakeTxData], }); } catch (err) { // Even if this transaction failed - we've already recorded it's trace. } const jsonRPCResponse = await this.emitPayloadAsync({ method: 'evm_revert', params: [snapshotId] }); this._lock.release(); const didRevert = jsonRPCResponse.result; if (!didRevert) { throw new Error('Failed to revert the snapshot'); } } private async _getContractCodeAsync(address: string): Promise { const payload = { method: 'eth_getCode', params: [address, BlockParamLiteral.Latest], }; const jsonRPCResponsePayload = await this.emitPayloadAsync(payload); const contractCode: string = jsonRPCResponsePayload.result; return contractCode; } }