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-rw-r--r--packages/sol-cov/src/trace_collection_subprovider.ts185
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diff --git a/packages/sol-cov/src/trace_collection_subprovider.ts b/packages/sol-cov/src/trace_collection_subprovider.ts
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+import { BlockchainLifecycle } from '@0xproject/dev-utils';
+import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0xproject/subproviders';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { CallData, JSONRPCRequestPayload, Provider, TxData } from 'ethereum-types';
+import * as _ from 'lodash';
+import { Lock } from 'semaphore-async-await';
+
+import { constants } from './constants';
+import { BlockParamLiteral } from './types';
+
+interface MaybeFakeTxData extends TxData {
+ isFakeTransaction?: boolean;
+}
+
+const BLOCK_GAS_LIMIT = 6000000;
+
+export interface TraceCollectionSubproviderConfig {
+ shouldCollectTransactionTraces: boolean;
+ shouldCollectCallTraces: boolean;
+ shouldCollectGasEstimateTraces: 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. It must
+ * be extended by implementing the _recordTxTraceAsync method which is called for every transaction.
+ */
+export abstract class TraceCollectionSubprovider extends Subprovider {
+ protected _web3Wrapper!: Web3Wrapper;
+ // Lock is used to not accept normal transactions while doing call/snapshot magic because they'll be reverted later otherwise
+ private _lock = new Lock();
+ private _defaultFromAddress: string;
+ private _isEnabled = true;
+ private _config: TraceCollectionSubproviderConfig;
+ /**
+ * Instantiates a TraceCollectionSubprovider instance
+ * @param defaultFromAddress default from address to use when sending transactions
+ */
+ constructor(defaultFromAddress: string, config: TraceCollectionSubproviderConfig) {
+ super();
+ this._defaultFromAddress = defaultFromAddress;
+ this._config = config;
+ }
+ /**
+ * Starts trace collection
+ */
+ public start(): void {
+ this._isEnabled = true;
+ }
+ /**
+ * Stops trace collection
+ */
+ public stop(): void {
+ this._isEnabled = false;
+ }
+ /**
+ * 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<void> {
+ if (this._isEnabled) {
+ switch (payload.method) {
+ case 'eth_sendTransaction':
+ if (!this._config.shouldCollectTransactionTraces) {
+ next();
+ } else {
+ const txData = payload.params[0];
+ next(this._onTransactionSentAsync.bind(this, txData));
+ }
+ return;
+
+ case 'eth_call':
+ if (!this._config.shouldCollectCallTraces) {
+ next();
+ } else {
+ const callData = payload.params[0];
+ next(this._onCallOrGasEstimateExecutedAsync.bind(this, callData));
+ }
+ return;
+
+ case 'eth_estimateGas':
+ if (!this._config.shouldCollectGasEstimateTraces) {
+ next();
+ } else {
+ const estimateGasData = payload.params[0];
+ next(this._onCallOrGasEstimateExecutedAsync.bind(this, estimateGasData));
+ }
+ return;
+
+ default:
+ next();
+ return;
+ }
+ } else {
+ next();
+ return;
+ }
+ }
+ /**
+ * Set's the subprovider's engine to the ProviderEngine it is added to.
+ * This is only called within the ProviderEngine source code, do not call
+ * directly.
+ */
+ public setEngine(engine: Provider): void {
+ super.setEngine(engine);
+ this._web3Wrapper = new Web3Wrapper(engine);
+ }
+ protected abstract async _recordTxTraceAsync(
+ address: string,
+ data: string | undefined,
+ txHash: string,
+ ): Promise<void>;
+ private async _onTransactionSentAsync(
+ txData: MaybeFakeTxData,
+ err: Error | null,
+ txHash: string | undefined,
+ cb: Callback,
+ ): Promise<void> {
+ if (!txData.isFakeTransaction) {
+ // This transaction is a usual transaction. Not a call executed as one.
+ // And we don't want it to be executed within a snapshotting period
+ await this._lock.acquire();
+ }
+ const NULL_ADDRESS = '0x0';
+ if (_.isNull(err)) {
+ const toAddress =
+ _.isUndefined(txData.to) || txData.to === NULL_ADDRESS ? constants.NEW_CONTRACT : txData.to;
+ await this._recordTxTraceAsync(toAddress, txData.data, txHash as string);
+ } else {
+ const latestBlock = await this._web3Wrapper.getBlockWithTransactionDataAsync(BlockParamLiteral.Latest);
+ const transactions = latestBlock.transactions;
+ for (const transaction of transactions) {
+ const toAddress =
+ _.isUndefined(txData.to) || txData.to === NULL_ADDRESS ? constants.NEW_CONTRACT : txData.to;
+ await this._recordTxTraceAsync(toAddress, transaction.input, transaction.hash);
+ }
+ }
+ if (!txData.isFakeTransaction) {
+ // This transaction is a usual transaction. 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 _onCallOrGasEstimateExecutedAsync(
+ callData: Partial<CallData>,
+ _err: Error | null,
+ _callResult: string,
+ cb: Callback,
+ ): Promise<void> {
+ await this._recordCallOrGasEstimateTraceAsync(callData);
+ cb();
+ }
+ private async _recordCallOrGasEstimateTraceAsync(callData: Partial<CallData>): Promise<void> {
+ // 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 blockchainLifecycle = new BlockchainLifecycle(this._web3Wrapper);
+ await blockchainLifecycle.startAsync();
+ const fakeTxData: MaybeFakeTxData = {
+ gas: BLOCK_GAS_LIMIT,
+ isFakeTransaction: true, // This transaction (and only it) is allowed to come through when the lock is locked
+ ...callData,
+ from: callData.from || this._defaultFromAddress,
+ };
+ try {
+ const txHash = await this._web3Wrapper.sendTransactionAsync(fakeTxData);
+ await this._web3Wrapper.awaitTransactionMinedAsync(txHash, 0);
+ } catch (err) {
+ // Even if this transaction failed - we've already recorded it's trace.
+ _.noop();
+ }
+ await blockchainLifecycle.revertAsync();
+ this._lock.release();
+ }
+}