Make sol-cov work with truffle and other artifact adapters

8 files changed, 281 insertions, 80 deletions

diff --git a/packages/sol-cov/src/artifact_adapters/0x.ts b/packages/sol-cov/src/artifact_adapters/0x.ts
new file mode 100644
index 000000000..87d23b0aa
--- /dev/null
+++ b/packages/sol-cov/src/artifact_adapters/0x.ts
@@ -0,0 +1,41 @@
+import * as fs from 'fs';
+import * as glob from 'glob';
+import * as _ from 'lodash';
+import * as path from 'path';
+
+import { ContractData } from '../types';
+
+import { AbstractArtifactAdapter } from './abstract';
+
+export class ZeroExArtifactAdapter extends AbstractArtifactAdapter {
+    private _artifactsPath: string;
+    private _sourcesPath: string;
+    constructor(artifactsPath: string, sourcesPath: string) {
+        super();
+        this._artifactsPath = artifactsPath;
+        this._sourcesPath = sourcesPath;
+    }
+    public async collectContractsDataAsync(): Promise<ContractData[]> {
+        const artifactsGlob = `${this._artifactsPath}/**/*.json`;
+        const artifactFileNames = glob.sync(artifactsGlob, { absolute: true });
+        const contractsData: ContractData[] = [];
+        for (const artifactFileName of artifactFileNames) {
+            const artifact = JSON.parse(fs.readFileSync(artifactFileName).toString());
+            let sources = _.keys(artifact.sources);
+            sources = _.map(sources, relativeFilePath => path.resolve(this._sourcesPath, relativeFilePath));
+            const contractName = artifact.contractName;
+            // We don't compute coverage for dependencies
+            const sourceCodes = _.map(sources, (source: string) => fs.readFileSync(source).toString());
+            const contractData = {
+                sourceCodes,
+                sources,
+                bytecode: artifact.compilerOutput.evm.bytecode.object,
+                sourceMap: artifact.compilerOutput.evm.bytecode.sourceMap,
+                runtimeBytecode: artifact.compilerOutput.evm.deployedBytecode.object,
+                sourceMapRuntime: artifact.compilerOutput.evm.deployedBytecode.sourceMap,
+            };
+            contractsData.push(contractData);
+        }
+        return contractsData;
+    }
+}
diff --git a/packages/sol-cov/src/artifact_adapters/abstract.ts b/packages/sol-cov/src/artifact_adapters/abstract.ts
new file mode 100644
index 000000000..fcc6562ad
--- /dev/null
+++ b/packages/sol-cov/src/artifact_adapters/abstract.ts
@@ -0,0 +1,5 @@
+import { ContractData } from '../types';
+
+export abstract class AbstractArtifactAdapter {
+    public abstract async collectContractsDataAsync(): Promise<ContractData[]>;
+}
diff --git a/packages/sol-cov/src/artifact_adapters/truffle.ts b/packages/sol-cov/src/artifact_adapters/truffle.ts
new file mode 100644
index 000000000..e891bb464
--- /dev/null
+++ b/packages/sol-cov/src/artifact_adapters/truffle.ts
@@ -0,0 +1,43 @@
+import { Compiler, CompilerOptions } from '@0xproject/sol-compiler';
+import * as fs from 'fs';
+import * as glob from 'glob';
+import * as _ from 'lodash';
+import * as path from 'path';
+import * as rimraf from 'rimraf';
+
+import { ContractData } from '../types';
+
+import { ZeroExArtifactAdapter } from './0x';
+import { AbstractArtifactAdapter } from './abstract';
+
+export class TruffleArtifactAdapter extends AbstractArtifactAdapter {
+    private _solcVersion: string;
+    private _sourcesPath: string;
+    constructor(sourcesPath: string, solcVersion: string) {
+        super();
+        this._solcVersion = solcVersion;
+        this._sourcesPath = sourcesPath;
+    }
+    public async collectContractsDataAsync(): Promise<ContractData[]> {
+        const artifactsDir = '0x-artifacts';
+        const compilerOptions: CompilerOptions = {
+            contractsDir: this._sourcesPath,
+            artifactsDir,
+            compilerSettings: {
+                outputSelection: {
+                    ['*']: {
+                        ['*']: ['abi', 'evm.bytecode.object', 'evm.deployedBytecode.object'],
+                    },
+                },
+            },
+            contracts: '*',
+            solcVersion: this._solcVersion,
+        };
+        const compiler = new Compiler(compilerOptions);
+        await compiler.compileAsync();
+        const zeroExArtifactAdapter = new ZeroExArtifactAdapter(artifactsDir, this._sourcesPath);
+        const contractsDataFrom0xArtifacts = await zeroExArtifactAdapter.collectContractsDataAsync();
+        rimraf.sync(artifactsDir);
+        return contractsDataFrom0xArtifacts;
+    }
+}
diff --git a/packages/sol-cov/src/collect_contract_data.ts b/packages/sol-cov/src/collect_contract_data.ts
deleted file mode 100644
index 2c2a12835..000000000
--- a/packages/sol-cov/src/collect_contract_data.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import * as fs from 'fs';
-import * as glob from 'glob';
-import * as _ from 'lodash';
-import * as path from 'path';
-
-import { ContractData } from './types';
-
-export const collectContractsData = (artifactsPath: string, sourcesPath: string) => {
-    const artifactsGlob = `${artifactsPath}/**/*.json`;
-    const artifactFileNames = glob.sync(artifactsGlob, { absolute: true });
-    const contractsData: ContractData[] = [];
-    _.forEach(artifactFileNames, artifactFileName => {
-        const artifact = JSON.parse(fs.readFileSync(artifactFileName).toString());
-        const sources = _.keys(artifact.sources);
-        const contractName = artifact.contractName;
-        // We don't compute coverage for dependencies
-        const sourceCodes = _.map(sources, (source: string) =>
-            fs.readFileSync(path.join(sourcesPath, source)).toString(),
-        );
-        const contractData = {
-            sourceCodes,
-            sources,
-            bytecode: artifact.compilerOutput.evm.bytecode.object,
-            sourceMap: artifact.compilerOutput.evm.bytecode.sourceMap,
-            runtimeBytecode: artifact.compilerOutput.evm.deployedBytecode.object,
-            sourceMapRuntime: artifact.compilerOutput.evm.deployedBytecode.sourceMap,
-        };
-        contractsData.push(contractData);
-    });
-    return contractsData;
-};
diff --git a/packages/sol-cov/src/coverage_manager.ts b/packages/sol-cov/src/coverage_manager.ts
index 800ca96dd..65a6086c0 100644
--- a/packages/sol-cov/src/coverage_manager.ts
+++ b/packages/sol-cov/src/coverage_manager.ts
@@ -6,7 +6,7 @@ import * as _ from 'lodash';
 import * as mkdirp from 'mkdirp';
 import * as path from 'path';
 
-import { collectContractsData } from './collect_contract_data';
+import { AbstractArtifactAdapter } from './artifact_adapters/abstract';
 import { collectCoverageEntries } from './collect_coverage_entries';
 import { constants } from './constants';
 import { parseSourceMap } from './source_maps';
@@ -34,41 +34,23 @@ import { utils } from './utils';
 const mkdirpAsync = promisify<undefined>(mkdirp);
 
 export class CoverageManager {
-    private _sourcesPath: string;
+    private _artifactAdapter: AbstractArtifactAdapter;
+    private _verbose: boolean;
     private _traceInfos: TraceInfo[] = [];
-    private _contractsData: ContractData[] = [];
     private _getContractCodeAsync: (address: string) => Promise<string>;
-    constructor(
-        artifactsPath: string,
-        sourcesPath: string,
-        getContractCodeAsync: (address: string) => Promise<string>,
-    ) {
-        this._getContractCodeAsync = getContractCodeAsync;
-        this._sourcesPath = sourcesPath;
-        this._contractsData = collectContractsData(artifactsPath, this._sourcesPath);
-    }
-    public appendTraceInfo(traceInfo: TraceInfo): void {
-        this._traceInfos.push(traceInfo);
-    }
-    public async writeCoverageAsync(): Promise<void> {
-        const finalCoverage = await this._computeCoverageAsync();
-        const stringifiedCoverage = JSON.stringify(finalCoverage, null, '\t');
-        await mkdirpAsync('coverage');
-        fs.writeFileSync('coverage/coverage.json', stringifiedCoverage);
-    }
-    private _getSingleFileCoverageForTrace(
+    private static _getSingleFileCoverageForTrace(
         contractData: ContractData,
         coveredPcs: number[],
         pcToSourceRange: { [programCounter: number]: SourceRange },
         fileIndex: number,
     ): Coverage {
-        const fileName = contractData.sources[fileIndex];
+        const absoluteFileName = contractData.sources[fileIndex];
         const coverageEntriesDescription = collectCoverageEntries(contractData.sourceCodes[fileIndex]);
         let sourceRanges = _.map(coveredPcs, coveredPc => pcToSourceRange[coveredPc]);
         sourceRanges = _.compact(sourceRanges); // Some PC's don't map to a source range and we just ignore them.
         // By default lodash does a shallow object comparasion. We JSON.stringify them and compare as strings.
         sourceRanges = _.uniqBy(sourceRanges, s => JSON.stringify(s)); // We don't care if one PC was covered multiple times within a single transaction
-        sourceRanges = _.filter(sourceRanges, sourceRange => sourceRange.fileName === fileName);
+        sourceRanges = _.filter(sourceRanges, sourceRange => sourceRange.fileName === absoluteFileName);
         const branchCoverage: BranchCoverage = {};
         const branchIds = _.keys(coverageEntriesDescription.branchMap);
         for (const branchId of branchIds) {
@@ -118,7 +100,6 @@ export class CoverageManager {
             );
             statementCoverage[modifierStatementId] = isModifierCovered;
         }
-        const absoluteFileName = path.join(this._sourcesPath, fileName);
         const partialCoverage = {
             [absoluteFileName]: {
                 ...coverageEntriesDescription,
@@ -131,18 +112,53 @@ export class CoverageManager {
         };
         return partialCoverage;
     }
+    constructor(
+        artifactAdapter: AbstractArtifactAdapter,
+        getContractCodeAsync: (address: string) => Promise<string>,
+        verbose: boolean,
+    ) {
+        this._getContractCodeAsync = getContractCodeAsync;
+        this._artifactAdapter = artifactAdapter;
+        this._verbose = verbose;
+    }
+    public appendTraceInfo(traceInfo: TraceInfo): void {
+        // console.log(JSON.stringify(traceInfo, null, '\n'));
+        this._traceInfos.push(traceInfo);
+    }
+    public async writeCoverageAsync(): Promise<void> {
+        const finalCoverage = await this._computeCoverageAsync();
+        const stringifiedCoverage = JSON.stringify(finalCoverage, null, '\t');
+        await mkdirpAsync('coverage');
+        fs.writeFileSync('coverage/coverage.json', stringifiedCoverage);
+    }
     private async _computeCoverageAsync(): Promise<Coverage> {
+        const contractsData = await this._artifactAdapter.collectContractsDataAsync();
         const collector = new Collector();
         for (const traceInfo of this._traceInfos) {
             if (traceInfo.address !== constants.NEW_CONTRACT) {
                 // Runtime transaction
                 let runtimeBytecode = (traceInfo as TraceInfoExistingContract).runtimeBytecode;
                 runtimeBytecode = addHexPrefix(runtimeBytecode);
-                const contractData = _.find(this._contractsData, { runtimeBytecode }) as ContractData;
+                const contractData = _.find(contractsData, contractDataCandidate => {
+                    // Library linking placeholder: __ConvertLib____________________________
+                    let runtimeBytecodeRegex = contractDataCandidate.runtimeBytecode.replace(/_.*_/, '.*');
+                    // Last 86 characters is solidity compiler metadata that's different between compilations
+                    runtimeBytecodeRegex = runtimeBytecodeRegex.replace(/.{86}$/, '');
+                    // Libraries contain their own address at the beginning of the code and it's impossible to know it in advance
+                    runtimeBytecodeRegex = runtimeBytecodeRegex.replace(
+                        /^0x730000000000000000000000000000000000000000/,
+                        '0x73........................................',
+                    );
+                    return !_.isNull(runtimeBytecode.match(runtimeBytecodeRegex));
+                }) as ContractData;
                 if (_.isUndefined(contractData)) {
-                    throw new Error(`Transaction to an unknown address: ${traceInfo.address}`);
+                    if (this._verbose) {
+                        // tslint:disable-next-line:no-console
+                        console.warn(`Transaction to an unknown address: ${traceInfo.address}`);
+                    }
+                    continue;
                 }
-                const bytecodeHex = contractData.runtimeBytecode.slice(2);
+                const bytecodeHex = runtimeBytecode.slice(2);
                 const sourceMap = contractData.sourceMapRuntime;
                 const pcToSourceRange = parseSourceMap(
                     contractData.sourceCodes,
@@ -151,7 +167,7 @@ export class CoverageManager {
                     contractData.sources,
                 );
                 for (let fileIndex = 0; fileIndex < contractData.sources.length; fileIndex++) {
-                    const singleFileCoverageForTrace = this._getSingleFileCoverageForTrace(
+                    const singleFileCoverageForTrace = CoverageManager._getSingleFileCoverageForTrace(
                         contractData,
                         traceInfo.coveredPcs,
                         pcToSourceRange,
@@ -163,13 +179,26 @@ export class CoverageManager {
                 // Contract creation transaction
                 let bytecode = (traceInfo as TraceInfoNewContract).bytecode;
                 bytecode = addHexPrefix(bytecode);
-                const contractData = _.find(this._contractsData, contractDataCandidate =>
-                    bytecode.startsWith(contractDataCandidate.bytecode),
-                ) as ContractData;
+                const contractData = _.find(contractsData, contractDataCandidate => {
+                    // Library linking placeholder: __ConvertLib____________________________
+                    let bytecodeRegex = contractDataCandidate.bytecode.replace(/_.*_/, '.*');
+                    // Last 86 characters is solidity compiler metadata that's different between compilations
+                    bytecodeRegex = bytecodeRegex.replace(/.{86}$/, '');
+                    // Libraries contain their own address at the beginning of the code and it's impossible to know it in advance
+                    bytecodeRegex = bytecodeRegex.replace(
+                        /^0x730000000000000000000000000000000000000000/,
+                        '0x73........................................',
+                    );
+                    return !_.isNull(bytecode.match(bytecodeRegex));
+                }) as ContractData;
                 if (_.isUndefined(contractData)) {
-                    throw new Error(`Unknown contract creation transaction`);
+                    if (this._verbose) {
+                        // tslint:disable-next-line:no-console
+                        console.warn(`Unknown contract creation transaction`);
+                    }
+                    continue;
                 }
-                const bytecodeHex = contractData.bytecode.slice(2);
+                const bytecodeHex = bytecode.slice(2);
                 const sourceMap = contractData.sourceMap;
                 const pcToSourceRange = parseSourceMap(
                     contractData.sourceCodes,
@@ -178,7 +207,7 @@ export class CoverageManager {
                     contractData.sources,
                 );
                 for (let fileIndex = 0; fileIndex < contractData.sources.length; fileIndex++) {
-                    const singleFileCoverageForTrace = this._getSingleFileCoverageForTrace(
+                    const singleFileCoverageForTrace = CoverageManager._getSingleFileCoverageForTrace(
                         contractData,
                         traceInfo.coveredPcs,
                         pcToSourceRange,
diff --git a/packages/sol-cov/src/coverage_subprovider.ts b/packages/sol-cov/src/coverage_subprovider.ts
index 08efeaa24..f421a17fd 100644
--- a/packages/sol-cov/src/coverage_subprovider.ts
+++ b/packages/sol-cov/src/coverage_subprovider.ts
@@ -1,10 +1,13 @@
 import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0xproject/subproviders';
 import { BlockParam, CallData, JSONRPCRequestPayload, TransactionTrace, TxData } from '@0xproject/types';
+import * as fs from 'fs';
 import * as _ from 'lodash';
 import { Lock } from 'semaphore-async-await';
 
+import { AbstractArtifactAdapter } from './artifact_adapters/abstract';
 import { constants } from './constants';
 import { CoverageManager } from './coverage_manager';
+import { getTracesByContractAddress } from './trace';
 import { TraceInfoExistingContract, TraceInfoNewContract } from './types';
 
 interface MaybeFakeTxData extends TxData {
@@ -26,15 +29,15 @@ export class CoverageSubprovider extends Subprovider {
     private _defaultFromAddress: string;
     /**
      * Instantiates a CoverageSubprovider instance
-     * @param artifactsPath Path to the smart contract artifacts
-     * @param sourcesPath Path to the smart contract source files
+     * @param artifactAdapter Adapter for used artifacts format (0x, truffle, giveth, etc.)
      * @param defaultFromAddress default from address to use when sending transactions
+     * @param verbose If true, we will log any unknown transactions. Otherwise we will ignore them
      */
-    constructor(artifactsPath: string, sourcesPath: string, defaultFromAddress: string) {
+    constructor(artifactAdapter: AbstractArtifactAdapter, defaultFromAddress: string, verbose: boolean = true) {
         super();
         this._lock = new Lock();
         this._defaultFromAddress = defaultFromAddress;
-        this._coverageManager = new CoverageManager(artifactsPath, sourcesPath, this._getContractCodeAsync.bind(this));
+        this._coverageManager = new CoverageManager(artifactAdapter, this._getContractCodeAsync.bind(this), verbose);
     }
     /**
      * Write the test coverage results to a file in Istanbul format.
@@ -119,8 +122,10 @@ export class CoverageSubprovider extends Subprovider {
         };
         const jsonRPCResponsePayload = await this.emitPayloadAsync(payload);
         const trace: TransactionTrace = jsonRPCResponsePayload.result;
-        const coveredPcs = _.map(trace.structLogs, log => log.pc);
         if (address === constants.NEW_CONTRACT) {
+            // TODO handle calls to external contracts and contract creations from within the constructor
+            const structLogsOnDepth0 = _.filter(trace.structLogs, { depth: 0 });
+            const coveredPcs = _.map(structLogsOnDepth0, log => log.pc);
             const traceInfo: TraceInfoNewContract = {
                 coveredPcs,
                 txHash,
@@ -129,15 +134,20 @@ export class CoverageSubprovider extends Subprovider {
             };
             this._coverageManager.appendTraceInfo(traceInfo);
         } else {
-            payload = { method: 'eth_getCode', params: [address, 'latest'] };
-            const runtimeBytecode = (await this.emitPayloadAsync(payload)).result;
-            const traceInfo: TraceInfoExistingContract = {
-                coveredPcs,
-                txHash,
-                address,
-                runtimeBytecode,
-            };
-            this._coverageManager.appendTraceInfo(traceInfo);
+            const tracesByContractAddress = getTracesByContractAddress(trace.structLogs, address);
+            for (const subcallAddress of _.keys(tracesByContractAddress)) {
+                payload = { method: 'eth_getCode', params: [subcallAddress, 'latest'] };
+                const runtimeBytecode = (await this.emitPayloadAsync(payload)).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<CallData>, blockNumber: BlockParam): Promise<void> {
diff --git a/packages/sol-cov/src/index.ts b/packages/sol-cov/src/index.ts
index e5c5e5be3..18031372b 100644
--- a/packages/sol-cov/src/index.ts
+++ b/packages/sol-cov/src/index.ts
@@ -1 +1,5 @@
 export { CoverageSubprovider } from './coverage_subprovider';
+export { ZeroExArtifactAdapter } from './artifact_adapters/0x';
+export { TruffleArtifactAdapter } from './artifact_adapters/truffle';
+export { AbstractArtifactAdapter } from './artifact_adapters/abstract';
+export { ContractData } from './types';
diff --git a/packages/sol-cov/src/trace.ts b/packages/sol-cov/src/trace.ts
new file mode 100644
index 000000000..6bc28989d
--- /dev/null
+++ b/packages/sol-cov/src/trace.ts
@@ -0,0 +1,100 @@
+import { StructLog, TransactionTrace } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
+import * as fs from 'fs';
+import * as _ from 'lodash';
+
+export interface TraceByContractAddress {
+    [contractAddress: string]: StructLog[];
+}
+function padZeros(address: string) {
+    return addHexPrefix(_.padStart(stripHexPrefix(address), 40, '0'));
+}
+
+export function getTracesByContractAddress(structLogs: StructLog[], startAddress: string): TraceByContractAddress {
+    const traceByContractAddress: TraceByContractAddress = {};
+    let currentTraceSegment = [];
+    const callStack = [startAddress];
+    // tslint:disable-next-line: prefer-for-of
+    for (let i = 0; i < structLogs.length; ++i) {
+        const structLog = structLogs[i];
+        if (structLog.depth !== callStack.length - 1) {
+            throw new Error("Malformed trace. trace depth doesn't match call stack depth");
+        }
+        // After that check we have a guarantee that call stack is never empty
+        // If it would: callStack.length - 1 === structLog.depth === -1
+        // That means that we can always safely pop from it
+        currentTraceSegment.push(structLog);
+
+        if (structLog.op === 'DELEGATECALL') {
+            const currentAddress = _.last(callStack) as string;
+            const jumpAddressOffset = 4;
+            const newAddress = padZeros(new BigNumber(addHexPrefix(structLog.stack[jumpAddressOffset])).toString(16));
+            callStack.push(newAddress);
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+        } else if (structLog.op === 'RETURN') {
+            const currentAddress = callStack.pop() as string;
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+        } else if (structLog.op === 'STOP') {
+            const currentAddress = callStack.pop() as string;
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+            if (i !== structLogs.length - 1) {
+                throw new Error('Malformed trace. STOP is not the last opcode executed');
+            }
+        } else if (structLog.op === 'CREATE') {
+            console.warn(
+                "Detected a contract created from within another contract. Sol-cov currently doesn't support that scenario. We'll just skip that trace",
+            );
+            return traceByContractAddress;
+        } else if (structLog.op === 'CALL') {
+            const currentAddress = _.last(callStack) as string;
+            const jumpAddressOffset = 2;
+            const newAddress = padZeros(new BigNumber(addHexPrefix(structLog.stack[jumpAddressOffset])).toString(16));
+            callStack.push(newAddress);
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+        } else if (structLog.op === 'CALLCODE') {
+            throw new Error('CALLCODE opcode unsupported by coverage');
+        } else if (structLog.op === 'STATICCALL') {
+            throw new Error('STATICCALL opcode unsupported by coverage');
+        } else if (structLog.op === 'REVERT') {
+            const currentAddress = callStack.pop() as string;
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+            if (i !== structLogs.length - 1) {
+                throw new Error('Malformed trace. REVERT is not the last opcode executed');
+            }
+        } else if (structLog.op === 'INVALID') {
+            const currentAddress = callStack.pop() as string;
+            traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+                currentTraceSegment,
+            );
+            currentTraceSegment = [];
+            if (i !== structLogs.length - 1) {
+                throw new Error('Malformed trace. INVALID is not the last opcode executed');
+            }
+        } else if (structLog.op === 'SELFDESTRUCT') {
+            throw new Error('SELFDESTRUCT opcode unsupported by coverage');
+        }
+    }
+    if (callStack.length !== 0) {
+        throw new Error('Malformed trace. Call stack non empty at the end');
+    }
+    if (currentTraceSegment.length !== 0) {
+        throw new Error('Malformed trace. currentTraceSegment non empty at the end');
+    }
+    return traceByContractAddress;
+}