Merge branch 'v2-prototype' into bug/contracts/eip712-191-prefix

21 files changed, 930 insertions, 462 deletions

diff --git a/packages/sol-cov/CHANGELOG.json b/packages/sol-cov/CHANGELOG.json
index 0d3303231..7e934ad6e 100644
--- a/packages/sol-cov/CHANGELOG.json
+++ b/packages/sol-cov/CHANGELOG.json
@@ -1,5 +1,58 @@
 [
     {
+        "version": "0.2.0",
+        "changes": [
+            {
+                "note": "Fixed a bug causing RegExp to crash if contract code is longer that 32767 characters",
+                "pr": 675
+            },
+            {
+                "note": "Fixed a bug caused by Geth debug trace depth being 1-indexed",
+                "pr": 675
+            },
+            {
+                "note": "Fixed a bug when the tool crashed on empty traces",
+                "pr": 675
+            },
+            {
+                "note": "Use `BlockchainLifecycle` to support reverts on Geth",
+                "pr": 675
+            },
+            {
+                "note": "Add `ProfilerSubprovider` as a hacky way to profile code using coverage tools",
+                "pr": 675
+            },
+            {
+                "note": "Collect traces from `estimate_gas` calls",
+                "pr": 675
+            },
+            {
+                "note": "Fix a race condition caused by not awaiting the transaction before getting a trace",
+                "pr": 675
+            },
+            {
+                "note": "Add `start`/`stop` functionality to `CoverageSubprovider` and `ProfilerSubprovider`",
+                "pr": 675
+            },
+            {
+                "note": "Skip interface artifacts with a warning instead of failing",
+                "pr": 675
+            },
+            {
+                "note": "Fix solcVersion regex in parameter validation",
+                "pr": 690
+            },
+            {
+                "note": "Fix a bug when in TruffleArtifactsAdapter causing it to throw if compiler.json is not there",
+                "pr": 690
+            },
+            {
+                "note": "HUGE perf improvements",
+                "pr": 690
+            }
+        ]
+    },
+    {
         "timestamp": 1527009134,
         "version": "0.1.0",
         "changes": [
diff --git a/packages/sol-cov/package.json b/packages/sol-cov/package.json
index 4d92a610b..1d9d7f94d 100644
--- a/packages/sol-cov/package.json
+++ b/packages/sol-cov/package.json
@@ -8,15 +8,18 @@
     "main": "lib/src/index.js",
     "types": "lib/src/index.d.ts",
     "scripts": {
-        "watch": "tsc -w",
+        "watch_without_deps": "yarn pre_build && tsc -w",
+        "build": "yarn pre_build && tsc && copyfiles -u 3 './lib/src/monorepo_scripts/**/*' ./scripts",
+        "pre_build": "run-s copy_test_fixtures",
         "lint": "tslint --project .",
-        "test": "run-s clean build compile_test run_mocha",
+        "test": "run-s compile_test run_mocha",
+        "rebuild_and_test": "run-s clean build test",
         "test:coverage": "nyc npm run test --all && yarn coverage:report:lcov",
         "coverage:report:lcov": "nyc report --reporter=text-lcov > coverage/lcov.info",
         "test:circleci": "yarn test:coverage",
-        "run_mocha": "mocha lib/test/**/*_test.js --exit",
+        "run_mocha": "mocha --require source-map-support/register lib/test/**/*_test.js --exit",
         "clean": "shx rm -rf lib scripts test/fixtures/artifacts src/artifacts",
-        "build": "copyfiles 'test/fixtures/**/*' ./lib && tsc && copyfiles -u 3 './lib/src/monorepo_scripts/**/*' ./scripts",
+        "copy_test_fixtures": "copyfiles 'test/fixtures/**/*' ./lib",
         "compile_test": "sol-compiler compile",
         "manual:postpublish": "yarn build; node ./scripts/postpublish.js",
         "docs:stage": "node scripts/stage_docs.js",
@@ -51,6 +54,8 @@
         "@0xproject/subproviders": "^0.10.2",
         "@0xproject/typescript-typings": "^0.3.2",
         "@0xproject/utils": "^0.6.2",
+        "@0xproject/web3-wrapper": "^0.6.4",
+        "@0xproject/dev-utils": "^0.4.2",
         "ethereum-types": "^0.0.1",
         "ethereumjs-util": "^5.1.1",
         "glob": "^7.1.2",
@@ -60,7 +65,7 @@
         "mkdirp": "^0.5.1",
         "rimraf": "^2.6.2",
         "semaphore-async-await": "^1.5.1",
-        "solidity-parser-antlr": "^0.2.11"
+        "solidity-parser-antlr": "^0.2.12"
     },
     "devDependencies": {
         "@0xproject/monorepo-scripts": "^0.1.20",
diff --git a/packages/sol-cov/src/artifact_adapters/sol_compiler_artifact_adapter.ts b/packages/sol-cov/src/artifact_adapters/sol_compiler_artifact_adapter.ts
index d08828bf6..220a9f98c 100644
--- a/packages/sol-cov/src/artifact_adapters/sol_compiler_artifact_adapter.ts
+++ b/packages/sol-cov/src/artifact_adapters/sol_compiler_artifact_adapter.ts
@@ -1,3 +1,5 @@
+import { CompilerOptions, ContractArtifact } from '@0xproject/sol-compiler';
+import { logUtils } from '@0xproject/utils';
 import * as fs from 'fs';
 import * as glob from 'glob';
 import * as _ from 'lodash';
@@ -14,25 +16,30 @@ export class SolCompilerArtifactAdapter extends AbstractArtifactAdapter {
     private _sourcesPath: string;
     constructor(artifactsPath?: string, sourcesPath?: string) {
         super();
-        const config = JSON.parse(fs.readFileSync(CONFIG_FILE).toString());
+        const config: CompilerOptions = fs.existsSync(CONFIG_FILE)
+            ? JSON.parse(fs.readFileSync(CONFIG_FILE).toString())
+            : {};
         if (_.isUndefined(artifactsPath) && _.isUndefined(config.artifactsDir)) {
             throw new Error(`artifactsDir not found in ${CONFIG_FILE}`);
         }
-        this._artifactsPath = config.artifactsDir;
+        this._artifactsPath = (artifactsPath || config.artifactsDir) as string;
         if (_.isUndefined(sourcesPath) && _.isUndefined(config.contractsDir)) {
             throw new Error(`contractsDir not found in ${CONFIG_FILE}`);
         }
-        this._sourcesPath = config.contractsDir;
+        this._sourcesPath = (sourcesPath || config.contractsDir) as string;
     }
     public async collectContractsDataAsync(): Promise<ContractData[]> {
         const artifactsGlob = `${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());
+            const artifact: ContractArtifact = JSON.parse(fs.readFileSync(artifactFileName).toString());
+            if (_.isUndefined(artifact.compilerOutput.evm)) {
+                logUtils.warn(`${artifactFileName} doesn't contain bytecode. Skipping...`);
+                continue;
+            }
             let sources = _.keys(artifact.sources);
             sources = _.map(sources, relativeFilePath => path.resolve(this._sourcesPath, relativeFilePath));
-            const contractName = artifact.contractName;
             const sourceCodes = _.map(sources, (source: string) => fs.readFileSync(source).toString());
             const contractData = {
                 sourceCodes,
diff --git a/packages/sol-cov/src/artifact_adapters/truffle_artifact_adapter.ts b/packages/sol-cov/src/artifact_adapters/truffle_artifact_adapter.ts
index c7f21b6eb..53449e5e1 100644
--- a/packages/sol-cov/src/artifact_adapters/truffle_artifact_adapter.ts
+++ b/packages/sol-cov/src/artifact_adapters/truffle_artifact_adapter.ts
@@ -1,8 +1,4 @@
 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';
diff --git a/packages/sol-cov/src/ast_visitor.ts b/packages/sol-cov/src/ast_visitor.ts
index 88309d3eb..16984b5ec 100644
--- a/packages/sol-cov/src/ast_visitor.ts
+++ b/packages/sol-cov/src/ast_visitor.ts
@@ -57,6 +57,9 @@ export class ASTVisitor {
     public ContinueStatement(ast: Parser.ContinueStatement): void {
         this._visitStatement(ast);
     }
+    public EmitStatement(ast: any /* TODO: Parser.EmitStatement */): void {
+        this._visitStatement(ast);
+    }
     public VariableDeclarationStatement(ast: Parser.VariableDeclarationStatement): void {
         this._visitStatement(ast);
     }
diff --git a/packages/sol-cov/src/collect_coverage_entries.ts b/packages/sol-cov/src/collect_coverage_entries.ts
index 97218616c..b145f044e 100644
--- a/packages/sol-cov/src/collect_coverage_entries.ts
+++ b/packages/sol-cov/src/collect_coverage_entries.ts
@@ -1,7 +1,5 @@
 import * as ethUtil from 'ethereumjs-util';
-import * as fs from 'fs';
 import * as _ from 'lodash';
-import * as path from 'path';
 import * as parser from 'solidity-parser-antlr';
 
 import { ASTVisitor, CoverageEntriesDescription } from './ast_visitor';
diff --git a/packages/sol-cov/src/coverage_manager.ts b/packages/sol-cov/src/coverage_manager.ts
deleted file mode 100644
index 31b0e6fbc..000000000
--- a/packages/sol-cov/src/coverage_manager.ts
+++ /dev/null
@@ -1,218 +0,0 @@
-import { promisify } from '@0xproject/utils';
-import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
-import * as fs from 'fs';
-import { Collector } from 'istanbul';
-import * as _ from 'lodash';
-import { getLogger, levels, Logger, LogLevel } from 'loglevel';
-import * as mkdirp from 'mkdirp';
-import * as path from 'path';
-
-import { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter';
-import { collectCoverageEntries } from './collect_coverage_entries';
-import { constants } from './constants';
-import { parseSourceMap } from './source_maps';
-import {
-    BranchCoverage,
-    BranchDescription,
-    BranchMap,
-    ContractData,
-    Coverage,
-    FnMap,
-    FunctionCoverage,
-    FunctionDescription,
-    LineColumn,
-    SingleFileSourceRange,
-    SourceRange,
-    StatementCoverage,
-    StatementDescription,
-    StatementMap,
-    TraceInfo,
-    TraceInfoExistingContract,
-    TraceInfoNewContract,
-} from './types';
-import { utils } from './utils';
-
-const mkdirpAsync = promisify<undefined>(mkdirp);
-
-export class CoverageManager {
-    private _artifactAdapter: AbstractArtifactAdapter;
-    private _logger: Logger;
-    private _traceInfos: TraceInfo[] = [];
-    private _getContractCodeAsync: (address: string) => Promise<string>;
-    private static _getSingleFileCoverageForTrace(
-        contractData: ContractData,
-        coveredPcs: number[],
-        pcToSourceRange: { [programCounter: number]: SourceRange },
-        fileIndex: number,
-    ): Coverage {
-        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 === absoluteFileName);
-        const branchCoverage: BranchCoverage = {};
-        const branchIds = _.keys(coverageEntriesDescription.branchMap);
-        for (const branchId of branchIds) {
-            const branchDescription = coverageEntriesDescription.branchMap[branchId];
-            const isCoveredByBranchIndex = _.map(branchDescription.locations, location =>
-                _.some(sourceRanges, range => utils.isRangeInside(range.location, location)),
-            );
-            branchCoverage[branchId] = isCoveredByBranchIndex;
-        }
-        const statementCoverage: StatementCoverage = {};
-        const statementIds = _.keys(coverageEntriesDescription.statementMap);
-        for (const statementId of statementIds) {
-            const statementDescription = coverageEntriesDescription.statementMap[statementId];
-            const isCovered = _.some(sourceRanges, range => utils.isRangeInside(range.location, statementDescription));
-            statementCoverage[statementId] = isCovered;
-        }
-        const functionCoverage: FunctionCoverage = {};
-        const functionIds = _.keys(coverageEntriesDescription.fnMap);
-        for (const fnId of functionIds) {
-            const functionDescription = coverageEntriesDescription.fnMap[fnId];
-            const isCovered = _.some(sourceRanges, range =>
-                utils.isRangeInside(range.location, functionDescription.loc),
-            );
-            functionCoverage[fnId] = isCovered;
-        }
-        // HACK: Solidity doesn't emit any opcodes that map back to modifiers with no args, that's why we map back to the
-        // function range and check if there is any covered statement within that range.
-        for (const modifierStatementId of coverageEntriesDescription.modifiersStatementIds) {
-            if (statementCoverage[modifierStatementId]) {
-                // Already detected as covered
-                continue;
-            }
-            const modifierDescription = coverageEntriesDescription.statementMap[modifierStatementId];
-            const enclosingFunction = _.find(coverageEntriesDescription.fnMap, functionDescription =>
-                utils.isRangeInside(modifierDescription, functionDescription.loc),
-            ) as FunctionDescription;
-            const isModifierCovered = _.some(
-                coverageEntriesDescription.statementMap,
-                (statementDescription: StatementDescription, statementId: number) => {
-                    const isInsideTheModifierEnclosingFunction = utils.isRangeInside(
-                        statementDescription,
-                        enclosingFunction.loc,
-                    );
-                    const isCovered = statementCoverage[statementId];
-                    return isInsideTheModifierEnclosingFunction && isCovered;
-                },
-            );
-            statementCoverage[modifierStatementId] = isModifierCovered;
-        }
-        const partialCoverage = {
-            [absoluteFileName]: {
-                ...coverageEntriesDescription,
-                l: {}, // It's able to derive it from statement coverage
-                path: absoluteFileName,
-                f: functionCoverage,
-                s: statementCoverage,
-                b: branchCoverage,
-            },
-        };
-        return partialCoverage;
-    }
-    private static _bytecodeToBytecodeRegex(bytecode: string): string {
-        const bytecodeRegex = bytecode
-            // Library linking placeholder: __ConvertLib____________________________
-            .replace(/_.*_/, '.*')
-            // Last 86 characters is solidity compiler metadata that's different between compilations
-            .replace(/.{86}$/, '')
-            // Libraries contain their own address at the beginning of the code and it's impossible to know it in advance
-            .replace(/^0x730000000000000000000000000000000000000000/, '0x73........................................');
-        return bytecodeRegex;
-    }
-    private static _getContractDataIfExists(contractsData: ContractData[], bytecode: string): ContractData | undefined {
-        if (!bytecode.startsWith('0x')) {
-            throw new Error(`0x hex prefix missing: ${bytecode}`);
-        }
-        const contractData = _.find(contractsData, contractDataCandidate => {
-            const bytecodeRegex = CoverageManager._bytecodeToBytecodeRegex(contractDataCandidate.bytecode);
-            const runtimeBytecodeRegex = CoverageManager._bytecodeToBytecodeRegex(
-                contractDataCandidate.runtimeBytecode,
-            );
-            // We use that function to find by bytecode or runtimeBytecode. Those are quasi-random strings so
-            // collisions are practically impossible and it allows us to reuse that code
-            return !_.isNull(bytecode.match(bytecodeRegex)) || !_.isNull(bytecode.match(runtimeBytecodeRegex));
-        });
-        return contractData;
-    }
-    constructor(
-        artifactAdapter: AbstractArtifactAdapter,
-        getContractCodeAsync: (address: string) => Promise<string>,
-        isVerbose: boolean,
-    ) {
-        this._getContractCodeAsync = getContractCodeAsync;
-        this._artifactAdapter = artifactAdapter;
-        this._logger = getLogger('sol-cov');
-        this._logger.setLevel(isVerbose ? levels.TRACE : levels.ERROR);
-    }
-    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 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
-                const runtimeBytecode = (traceInfo as TraceInfoExistingContract).runtimeBytecode;
-                const contractData = CoverageManager._getContractDataIfExists(contractsData, runtimeBytecode);
-                if (_.isUndefined(contractData)) {
-                    this._logger.warn(`Transaction to an unknown address: ${traceInfo.address}`);
-                    continue;
-                }
-                const bytecodeHex = stripHexPrefix(runtimeBytecode);
-                const sourceMap = contractData.sourceMapRuntime;
-                const pcToSourceRange = parseSourceMap(
-                    contractData.sourceCodes,
-                    sourceMap,
-                    bytecodeHex,
-                    contractData.sources,
-                );
-                for (let fileIndex = 0; fileIndex < contractData.sources.length; fileIndex++) {
-                    const singleFileCoverageForTrace = CoverageManager._getSingleFileCoverageForTrace(
-                        contractData,
-                        traceInfo.coveredPcs,
-                        pcToSourceRange,
-                        fileIndex,
-                    );
-                    collector.add(singleFileCoverageForTrace);
-                }
-            } else {
-                // Contract creation transaction
-                const bytecode = (traceInfo as TraceInfoNewContract).bytecode;
-                const contractData = CoverageManager._getContractDataIfExists(contractsData, bytecode);
-                if (_.isUndefined(contractData)) {
-                    this._logger.warn(`Unknown contract creation transaction`);
-                    continue;
-                }
-                const bytecodeHex = stripHexPrefix(bytecode);
-                const sourceMap = contractData.sourceMap;
-                const pcToSourceRange = parseSourceMap(
-                    contractData.sourceCodes,
-                    sourceMap,
-                    bytecodeHex,
-                    contractData.sources,
-                );
-                for (let fileIndex = 0; fileIndex < contractData.sources.length; fileIndex++) {
-                    const singleFileCoverageForTrace = CoverageManager._getSingleFileCoverageForTrace(
-                        contractData,
-                        traceInfo.coveredPcs,
-                        pcToSourceRange,
-                        fileIndex,
-                    );
-                    collector.add(singleFileCoverageForTrace);
-                }
-            }
-        }
-        return collector.getFinalCoverage();
-    }
-}
diff --git a/packages/sol-cov/src/coverage_subprovider.ts b/packages/sol-cov/src/coverage_subprovider.ts
index ca7f4aed2..065a48434 100644
--- a/packages/sol-cov/src/coverage_subprovider.ts
+++ b/packages/sol-cov/src/coverage_subprovider.ts
@@ -1,32 +1,29 @@
-import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0xproject/subproviders';
-import { BlockParam, CallData, JSONRPCRequestPayload, TransactionTrace, TxData } from 'ethereum-types';
-import * as fs from 'fs';
 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.
+import { collectCoverageEntries } from './collect_coverage_entries';
+import { SingleFileSubtraceHandler, TraceCollector } from './trace_collector';
+import { TraceInfoSubprovider } from './trace_info_subprovider';
+import {
+    BranchCoverage,
+    ContractData,
+    Coverage,
+    FunctionCoverage,
+    FunctionDescription,
+    SourceRange,
+    StatementCoverage,
+    StatementDescription,
+    Subtrace,
+    TraceInfo,
+} from './types';
+import { utils } from './utils';
 
 /**
  * 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's used to compute your code coverage while running solidity tests.
  */
-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;
+export class CoverageSubprovider extends TraceInfoSubprovider {
+    private _coverageCollector: TraceCollector;
     /**
      * Instantiates a CoverageSubprovider instance
      * @param artifactAdapter Adapter for used artifacts format (0x, truffle, giveth, etc.)
@@ -34,172 +31,110 @@ export class CoverageSubprovider extends Subprovider {
      * @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);
+        const traceCollectionSubproviderConfig = {
+            shouldCollectTransactionTraces: true,
+            shouldCollectGasEstimateTraces: true,
+            shouldCollectCallTraces: true,
+        };
+        super(defaultFromAddress, traceCollectionSubproviderConfig);
+        this._coverageCollector = new TraceCollector(artifactAdapter, isVerbose, coverageHandler);
+    }
+    protected async _handleTraceInfoAsync(traceInfo: TraceInfo): Promise<void> {
+        await this._coverageCollector.computeSingleTraceCoverageAsync(traceInfo);
     }
     /**
      * Write the test coverage results to a file in Istanbul format.
      */
     public async writeCoverageAsync(): Promise<void> {
-        await this._coverageManager.writeCoverageAsync();
+        await this._coverageCollector.writeOutputAsync();
     }
-    /**
-     * 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> {
-        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<void> {
-        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();
+/**
+ * Computed partial coverage for a single file & subtrace.
+ * @param contractData      Contract metadata (source, srcMap, bytecode)
+ * @param subtrace          A subset of a transcation/call trace that was executed within that contract
+ * @param pcToSourceRange   A mapping from program counters to source ranges
+ * @param fileIndex         Index of a file to compute coverage for
+ * @return Partial istanbul coverage for that file & subtrace
+ */
+export const coverageHandler: SingleFileSubtraceHandler = (
+    contractData: ContractData,
+    subtrace: Subtrace,
+    pcToSourceRange: { [programCounter: number]: SourceRange },
+    fileIndex: number,
+): Coverage => {
+    const absoluteFileName = contractData.sources[fileIndex];
+    const coverageEntriesDescription = collectCoverageEntries(contractData.sourceCodes[fileIndex]);
+    let sourceRanges = _.map(subtrace, structLog => pcToSourceRange[structLog.pc]);
+    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 === absoluteFileName);
+    const branchCoverage: BranchCoverage = {};
+    const branchIds = _.keys(coverageEntriesDescription.branchMap);
+    for (const branchId of branchIds) {
+        const branchDescription = coverageEntriesDescription.branchMap[branchId];
+        const isBranchCoveredByBranchIndex = _.map(branchDescription.locations, location => {
+            const isBranchCovered = _.some(sourceRanges, range => utils.isRangeInside(range.location, location));
+            const timesBranchCovered = Number(isBranchCovered);
+            return timesBranchCovered;
+        });
+        branchCoverage[branchId] = isBranchCoveredByBranchIndex;
     }
-    private async _onCallExecutedAsync(
-        callData: Partial<CallData>,
-        blockNumber: BlockParam,
-        err: Error | null,
-        callResult: string,
-        cb: Callback,
-    ): Promise<void> {
-        await this._recordCallTraceAsync(callData, blockNumber);
-        cb();
+    const statementCoverage: StatementCoverage = {};
+    const statementIds = _.keys(coverageEntriesDescription.statementMap);
+    for (const statementId of statementIds) {
+        const statementDescription = coverageEntriesDescription.statementMap[statementId];
+        const isStatementCovered = _.some(sourceRanges, range =>
+            utils.isRangeInside(range.location, statementDescription),
+        );
+        const timesStatementCovered = Number(isStatementCovered);
+        statementCoverage[statementId] = timesStatementCovered;
     }
-    private async _recordTxTraceAsync(address: string, data: string | undefined, txHash: string): Promise<void> {
-        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);
-            }
-        }
+    const functionCoverage: FunctionCoverage = {};
+    const functionIds = _.keys(coverageEntriesDescription.fnMap);
+    for (const fnId of functionIds) {
+        const functionDescription = coverageEntriesDescription.fnMap[fnId];
+        const isFunctionCovered = _.some(sourceRanges, range =>
+            utils.isRangeInside(range.location, functionDescription.loc),
+        );
+        const timesFunctionCovered = Number(isFunctionCovered);
+        functionCoverage[fnId] = timesFunctionCovered;
     }
-    private async _recordCallTraceAsync(callData: Partial<CallData>, blockNumber: BlockParam): 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 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');
+    // HACK: Solidity doesn't emit any opcodes that map back to modifiers with no args, that's why we map back to the
+    // function range and check if there is any covered statement within that range.
+    for (const modifierStatementId of coverageEntriesDescription.modifiersStatementIds) {
+        if (statementCoverage[modifierStatementId]) {
+            // Already detected as covered
+            continue;
         }
+        const modifierDescription = coverageEntriesDescription.statementMap[modifierStatementId];
+        const enclosingFunction = _.find(coverageEntriesDescription.fnMap, functionDescription =>
+            utils.isRangeInside(modifierDescription, functionDescription.loc),
+        ) as FunctionDescription;
+        const isModifierCovered = _.some(
+            coverageEntriesDescription.statementMap,
+            (statementDescription: StatementDescription, statementId: number) => {
+                const isInsideTheModifierEnclosingFunction = utils.isRangeInside(
+                    statementDescription,
+                    enclosingFunction.loc,
+                );
+                const isCovered = statementCoverage[statementId];
+                return isInsideTheModifierEnclosingFunction && isCovered;
+            },
+        );
+        const timesModifierCovered = Number(isModifierCovered);
+        statementCoverage[modifierStatementId] = timesModifierCovered;
     }
-    private async _getContractCodeAsync(address: string): Promise<string> {
-        const payload = {
-            method: 'eth_getCode',
-            params: [address, BlockParamLiteral.Latest],
-        };
-        const jsonRPCResponsePayload = await this.emitPayloadAsync(payload);
-        const contractCode: string = jsonRPCResponsePayload.result;
-        return contractCode;
-    }
-}
+    const partialCoverage = {
+        [absoluteFileName]: {
+            ...coverageEntriesDescription,
+            path: absoluteFileName,
+            f: functionCoverage,
+            s: statementCoverage,
+            b: branchCoverage,
+        },
+    };
+    return partialCoverage;
+};
diff --git a/packages/sol-cov/src/index.ts b/packages/sol-cov/src/index.ts
index 7a2afbe80..003a27374 100644
--- a/packages/sol-cov/src/index.ts
+++ b/packages/sol-cov/src/index.ts
@@ -1,4 +1,7 @@
 export { CoverageSubprovider } from './coverage_subprovider';
+// HACK: ProfilerSubprovider is a hacky way to do profiling using coverage tools. Not production ready
+export { ProfilerSubprovider } from './profiler_subprovider';
+export { RevertTraceSubprovider } from './revert_trace_subprovider';
 export { SolCompilerArtifactAdapter } from './artifact_adapters/sol_compiler_artifact_adapter';
 export { TruffleArtifactAdapter } from './artifact_adapters/truffle_artifact_adapter';
 export { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter';
diff --git a/packages/sol-cov/src/profiler_subprovider.ts b/packages/sol-cov/src/profiler_subprovider.ts
new file mode 100644
index 000000000..9f98da524
--- /dev/null
+++ b/packages/sol-cov/src/profiler_subprovider.ts
@@ -0,0 +1,91 @@
+import * as _ from 'lodash';
+
+import { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter';
+import { collectCoverageEntries } from './collect_coverage_entries';
+import { SingleFileSubtraceHandler, TraceCollector } from './trace_collector';
+import { TraceInfoSubprovider } from './trace_info_subprovider';
+import { ContractData, Coverage, SourceRange, Subtrace, TraceInfo } from './types';
+import { utils } from './utils';
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * ProfilerSubprovider is used to profile Solidity code while running tests.
+ */
+export class ProfilerSubprovider extends TraceInfoSubprovider {
+    private _profilerCollector: TraceCollector;
+    /**
+     * Instantiates a ProfilerSubprovider 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) {
+        const traceCollectionSubproviderConfig = {
+            shouldCollectTransactionTraces: true,
+            shouldCollectGasEstimateTraces: false,
+            shouldCollectCallTraces: false,
+        };
+        super(defaultFromAddress, traceCollectionSubproviderConfig);
+        this._profilerCollector = new TraceCollector(artifactAdapter, isVerbose, profilerHandler);
+    }
+    protected async _handleTraceInfoAsync(traceInfo: TraceInfo): Promise<void> {
+        await this._profilerCollector.computeSingleTraceCoverageAsync(traceInfo);
+    }
+    /**
+     * Write the test profiler results to a file in Istanbul format.
+     */
+    public async writeProfilerOutputAsync(): Promise<void> {
+        await this._profilerCollector.writeOutputAsync();
+    }
+}
+
+/**
+ * Computed partial coverage for a single file & subtrace for the purposes of
+ * gas profiling.
+ * @param contractData      Contract metadata (source, srcMap, bytecode)
+ * @param subtrace          A subset of a transcation/call trace that was executed within that contract
+ * @param pcToSourceRange   A mapping from program counters to source ranges
+ * @param fileIndex         Index of a file to compute coverage for
+ * @return Partial istanbul coverage for that file & subtrace
+ */
+export const profilerHandler: SingleFileSubtraceHandler = (
+    contractData: ContractData,
+    subtrace: Subtrace,
+    pcToSourceRange: { [programCounter: number]: SourceRange },
+    fileIndex: number,
+): Coverage => {
+    const absoluteFileName = contractData.sources[fileIndex];
+    const profilerEntriesDescription = collectCoverageEntries(contractData.sourceCodes[fileIndex]);
+    const gasConsumedByStatement: { [statementId: string]: number } = {};
+    const statementIds = _.keys(profilerEntriesDescription.statementMap);
+    for (const statementId of statementIds) {
+        const statementDescription = profilerEntriesDescription.statementMap[statementId];
+        const totalGasCost = _.sum(
+            _.map(subtrace, structLog => {
+                const sourceRange = pcToSourceRange[structLog.pc];
+                if (_.isUndefined(sourceRange)) {
+                    return 0;
+                }
+                if (sourceRange.fileName !== absoluteFileName) {
+                    return 0;
+                }
+                if (utils.isRangeInside(sourceRange.location, statementDescription)) {
+                    return structLog.gasCost;
+                } else {
+                    return 0;
+                }
+            }),
+        );
+        gasConsumedByStatement[statementId] = totalGasCost;
+    }
+    const partialProfilerOutput = {
+        [absoluteFileName]: {
+            ...profilerEntriesDescription,
+            path: absoluteFileName,
+            f: {}, // I's meaningless in profiling context
+            s: gasConsumedByStatement,
+            b: {}, // I's meaningless in profiling context
+        },
+    };
+    return partialProfilerOutput;
+};
diff --git a/packages/sol-cov/src/revert_trace.ts b/packages/sol-cov/src/revert_trace.ts
new file mode 100644
index 000000000..a78d1afa8
--- /dev/null
+++ b/packages/sol-cov/src/revert_trace.ts
@@ -0,0 +1,90 @@
+import { logUtils } from '@0xproject/utils';
+import { OpCode, StructLog } from 'ethereum-types';
+
+import * as _ from 'lodash';
+
+import { EvmCallStack } from './types';
+import { utils } from './utils';
+
+export function getRevertTrace(structLogs: StructLog[], startAddress: string): EvmCallStack {
+    const evmCallStack: EvmCallStack = [];
+    const addressStack = [startAddress];
+    if (_.isEmpty(structLogs)) {
+        return [];
+    }
+    const normalizedStructLogs = utils.normalizeStructLogs(structLogs);
+    // tslint:disable-next-line:prefer-for-of
+    for (let i = 0; i < normalizedStructLogs.length; i++) {
+        const structLog = normalizedStructLogs[i];
+        if (structLog.depth !== addressStack.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
+
+        if (utils.isCallLike(structLog.op)) {
+            const currentAddress = _.last(addressStack) as string;
+            const jumpAddressOffset = 1;
+            const newAddress = utils.getAddressFromStackEntry(
+                structLog.stack[structLog.stack.length - jumpAddressOffset - 1],
+            );
+
+            // Sometimes calls don't change the execution context (current address). When we do a transfer to an
+            // externally owned account - it does the call and immediately returns because there is no fallback
+            // function. We manually check if the call depth had changed to handle that case.
+            const nextStructLog = normalizedStructLogs[i + 1];
+            if (nextStructLog.depth !== structLog.depth) {
+                addressStack.push(newAddress);
+                evmCallStack.push({
+                    address: currentAddress,
+                    structLog,
+                });
+            }
+        } else if (utils.isEndOpcode(structLog.op) && structLog.op !== OpCode.Revert) {
+            // Just like with calls, sometimes returns/stops don't change the execution context (current address).
+            const nextStructLog = normalizedStructLogs[i + 1];
+            if (_.isUndefined(nextStructLog) || nextStructLog.depth !== structLog.depth) {
+                evmCallStack.pop();
+                addressStack.pop();
+            }
+            if (structLog.op === OpCode.SelfDestruct) {
+                // After contract execution, we look at all sub-calls to external contracts, and for each one, fetch
+                // the bytecode and compute the coverage for the call. If the contract is destroyed with a call
+                // to `selfdestruct`, we are unable to fetch it's bytecode and compute coverage.
+                // TODO: Refactor this logic to fetch the sub-called contract bytecode before the selfdestruct is called
+                // in order to handle this edge-case.
+                logUtils.warn(
+                    "Detected a selfdestruct. Sol-cov currently doesn't support that scenario. We'll just skip the trace part for a destructed contract",
+                );
+            }
+        } else if (structLog.op === OpCode.Revert) {
+            evmCallStack.push({
+                address: _.last(addressStack) as string,
+                structLog,
+            });
+            return evmCallStack;
+        } else if (structLog.op === OpCode.Create) {
+            // TODO: Extract the new contract address from the stack and handle that scenario
+            logUtils.warn(
+                "Detected a contract created from within another contract. Sol-cov currently doesn't support that scenario. We'll just skip that trace",
+            );
+            return [];
+        } else {
+            if (structLog !== _.last(normalizedStructLogs)) {
+                const nextStructLog = normalizedStructLogs[i + 1];
+                if (nextStructLog.depth === structLog.depth) {
+                    continue;
+                } else if (nextStructLog.depth === structLog.depth - 1) {
+                    addressStack.pop();
+                } else {
+                    throw new Error('Malformed trace. Unexpected call depth change');
+                }
+            }
+        }
+    }
+    if (evmCallStack.length !== 0) {
+        logUtils.warn('Malformed trace. Call stack non empty at the end. (probably out of gas)');
+    }
+    return [];
+}
diff --git a/packages/sol-cov/src/revert_trace_subprovider.ts b/packages/sol-cov/src/revert_trace_subprovider.ts
new file mode 100644
index 000000000..b1d4da10c
--- /dev/null
+++ b/packages/sol-cov/src/revert_trace_subprovider.ts
@@ -0,0 +1,114 @@
+import { stripHexPrefix } from 'ethereumjs-util';
+import * as _ from 'lodash';
+import { getLogger, levels, Logger } from 'loglevel';
+
+import { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter';
+import { constants } from './constants';
+import { getRevertTrace } from './revert_trace';
+import { parseSourceMap } from './source_maps';
+import { TraceCollectionSubprovider } from './trace_collection_subprovider';
+import { ContractData, EvmCallStack, SourceRange } from './types';
+import { utils } from './utils';
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It is used to report call stack traces whenever a revert occurs.
+ */
+export class RevertTraceSubprovider extends TraceCollectionSubprovider {
+    // Lock is used to not accept normal transactions while doing call/snapshot magic because they'll be reverted later otherwise
+    private _contractsData!: ContractData[];
+    private _artifactAdapter: AbstractArtifactAdapter;
+    private _logger: Logger;
+
+    /**
+     * Instantiates a RevertTraceSubprovider 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) {
+        const traceCollectionSubproviderConfig = {
+            shouldCollectTransactionTraces: true,
+            shouldCollectGasEstimateTraces: true,
+            shouldCollectCallTraces: true,
+        };
+        super(defaultFromAddress, traceCollectionSubproviderConfig);
+        this._artifactAdapter = artifactAdapter;
+        this._logger = getLogger('sol-cov');
+        this._logger.setLevel(isVerbose ? levels.TRACE : levels.ERROR);
+    }
+    // tslint:disable-next-line:no-unused-variable
+    protected async _recordTxTraceAsync(address: string, data: string | undefined, txHash: string): Promise<void> {
+        await this._web3Wrapper.awaitTransactionMinedAsync(txHash, 0);
+        const trace = await this._web3Wrapper.getTransactionTraceAsync(txHash, {
+            disableMemory: true,
+            disableStack: false,
+            disableStorage: true,
+        });
+        const evmCallStack = getRevertTrace(trace.structLogs, address);
+        if (evmCallStack.length > 0) {
+            // if getRevertTrace returns a call stack it means there was a
+            // revert.
+            await this._printStackTraceAsync(evmCallStack);
+        }
+    }
+    private async _printStackTraceAsync(evmCallStack: EvmCallStack): Promise<void> {
+        const sourceRanges: SourceRange[] = [];
+        if (_.isUndefined(this._contractsData)) {
+            this._contractsData = await this._artifactAdapter.collectContractsDataAsync();
+        }
+        for (const evmCallStackEntry of evmCallStack) {
+            const isContractCreation = evmCallStackEntry.address === constants.NEW_CONTRACT;
+            if (isContractCreation) {
+                this._logger.error('Contract creation not supported');
+                continue;
+            }
+            const bytecode = await this._web3Wrapper.getContractCodeAsync(evmCallStackEntry.address);
+            const contractData = utils.getContractDataIfExists(this._contractsData, bytecode);
+            if (_.isUndefined(contractData)) {
+                const errMsg = isContractCreation
+                    ? `Unknown contract creation transaction`
+                    : `Transaction to an unknown address: ${evmCallStackEntry.address}`;
+                this._logger.warn(errMsg);
+                continue;
+            }
+            const bytecodeHex = stripHexPrefix(bytecode);
+            const sourceMap = isContractCreation ? contractData.sourceMap : contractData.sourceMapRuntime;
+            const pcToSourceRange = parseSourceMap(
+                contractData.sourceCodes,
+                sourceMap,
+                bytecodeHex,
+                contractData.sources,
+            );
+            // tslint:disable-next-line:no-unnecessary-initializer
+            let sourceRange: SourceRange | undefined = undefined;
+            let pc = evmCallStackEntry.structLog.pc;
+            // Sometimes there is not a mapping for this pc (e.g. if the revert
+            // actually happens in assembly). In that case, we want to keep
+            // searching backwards by decrementing the pc until we find a
+            // mapped source range.
+            while (_.isUndefined(sourceRange)) {
+                sourceRange = pcToSourceRange[pc];
+                pc -= 1;
+                if (pc <= 0) {
+                    this._logger.warn(
+                        `could not find matching sourceRange for structLog: ${evmCallStackEntry.structLog}`,
+                    );
+                    continue;
+                }
+            }
+            sourceRanges.push(sourceRange);
+        }
+        if (sourceRanges.length > 0) {
+            this._logger.error('\n\nStack trace for REVERT:\n');
+            _.forEach(_.reverse(sourceRanges), sourceRange => {
+                this._logger.error(
+                    `${sourceRange.fileName}:${sourceRange.location.start.line}:${sourceRange.location.start.column}`,
+                );
+            });
+            this._logger.error('\n');
+        } else {
+            this._logger.error('Could not determine stack trace');
+        }
+    }
+}
diff --git a/packages/sol-cov/src/source_maps.ts b/packages/sol-cov/src/source_maps.ts
index 694171442..f9503e16c 100644
--- a/packages/sol-cov/src/source_maps.ts
+++ b/packages/sol-cov/src/source_maps.ts
@@ -38,10 +38,10 @@ export function parseSourceMap(
     const pcToInstructionIndex: { [programCounter: number]: number } = getPcToInstructionIndexMapping(bytecode);
     const locationByOffsetByFileIndex = _.map(sourceCodes, getLocationByOffset);
     const entries = srcMap.split(';');
-    const parsedEntries: SourceLocation[] = [];
     let lastParsedEntry: SourceLocation = {} as any;
     const instructionIndexToSourceRange: { [instructionIndex: number]: SourceRange } = {};
     _.each(entries, (entry: string, i: number) => {
+        // tslint:disable-next-line:no-unused-variable
         const [instructionIndexStrIfExists, lengthStrIfExists, fileIndexStrIfExists, jumpTypeStrIfExists] = entry.split(
             ':',
         );
diff --git a/packages/sol-cov/src/trace.ts b/packages/sol-cov/src/trace.ts
index 1c21c8e5c..635019fc0 100644
--- a/packages/sol-cov/src/trace.ts
+++ b/packages/sol-cov/src/trace.ts
@@ -1,26 +1,25 @@
-import { addressUtils, BigNumber, logUtils } from '@0xproject/utils';
-import { OpCode, StructLog, TransactionTrace } from 'ethereum-types';
-import { addHexPrefix, stripHexPrefix } from 'ethereumjs-util';
-import * as fs from 'fs';
+import { logUtils } from '@0xproject/utils';
+import { OpCode, StructLog } from 'ethereum-types';
 import * as _ from 'lodash';
 
+import { utils } from './utils';
+
 export interface TraceByContractAddress {
     [contractAddress: string]: StructLog[];
 }
 
-function getAddressFromStackEntry(stackEntry: string): string {
-    const hexBase = 16;
-    return addressUtils.padZeros(new BigNumber(addHexPrefix(stackEntry)).toString(hexBase));
-}
-
 export function getTracesByContractAddress(structLogs: StructLog[], startAddress: string): TraceByContractAddress {
     const traceByContractAddress: TraceByContractAddress = {};
     let currentTraceSegment = [];
-    const callStack = [startAddress];
+    const addressStack = [startAddress];
+    if (_.isEmpty(structLogs)) {
+        return traceByContractAddress;
+    }
+    const normalizedStructLogs = utils.normalizeStructLogs(structLogs);
     // 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) {
+    for (let i = 0; i < normalizedStructLogs.length; i++) {
+        const structLog = normalizedStructLogs[i];
+        if (structLog.depth !== addressStack.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
@@ -28,36 +27,26 @@ export function getTracesByContractAddress(structLogs: StructLog[], startAddress
         // That means that we can always safely pop from it
         currentTraceSegment.push(structLog);
 
-        const isCallLike = _.includes(
-            [OpCode.CallCode, OpCode.StaticCall, OpCode.Call, OpCode.DelegateCall],
-            structLog.op,
-        );
-        const isEndOpcode = _.includes(
-            [OpCode.Return, OpCode.Stop, OpCode.Revert, OpCode.Invalid, OpCode.SelfDestruct],
-            structLog.op,
-        );
-        if (isCallLike) {
-            const currentAddress = _.last(callStack) as string;
+        if (utils.isCallLike(structLog.op)) {
+            const currentAddress = _.last(addressStack) as string;
             const jumpAddressOffset = 1;
-            const newAddress = getAddressFromStackEntry(
+            const newAddress = utils.getAddressFromStackEntry(
                 structLog.stack[structLog.stack.length - jumpAddressOffset - 1],
             );
-            if (structLog === _.last(structLogs)) {
-                throw new Error('Malformed trace. CALL-like opcode can not be the last one');
-            }
+
             // Sometimes calls don't change the execution context (current address). When we do a transfer to an
             // externally owned account - it does the call and immediately returns because there is no fallback
             // function. We manually check if the call depth had changed to handle that case.
-            const nextStructLog = structLogs[i + 1];
+            const nextStructLog = normalizedStructLogs[i + 1];
             if (nextStructLog.depth !== structLog.depth) {
-                callStack.push(newAddress);
+                addressStack.push(newAddress);
                 traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
                     currentTraceSegment,
                 );
                 currentTraceSegment = [];
             }
-        } else if (isEndOpcode) {
-            const currentAddress = callStack.pop() as string;
+        } else if (utils.isEndOpcode(structLog.op)) {
+            const currentAddress = addressStack.pop() as string;
             traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
                 currentTraceSegment,
             );
@@ -79,12 +68,12 @@ export function getTracesByContractAddress(structLogs: StructLog[], startAddress
             );
             return traceByContractAddress;
         } else {
-            if (structLog !== _.last(structLogs)) {
-                const nextStructLog = structLogs[i + 1];
+            if (structLog !== _.last(normalizedStructLogs)) {
+                const nextStructLog = normalizedStructLogs[i + 1];
                 if (nextStructLog.depth === structLog.depth) {
                     continue;
                 } else if (nextStructLog.depth === structLog.depth - 1) {
-                    const currentAddress = callStack.pop() as string;
+                    const currentAddress = addressStack.pop() as string;
                     traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
                         currentTraceSegment,
                     );
@@ -95,11 +84,16 @@ export function getTracesByContractAddress(structLogs: StructLog[], startAddress
             }
         }
     }
-    if (callStack.length !== 0) {
-        throw new Error('Malformed trace. Call stack non empty at the end');
+    if (addressStack.length !== 0) {
+        logUtils.warn('Malformed trace. Call stack non empty at the end');
     }
     if (currentTraceSegment.length !== 0) {
-        throw new Error('Malformed trace. Current trace segment non empty at the end');
+        const currentAddress = addressStack.pop() as string;
+        traceByContractAddress[currentAddress] = (traceByContractAddress[currentAddress] || []).concat(
+            currentTraceSegment,
+        );
+        currentTraceSegment = [];
+        logUtils.warn('Malformed trace. Current trace segment non empty at the end');
     }
     return traceByContractAddress;
 }
diff --git a/packages/sol-cov/src/trace_collection_subprovider.ts b/packages/sol-cov/src/trace_collection_subprovider.ts
new file mode 100644
index 000000000..9866472b9
--- /dev/null
+++ b/packages/sol-cov/src/trace_collection_subprovider.ts
@@ -0,0 +1,185 @@
+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();
+    }
+}
diff --git a/packages/sol-cov/src/trace_collector.ts b/packages/sol-cov/src/trace_collector.ts
new file mode 100644
index 000000000..1b458edec
--- /dev/null
+++ b/packages/sol-cov/src/trace_collector.ts
@@ -0,0 +1,93 @@
+import { promisify } from '@0xproject/utils';
+import { stripHexPrefix } from 'ethereumjs-util';
+import * as fs from 'fs';
+import { Collector } from 'istanbul';
+import * as _ from 'lodash';
+import { getLogger, levels, Logger } from 'loglevel';
+import * as mkdirp from 'mkdirp';
+
+import { AbstractArtifactAdapter } from './artifact_adapters/abstract_artifact_adapter';
+import { constants } from './constants';
+import { parseSourceMap } from './source_maps';
+import {
+    ContractData,
+    Coverage,
+    SourceRange,
+    Subtrace,
+    TraceInfo,
+    TraceInfoExistingContract,
+    TraceInfoNewContract,
+} from './types';
+import { utils } from './utils';
+
+const mkdirpAsync = promisify<undefined>(mkdirp);
+
+export type SingleFileSubtraceHandler = (
+    contractData: ContractData,
+    subtrace: Subtrace,
+    pcToSourceRange: { [programCounter: number]: SourceRange },
+    fileIndex: number,
+) => Coverage;
+
+/**
+ * TraceCollector is used by CoverageSubprovider to compute code coverage based on collected trace data.
+ */
+export class TraceCollector {
+    private _artifactAdapter: AbstractArtifactAdapter;
+    private _logger: Logger;
+    private _contractsData!: ContractData[];
+    private _collector = new Collector();
+    private _singleFileSubtraceHandler: SingleFileSubtraceHandler;
+
+    /**
+     * Instantiates a TraceCollector instance
+     * @param artifactAdapter Adapter for used artifacts format (0x, truffle, giveth, etc.)
+     * @param isVerbose If true, we will log any unknown transactions. Otherwise we will ignore them
+     * @param singleFileSubtraceHandler A handler function for computing partial coverage for a single file & subtrace
+     */
+    constructor(
+        artifactAdapter: AbstractArtifactAdapter,
+        isVerbose: boolean,
+        singleFileSubtraceHandler: SingleFileSubtraceHandler,
+    ) {
+        this._artifactAdapter = artifactAdapter;
+        this._logger = getLogger('sol-cov');
+        this._logger.setLevel(isVerbose ? levels.TRACE : levels.ERROR);
+        this._singleFileSubtraceHandler = singleFileSubtraceHandler;
+    }
+    public async writeOutputAsync(): Promise<void> {
+        const finalCoverage = this._collector.getFinalCoverage();
+        const stringifiedCoverage = JSON.stringify(finalCoverage, null, '\t');
+        await mkdirpAsync('coverage');
+        fs.writeFileSync('coverage/coverage.json', stringifiedCoverage);
+    }
+    public async computeSingleTraceCoverageAsync(traceInfo: TraceInfo): Promise<void> {
+        if (_.isUndefined(this._contractsData)) {
+            this._contractsData = await this._artifactAdapter.collectContractsDataAsync();
+        }
+        const isContractCreation = traceInfo.address === constants.NEW_CONTRACT;
+        const bytecode = isContractCreation
+            ? (traceInfo as TraceInfoNewContract).bytecode
+            : (traceInfo as TraceInfoExistingContract).runtimeBytecode;
+        const contractData = utils.getContractDataIfExists(this._contractsData, bytecode);
+        if (_.isUndefined(contractData)) {
+            const errMsg = isContractCreation
+                ? `Unknown contract creation transaction`
+                : `Transaction to an unknown address: ${traceInfo.address}`;
+            this._logger.warn(errMsg);
+            return;
+        }
+        const bytecodeHex = stripHexPrefix(bytecode);
+        const sourceMap = isContractCreation ? contractData.sourceMap : contractData.sourceMapRuntime;
+        const pcToSourceRange = parseSourceMap(contractData.sourceCodes, sourceMap, bytecodeHex, contractData.sources);
+        for (let fileIndex = 0; fileIndex < contractData.sources.length; fileIndex++) {
+            const singleFileCoverageForTrace = this._singleFileSubtraceHandler(
+                contractData,
+                traceInfo.subtrace,
+                pcToSourceRange,
+                fileIndex,
+            );
+            this._collector.add(singleFileCoverageForTrace);
+        }
+    }
+}
diff --git a/packages/sol-cov/src/trace_info_subprovider.ts b/packages/sol-cov/src/trace_info_subprovider.ts
new file mode 100644
index 000000000..635a68f58
--- /dev/null
+++ b/packages/sol-cov/src/trace_info_subprovider.ts
@@ -0,0 +1,59 @@
+import * as _ from 'lodash';
+
+import { constants } from './constants';
+import { getTracesByContractAddress } from './trace';
+import { TraceCollectionSubprovider } from './trace_collection_subprovider';
+import { TraceInfo, TraceInfoExistingContract, TraceInfoNewContract } from './types';
+
+// TraceInfoSubprovider is extended by subproviders which need to work with one
+// TraceInfo at a time. It has one abstract method: _handleTraceInfoAsync, which
+// is called for each TraceInfo.
+export abstract class TraceInfoSubprovider extends TraceCollectionSubprovider {
+    protected abstract _handleTraceInfoAsync(traceInfo: TraceInfo): Promise<void>;
+    protected async _recordTxTraceAsync(address: string, data: string | undefined, txHash: string): Promise<void> {
+        await this._web3Wrapper.awaitTransactionMinedAsync(txHash, 0);
+        const trace = await this._web3Wrapper.getTransactionTraceAsync(txHash, {
+            disableMemory: true,
+            disableStack: false,
+            disableStorage: true,
+        });
+        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];
+                    traceInfo = {
+                        subtrace: traceForThatSubcall,
+                        txHash,
+                        address: subcallAddress,
+                        bytecode: data as string,
+                    };
+                } else {
+                    const runtimeBytecode = await this._web3Wrapper.getContractCodeAsync(subcallAddress);
+                    const traceForThatSubcall = tracesByContractAddress[subcallAddress];
+                    traceInfo = {
+                        subtrace: traceForThatSubcall,
+                        txHash,
+                        address: subcallAddress,
+                        runtimeBytecode,
+                    };
+                }
+                await this._handleTraceInfoAsync(traceInfo);
+            }
+        } else {
+            for (const subcallAddress of subcallAddresses) {
+                const runtimeBytecode = await this._web3Wrapper.getContractCodeAsync(subcallAddress);
+                const traceForThatSubcall = tracesByContractAddress[subcallAddress];
+                const traceInfo: TraceInfoExistingContract = {
+                    subtrace: traceForThatSubcall,
+                    txHash,
+                    address: subcallAddress,
+                    runtimeBytecode,
+                };
+                await this._handleTraceInfoAsync(traceInfo);
+            }
+        }
+    }
+}
diff --git a/packages/sol-cov/src/types.ts b/packages/sol-cov/src/types.ts
index 4c3de55a1..cef7141cb 100644
--- a/packages/sol-cov/src/types.ts
+++ b/packages/sol-cov/src/types.ts
@@ -1,3 +1,5 @@
+import { StructLog } from 'ethereum-types';
+
 export interface LineColumn {
     line: number;
     column: number;
@@ -45,24 +47,24 @@ export interface StatementMap {
 }
 
 export interface LineCoverage {
-    [lineNo: number]: boolean;
+    [lineNo: number]: number;
 }
 
 export interface FunctionCoverage {
-    [functionId: string]: boolean;
+    [functionId: string]: number;
 }
 
 export interface StatementCoverage {
-    [statementId: string]: boolean;
+    [statementId: string]: number;
 }
 
 export interface BranchCoverage {
-    [branchId: string]: boolean[];
+    [branchId: string]: number[];
 }
 
 export interface Coverage {
     [fineName: string]: {
-        l: LineCoverage;
+        l?: LineCoverage;
         f: FunctionCoverage;
         s: StatementCoverage;
         b: BranchCoverage;
@@ -82,8 +84,11 @@ export interface ContractData {
     sources: string[];
 }
 
+// Part of the trace executed within the same context
+export type Subtrace = StructLog[];
+
 export interface TraceInfoBase {
-    coveredPcs: number[];
+    subtrace: Subtrace;
     txHash: string;
 }
 
@@ -102,3 +107,10 @@ export type TraceInfo = TraceInfoNewContract | TraceInfoExistingContract;
 export enum BlockParamLiteral {
     Latest = 'latest',
 }
+
+export interface EvmCallStackEntry {
+    structLog: StructLog;
+    address: string;
+}
+
+export type EvmCallStack = EvmCallStackEntry[];
diff --git a/packages/sol-cov/src/utils.ts b/packages/sol-cov/src/utils.ts
index d970c42ee..4f16a1cda 100644
--- a/packages/sol-cov/src/utils.ts
+++ b/packages/sol-cov/src/utils.ts
@@ -1,4 +1,9 @@
-import { LineColumn, SingleFileSourceRange } from './types';
+import { addressUtils, BigNumber } from '@0xproject/utils';
+import { OpCode, StructLog } from 'ethereum-types';
+import { addHexPrefix } from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { ContractData, LineColumn, SingleFileSourceRange } from './types';
 
 export const utils = {
     compareLineColumn(lhs: LineColumn, rhs: LineColumn): number {
@@ -14,4 +19,51 @@ export const utils = {
             utils.compareLineColumn(childRange.end, parentRange.end) <= 0
         );
     },
+    bytecodeToBytecodeRegex(bytecode: string): string {
+        const bytecodeRegex = bytecode
+            // Library linking placeholder: __ConvertLib____________________________
+            .replace(/_.*_/, '.*')
+            // Last 86 characters is solidity compiler metadata that's different between compilations
+            .replace(/.{86}$/, '')
+            // Libraries contain their own address at the beginning of the code and it's impossible to know it in advance
+            .replace(/^0x730000000000000000000000000000000000000000/, '0x73........................................');
+        // HACK: Node regexes can't be longer that 32767 characters. Contracts bytecode can. We just truncate the regexes. It's safe in practice.
+        const MAX_REGEX_LENGTH = 32767;
+        const truncatedBytecodeRegex = bytecodeRegex.slice(0, MAX_REGEX_LENGTH);
+        return truncatedBytecodeRegex;
+    },
+    getContractDataIfExists(contractsData: ContractData[], bytecode: string): ContractData | undefined {
+        if (!bytecode.startsWith('0x')) {
+            throw new Error(`0x hex prefix missing: ${bytecode}`);
+        }
+        const contractData = _.find(contractsData, contractDataCandidate => {
+            const bytecodeRegex = utils.bytecodeToBytecodeRegex(contractDataCandidate.bytecode);
+            const runtimeBytecodeRegex = utils.bytecodeToBytecodeRegex(contractDataCandidate.runtimeBytecode);
+            // We use that function to find by bytecode or runtimeBytecode. Those are quasi-random strings so
+            // collisions are practically impossible and it allows us to reuse that code
+            return !_.isNull(bytecode.match(bytecodeRegex)) || !_.isNull(bytecode.match(runtimeBytecodeRegex));
+        });
+        return contractData;
+    },
+    isCallLike(op: OpCode): boolean {
+        return _.includes([OpCode.CallCode, OpCode.StaticCall, OpCode.Call, OpCode.DelegateCall], op);
+    },
+    isEndOpcode(op: OpCode): boolean {
+        return _.includes([OpCode.Return, OpCode.Stop, OpCode.Revert, OpCode.Invalid, OpCode.SelfDestruct], op);
+    },
+    getAddressFromStackEntry(stackEntry: string): string {
+        const hexBase = 16;
+        return addressUtils.padZeros(new BigNumber(addHexPrefix(stackEntry)).toString(hexBase));
+    },
+    normalizeStructLogs(structLogs: StructLog[]): StructLog[] {
+        if (structLogs[0].depth === 1) {
+            // Geth uses 1-indexed depth counter whilst ganache starts from 0
+            const newStructLogs = _.map(structLogs, structLog => ({
+                ...structLog,
+                depth: structLog.depth - 1,
+            }));
+            return newStructLogs;
+        }
+        return structLogs;
+    },
 };
diff --git a/packages/sol-cov/test/instructions_test.ts b/packages/sol-cov/test/instructions_test.ts
index 8012674f5..02f30a5ca 100644
--- a/packages/sol-cov/test/instructions_test.ts
+++ b/packages/sol-cov/test/instructions_test.ts
@@ -1,8 +1,6 @@
 import * as chai from 'chai';
-import * as fs from 'fs';
 import 'make-promises-safe';
 import 'mocha';
-import * as path from 'path';
 
 import { constants } from '../src/constants';
 import { getPcToInstructionIndexMapping } from '../src/instructions';
diff --git a/packages/sol-cov/test/trace_test.ts b/packages/sol-cov/test/trace_test.ts
index 07e270b71..7a034362c 100644
--- a/packages/sol-cov/test/trace_test.ts
+++ b/packages/sol-cov/test/trace_test.ts
@@ -1,9 +1,7 @@
 import * as chai from 'chai';
 import { OpCode, StructLog } from 'ethereum-types';
-import * as fs from 'fs';
 import * as _ from 'lodash';
 import 'mocha';
-import * as path from 'path';
 
 import { getTracesByContractAddress } from '../src/trace';