Merge pull request #1461 from 0xProject/feature/sol-compiler-watch

Sol-compiler watch mode

31 files changed, 463 insertions, 228 deletions

diff --git a/contracts/examples/package.json b/contracts/examples/package.json
index 77846241e..37b73f98c 100644
--- a/contracts/examples/package.json
+++ b/contracts/examples/package.json
@@ -13,7 +13,8 @@
         "build": "yarn pre_build && tsc -b",
         "build:ci": "yarn build",
         "pre_build": "run-s compile generate_contract_wrappers",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/extensions/package.json b/contracts/extensions/package.json
index 2d9ed4dcd..aa5cef462 100644
--- a/contracts/extensions/package.json
+++ b/contracts/extensions/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/interfaces/package.json b/contracts/interfaces/package.json
index 4d3e4b7f9..15385a154 100644
--- a/contracts/interfaces/package.json
+++ b/contracts/interfaces/package.json
@@ -10,7 +10,8 @@
         "build": "yarn pre_build && tsc -b",
         "build:ci": "yarn build",
         "pre_build": "run-s compile generate_contract_wrappers",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/libs/compiler.json b/contracts/libs/compiler.json
index cf7c52a73..349d3063b 100644
--- a/contracts/libs/compiler.json
+++ b/contracts/libs/compiler.json
@@ -18,5 +18,14 @@
             }
         }
     },
-    "contracts": ["TestLibs", "LibOrder", "LibMath", "LibFillResults", "LibAbiEncoder", "LibEIP712"]
+    "contracts": [
+        "TestLibs",
+        "LibOrder",
+        "LibMath",
+        "LibFillResults",
+        "LibAbiEncoder",
+        "LibEIP712",
+        "LibAssetProxyErrors",
+        "LibConstants"
+    ]
 }
diff --git a/contracts/libs/package.json b/contracts/libs/package.json
index fa4b6e523..ce7b97502 100644
--- a/contracts/libs/package.json
+++ b/contracts/libs/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/multisig/package.json b/contracts/multisig/package.json
index b338f67f7..2d7b4aa05 100644
--- a/contracts/multisig/package.json
+++ b/contracts/multisig/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../packages/abi-gen-templates/contract.handlebars --partials '../../packages/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/protocol/package.json b/contracts/protocol/package.json
index 122ce07c3..d37a0302a 100644
--- a/contracts/protocol/package.json
+++ b/contracts/protocol/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/tokens/package.json b/contracts/tokens/package.json
index 6f8a366dd..79afc4820 100644
--- a/contracts/tokens/package.json
+++ b/contracts/tokens/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/contracts/utils/package.json b/contracts/utils/package.json
index a776bdfbb..cf94af0f6 100644
--- a/contracts/utils/package.json
+++ b/contracts/utils/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
diff --git a/packages/sol-compiler/CHANGELOG.json b/packages/sol-compiler/CHANGELOG.json
index 0a757f519..8548fd73f 100644
--- a/packages/sol-compiler/CHANGELOG.json
+++ b/packages/sol-compiler/CHANGELOG.json
@@ -1,5 +1,18 @@
 [
     {
+        "version": "2.0.0",
+        "changes": [
+            {
+                "note": "Add sol-compiler watch mode with -w flag",
+                "pr": 1461
+            },
+            {
+                "note": "Make error and warning colouring more visually pleasant and consistent with other compilers",
+                "pr": 1461
+            }
+        ]
+    },
+    {
         "version": "1.1.16",
         "changes": [
             {
diff --git a/packages/sol-compiler/package.json b/packages/sol-compiler/package.json
index 0ad620b1f..86167a603 100644
--- a/packages/sol-compiler/package.json
+++ b/packages/sol-compiler/package.json
@@ -44,7 +44,9 @@
     "devDependencies": {
         "@0x/dev-utils": "^1.0.21",
         "@0x/tslint-config": "^2.0.0",
+        "@types/chokidar": "^1.7.5",
         "@types/mkdirp": "^0.5.2",
+        "@types/pluralize": "^0.0.29",
         "@types/require-from-string": "^1.2.0",
         "@types/semver": "^5.5.0",
         "chai": "^4.0.1",
@@ -74,10 +76,12 @@
         "@0x/web3-wrapper": "^3.2.1",
         "@types/yargs": "^11.0.0",
         "chalk": "^2.3.0",
+        "chokidar": "^2.0.4",
         "ethereum-types": "^1.1.4",
         "ethereumjs-util": "^5.1.1",
         "lodash": "^4.17.5",
         "mkdirp": "^0.5.1",
+        "pluralize": "^7.0.0",
         "require-from-string": "^2.0.1",
         "semver": "5.5.0",
         "solc": "^0.4.23",
diff --git a/packages/sol-compiler/src/cli.ts b/packages/sol-compiler/src/cli.ts
index 0a9db6e05..18cc68aaf 100644
--- a/packages/sol-compiler/src/cli.ts
+++ b/packages/sol-compiler/src/cli.ts
@@ -25,6 +25,10 @@ const SEPARATOR = ',';
             type: 'string',
             description: 'comma separated list of contracts to compile',
         })
+        .option('watch', {
+            alias: 'w',
+            default: false,
+        })
         .help().argv;
     const contracts = _.isUndefined(argv.contracts)
         ? undefined
@@ -37,7 +41,11 @@ const SEPARATOR = ',';
         contracts,
     };
     const compiler = new Compiler(opts);
-    await compiler.compileAsync();
+    if (argv.watch) {
+        await compiler.watchAsync();
+    } else {
+        await compiler.compileAsync();
+    }
 })().catch(err => {
     logUtils.log(err);
     process.exit(1);
diff --git a/packages/sol-compiler/src/compiler.ts b/packages/sol-compiler/src/compiler.ts
index 85df8209e..d38ccbf39 100644
--- a/packages/sol-compiler/src/compiler.ts
+++ b/packages/sol-compiler/src/compiler.ts
@@ -6,26 +6,29 @@ import {
     NPMResolver,
     RelativeFSResolver,
     Resolver,
+    SpyResolver,
     URLResolver,
 } from '@0x/sol-resolver';
-import { fetchAsync, logUtils } from '@0x/utils';
-import chalk from 'chalk';
+import { logUtils } from '@0x/utils';
+import * as chokidar from 'chokidar';
 import { CompilerOptions, ContractArtifact, ContractVersionData, StandardOutput } from 'ethereum-types';
-import * as ethUtil from 'ethereumjs-util';
 import * as fs from 'fs';
 import * as _ from 'lodash';
 import * as path from 'path';
-import * as requireFromString from 'require-from-string';
+import * as pluralize from 'pluralize';
 import * as semver from 'semver';
 import solc = require('solc');
 
 import { compilerOptionsSchema } from './schemas/compiler_options_schema';
 import { binPaths } from './solc/bin_paths';
 import {
+    addHexPrefixToContractBytecode,
+    compile,
     createDirIfDoesNotExistAsync,
     getContractArtifactIfExistsAsync,
-    getNormalizedErrMsg,
-    parseDependencies,
+    getSolcAsync,
+    getSourcesWithDependencies,
+    getSourceTreeHash,
     parseSolidityVersionRange,
 } from './utils/compiler';
 import { constants } from './utils/constants';
@@ -35,7 +38,6 @@ import { utils } from './utils/utils';
 type TYPE_ALL_FILES_IDENTIFIER = '*';
 const ALL_CONTRACTS_IDENTIFIER = '*';
 const ALL_FILES_IDENTIFIER = '*';
-const SOLC_BIN_DIR = path.join(__dirname, '..', '..', 'solc_bin');
 const DEFAULT_CONTRACTS_DIR = path.resolve('contracts');
 const DEFAULT_ARTIFACTS_DIR = path.resolve('artifacts');
 // Solc compiler settings cannot be configured from the commandline.
@@ -82,49 +84,6 @@ export class Compiler {
     private readonly _artifactsDir: string;
     private readonly _solcVersionIfExists: string | undefined;
     private readonly _specifiedContracts: string[] | TYPE_ALL_FILES_IDENTIFIER;
-    private static async _getSolcAsync(
-        solcVersion: string,
-    ): Promise<{ solcInstance: solc.SolcInstance; fullSolcVersion: string }> {
-        const fullSolcVersion = binPaths[solcVersion];
-        if (_.isUndefined(fullSolcVersion)) {
-            throw new Error(`${solcVersion} is not a known compiler version`);
-        }
-        const compilerBinFilename = path.join(SOLC_BIN_DIR, fullSolcVersion);
-        let solcjs: string;
-        if (await fsWrapper.doesFileExistAsync(compilerBinFilename)) {
-            solcjs = (await fsWrapper.readFileAsync(compilerBinFilename)).toString();
-        } else {
-            logUtils.warn(`Downloading ${fullSolcVersion}...`);
-            const url = `${constants.BASE_COMPILER_URL}${fullSolcVersion}`;
-            const response = await fetchAsync(url);
-            const SUCCESS_STATUS = 200;
-            if (response.status !== SUCCESS_STATUS) {
-                throw new Error(`Failed to load ${fullSolcVersion}`);
-            }
-            solcjs = await response.text();
-            await fsWrapper.writeFileAsync(compilerBinFilename, solcjs);
-        }
-        if (solcjs.length === 0) {
-            throw new Error('No compiler available');
-        }
-        const solcInstance = solc.setupMethods(requireFromString(solcjs, compilerBinFilename));
-        return { solcInstance, fullSolcVersion };
-    }
-    private static _addHexPrefixToContractBytecode(compiledContract: solc.StandardContractOutput): void {
-        if (!_.isUndefined(compiledContract.evm)) {
-            if (!_.isUndefined(compiledContract.evm.bytecode) && !_.isUndefined(compiledContract.evm.bytecode.object)) {
-                compiledContract.evm.bytecode.object = ethUtil.addHexPrefix(compiledContract.evm.bytecode.object);
-            }
-            if (
-                !_.isUndefined(compiledContract.evm.deployedBytecode) &&
-                !_.isUndefined(compiledContract.evm.deployedBytecode.object)
-            ) {
-                compiledContract.evm.deployedBytecode.object = ethUtil.addHexPrefix(
-                    compiledContract.evm.deployedBytecode.object,
-                );
-            }
-        }
-    }
     /**
      * Instantiates a new instance of the Compiler class.
      * @param opts Optional compiler options
@@ -158,7 +117,7 @@ export class Compiler {
      */
     public async compileAsync(): Promise<void> {
         await createDirIfDoesNotExistAsync(this._artifactsDir);
-        await createDirIfDoesNotExistAsync(SOLC_BIN_DIR);
+        await createDirIfDoesNotExistAsync(constants.SOLC_BIN_DIR);
         await this._compileContractsAsync(this._getContractNamesToCompile(), true);
     }
     /**
@@ -173,6 +132,54 @@ export class Compiler {
         const promisedOutputs = this._compileContractsAsync(this._getContractNamesToCompile(), false);
         return promisedOutputs;
     }
+    public async watchAsync(): Promise<void> {
+        console.clear(); // tslint:disable-line:no-console
+        logUtils.logWithTime('Starting compilation in watch mode...');
+        const MATCH_NOTHING_REGEX = '^$';
+        const IGNORE_DOT_FILES_REGEX = /(^|[\/\\])\../;
+        // Initially we watch nothing. We'll add the paths later.
+        const watcher = chokidar.watch(MATCH_NOTHING_REGEX, { ignored: IGNORE_DOT_FILES_REGEX });
+        const onFileChangedAsync = async () => {
+            watcher.unwatch('*'); // Stop watching
+            try {
+                await this.compileAsync();
+                logUtils.logWithTime('Found 0 errors. Watching for file changes.');
+            } catch (err) {
+                if (err.typeName === 'CompilationError') {
+                    logUtils.logWithTime(
+                        `Found ${err.errorsCount} ${pluralize('error', err.errorsCount)}. Watching for file changes.`,
+                    );
+                } else {
+                    logUtils.logWithTime('Found errors. Watching for file changes.');
+                }
+            }
+
+            const pathsToWatch = this._getPathsToWatch();
+            watcher.add(pathsToWatch);
+        };
+        await onFileChangedAsync();
+        watcher.on('change', (changedFilePath: string) => {
+            console.clear(); // tslint:disable-line:no-console
+            logUtils.logWithTime('File change detected. Starting incremental compilation...');
+            // NOTE: We can't await it here because that's a callback.
+            // Instead we stop watching inside of it and start it again when we're finished.
+            onFileChangedAsync(); // tslint:disable-line no-floating-promises
+        });
+    }
+    private _getPathsToWatch(): string[] {
+        const contractNames = this._getContractNamesToCompile();
+        const spyResolver = new SpyResolver(this._resolver);
+        for (const contractName of contractNames) {
+            const contractSource = spyResolver.resolve(contractName);
+            // NOTE: We ignore the return value here. We don't want to compute the source tree hash.
+            // We just want to call a SpyResolver on each contracts and it's dependencies and
+            // this is a convenient way to reuse the existing code that does that.
+            // We can then get all the relevant paths from the `spyResolver` below.
+            getSourceTreeHash(spyResolver, contractSource.path);
+        }
+        const pathsToWatch = _.uniq(spyResolver.resolvedContractSources.map(cs => cs.absolutePath));
+        return pathsToWatch;
+    }
     private _getContractNamesToCompile(): string[] {
         let contractNamesToCompile;
         if (this._specifiedContracts === ALL_CONTRACTS_IDENTIFIER) {
@@ -201,12 +208,14 @@ export class Compiler {
 
         for (const contractName of contractNames) {
             const contractSource = this._resolver.resolve(contractName);
+            const sourceTreeHashHex = getSourceTreeHash(
+                this._resolver,
+                path.join(this._contractsDir, contractSource.path),
+            ).toString('hex');
             const contractData = {
                 contractName,
                 currentArtifactIfExists: await getContractArtifactIfExistsAsync(this._artifactsDir, contractName),
-                sourceTreeHashHex: `0x${this._getSourceTreeHash(
-                    path.join(this._contractsDir, contractSource.path),
-                ).toString('hex')}`,
+                sourceTreeHashHex: `0x${sourceTreeHashHex}`,
             };
             if (!this._shouldCompile(contractData)) {
                 continue;
@@ -244,9 +253,8 @@ export class Compiler {
                 }) with Solidity v${solcVersion}...`,
             );
 
-            const { solcInstance, fullSolcVersion } = await Compiler._getSolcAsync(solcVersion);
-
-            const compilerOutput = this._compile(solcInstance, input.standardInput);
+            const { solcInstance, fullSolcVersion } = await getSolcAsync(solcVersion);
+            const compilerOutput = compile(this._resolver, solcInstance, input.standardInput);
             compilerOutputs.push(compilerOutput);
 
             for (const contractPath of input.contractsToCompile) {
@@ -259,7 +267,7 @@ export class Compiler {
                     );
                 }
 
-                Compiler._addHexPrefixToContractBytecode(compiledContract);
+                addHexPrefixToContractBytecode(compiledContract);
 
                 if (shouldPersist) {
                     await this._persistCompiledContractAsync(
@@ -298,10 +306,14 @@ export class Compiler {
         const compiledContract = compilerOutput.contracts[contractPath][contractName];
 
         // need to gather sourceCodes for this artifact, but compilerOutput.sources (the list of contract modules)
-        // contains listings for for every contract compiled during the compiler invocation that compiled the contract
+        // contains listings for every contract compiled during the compiler invocation that compiled the contract
         // to be persisted, which could include many that are irrelevant to the contract at hand.  So, gather up only
         // the relevant sources:
-        const { sourceCodes, sources } = this._getSourcesWithDependencies(contractPath, compilerOutput.sources);
+        const { sourceCodes, sources } = getSourcesWithDependencies(
+            this._resolver,
+            contractPath,
+            compilerOutput.sources,
+        );
 
         const contractVersion: ContractVersionData = {
             compilerOutput: compiledContract,
@@ -336,130 +348,4 @@ export class Compiler {
         await fsWrapper.writeFileAsync(currentArtifactPath, artifactString);
         logUtils.warn(`${contractName} artifact saved!`);
     }
-    /**
-     * For the given @param contractPath, populates JSON objects to be used in the ContractVersionData interface's
-     * properties `sources` (source code file names mapped to ID numbers) and `sourceCodes` (source code content of
-     * contracts) for that contract.  The source code pointed to by contractPath is read and parsed directly (via
-     * `this._resolver.resolve().source`), as are its imports, recursively.  The ID numbers for @return `sources` are
-     * taken from the corresponding ID's in @param fullSources, and the content for @return sourceCodes is read from
-     * disk (via the aforementioned `resolver.source`).
-     */
-    private _getSourcesWithDependencies(
-        contractPath: string,
-        fullSources: { [sourceName: string]: { id: number } },
-    ): { sourceCodes: { [sourceName: string]: string }; sources: { [sourceName: string]: { id: number } } } {
-        const sources = { [contractPath]: { id: fullSources[contractPath].id } };
-        const sourceCodes = { [contractPath]: this._resolver.resolve(contractPath).source };
-        this._recursivelyGatherDependencySources(
-            contractPath,
-            sourceCodes[contractPath],
-            fullSources,
-            sources,
-            sourceCodes,
-        );
-        return { sourceCodes, sources };
-    }
-    private _recursivelyGatherDependencySources(
-        contractPath: string,
-        contractSource: string,
-        fullSources: { [sourceName: string]: { id: number } },
-        sourcesToAppendTo: { [sourceName: string]: { id: number } },
-        sourceCodesToAppendTo: { [sourceName: string]: string },
-    ): void {
-        const importStatementMatches = contractSource.match(/\nimport[^;]*;/g);
-        if (importStatementMatches === null) {
-            return;
-        }
-        for (const importStatementMatch of importStatementMatches) {
-            const importPathMatches = importStatementMatch.match(/\"([^\"]*)\"/);
-            if (importPathMatches === null || importPathMatches.length === 0) {
-                continue;
-            }
-
-            let importPath = importPathMatches[1];
-            // HACK(ablrow): We have, e.g.:
-            //
-            //      importPath   = "../../utils/LibBytes/LibBytes.sol"
-            //      contractPath = "2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol"
-            //
-            // Resolver doesn't understand "../" so we want to pass
-            // "2.0.0/utils/LibBytes/LibBytes.sol" to resolver.
-            //
-            // This hack involves using path.resolve. But path.resolve returns
-            // absolute directories by default. We trick it into thinking that
-            // contractPath is a root directory by prepending a '/' and then
-            // removing the '/' the end.
-            //
-            //      path.resolve("/a/b/c", ""../../d/e") === "/a/d/e"
-            //
-            const lastPathSeparatorPos = contractPath.lastIndexOf('/');
-            const contractFolder = lastPathSeparatorPos === -1 ? '' : contractPath.slice(0, lastPathSeparatorPos + 1);
-            if (importPath.startsWith('.')) {
-                /**
-                 * Some imports path are relative ("../Token.sol", "./Wallet.sol")
-                 * while others are absolute ("Token.sol", "@0x/contracts/Wallet.sol")
-                 * And we need to append the base path for relative imports.
-                 */
-                importPath = path.resolve(`/${contractFolder}`, importPath).replace('/', '');
-            }
-
-            if (_.isUndefined(sourcesToAppendTo[importPath])) {
-                sourcesToAppendTo[importPath] = { id: fullSources[importPath].id };
-                sourceCodesToAppendTo[importPath] = this._resolver.resolve(importPath).source;
-
-                this._recursivelyGatherDependencySources(
-                    importPath,
-                    this._resolver.resolve(importPath).source,
-                    fullSources,
-                    sourcesToAppendTo,
-                    sourceCodesToAppendTo,
-                );
-            }
-        }
-    }
-    private _compile(solcInstance: solc.SolcInstance, standardInput: solc.StandardInput): solc.StandardOutput {
-        const compiled: solc.StandardOutput = JSON.parse(
-            solcInstance.compileStandardWrapper(JSON.stringify(standardInput), importPath => {
-                const sourceCodeIfExists = this._resolver.resolve(importPath);
-                return { contents: sourceCodeIfExists.source };
-            }),
-        );
-        if (!_.isUndefined(compiled.errors)) {
-            const SOLIDITY_WARNING = 'warning';
-            const errors = _.filter(compiled.errors, entry => entry.severity !== SOLIDITY_WARNING);
-            const warnings = _.filter(compiled.errors, entry => entry.severity === SOLIDITY_WARNING);
-            if (!_.isEmpty(errors)) {
-                errors.forEach(error => {
-                    const normalizedErrMsg = getNormalizedErrMsg(error.formattedMessage || error.message);
-                    logUtils.warn(chalk.red(normalizedErrMsg));
-                });
-                throw new Error('Compilation errors encountered');
-            } else {
-                warnings.forEach(warning => {
-                    const normalizedWarningMsg = getNormalizedErrMsg(warning.formattedMessage || warning.message);
-                    logUtils.warn(chalk.yellow(normalizedWarningMsg));
-                });
-            }
-        }
-        return compiled;
-    }
-    /**
-     * Gets the source tree hash for a file and its dependencies.
-     * @param fileName Name of contract file.
-     */
-    private _getSourceTreeHash(importPath: string): Buffer {
-        const contractSource = this._resolver.resolve(importPath);
-        const dependencies = parseDependencies(contractSource);
-        const sourceHash = ethUtil.sha3(contractSource.source);
-        if (dependencies.length === 0) {
-            return sourceHash;
-        } else {
-            const dependencySourceTreeHashes = _.map(dependencies, (dependency: string) =>
-                this._getSourceTreeHash(dependency),
-            );
-            const sourceTreeHashesBuffer = Buffer.concat([sourceHash, ...dependencySourceTreeHashes]);
-            const sourceTreeHash = ethUtil.sha3(sourceTreeHashesBuffer);
-            return sourceTreeHash;
-        }
-    }
 }
diff --git a/packages/sol-compiler/src/utils/compiler.ts b/packages/sol-compiler/src/utils/compiler.ts
index cda67a414..db308f2b5 100644
--- a/packages/sol-compiler/src/utils/compiler.ts
+++ b/packages/sol-compiler/src/utils/compiler.ts
@@ -1,10 +1,18 @@
-import { ContractSource } from '@0x/sol-resolver';
-import { logUtils } from '@0x/utils';
+import { ContractSource, Resolver } from '@0x/sol-resolver';
+import { fetchAsync, logUtils } from '@0x/utils';
+import chalk from 'chalk';
 import { ContractArtifact } from 'ethereum-types';
+import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 import * as path from 'path';
+import * as requireFromString from 'require-from-string';
+import * as solc from 'solc';
 
+import { binPaths } from '../solc/bin_paths';
+
+import { constants } from './constants';
 import { fsWrapper } from './fs_wrapper';
+import { CompilationError } from './types';
 
 /**
  * Gets contract data on network or returns if an artifact does not exist.
@@ -106,3 +114,208 @@ export function parseDependencies(contractSource: ContractSource): string[] {
     });
     return dependencies;
 }
+
+/**
+ * Compiles the contracts and prints errors/warnings
+ * @param resolver Resolver
+ * @param solcInstance Instance of a solc compiler
+ * @param standardInput Solidity standard JSON input
+ */
+export function compile(
+    resolver: Resolver,
+    solcInstance: solc.SolcInstance,
+    standardInput: solc.StandardInput,
+): solc.StandardOutput {
+    const standardInputStr = JSON.stringify(standardInput);
+    const standardOutputStr = solcInstance.compileStandardWrapper(standardInputStr, importPath => {
+        const sourceCodeIfExists = resolver.resolve(importPath);
+        return { contents: sourceCodeIfExists.source };
+    });
+    const compiled: solc.StandardOutput = JSON.parse(standardOutputStr);
+    if (!_.isUndefined(compiled.errors)) {
+        printCompilationErrorsAndWarnings(compiled.errors);
+    }
+    return compiled;
+}
+/**
+ * Separates errors from warnings, formats the messages and prints them. Throws if there is any compilation error (not warning).
+ * @param solcErrors The errors field of standard JSON output that contains errors and warnings.
+ */
+function printCompilationErrorsAndWarnings(solcErrors: solc.SolcError[]): void {
+    const SOLIDITY_WARNING = 'warning';
+    const errors = _.filter(solcErrors, entry => entry.severity !== SOLIDITY_WARNING);
+    const warnings = _.filter(solcErrors, entry => entry.severity === SOLIDITY_WARNING);
+    if (!_.isEmpty(errors)) {
+        errors.forEach(error => {
+            const normalizedErrMsg = getNormalizedErrMsg(error.formattedMessage || error.message);
+            logUtils.log(chalk.red('error'), normalizedErrMsg);
+        });
+        throw new CompilationError(errors.length);
+    } else {
+        warnings.forEach(warning => {
+            const normalizedWarningMsg = getNormalizedErrMsg(warning.formattedMessage || warning.message);
+            logUtils.log(chalk.yellow('warning'), normalizedWarningMsg);
+        });
+    }
+}
+
+/**
+ * Gets the source tree hash for a file and its dependencies.
+ * @param fileName Name of contract file.
+ */
+export function getSourceTreeHash(resolver: Resolver, importPath: string): Buffer {
+    const contractSource = resolver.resolve(importPath);
+    const dependencies = parseDependencies(contractSource);
+    const sourceHash = ethUtil.sha3(contractSource.source);
+    if (dependencies.length === 0) {
+        return sourceHash;
+    } else {
+        const dependencySourceTreeHashes = _.map(dependencies, (dependency: string) =>
+            getSourceTreeHash(resolver, dependency),
+        );
+        const sourceTreeHashesBuffer = Buffer.concat([sourceHash, ...dependencySourceTreeHashes]);
+        const sourceTreeHash = ethUtil.sha3(sourceTreeHashesBuffer);
+        return sourceTreeHash;
+    }
+}
+
+/**
+ * For the given @param contractPath, populates JSON objects to be used in the ContractVersionData interface's
+ * properties `sources` (source code file names mapped to ID numbers) and `sourceCodes` (source code content of
+ * contracts) for that contract.  The source code pointed to by contractPath is read and parsed directly (via
+ * `resolver.resolve().source`), as are its imports, recursively.  The ID numbers for @return `sources` are
+ * taken from the corresponding ID's in @param fullSources, and the content for @return sourceCodes is read from
+ * disk (via the aforementioned `resolver.source`).
+ */
+export function getSourcesWithDependencies(
+    resolver: Resolver,
+    contractPath: string,
+    fullSources: { [sourceName: string]: { id: number } },
+): { sourceCodes: { [sourceName: string]: string }; sources: { [sourceName: string]: { id: number } } } {
+    const sources = { [contractPath]: { id: fullSources[contractPath].id } };
+    const sourceCodes = { [contractPath]: resolver.resolve(contractPath).source };
+    recursivelyGatherDependencySources(
+        resolver,
+        contractPath,
+        sourceCodes[contractPath],
+        fullSources,
+        sources,
+        sourceCodes,
+    );
+    return { sourceCodes, sources };
+}
+
+function recursivelyGatherDependencySources(
+    resolver: Resolver,
+    contractPath: string,
+    contractSource: string,
+    fullSources: { [sourceName: string]: { id: number } },
+    sourcesToAppendTo: { [sourceName: string]: { id: number } },
+    sourceCodesToAppendTo: { [sourceName: string]: string },
+): void {
+    const importStatementMatches = contractSource.match(/\nimport[^;]*;/g);
+    if (importStatementMatches === null) {
+        return;
+    }
+    for (const importStatementMatch of importStatementMatches) {
+        const importPathMatches = importStatementMatch.match(/\"([^\"]*)\"/);
+        if (importPathMatches === null || importPathMatches.length === 0) {
+            continue;
+        }
+
+        let importPath = importPathMatches[1];
+        // HACK(albrow): We have, e.g.:
+        //
+        //      importPath   = "../../utils/LibBytes/LibBytes.sol"
+        //      contractPath = "2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol"
+        //
+        // Resolver doesn't understand "../" so we want to pass
+        // "2.0.0/utils/LibBytes/LibBytes.sol" to resolver.
+        //
+        // This hack involves using path.resolve. But path.resolve returns
+        // absolute directories by default. We trick it into thinking that
+        // contractPath is a root directory by prepending a '/' and then
+        // removing the '/' the end.
+        //
+        //      path.resolve("/a/b/c", ""../../d/e") === "/a/d/e"
+        //
+        const lastPathSeparatorPos = contractPath.lastIndexOf('/');
+        const contractFolder = lastPathSeparatorPos === -1 ? '' : contractPath.slice(0, lastPathSeparatorPos + 1);
+        if (importPath.startsWith('.')) {
+            /**
+             * Some imports path are relative ("../Token.sol", "./Wallet.sol")
+             * while others are absolute ("Token.sol", "@0x/contracts/Wallet.sol")
+             * And we need to append the base path for relative imports.
+             */
+            importPath = path.resolve(`/${contractFolder}`, importPath).replace('/', '');
+        }
+
+        if (_.isUndefined(sourcesToAppendTo[importPath])) {
+            sourcesToAppendTo[importPath] = { id: fullSources[importPath].id };
+            sourceCodesToAppendTo[importPath] = resolver.resolve(importPath).source;
+
+            recursivelyGatherDependencySources(
+                resolver,
+                importPath,
+                resolver.resolve(importPath).source,
+                fullSources,
+                sourcesToAppendTo,
+                sourceCodesToAppendTo,
+            );
+        }
+    }
+}
+
+/**
+ * Gets the solidity compiler instance and full version name. If the compiler is already cached - gets it from FS,
+ * otherwise - fetches it and caches it.
+ * @param solcVersion The compiler version. e.g. 0.5.0
+ */
+export async function getSolcAsync(
+    solcVersion: string,
+): Promise<{ solcInstance: solc.SolcInstance; fullSolcVersion: string }> {
+    const fullSolcVersion = binPaths[solcVersion];
+    if (_.isUndefined(fullSolcVersion)) {
+        throw new Error(`${solcVersion} is not a known compiler version`);
+    }
+    const compilerBinFilename = path.join(constants.SOLC_BIN_DIR, fullSolcVersion);
+    let solcjs: string;
+    if (await fsWrapper.doesFileExistAsync(compilerBinFilename)) {
+        solcjs = (await fsWrapper.readFileAsync(compilerBinFilename)).toString();
+    } else {
+        logUtils.warn(`Downloading ${fullSolcVersion}...`);
+        const url = `${constants.BASE_COMPILER_URL}${fullSolcVersion}`;
+        const response = await fetchAsync(url);
+        const SUCCESS_STATUS = 200;
+        if (response.status !== SUCCESS_STATUS) {
+            throw new Error(`Failed to load ${fullSolcVersion}`);
+        }
+        solcjs = await response.text();
+        await fsWrapper.writeFileAsync(compilerBinFilename, solcjs);
+    }
+    if (solcjs.length === 0) {
+        throw new Error('No compiler available');
+    }
+    const solcInstance = solc.setupMethods(requireFromString(solcjs, compilerBinFilename));
+    return { solcInstance, fullSolcVersion };
+}
+
+/**
+ * Solidity compiler emits the bytecode without a 0x prefix for a hex. This function fixes it if bytecode is present.
+ * @param compiledContract The standard JSON output section for a contract. Geth modified in place.
+ */
+export function addHexPrefixToContractBytecode(compiledContract: solc.StandardContractOutput): void {
+    if (!_.isUndefined(compiledContract.evm)) {
+        if (!_.isUndefined(compiledContract.evm.bytecode) && !_.isUndefined(compiledContract.evm.bytecode.object)) {
+            compiledContract.evm.bytecode.object = ethUtil.addHexPrefix(compiledContract.evm.bytecode.object);
+        }
+        if (
+            !_.isUndefined(compiledContract.evm.deployedBytecode) &&
+            !_.isUndefined(compiledContract.evm.deployedBytecode.object)
+        ) {
+            compiledContract.evm.deployedBytecode.object = ethUtil.addHexPrefix(
+                compiledContract.evm.deployedBytecode.object,
+            );
+        }
+    }
+}
diff --git a/packages/sol-compiler/src/utils/constants.ts b/packages/sol-compiler/src/utils/constants.ts
index df2ddb3b2..433897f8a 100644
--- a/packages/sol-compiler/src/utils/constants.ts
+++ b/packages/sol-compiler/src/utils/constants.ts
@@ -1,5 +1,8 @@
+import * as path from 'path';
+
 export const constants = {
     SOLIDITY_FILE_EXTENSION: '.sol',
     BASE_COMPILER_URL: 'https://ethereum.github.io/solc-bin/bin/',
     LATEST_ARTIFACT_VERSION: '2.0.0',
+    SOLC_BIN_DIR: path.join(__dirname, '..', '..', 'solc_bin'),
 };
diff --git a/packages/sol-compiler/src/utils/types.ts b/packages/sol-compiler/src/utils/types.ts
index b211cfcbc..64328899d 100644
--- a/packages/sol-compiler/src/utils/types.ts
+++ b/packages/sol-compiler/src/utils/types.ts
@@ -29,3 +29,12 @@ export interface Token {
 }
 
 export type DoneCallback = (err?: Error) => void;
+
+export class CompilationError extends Error {
+    public errorsCount: number;
+    public typeName = 'CompilationError';
+    constructor(errorsCount: number) {
+        super('Compilation errors encountered');
+        this.errorsCount = errorsCount;
+    }
+}
diff --git a/packages/sol-compiler/test/compiler_utils_test.ts b/packages/sol-compiler/test/compiler_utils_test.ts
index 4fe7b994e..b8c18110c 100644
--- a/packages/sol-compiler/test/compiler_utils_test.ts
+++ b/packages/sol-compiler/test/compiler_utils_test.ts
@@ -52,7 +52,7 @@ describe('Compiler utils', () => {
             const source = await fsWrapper.readFileAsync(path, {
                 encoding: 'utf8',
             });
-            const dependencies = parseDependencies({ source, path });
+            const dependencies = parseDependencies({ source, path, absolutePath: path });
             const expectedDependencies = [
                 'zeppelin-solidity/contracts/token/ERC20/ERC20.sol',
                 'packages/sol-compiler/lib/test/fixtures/contracts/TokenTransferProxy.sol',
@@ -68,7 +68,7 @@ describe('Compiler utils', () => {
             const source = await fsWrapper.readFileAsync(path, {
                 encoding: 'utf8',
             });
-            expect(parseDependencies({ source, path })).to.be.deep.equal([
+            expect(parseDependencies({ source, path, absolutePath: path })).to.be.deep.equal([
                 'zeppelin-solidity/contracts/ownership/Ownable.sol',
                 'zeppelin-solidity/contracts/token/ERC20/ERC20.sol',
             ]);
@@ -77,7 +77,7 @@ describe('Compiler utils', () => {
         it.skip('correctly parses commented out dependencies', async () => {
             const path = '';
             const source = `// import "./TokenTransferProxy.sol";`;
-            expect(parseDependencies({ path, source })).to.be.deep.equal([]);
+            expect(parseDependencies({ path, source, absolutePath: path })).to.be.deep.equal([]);
         });
     });
 });
diff --git a/packages/sol-resolver/CHANGELOG.json b/packages/sol-resolver/CHANGELOG.json
index 85398e624..74c4d39c5 100644
--- a/packages/sol-resolver/CHANGELOG.json
+++ b/packages/sol-resolver/CHANGELOG.json
@@ -1,5 +1,18 @@
 [
     {
+        "version": "1.2.1",
+        "changes": [
+            {
+                "note": "Add `absolutePath` to `ContractSource` type",
+                "pr": 1461
+            },
+            {
+                "note": "Add `SpyResolver` that records all resolved contracts data",
+                "pr": 1461
+            }
+        ]
+    },
+    {
         "version": "1.1.1",
         "changes": [
             {
diff --git a/packages/sol-resolver/src/index.ts b/packages/sol-resolver/src/index.ts
index a86053259..f55aca070 100644
--- a/packages/sol-resolver/src/index.ts
+++ b/packages/sol-resolver/src/index.ts
@@ -5,5 +5,6 @@ export { NPMResolver } from './resolvers/npm_resolver';
 export { FSResolver } from './resolvers/fs_resolver';
 export { RelativeFSResolver } from './resolvers/relative_fs_resolver';
 export { NameResolver } from './resolvers/name_resolver';
+export { SpyResolver } from './resolvers/spy_resolver';
 export { EnumerableResolver } from './resolvers/enumerable_resolver';
 export { Resolver } from './resolvers/resolver';
diff --git a/packages/sol-resolver/src/resolvers/fs_resolver.ts b/packages/sol-resolver/src/resolvers/fs_resolver.ts
index 63fc3448e..86128023d 100644
--- a/packages/sol-resolver/src/resolvers/fs_resolver.ts
+++ b/packages/sol-resolver/src/resolvers/fs_resolver.ts
@@ -9,10 +9,7 @@ export class FSResolver extends Resolver {
     public resolveIfExists(importPath: string): ContractSource | undefined {
         if (fs.existsSync(importPath) && fs.lstatSync(importPath).isFile()) {
             const fileContent = fs.readFileSync(importPath).toString();
-            return {
-                source: fileContent,
-                path: importPath,
-            };
+            return { source: fileContent, path: importPath, absolutePath: importPath };
         }
         return undefined;
     }
diff --git a/packages/sol-resolver/src/resolvers/name_resolver.ts b/packages/sol-resolver/src/resolvers/name_resolver.ts
index d6ac6a499..aee326fb7 100644
--- a/packages/sol-resolver/src/resolvers/name_resolver.ts
+++ b/packages/sol-resolver/src/resolvers/name_resolver.ts
@@ -20,10 +20,7 @@ export class NameResolver extends EnumerableResolver {
             if (contractName === lookupContractName) {
                 const absoluteContractPath = path.join(this._contractsDir, filePath);
                 const source = fs.readFileSync(absoluteContractPath).toString();
-                contractSource = {
-                    source,
-                    path: filePath,
-                };
+                contractSource = { source, path: filePath, absolutePath: absoluteContractPath };
                 return true;
             }
             return undefined;
@@ -36,10 +33,7 @@ export class NameResolver extends EnumerableResolver {
         const onFile = (filePath: string) => {
             const absoluteContractPath = path.join(this._contractsDir, filePath);
             const source = fs.readFileSync(absoluteContractPath).toString();
-            const contractSource = {
-                source,
-                path: filePath,
-            };
+            const contractSource = { source, path: filePath, absolutePath: absoluteContractPath };
             contractSources.push(contractSource);
         };
         this._traverseContractsDir(this._contractsDir, onFile);
diff --git a/packages/sol-resolver/src/resolvers/npm_resolver.ts b/packages/sol-resolver/src/resolvers/npm_resolver.ts
index eeb2b5493..3c1d09557 100644
--- a/packages/sol-resolver/src/resolvers/npm_resolver.ts
+++ b/packages/sol-resolver/src/resolvers/npm_resolver.ts
@@ -32,10 +32,7 @@ export class NPMResolver extends Resolver {
                 const lookupPath = path.join(currentPath, 'node_modules', packagePath, pathWithinPackage);
                 if (fs.existsSync(lookupPath) && fs.lstatSync(lookupPath).isFile()) {
                     const fileContent = fs.readFileSync(lookupPath).toString();
-                    return {
-                        source: fileContent,
-                        path: lookupPath,
-                    };
+                    return { source: fileContent, path: importPath, absolutePath: lookupPath };
                 }
                 currentPath = path.dirname(currentPath);
             }
diff --git a/packages/sol-resolver/src/resolvers/relative_fs_resolver.ts b/packages/sol-resolver/src/resolvers/relative_fs_resolver.ts
index ed96040d3..cfff145f9 100644
--- a/packages/sol-resolver/src/resolvers/relative_fs_resolver.ts
+++ b/packages/sol-resolver/src/resolvers/relative_fs_resolver.ts
@@ -13,13 +13,10 @@ export class RelativeFSResolver extends Resolver {
     }
     // tslint:disable-next-line:prefer-function-over-method
     public resolveIfExists(importPath: string): ContractSource | undefined {
-        const filePath = path.join(this._contractsDir, importPath);
+        const filePath = path.resolve(path.join(this._contractsDir, importPath));
         if (fs.existsSync(filePath) && !fs.lstatSync(filePath).isDirectory()) {
             const fileContent = fs.readFileSync(filePath).toString();
-            return {
-                source: fileContent,
-                path: importPath,
-            };
+            return { source: fileContent, path: importPath, absolutePath: filePath };
         }
         return undefined;
     }
diff --git a/packages/sol-resolver/src/resolvers/spy_resolver.ts b/packages/sol-resolver/src/resolvers/spy_resolver.ts
new file mode 100644
index 000000000..5582d771a
--- /dev/null
+++ b/packages/sol-resolver/src/resolvers/spy_resolver.ts
@@ -0,0 +1,25 @@
+import * as _ from 'lodash';
+
+import { ContractSource } from '../types';
+
+import { Resolver } from './resolver';
+
+/**
+ * This resolver is a passthrough proxy to any resolver that records all the resolved contracts sources.
+ * You can access them later using the `resolvedContractSources` public field.
+ */
+export class SpyResolver extends Resolver {
+    public resolvedContractSources: ContractSource[] = [];
+    private readonly _resolver: Resolver;
+    constructor(resolver: Resolver) {
+        super();
+        this._resolver = resolver;
+    }
+    public resolveIfExists(importPath: string): ContractSource | undefined {
+        const contractSourceIfExists = this._resolver.resolveIfExists(importPath);
+        if (!_.isUndefined(contractSourceIfExists)) {
+            this.resolvedContractSources.push(contractSourceIfExists);
+        }
+        return contractSourceIfExists;
+    }
+}
diff --git a/packages/sol-resolver/src/resolvers/url_resolver.ts b/packages/sol-resolver/src/resolvers/url_resolver.ts
index 180b0c9f6..ef300e6db 100644
--- a/packages/sol-resolver/src/resolvers/url_resolver.ts
+++ b/packages/sol-resolver/src/resolvers/url_resolver.ts
@@ -11,10 +11,7 @@ export class URLResolver extends Resolver {
         if (importPath.startsWith(FILE_URL_PREXIF)) {
             const filePath = importPath.substr(FILE_URL_PREXIF.length);
             const fileContent = fs.readFileSync(filePath).toString();
-            return {
-                source: fileContent,
-                path: importPath,
-            };
+            return { source: fileContent, path: importPath, absolutePath: filePath };
         }
         return undefined;
     }
diff --git a/packages/sol-resolver/src/types.ts b/packages/sol-resolver/src/types.ts
index 41492622d..b4ba164c8 100644
--- a/packages/sol-resolver/src/types.ts
+++ b/packages/sol-resolver/src/types.ts
@@ -1,6 +1,7 @@
 export interface ContractSource {
     source: string;
     path: string;
+    absolutePath: string;
 }
 
 export interface ContractSources {
diff --git a/packages/typescript-typings/tsconfig.json b/packages/typescript-typings/tsconfig.json
index 7f0fe2f7a..8ea3bfb0c 100644
--- a/packages/typescript-typings/tsconfig.json
+++ b/packages/typescript-typings/tsconfig.json
@@ -3,5 +3,6 @@
     "compilerOptions": {
         "outDir": "lib",
         "rootDir": "."
-    }
+    },
+    "include": ["types"]
 }
diff --git a/packages/utils/CHANGELOG.json b/packages/utils/CHANGELOG.json
index fe66d3f31..605151fb6 100644
--- a/packages/utils/CHANGELOG.json
+++ b/packages/utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.1.0",
+        "changes": [
+            {
+                "note": "Add `logWithTime` to `logUtils`",
+                "pr": 1461
+            }
+        ]
+    },
+    {
         "version": "2.0.8",
         "changes": [
             {
diff --git a/packages/utils/package.json b/packages/utils/package.json
index a25dc9cff..5ffec049a 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -49,6 +49,7 @@
         "@types/node": "*",
         "abortcontroller-polyfill": "^1.1.9",
         "bignumber.js": "~4.1.0",
+        "chalk": "^2.4.1",
         "detect-node": "2.0.3",
         "ethereum-types": "^1.1.4",
         "ethereumjs-util": "^5.1.1",
diff --git a/packages/utils/src/log_utils.ts b/packages/utils/src/log_utils.ts
index 87f8479b5..6d9996c67 100644
--- a/packages/utils/src/log_utils.ts
+++ b/packages/utils/src/log_utils.ts
@@ -1,3 +1,5 @@
+import chalk from 'chalk';
+
 export const logUtils = {
     log(...args: any[]): void {
         console.log(...args); // tslint:disable-line:no-console
@@ -5,4 +7,7 @@ export const logUtils = {
     warn(...args: any[]): void {
         console.warn(...args); // tslint:disable-line:no-console
     },
+    logWithTime(arg: string): void {
+        logUtils.log(`[${chalk.gray(new Date().toLocaleTimeString())}] ${arg}`);
+    },
 };
diff --git a/yarn.lock b/yarn.lock
index 8327a4ee8..bf8b73525 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1268,6 +1268,14 @@
   version "0.22.9"
   resolved "https://registry.npmjs.org/@types/cheerio/-/cheerio-0.22.9.tgz#b5990152604c2ada749b7f88cab3476f21f39d7b"
 
+"@types/chokidar@^1.7.5":
+  version "1.7.5"
+  resolved "https://registry.yarnpkg.com/@types/chokidar/-/chokidar-1.7.5.tgz#1fa78c8803e035bed6d98e6949e514b133b0c9b6"
+  integrity sha512-PDkSRY7KltW3M60hSBlerxI8SFPXsO3AL/aRVsO4Kh9IHRW74Ih75gUuTd/aE4LSSFqypb10UIX3QzOJwBQMGQ==
+  dependencies:
+    "@types/events" "*"
+    "@types/node" "*"
+
 "@types/compare-versions@^3.0.0":
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/@types/compare-versions/-/compare-versions-3.0.0.tgz#4a45dffe0ebbc00d0f2daef8a0e96ffc66cf5955"
@@ -1519,6 +1527,11 @@
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@types/p-limit/-/p-limit-2.0.0.tgz#c076b7daa9163108a35899ea6a9d927526943ea2"
 
+"@types/pluralize@^0.0.29":
+  version "0.0.29"
+  resolved "https://registry.yarnpkg.com/@types/pluralize/-/pluralize-0.0.29.tgz#6ffa33ed1fc8813c469b859681d09707eb40d03c"
+  integrity sha512-BYOID+l2Aco2nBik+iYS4SZX0Lf20KPILP5RGmM1IgzdwNdTs0eebiFriOPcej1sX9mLnSoiNte5zcFxssgpGA==
+
 "@types/prop-types@*":
   version "15.5.5"
   resolved "https://registry.npmjs.org/@types/prop-types/-/prop-types-15.5.5.tgz#17038dd322c2325f5da650a94d5f9974943625e3"
@@ -3951,6 +3964,26 @@ chokidar@^2.0.0, chokidar@^2.0.2:
   optionalDependencies:
     fsevents "^1.1.2"
 
+chokidar@^2.0.4:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.0.4.tgz#356ff4e2b0e8e43e322d18a372460bbcf3accd26"
+  integrity sha512-z9n7yt9rOvIJrMhvDtDictKrkFHeihkNl6uWMmZlmL6tJtX9Cs+87oK+teBx+JIgzvbX3yZHT3eF8vpbDxHJXQ==
+  dependencies:
+    anymatch "^2.0.0"
+    async-each "^1.0.0"
+    braces "^2.3.0"
+    glob-parent "^3.1.0"
+    inherits "^2.0.1"
+    is-binary-path "^1.0.0"
+    is-glob "^4.0.0"
+    lodash.debounce "^4.0.8"
+    normalize-path "^2.1.1"
+    path-is-absolute "^1.0.0"
+    readdirp "^2.0.0"
+    upath "^1.0.5"
+  optionalDependencies:
+    fsevents "^1.2.2"
+
 chownr@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/chownr/-/chownr-1.0.1.tgz#e2a75042a9551908bebd25b8523d5f9769d79181"
@@ -6935,7 +6968,7 @@ fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
 
-fsevents@^1.0.0, fsevents@^1.2.3:
+fsevents@^1.0.0, fsevents@^1.2.2, fsevents@^1.2.3:
   version "1.2.4"
   resolved "https://registry.npmjs.org/fsevents/-/fsevents-1.2.4.tgz#f41dcb1af2582af3692da36fc55cbd8e1041c426"
   dependencies:
@@ -9858,6 +9891,11 @@ lodash.camelcase@^3.0.1:
   dependencies:
     lodash._createcompounder "^3.0.0"
 
+lodash.debounce@^4.0.8:
+  version "4.0.8"
+  resolved "https://registry.yarnpkg.com/lodash.debounce/-/lodash.debounce-4.0.8.tgz#82d79bff30a67c4005ffd5e2515300ad9ca4d7af"
+  integrity sha1-gteb/zCmfEAF/9XiUVMArZyk168=
+
 lodash.deburr@^3.0.0:
   version "3.2.0"
   resolved "https://registry.yarnpkg.com/lodash.deburr/-/lodash.deburr-3.2.0.tgz#6da8f54334a366a7cf4c4c76ef8d80aa1b365ed5"
@@ -11973,6 +12011,7 @@ pkginfo@0.x.x:
 pluralize@^7.0.0:
   version "7.0.0"
   resolved "https://registry.yarnpkg.com/pluralize/-/pluralize-7.0.0.tgz#298b89df8b93b0221dbf421ad2b1b1ea23fc6777"
+  integrity sha512-ARhBOdzS3e41FbkW/XWrTEtukqqLoK5+Z/4UeDaLuSW+39JPeFgs4gCGqsrJHVZX0fUrx//4OF0K1CUGwlIFow==
 
 pn@^1.1.0:
   version "1.1.0"
@@ -16047,6 +16086,11 @@ upath@^1.0.0:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/upath/-/upath-1.0.4.tgz#ee2321ba0a786c50973db043a50b7bcba822361d"
 
+upath@^1.0.5:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/upath/-/upath-1.1.0.tgz#35256597e46a581db4793d0ce47fa9aebfc9fabd"
+  integrity sha512-bzpH/oBhoS/QI/YtbkqCg6VEiPYjSZtrHQM6/QnJS6OL9pKUFLqb3aFh4Scvwm45+7iAgiMkLhSbaZxUqmrprw==
+
 update-notifier@^2.3.0, update-notifier@^2.5.0:
   version "2.5.0"
   resolved "https://registry.yarnpkg.com/update-notifier/-/update-notifier-2.5.0.tgz#d0744593e13f161e406acb1d9408b72cad08aff6"