Updated deployer to accept a list of contract directories as input. Contract directories are namespaced to a void clashes. Also in this commit is a fix for overloading contract functions.

27 files changed, 619 insertions, 132 deletions

diff --git a/packages/abi-gen/src/index.ts b/packages/abi-gen/src/index.ts
index 942bb12db..9ceebe02b 100644
--- a/packages/abi-gen/src/index.ts
+++ b/packages/abi-gen/src/index.ts
@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 
 import { AbiDefinition, ConstructorAbi, EventAbi, MethodAbi } from '@0xproject/types';
-import { logUtils } from '@0xproject/utils';
+import { abiUtils, logUtils } from '@0xproject/utils';
 import chalk from 'chalk';
 import * as fs from 'fs';
 import { sync as globSync } from 'glob';
@@ -12,7 +12,7 @@ import * as yargs from 'yargs';
 
 import toSnakeCase = require('to-snake-case');
 
-import { ContextData, ContractsBackend, ParamKind } from './types';
+import { ContextData, ContractsBackend, Method, ParamKind } from './types';
 import { utils } from './utils';
 
 const ABI_TYPE_CONSTRUCTOR = 'constructor';
@@ -83,7 +83,6 @@ function writeOutputFile(name: string, renderedTsCode: string): void {
 
 Handlebars.registerHelper('parameterType', utils.solTypeToTsType.bind(utils, ParamKind.Input, args.backend));
 Handlebars.registerHelper('returnType', utils.solTypeToTsType.bind(utils, ParamKind.Output, args.backend));
-
 if (args.partials) {
     registerPartials(args.partials);
 }
@@ -126,11 +125,12 @@ for (const abiFileName of abiFileNames) {
     }
 
     const methodAbis = ABI.filter((abi: AbiDefinition) => abi.type === ABI_TYPE_METHOD) as MethodAbi[];
-    const methodsData = _.map(methodAbis, methodAbi => {
-        _.map(methodAbi.inputs, (input, i: number) => {
+    const methodAbisSanitized = abiUtils.renameOverloadedMethods(methodAbis) as MethodAbi[];
+    const methodsData = _.map(methodAbis, (methodAbi, methodAbiIndex: number) => {
+        _.forEach(methodAbi.inputs, (input, inputIndex: number) => {
             if (_.isEmpty(input.name)) {
                 // Auto-generated getters don't have parameter names
-                input.name = `index_${i}`;
+                input.name = `index_${inputIndex}`;
             }
         });
         // This will make templates simpler
@@ -138,6 +138,8 @@ for (const abiFileName of abiFileNames) {
             ...methodAbi,
             singleReturnValue: methodAbi.outputs.length === 1,
             hasReturnValue: methodAbi.outputs.length !== 0,
+            tsName: methodAbisSanitized[methodAbiIndex].name,
+            functionSignature: abiUtils.getFunctionSignature(methodAbi),
         };
         return methodData;
     });
diff --git a/packages/abi-gen/src/types.ts b/packages/abi-gen/src/types.ts
index df5b1feaf..648281774 100644
--- a/packages/abi-gen/src/types.ts
+++ b/packages/abi-gen/src/types.ts
@@ -5,13 +5,6 @@ export enum ParamKind {
     Output = 'output',
 }
 
-export enum AbiType {
-    Function = 'function',
-    Constructor = 'constructor',
-    Event = 'event',
-    Fallback = 'fallback',
-}
-
 export enum ContractsBackend {
     Web3 = 'web3',
     Ethers = 'ethers',
@@ -20,6 +13,8 @@ export enum ContractsBackend {
 export interface Method extends MethodAbi {
     singleReturnValue: boolean;
     hasReturnValue: boolean;
+    tsName: string;
+    functionSignature: string;
 }
 
 export interface ContextData {
diff --git a/packages/abi-gen/src/utils.ts b/packages/abi-gen/src/utils.ts
index 755fbc71a..20b734959 100644
--- a/packages/abi-gen/src/utils.ts
+++ b/packages/abi-gen/src/utils.ts
@@ -1,9 +1,9 @@
-import { ConstructorAbi, DataItem } from '@0xproject/types';
+import { AbiType, ConstructorAbi, DataItem } from '@0xproject/types';
 import * as fs from 'fs';
 import * as _ from 'lodash';
 import * as path from 'path';
 
-import { AbiType, ContractsBackend, ParamKind } from './types';
+import { ContractsBackend, ParamKind } from './types';
 
 export const utils = {
     solTypeToTsType(paramKind: ParamKind, backend: ContractsBackend, solType: string, components?: DataItem[]): string {
diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index bba686f8b..f6cea53fa 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -1,13 +1,26 @@
-import { ContractAbi, DataItem, Provider, TxData, TxDataPayable } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
+import {
+    AbiDefinition,
+    AbiType,
+    ContractAbi,
+    DataItem,
+    MethodAbi,
+    Provider,
+    TxData,
+    TxDataPayable,
+} from '@0xproject/types';
+import { abiUtils, BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as ethersContracts from 'ethers-contracts';
 import * as _ from 'lodash';
 
 import { formatABIDataItem } from './utils';
 
+export interface EthersInterfaceByFunctionSignature {
+    [key: string]: ethersContracts.Interface;
+}
+
 export class BaseContract {
-    protected _ethersInterface: ethersContracts.Interface;
+    protected _ethersInterfacesByFunctionSignature: EthersInterfaceByFunctionSignature;
     protected _web3Wrapper: Web3Wrapper;
     public abi: ContractAbi;
     public address: string;
@@ -49,10 +62,40 @@ export class BaseContract {
         }
         return txDataWithDefaults;
     }
+    protected _lookupEthersInterface(functionSignature: string): ethersContracts.Interface {
+        const ethersInterface = this._ethersInterfacesByFunctionSignature[functionSignature];
+        if (_.isUndefined(ethersInterface)) {
+            throw new Error(`Failed to lookup method with function signature '${functionSignature}'`);
+        }
+        return ethersInterface;
+    }
+    protected _lookupAbi(functionSignature: string): MethodAbi {
+        const methodAbi = _.find(this.abi, (abiDefinition: AbiDefinition) => {
+            if (abiDefinition.type !== AbiType.Function) {
+                return false;
+            }
+            const abiFunctionSignature = abiUtils.getFunctionSignature(abiDefinition);
+            if (abiFunctionSignature === functionSignature) {
+                return true;
+            }
+            return false;
+        }) as MethodAbi;
+        return methodAbi;
+    }
     constructor(abi: ContractAbi, address: string, provider: Provider, defaults?: Partial<TxData>) {
         this._web3Wrapper = new Web3Wrapper(provider, defaults);
         this.abi = abi;
         this.address = address;
-        this._ethersInterface = new ethersContracts.Interface(abi);
+        const methodAbis = this.abi.filter(
+            (abiDefinition: AbiDefinition) => abiDefinition.type === AbiType.Function,
+        ) as MethodAbi[];
+        this._ethersInterfacesByFunctionSignature = _.transform(
+            methodAbis,
+            (result: EthersInterfaceByFunctionSignature, methodAbi) => {
+                const functionSignature = abiUtils.getFunctionSignature(methodAbi);
+                result[functionSignature] = new ethersContracts.Interface([methodAbi]);
+            },
+            {},
+        );
     }
 }
diff --git a/packages/contract_templates/contract.handlebars b/packages/contract_templates/contract.handlebars
index 3e3f87f10..472452d74 100644
--- a/packages/contract_templates/contract.handlebars
+++ b/packages/contract_templates/contract.handlebars
@@ -41,6 +41,6 @@ export class {{contractName}}Contract extends BaseContract {
 {{/each}}
     constructor(abi: ContractAbi, address: string, provider: Provider, defaults?: Partial<TxData>) {
         super(abi, address, provider, defaults);
-        classUtils.bindAll(this, ['_ethersInterface', 'address', 'abi', '_web3Wrapper']);
+        classUtils.bindAll(this, ['_ethersInterfacesByFunctionSignature', 'address', 'abi', '_web3Wrapper']);
     }
 } // tslint:disable:max-file-line-count
diff --git a/packages/contract_templates/partials/callAsync.handlebars b/packages/contract_templates/partials/callAsync.handlebars
index 8de69203e..a6f4abdf2 100644
--- a/packages/contract_templates/partials/callAsync.handlebars
+++ b/packages/contract_templates/partials/callAsync.handlebars
@@ -5,9 +5,9 @@ async callAsync(
     defaultBlock?: BlockParam,
 ): Promise<{{> return_type outputs=outputs}}> {
     const self = this as any as {{contractName}}Contract;
-    const inputAbi = (_.find(self.abi, {name: '{{this.name}}'}) as MethodAbi).inputs;
+    const inputAbi = self._lookupAbi('{{this.functionSignature}}').inputs;
     [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(self));
-    const encodedData = self._ethersInterface.functions.{{this.name}}(
+    const encodedData = self._lookupEthersInterface('{{this.functionSignature}}').functions.{{this.name}}(
         {{> params inputs=inputs}}
     ).data;
     const callDataWithDefaults = await self._applyDefaultsToTxDataAsync(
diff --git a/packages/contract_templates/partials/tx.handlebars b/packages/contract_templates/partials/tx.handlebars
index 41ba6d3f7..22fe0c597 100644
--- a/packages/contract_templates/partials/tx.handlebars
+++ b/packages/contract_templates/partials/tx.handlebars
@@ -1,4 +1,4 @@
-public {{this.name}} = {
+public {{this.tsName}} = {
     async sendTransactionAsync(
     {{> typed_params inputs=inputs}}
     {{#this.payable}}
@@ -9,17 +9,17 @@ public {{this.name}} = {
     {{/this.payable}}
     ): Promise<string> {
         const self = this as any as {{contractName}}Contract;
-        const inputAbi = (_.find(self.abi, {name: '{{this.name}}'}) as MethodAbi).inputs;
+        const inputAbi = self._lookupAbi('{{this.functionSignature}}').inputs;
         [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(self));
-        const encodedData = self._ethersInterface.functions.{{this.name}}(
+        const encodedData = self._lookupEthersInterface('{{this.functionSignature}}').functions.{{this.name}}(
             {{> params inputs=inputs}}
-        ).data
+        ).data;
         const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(
             {
                 ...txData,
                 data: encodedData,
             },
-            self.{{this.name}}.estimateGasAsync.bind(
+            self.{{this.tsName}}.estimateGasAsync.bind(
                 self,
                 {{> params inputs=inputs}}
             ),
@@ -32,11 +32,11 @@ public {{this.name}} = {
         txData: Partial<TxData> = {},
     ): Promise<number> {
         const self = this as any as {{contractName}}Contract;
-        const inputAbi = (_.find(self.abi, {name: '{{this.name}}'}) as MethodAbi).inputs;
+        const inputAbi = self._lookupAbi('{{this.functionSignature}}').inputs;
         [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(this));
-        const encodedData = self._ethersInterface.functions.{{this.name}}(
+        const encodedData = self._lookupEthersInterface('{{this.functionSignature}}').functions.{{this.name}}(
             {{> params inputs=inputs}}
-        ).data
+        ).data;
         const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(
             {
                 ...txData,
@@ -50,11 +50,11 @@ public {{this.name}} = {
     {{> typed_params inputs=inputs}}
     ): string {
         const self = this as any as {{contractName}}Contract;
-        const inputAbi = (_.find(self.abi, {name: '{{this.name}}'}) as MethodAbi).inputs;
+        const inputAbi = self._lookupAbi('{{this.functionSignature}}').inputs;
         [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(self));
-        const abiEncodedTransactionData = self._ethersInterface.functions.{{this.name}}(
+        const abiEncodedTransactionData = self._lookupEthersInterface('{{this.name}}').functions.{{this.name}}(
             {{> params inputs=inputs}}
-        ).data
+        ).data;
         return abiEncodedTransactionData;
     },
     {{> callAsync}}
diff --git a/packages/contracts/package.json b/packages/contracts/package.json
index 8152a9afe..6b7776422 100644
--- a/packages/contracts/package.json
+++ b/packages/contracts/package.json
@@ -16,7 +16,7 @@
         "test:coverage": "SOLIDITY_COVERAGE=true run-s build run_mocha coverage:report:text coverage:report:lcov",
         "run_mocha": "mocha 'lib/test/**/*.js' --timeout 100000 --bail --exit",
         "compile:comment": "Yarn workspaces do not link binaries correctly so we need to reference them directly https://github.com/yarnpkg/yarn/issues/3846",
-        "compile": "node ../deployer/lib/src/cli.js compile --contracts ${npm_package_config_contracts} --contracts-dir src/contracts --artifacts-dir src/artifacts",
+        "compile": "node ../deployer/lib/src/cli.js compile --contracts ${npm_package_config_contracts} --contract-dirs src/contracts --artifacts-dir src/artifacts",
         "clean": "shx rm -rf ./lib",
         "generate_contract_wrappers": "node ../abi-gen/lib/index.js --abis  ${npm_package_config_abis} --template ../contract_templates/contract.handlebars --partials '../contract_templates/partials/**/*.handlebars' --output src/contract_wrappers/generated --backend ethers && prettier --write 'src/contract_wrappers/generated/**.ts'",
         "migrate": "yarn build && yarn compile && node ./lib/migrations/index.js",
diff --git a/packages/deployer/package.json b/packages/deployer/package.json
index f6eff9973..34d27081b 100644
--- a/packages/deployer/package.json
+++ b/packages/deployer/package.json
@@ -47,12 +47,14 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/packages/deployer/README.md",
     "devDependencies": {
+        "@0xproject/dev-utils": "^0.2.1",
         "@0xproject/monorepo-scripts": "^0.1.16",
         "@0xproject/tslint-config": "^0.4.14",
         "@types/require-from-string": "^1.2.0",
         "@types/semver": "^5.5.0",
         "@types/yargs": "^11.0.0",
         "chai": "^4.0.1",
+        "chai-as-promised": "^7.1.0",
         "copyfiles": "^1.2.0",
         "dirty-chai": "^2.0.1",
         "mocha": "^4.0.1",
diff --git a/packages/deployer/src/cli.ts b/packages/deployer/src/cli.ts
index d1bd645b3..3d69925a8 100644
--- a/packages/deployer/src/cli.ts
+++ b/packages/deployer/src/cli.ts
@@ -11,7 +11,7 @@ import * as yargs from 'yargs';
 import { commands } from './commands';
 import { constants } from './utils/constants';
 import { consoleReporter } from './utils/error_reporter';
-import { CliOptions, CompilerOptions, DeployerOptions } from './utils/types';
+import { CliOptions, CompilerOptions, ContractDirectory, DeployerOptions } from './utils/types';
 
 const DEFAULT_OPTIMIZER_ENABLED = false;
 const DEFAULT_CONTRACTS_DIR = path.resolve('src/contracts');
@@ -27,7 +27,7 @@ const DEFAULT_CONTRACTS_LIST = '*';
  */
 async function onCompileCommandAsync(argv: CliOptions): Promise<void> {
     const opts: CompilerOptions = {
-        contractsDir: argv.contractsDir,
+        contractDirs: getContractDirectoriesFromList(argv.contractDirs),
         networkId: argv.networkId,
         optimizerEnabled: argv.shouldOptimize,
         artifactsDir: argv.artifactsDir,
@@ -45,7 +45,7 @@ async function onDeployCommandAsync(argv: CliOptions): Promise<void> {
     const web3Wrapper = new Web3Wrapper(web3Provider);
     const networkId = await web3Wrapper.getNetworkIdAsync();
     const compilerOpts: CompilerOptions = {
-        contractsDir: argv.contractsDir,
+        contractDirs: getContractDirectoriesFromList(argv.contractsDir),
         networkId,
         optimizerEnabled: argv.shouldOptimize,
         artifactsDir: argv.artifactsDir,
@@ -69,6 +69,29 @@ async function onDeployCommandAsync(argv: CliOptions): Promise<void> {
 }
 /**
  * Creates a set of contracts to compile.
+ * @param contractDirectoriesList Comma separated list of contract directories
+ * @return Set of contract directories
+ */
+function getContractDirectoriesFromList(contractDirectoriesList: string): Set<ContractDirectory> {
+    const directories = new Set();
+    const possiblyNamespacedDirectories = contractDirectoriesList.split(',');
+    _.forEach(possiblyNamespacedDirectories, namespacedDirectory => {
+        const directoryComponents = namespacedDirectory.split(':');
+        if (directoryComponents.length === 1) {
+            const directory = { namespace: '', path: directoryComponents[0] };
+            directories.add(directory);
+        } else if (directoryComponents.length === 2) {
+            const directory = { namespace: directoryComponents[0], path: directoryComponents[1] };
+            directories.add(directory);
+        } else {
+            throw new Error(`Unable to parse contracts directory: '${namespacedDirectory}'`);
+        }
+    });
+
+    return directories;
+}
+/**
+ * Creates a set of contracts to compile.
  * @param contracts Comma separated list of contracts to compile
  */
 function getContractsSetFromList(contracts: string): Set<string> {
@@ -78,8 +101,7 @@ function getContractsSetFromList(contracts: string): Set<string> {
     }
     const contractsArray = contracts.split(',');
     _.forEach(contractsArray, contractName => {
-        const fileName = `${contractName}${constants.SOLIDITY_FILE_EXTENSION}`;
-        specifiedContracts.add(fileName);
+        specifiedContracts.add(contractName);
     });
     return specifiedContracts;
 }
@@ -104,10 +126,11 @@ function deployCommandBuilder(yargsInstance: any) {
 (() => {
     const identityCommandBuilder = _.identity;
     return yargs
-        .option('contracts-dir', {
+        .option('contract-dirs', {
             type: 'string',
             default: DEFAULT_CONTRACTS_DIR,
-            description: 'path of contracts directory to compile',
+            description:
+                "comma separated list of contract directories.\nTo avoid filename clashes, directories should be prefixed with a namespace as follows: 'namespace:/path/to/dir'.",
         })
         .option('network-id', {
             type: 'number',
diff --git a/packages/deployer/src/compiler.ts b/packages/deployer/src/compiler.ts
index ba360cb57..beaaab141 100644
--- a/packages/deployer/src/compiler.ts
+++ b/packages/deployer/src/compiler.ts
@@ -1,4 +1,4 @@
-import { ContractAbi } from '@0xproject/types';
+import { AbiType, ContractAbi, MethodAbi } from '@0xproject/types';
 import { logUtils, promisify } from '@0xproject/utils';
 import * as ethUtil from 'ethereumjs-util';
 import * as fs from 'fs';
@@ -11,6 +11,8 @@ import solc = require('solc');
 
 import { binPaths } from './solc/bin_paths';
 import {
+    constructContractId,
+    constructUniqueSourceFileId,
     createDirIfDoesNotExistAsync,
     findImportIfExist,
     getContractArtifactIfExistsAsync,
@@ -23,11 +25,14 @@ import { fsWrapper } from './utils/fs_wrapper';
 import {
     CompilerOptions,
     ContractArtifact,
+    ContractDirectory,
+    ContractIds,
     ContractNetworkData,
     ContractNetworks,
-    ContractSourceData,
+    ContractSourceDataByFileId,
     ContractSources,
     ContractSpecificSourceData,
+    FunctionNameToSeenCount,
 } from './utils/types';
 import { utils } from './utils/utils';
 
@@ -39,20 +44,22 @@ const SOLC_BIN_DIR = path.join(__dirname, '..', '..', 'solc_bin');
  * to artifact files.
  */
 export class Compiler {
-    private _contractsDir: string;
+    private _contractDirs: Set<ContractDirectory>;
     private _networkId: number;
     private _optimizerEnabled: boolean;
     private _artifactsDir: string;
     // This get's set in the beggining of `compileAsync` function. It's not called from a constructor, but it's the only public method of that class and could as well be.
     private _contractSources!: ContractSources;
     private _specifiedContracts: Set<string> = new Set();
-    private _contractSourceData: ContractSourceData = {};
+    private _contractSourceDataByFileId: ContractSourceDataByFileId = {};
+
     /**
      * Recursively retrieves Solidity source code from directory.
      * @param  dirPath Directory to search.
-     * @return Mapping of contract fileName to contract source.
+     * @param  contractBaseDir Base contracts directory of search tree.
+     * @return Mapping of sourceFilePath to the contract source.
      */
-    private static async _getContractSourcesAsync(dirPath: string): Promise<ContractSources> {
+    private static async _getContractSourcesAsync(dirPath: string, contractBaseDir: string): Promise<ContractSources> {
         let dirContents: string[] = [];
         try {
             dirContents = await fsWrapper.readdirAsync(dirPath);
@@ -68,14 +75,15 @@ export class Compiler {
                         encoding: 'utf8',
                     };
                     const source = await fsWrapper.readFileAsync(contentPath, opts);
-                    sources[fileName] = source;
-                    logUtils.log(`Reading ${fileName} source...`);
+                    const sourceFilePath = contentPath.slice(contractBaseDir.length);
+                    sources[sourceFilePath] = source;
+                    logUtils.log(`Reading ${sourceFilePath} source...`);
                 } catch (err) {
                     logUtils.log(`Could not find file at ${contentPath}`);
                 }
             } else {
                 try {
-                    const nestedSources = await Compiler._getContractSourcesAsync(contentPath);
+                    const nestedSources = await Compiler._getContractSourcesAsync(contentPath, contractBaseDir);
                     sources = {
                         ...sources,
                         ...nestedSources,
@@ -93,7 +101,7 @@ export class Compiler {
      * @return An instance of the Compiler class.
      */
     constructor(opts: CompilerOptions) {
-        this._contractsDir = opts.contractsDir;
+        this._contractDirs = opts.contractDirs;
         this._networkId = opts.networkId;
         this._optimizerEnabled = opts.optimizerEnabled;
         this._artifactsDir = opts.artifactsDir;
@@ -105,25 +113,47 @@ export class Compiler {
     public async compileAsync(): Promise<void> {
         await createDirIfDoesNotExistAsync(this._artifactsDir);
         await createDirIfDoesNotExistAsync(SOLC_BIN_DIR);
-        this._contractSources = await Compiler._getContractSourcesAsync(this._contractsDir);
+        this._contractSources = {};
+        const contractIds: ContractIds = {};
+        const contractDirs = Array.from(this._contractDirs.values());
+        for (const contractDir of contractDirs) {
+            const sources = await Compiler._getContractSourcesAsync(contractDir.path, contractDir.path);
+            _.forIn(sources, (source, sourceFilePath) => {
+                const sourceFileId = constructUniqueSourceFileId(contractDir.namespace, sourceFilePath);
+                // Record the file's source and data
+                if (!_.isUndefined(this._contractSources[sourceFileId])) {
+                    throw new Error(`Found duplicate source files with ID '${sourceFileId}'`);
+                }
+                this._contractSources[sourceFileId] = source;
+                // Create a mapping between the contract id and its source file id
+                const contractId = constructContractId(contractDir.namespace, sourceFilePath);
+                if (!_.isUndefined(contractIds[contractId])) {
+                    throw new Error(`Found duplicate contract with ID '${contractId}'`);
+                }
+                contractIds[contractId] = sourceFileId;
+            });
+        }
         _.forIn(this._contractSources, this._setContractSpecificSourceData.bind(this));
-        const fileNames = this._specifiedContracts.has(ALL_CONTRACTS_IDENTIFIER)
-            ? _.keys(this._contractSources)
+        const specifiedContractIds = this._specifiedContracts.has(ALL_CONTRACTS_IDENTIFIER)
+            ? _.keys(contractIds)
             : Array.from(this._specifiedContracts.values());
-        for (const fileName of fileNames) {
-            await this._compileContractAsync(fileName);
-        }
+        await Promise.all(
+            _.map(specifiedContractIds, async contractId => this._compileContractAsync(contractIds[contractId])),
+        );
     }
     /**
      * Compiles contract and saves artifact to artifactsDir.
-     * @param fileName Name of contract with '.sol' extension.
+     * @param sourceFileId Unique ID of the source file.
      */
-    private async _compileContractAsync(fileName: string): Promise<void> {
+    private async _compileContractAsync(sourceFileId: string): Promise<void> {
         if (_.isUndefined(this._contractSources)) {
             throw new Error('Contract sources not yet initialized');
         }
-        const contractSpecificSourceData = this._contractSourceData[fileName];
-        const currentArtifactIfExists = await getContractArtifactIfExistsAsync(this._artifactsDir, fileName);
+        if (_.isUndefined(this._contractSourceDataByFileId[sourceFileId])) {
+            throw new Error(`Contract source for ${sourceFileId} not yet initialized`);
+        }
+        const contractSpecificSourceData = this._contractSourceDataByFileId[sourceFileId];
+        const currentArtifactIfExists = await getContractArtifactIfExistsAsync(this._artifactsDir, sourceFileId);
         const sourceHash = `0x${contractSpecificSourceData.sourceHash.toString('hex')}`;
         const sourceTreeHash = `0x${contractSpecificSourceData.sourceTreeHash.toString('hex')}`;
 
@@ -162,16 +192,17 @@ export class Compiler {
         }
         const solcInstance = solc.setupMethods(requireFromString(solcjs, compilerBinFilename));
 
-        logUtils.log(`Compiling ${fileName} with Solidity v${solcVersion}...`);
-        const source = this._contractSources[fileName];
+        logUtils.log(`Compiling ${sourceFileId} with Solidity v${solcVersion}...`);
+        const source = this._contractSources[sourceFileId];
         const input = {
-            [fileName]: source,
+            [sourceFileId]: source,
         };
         const sourcesToCompile = {
             sources: input,
         };
+
         const compiled = solcInstance.compile(sourcesToCompile, Number(this._optimizerEnabled), importPath =>
-            findImportIfExist(this._contractSources, importPath),
+            findImportIfExist(this._contractSources, sourceFileId, importPath),
         );
 
         if (!_.isUndefined(compiled.errors)) {
@@ -193,11 +224,11 @@ export class Compiler {
                 });
             }
         }
-        const contractName = path.basename(fileName, constants.SOLIDITY_FILE_EXTENSION);
-        const contractIdentifier = `${fileName}:${contractName}`;
+        const contractName = path.basename(sourceFileId, constants.SOLIDITY_FILE_EXTENSION);
+        const contractIdentifier = `${sourceFileId}:${contractName}`;
         if (_.isUndefined(compiled.contracts[contractIdentifier])) {
             throw new Error(
-                `Contract ${contractName} not found in ${fileName}. Please make sure your contract has the same name as it's file name`,
+                `Contract ${contractName} not found in ${sourceFileId}. Please make sure your contract has the same name as it's file name`,
             );
         }
         const abi: ContractAbi = JSON.parse(compiled.contracts[contractIdentifier].interface);
@@ -207,6 +238,7 @@ export class Compiler {
         const sourceMapRuntime = compiled.contracts[contractIdentifier].srcmapRuntime;
         const sources = _.keys(compiled.sources);
         const updated_at = Date.now();
+
         const contractNetworkData: ContractNetworkData = {
             solc_version: solcVersion,
             keccak256: sourceHash,
@@ -243,28 +275,30 @@ export class Compiler {
         const artifactString = utils.stringifyWithFormatting(newArtifact);
         const currentArtifactPath = `${this._artifactsDir}/${contractName}.json`;
         await fsWrapper.writeFileAsync(currentArtifactPath, artifactString);
-        logUtils.log(`${fileName} artifact saved!`);
+        logUtils.log(`${sourceFileId} artifact saved!`);
     }
     /**
      * Gets contract dependendencies and keccak256 hash from source.
      * @param source Source code of contract.
+     * @param fileId FileId of the contract source file.
      * @return Object with contract dependencies and keccak256 hash of source.
      */
-    private _setContractSpecificSourceData(source: string, fileName: string): void {
-        if (!_.isUndefined(this._contractSourceData[fileName])) {
+    private _setContractSpecificSourceData(source: string, fileId: string): void {
+        if (!_.isUndefined(this._contractSourceDataByFileId[fileId])) {
             return;
         }
         const sourceHash = ethUtil.sha3(source);
         const solcVersionRange = parseSolidityVersionRange(source);
-        const dependencies = parseDependencies(source);
-        const sourceTreeHash = this._getSourceTreeHash(fileName, sourceHash, dependencies);
-        this._contractSourceData[fileName] = {
+        const dependencies = parseDependencies(source, fileId);
+        const sourceTreeHash = this._getSourceTreeHash(fileId, sourceHash, dependencies);
+        this._contractSourceDataByFileId[fileId] = {
             dependencies,
             solcVersionRange,
             sourceHash,
             sourceTreeHash,
         };
     }
+
     /**
      * Gets the source tree hash for a file and its dependencies.
      * @param fileName Name of contract file.
@@ -276,7 +310,7 @@ export class Compiler {
             const dependencySourceTreeHashes = _.map(dependencies, dependency => {
                 const source = this._contractSources[dependency];
                 this._setContractSpecificSourceData(source, dependency);
-                const sourceData = this._contractSourceData[dependency];
+                const sourceData = this._contractSourceDataByFileId[dependency];
                 return this._getSourceTreeHash(dependency, sourceData.sourceHash, sourceData.dependencies);
             });
             const sourceTreeHashesBuffer = Buffer.concat([sourceHash, ...dependencySourceTreeHashes]);
diff --git a/packages/deployer/src/utils/compiler.ts b/packages/deployer/src/utils/compiler.ts
index d5137d394..600495693 100644
--- a/packages/deployer/src/utils/compiler.ts
+++ b/packages/deployer/src/utils/compiler.ts
@@ -1,3 +1,4 @@
+import { AbiType, ContractAbi, MethodAbi } from '@0xproject/types';
 import { logUtils } from '@0xproject/utils';
 import * as _ from 'lodash';
 import * as path from 'path';
@@ -5,9 +6,49 @@ import * as solc from 'solc';
 
 import { constants } from './constants';
 import { fsWrapper } from './fs_wrapper';
-import { ContractArtifact, ContractSources } from './types';
+import { ContractArtifact, ContractSources, FunctionNameToSeenCount } from './types';
 
 /**
+ * Constructs a system-wide unique identifier for a source file.
+ * @param directoryNamespace Namespace of the source file's root contract directory.
+ * @param sourceFilePath Path to a source file, relative to contractBaseDir.
+ * @return sourceFileId A system-wide unique identifier for the source file.
+ */
+export function constructUniqueSourceFileId(directoryNamespace: string, sourceFilePath: string): string {
+    const namespacePrefix = !_.isEmpty(directoryNamespace) ? `/${directoryNamespace}` : '';
+    const sourceFilePathNoLeadingSlash = sourceFilePath.replace(/^\/+/g, '');
+    const sourceFileId = `${namespacePrefix}/${sourceFilePathNoLeadingSlash}`;
+    return sourceFileId;
+}
+/**
+ * Constructs a system-wide unique identifier for a dependency file.
+ * @param dependencyFilePath Path from a sourceFile to a dependency.
+ * @param  contractBaseDir Base contracts directory of search tree.
+ * @return sourceFileId A system-wide unique identifier for the source file.
+ */
+export function constructDependencyFileId(dependencyFilePath: string, sourceFilePath: string): string {
+    if (_.startsWith(dependencyFilePath, '/')) {
+        // Path of the form /namespace/path/to/dependency.sol
+        return dependencyFilePath;
+    } else {
+        // Dependency is relative to the source file: ./dependency.sol, ../../some/path/dependency.sol, etc.
+        // Join the two paths to construct a valid source file id: /namespace/path/to/dependency.sol
+        return path.join(path.dirname(sourceFilePath), dependencyFilePath);
+    }
+}
+/**
+ * Constructs a system-wide unique identifier for a contract.
+ * @param directoryNamespace Namespace of the source file's root contract directory.
+ * @param sourceFilePath Path to a source file, relative to contractBaseDir.
+ * @return sourceFileId A system-wide unique identifier for contract.
+ */
+export function constructContractId(directoryNamespace: string, sourceFilePath: string): string {
+    const namespacePrefix = !_.isEmpty(directoryNamespace) ? `${directoryNamespace}:` : '';
+    const sourceFileName = path.basename(sourceFilePath, constants.SOLIDITY_FILE_EXTENSION);
+    const contractId = `${namespacePrefix}${sourceFileName}`;
+    return contractId;
+}
+/**
  * Gets contract data on network or returns if an artifact does not exist.
  * @param artifactsDir Path to the artifacts directory.
  * @param fileName Name of contract file.
@@ -82,9 +123,10 @@ export function getNormalizedErrMsg(errMsg: string): string {
 /**
  * Parses the contract source code and extracts the dendencies
  * @param  source Contract source code
+ * @param sourceFilePath File path of the source code.
  * @return List of dependendencies
  */
-export function parseDependencies(source: string): string[] {
+export function parseDependencies(source: string, sourceFileId: string): string[] {
     // TODO: Use a proper parser
     const IMPORT_REGEX = /(import\s)/;
     const DEPENDENCY_PATH_REGEX = /"([^"]+)"/; // Source: https://github.com/BlockChainCompany/soljitsu/blob/master/lib/shared.js
@@ -95,8 +137,8 @@ export function parseDependencies(source: string): string[] {
             const dependencyMatch = line.match(DEPENDENCY_PATH_REGEX);
             if (!_.isNull(dependencyMatch)) {
                 const dependencyPath = dependencyMatch[1];
-                const basenName = path.basename(dependencyPath);
-                dependencies.push(basenName);
+                const dependencyId = constructDependencyFileId(dependencyPath, sourceFileId);
+                dependencies.push(dependencyId);
             }
         }
     });
@@ -107,14 +149,19 @@ export function parseDependencies(source: string): string[] {
  * Callback to resolve dependencies with `solc.compile`.
  * Throws error if contractSources not yet initialized.
  * @param  contractSources Source codes of contracts.
- * @param  importPath Path to an imported dependency.
+ * @param  sourceFileId ID of the source file.
+ * @param  importPath Path of dependency source file.
  * @return Import contents object containing source code of dependency.
  */
-export function findImportIfExist(contractSources: ContractSources, importPath: string): solc.ImportContents {
-    const fileName = path.basename(importPath);
-    const source = contractSources[fileName];
+export function findImportIfExist(
+    contractSources: ContractSources,
+    sourceFileId: string,
+    importPath: string,
+): solc.ImportContents {
+    const dependencyFileId = constructDependencyFileId(importPath, sourceFileId);
+    const source = contractSources[dependencyFileId];
     if (_.isUndefined(source)) {
-        throw new Error(`Contract source not found for ${fileName}`);
+        throw new Error(`Contract source not found for ${dependencyFileId}`);
     }
     const importContents: solc.ImportContents = {
         contents: source,
diff --git a/packages/deployer/src/utils/contract.ts b/packages/deployer/src/utils/contract.ts
index 9b7baac11..e8dd5218a 100644
--- a/packages/deployer/src/utils/contract.ts
+++ b/packages/deployer/src/utils/contract.ts
@@ -1,11 +1,9 @@
 import { schemas, SchemaValidator } from '@0xproject/json-schemas';
-import { ContractAbi, EventAbi, FunctionAbi, MethodAbi, TxData } from '@0xproject/types';
+import { AbiType, ContractAbi, EventAbi, FunctionAbi, MethodAbi, TxData } from '@0xproject/types';
 import { promisify } from '@0xproject/utils';
 import * as _ from 'lodash';
 import * as Web3 from 'web3';
 
-import { AbiType } from './types';
-
 export class Contract implements Web3.ContractInstance {
     public address: string;
     public abi: ContractAbi;
diff --git a/packages/deployer/src/utils/encoder.ts b/packages/deployer/src/utils/encoder.ts
index 4f62662e1..806efbbca 100644
--- a/packages/deployer/src/utils/encoder.ts
+++ b/packages/deployer/src/utils/encoder.ts
@@ -1,9 +1,7 @@
-import { AbiDefinition, ContractAbi, DataItem } from '@0xproject/types';
+import { AbiDefinition, AbiType, ContractAbi, DataItem } from '@0xproject/types';
 import * as _ from 'lodash';
 import * as web3Abi from 'web3-eth-abi';
 
-import { AbiType } from './types';
-
 export const encoder = {
     encodeConstructorArgsFromAbi(args: any[], abi: ContractAbi): string {
         const constructorTypes: string[] = [];
diff --git a/packages/deployer/src/utils/types.ts b/packages/deployer/src/utils/types.ts
index 7d131f5ce..08cab37b2 100644
--- a/packages/deployer/src/utils/types.ts
+++ b/packages/deployer/src/utils/types.ts
@@ -18,6 +18,11 @@ export interface ContractNetworks {
     [key: number]: ContractNetworkData;
 }
 
+export interface ContractDirectory {
+    path: string;
+    namespace: string;
+}
+
 export interface ContractNetworkData {
     solc_version: string;
     optimizer_enabled: boolean;
@@ -40,7 +45,7 @@ export interface SolcErrors {
 
 export interface CliOptions extends yargs.Arguments {
     artifactsDir: string;
-    contractsDir: string;
+    contractDirs: string;
     jsonrpcUrl: string;
     networkId: number;
     shouldOptimize: boolean;
@@ -51,7 +56,7 @@ export interface CliOptions extends yargs.Arguments {
 }
 
 export interface CompilerOptions {
-    contractsDir: string;
+    contractDirs: Set<ContractDirectory>;
     networkId: number;
     optimizerEnabled: boolean;
     artifactsDir: string;
@@ -78,7 +83,11 @@ export interface ContractSources {
     [key: string]: string;
 }
 
-export interface ContractSourceData {
+export interface ContractIds {
+    [key: string]: string;
+}
+
+export interface ContractSourceDataByFileId {
     [key: string]: ContractSpecificSourceData;
 }
 
@@ -98,4 +107,8 @@ export interface Token {
     swarmHash: string;
 }
 
+export interface FunctionNameToSeenCount {
+    [key: string]: number;
+}
+
 export type DoneCallback = (err?: Error) => void;
diff --git a/packages/deployer/test/compiler_test.ts b/packages/deployer/test/compiler_test.ts
index b03ae7935..817a3b3f9 100644
--- a/packages/deployer/test/compiler_test.ts
+++ b/packages/deployer/test/compiler_test.ts
@@ -3,7 +3,13 @@ import 'mocha';
 
 import { Compiler } from '../src/compiler';
 import { fsWrapper } from '../src/utils/fs_wrapper';
-import { CompilerOptions, ContractArtifact, ContractNetworkData, DoneCallback } from '../src/utils/types';
+import {
+    CompilerOptions,
+    ContractArtifact,
+    ContractDirectory,
+    ContractNetworkData,
+    DoneCallback,
+} from '../src/utils/types';
 
 import { exchange_binary } from './fixtures/exchange_bin';
 import { constants } from './util/constants';
@@ -13,11 +19,15 @@ const expect = chai.expect;
 describe('#Compiler', function() {
     this.timeout(constants.timeoutMs);
     const artifactsDir = `${__dirname}/fixtures/artifacts`;
-    const contractsDir = `${__dirname}/fixtures/contracts`;
+    const mainContractDir: ContractDirectory = { path: `${__dirname}/fixtures/contracts/main`, namespace: 'main' };
+    const baseContractDir: ContractDirectory = { path: `${__dirname}/fixtures/contracts/base`, namespace: 'base' };
+    const contractDirs: Set<ContractDirectory> = new Set();
+    contractDirs.add(mainContractDir);
+    contractDirs.add(baseContractDir);
     const exchangeArtifactPath = `${artifactsDir}/Exchange.json`;
     const compilerOpts: CompilerOptions = {
         artifactsDir,
-        contractsDir,
+        contractDirs,
         networkId: constants.networkId,
         optimizerEnabled: constants.optimizerEnabled,
         specifiedContracts: new Set(constants.specifiedContracts),
diff --git a/packages/deployer/test/compiler_utils_test.ts b/packages/deployer/test/compiler_utils_test.ts
index 246304858..5377d3308 100644
--- a/packages/deployer/test/compiler_utils_test.ts
+++ b/packages/deployer/test/compiler_utils_test.ts
@@ -47,28 +47,34 @@ describe('Compiler utils', () => {
     });
     describe('#parseDependencies', () => {
         it('correctly parses Exchange dependencies', async () => {
-            const exchangeSource = await fsWrapper.readFileAsync(`${__dirname}/fixtures/contracts/Exchange.sol`, {
+            const exchangeSource = await fsWrapper.readFileAsync(`${__dirname}/fixtures/contracts/main/Exchange.sol`, {
                 encoding: 'utf8',
             });
-            expect(parseDependencies(exchangeSource)).to.be.deep.equal([
-                'TokenTransferProxy.sol',
-                'Token.sol',
-                'SafeMath.sol',
+            const sourceFileId = '/main/Exchange.sol';
+            expect(parseDependencies(exchangeSource, sourceFileId)).to.be.deep.equal([
+                '/main/TokenTransferProxy.sol',
+                '/base/Token.sol',
+                '/base/SafeMath.sol',
             ]);
         });
         it('correctly parses TokenTransferProxy dependencies', async () => {
             const exchangeSource = await fsWrapper.readFileAsync(
-                `${__dirname}/fixtures/contracts/TokenTransferProxy.sol`,
+                `${__dirname}/fixtures/contracts/main/TokenTransferProxy.sol`,
                 {
                     encoding: 'utf8',
                 },
             );
-            expect(parseDependencies(exchangeSource)).to.be.deep.equal(['Token.sol', 'Ownable.sol']);
+            const sourceFileId = '/main/TokenTransferProxy.sol';
+            expect(parseDependencies(exchangeSource, sourceFileId)).to.be.deep.equal([
+                '/base/Token.sol',
+                '/base/Ownable.sol',
+            ]);
         });
         // TODO: For now that doesn't work. This will work after we switch to a grammar-based parser
         it.skip('correctly parses commented out dependencies', async () => {
             const contractWithCommentedOutDependencies = `// import "./TokenTransferProxy.sol";`;
-            expect(parseDependencies(contractWithCommentedOutDependencies)).to.be.deep.equal([]);
+            const sourceFileId = '/main/TokenTransferProxy.sol';
+            expect(parseDependencies(contractWithCommentedOutDependencies, sourceFileId)).to.be.deep.equal([]);
         });
     });
 });
diff --git a/packages/deployer/test/deployer_test.ts b/packages/deployer/test/deployer_test.ts
index 9c34d74aa..050cf7d02 100644
--- a/packages/deployer/test/deployer_test.ts
+++ b/packages/deployer/test/deployer_test.ts
@@ -4,7 +4,13 @@ import 'mocha';
 import { Compiler } from '../src/compiler';
 import { Deployer } from '../src/deployer';
 import { fsWrapper } from '../src/utils/fs_wrapper';
-import { CompilerOptions, ContractArtifact, ContractNetworkData, DoneCallback } from '../src/utils/types';
+import {
+    CompilerOptions,
+    ContractArtifact,
+    ContractDirectory,
+    ContractNetworkData,
+    DoneCallback,
+} from '../src/utils/types';
 
 import { constructor_args, exchange_binary } from './fixtures/exchange_bin';
 import { constants } from './util/constants';
@@ -13,11 +19,15 @@ const expect = chai.expect;
 
 describe('#Deployer', () => {
     const artifactsDir = `${__dirname}/fixtures/artifacts`;
-    const contractsDir = `${__dirname}/fixtures/contracts`;
     const exchangeArtifactPath = `${artifactsDir}/Exchange.json`;
+    const mainContractDir: ContractDirectory = { path: `${__dirname}/fixtures/contracts/main`, namespace: '' };
+    const baseContractDir: ContractDirectory = { path: `${__dirname}/fixtures/contracts/base`, namespace: 'base' };
+    const contractDirs: Set<ContractDirectory> = new Set();
+    contractDirs.add(mainContractDir);
+    contractDirs.add(baseContractDir);
     const compilerOpts: CompilerOptions = {
         artifactsDir,
-        contractsDir,
+        contractDirs,
         networkId: constants.networkId,
         optimizerEnabled: constants.optimizerEnabled,
         specifiedContracts: new Set(constants.specifiedContracts),
diff --git a/packages/deployer/test/fixtures/contracts/Exchange.sol b/packages/deployer/test/fixtures/contracts/main/Exchange.sol
index 1b6819700..ea9ca3afa 100644
--- a/packages/deployer/test/fixtures/contracts/Exchange.sol
+++ b/packages/deployer/test/fixtures/contracts/main/Exchange.sol
@@ -1,6 +1,6 @@
 /*
 
-  Copyright 2017 ZeroEx Intl.
+  Copyright 2018 ZeroEx Intl.
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
@@ -19,8 +19,8 @@
 pragma solidity 0.4.14;
 
 import "./TokenTransferProxy.sol";
-import "./base/Token.sol";
-import "./base/SafeMath.sol";
+import "/base/Token.sol";
+import "/base/SafeMath.sol";
 
 /// @title Exchange - Facilitates exchange of ERC20 tokens.
 /// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>
diff --git a/packages/deployer/test/fixtures/contracts/TokenTransferProxy.sol b/packages/deployer/test/fixtures/contracts/main/TokenTransferProxy.sol
index 90c8e7d66..99d16cb57 100644
--- a/packages/deployer/test/fixtures/contracts/TokenTransferProxy.sol
+++ b/packages/deployer/test/fixtures/contracts/main/TokenTransferProxy.sol
@@ -1,6 +1,6 @@
 /*
 
-  Copyright 2017 ZeroEx Intl.
+  Copyright 2018 ZeroEx Intl.
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
@@ -18,8 +18,8 @@
 
 pragma solidity 0.4.14;
 
-import "./base/Token.sol";
-import "./base/Ownable.sol";
+import "/base/Token.sol";
+import "/base/Ownable.sol";
 
 /// @title TokenTransferProxy - Transfers tokens on behalf of contracts that have been approved via decentralized governance.
 /// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>
diff --git a/packages/metacoin/artifacts/Metacoin.json b/packages/metacoin/artifacts/Metacoin.json
index 46c3ee71c..69ec22cac 100644
--- a/packages/metacoin/artifacts/Metacoin.json
+++ b/packages/metacoin/artifacts/Metacoin.json
@@ -3,11 +3,50 @@
     "networks": {
         "50": {
             "solc_version": "0.4.21",
-            "keccak256": "0x2c3aa2e9dbef58abf57cecc148464d0852a83d7f30bbd2066f2a13b8bd3b1dd0",
-            "source_tree_hash": "0x2c3aa2e9dbef58abf57cecc148464d0852a83d7f30bbd2066f2a13b8bd3b1dd0",
+            "keccak256": "0x85fb29ea6c21adcf07f754b2ad06482dd6fcd62d31935e36041b4d064c6a038e",
+            "source_tree_hash": "0x85fb29ea6c21adcf07f754b2ad06482dd6fcd62d31935e36041b4d064c6a038e",
             "optimizer_enabled": false,
             "abi": [
                 {
+                    "constant": false,
+                    "inputs": [
+                        {
+                            "components": [
+                                {
+                                    "components": [
+                                        {
+                                            "name": "to",
+                                            "type": "address"
+                                        },
+                                        {
+                                            "name": "amount",
+                                            "type": "uint256"
+                                        }
+                                    ],
+                                    "name": "transferData",
+                                    "type": "tuple"
+                                },
+                                {
+                                    "name": "callback",
+                                    "type": "uint32"
+                                }
+                            ],
+                            "name": "nestedTransferData",
+                            "type": "tuple"
+                        }
+                    ],
+                    "name": "transfer",
+                    "outputs": [
+                        {
+                            "name": "",
+                            "type": "int256"
+                        }
+                    ],
+                    "payable": false,
+                    "stateMutability": "nonpayable",
+                    "type": "function"
+                },
+                {
                     "constant": true,
                     "inputs": [
                         {
@@ -56,6 +95,39 @@
                     "type": "function"
                 },
                 {
+                    "constant": false,
+                    "inputs": [
+                        {
+                            "components": [
+                                {
+                                    "name": "to",
+                                    "type": "address"
+                                },
+                                {
+                                    "name": "amount",
+                                    "type": "uint256"
+                                }
+                            ],
+                            "name": "transferData",
+                            "type": "tuple"
+                        },
+                        {
+                            "name": "callback",
+                            "type": "uint32"
+                        }
+                    ],
+                    "name": "transfer",
+                    "outputs": [
+                        {
+                            "name": "",
+                            "type": "int256"
+                        }
+                    ],
+                    "payable": false,
+                    "stateMutability": "nonpayable",
+                    "type": "function"
+                },
+                {
                     "inputs": [],
                     "payable": false,
                     "stateMutability": "nonpayable",
@@ -84,15 +156,14 @@
                     "type": "event"
                 }
             ],
-            "bytecode":
-                "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",
-            "runtime_bytecode":
-                "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",
-            "updated_at": 1522318279735,
-            "source_map": "60:662:0:-;;;290:72;;;;;;;;350:5;327:8;:20;336:10;327:20;;;;;;;;;;;;;;;:28;;;;60:662;;;;;;",
-            "source_map_runtime":
-                "60:662:0:-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;84:41;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;368:352;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;84:41;;;;;;;;;;;;;;;;;:::o;368:352::-;429:12;480;:19;;;457:8;:20;466:10;457:20;;;;;;;;;;;;;;;;:42;453:60;;;508:5;501:12;;;;453:60;547:12;:19;;;523:8;:20;532:10;523:20;;;;;;;;;;;;;;;;:43;;;;;;;;;;;605:12;:19;;;576:8;:25;585:12;:15;;;576:25;;;;;;;;;;;;;;;;:48;;;;;;;;;;;655:12;:15;;;634:58;;643:10;634:58;;;672:12;:19;;;634:58;;;;;;;;;;;;;;;709:4;702:11;;368:352;;;;:::o;5:118:-1:-;;72:46;110:6;97:20;72:46;;;63:55;;57:66;;;;;165:469;;282:4;270:9;265:3;261:19;257:30;254:2;;;300:1;297;290:12;254:2;318:20;333:4;318:20;;;309:29;;386:1;417:49;462:3;453:6;442:9;438:22;417:49;;;411:3;404:5;400:15;393:74;348:130;530:2;563:49;608:3;599:6;588:9;584:22;563:49;;;556:4;549:5;545:16;538:75;488:136;248:386;;;;;641:118;;708:46;746:6;733:20;708:46;;;699:55;;693:66;;;;;766:241;;870:2;858:9;849:7;845:23;841:32;838:2;;;886:1;883;876:12;838:2;921:1;938:53;983:7;974:6;963:9;959:22;938:53;;;928:63;;900:97;832:175;;;;;1014:297;;1146:2;1134:9;1125:7;1121:23;1117:32;1114:2;;;1162:1;1159;1152:12;1114:2;1197:1;1214:81;1287:7;1278:6;1267:9;1263:22;1214:81;;;1204:91;;1176:125;1108:203;;;;;1318:101;1385:28;1407:5;1385:28;;;1380:3;1373:41;1367:52;;;1426:110;1499:31;1524:5;1499:31;;;1494:3;1487:44;1481:55;;;1543:181;;1645:2;1634:9;1630:18;1622:26;;1659:55;1711:1;1700:9;1696:17;1687:6;1659:55;;;1616:108;;;;;1731:193;;1839:2;1828:9;1824:18;1816:26;;1853:61;1911:1;1900:9;1896:17;1887:6;1853:61;;;1810:114;;;;;1931:256;;1993:2;1987:9;1977:19;;2031:4;2023:6;2019:17;2130:6;2118:10;2115:22;2094:18;2082:10;2079:34;2076:62;2073:2;;;2151:1;2148;2141:12;2073:2;2171:10;2167:2;2160:22;1971:216;;;;;2194:92;;2274:5;2267:13;2260:21;2249:32;;2243:43;;;;2293:79;;2362:5;2351:16;;2345:27;;;;2379:128;;2459:42;2452:5;2448:54;2437:65;;2431:76;;;;2514:79;;2583:5;2572:16;;2566:27;;;",
-            "sources": ["Metacoin.sol"]
+            "bytecode": "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",
+            "runtime_bytecode": "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",
+            "updated_at": 1522966321930,
+            "source_map": "60:1093:0:-;;;389:72;;;;;;;;449:5;426:8;:20;435:10;426:20;;;;;;;;;;;;;;;:28;;;;60:1093;;;;;;",
+            "source_map_runtime": "60:1093:0:-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;978:172;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;84:41;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;467:352;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;825:147;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;978:172;1051:3;1073:70;1082:18;:31;;;1115:18;:27;;;1073:8;:70::i;:::-;1066:77;;978:172;;;:::o;84:41::-;;;;;;;;;;;;;;;;;:::o;467:352::-;528:12;579;:19;;;556:8;:20;565:10;556:20;;;;;;;;;;;;;;;;:42;552:60;;;607:5;600:12;;;;552:60;646:12;:19;;;622:8;:20;631:10;622:20;;;;;;;;;;;;;;;;:43;;;;;;;;;;;704:12;:19;;;675:8;:25;684:12;:15;;;675:25;;;;;;;;;;;;;;;;:48;;;;;;;;;;;754:12;:15;;;733:58;;742:10;733:58;;;771:12;:19;;;733:58;;;;;;;;;;;;;;;808:4;801:11;;467:352;;;;:::o;825:147::-;903:3;918:22;927:12;918:8;:22::i;:::-;;957:8;950:15;;;;825:147;;;;:::o;5:118:-1:-;;72:46;110:6;97:20;72:46;;;63:55;;57:66;;;;;171:510;;294:4;282:9;277:3;273:19;269:30;266:2;;;312:1;309;302:12;266:2;330:20;345:4;330:20;;;321:29;;408:1;439:73;508:3;499:6;488:9;484:22;439:73;;;433:3;426:5;422:15;415:98;360:164;578:2;611:48;655:3;646:6;635:9;631:22;611:48;;;604:4;597:5;593:16;586:74;534:137;260:421;;;;;723:465;;836:4;824:9;819:3;815:19;811:30;808:2;;;854:1;851;844:12;808:2;872:20;887:4;872:20;;;863:29;;940:1;971:49;1016:3;1007:6;996:9;992:22;971:49;;;965:3;958:5;954:15;947:74;902:130;1084:2;1117:49;1162:3;1153:6;1142:9;1138:22;1117:49;;;1110:4;1103:5;1099:16;1092:75;1042:136;802:386;;;;;1230:469;;1347:4;1335:9;1330:3;1326:19;1322:30;1319:2;;;1365:1;1362;1355:12;1319:2;1383:20;1398:4;1383:20;;;1374:29;;1451:1;1482:49;1527:3;1518:6;1507:9;1503:22;1482:49;;;1476:3;1469:5;1465:15;1458:74;1413:130;1595:2;1628:49;1673:3;1664:6;1653:9;1649:22;1628:49;;;1621:4;1614:5;1610:16;1603:75;1553:136;1313:386;;;;;1706:118;;1773:46;1811:6;1798:20;1773:46;;;1764:55;;1758:66;;;;;1831:116;;1897:45;1934:6;1921:20;1897:45;;;1888:54;;1882:65;;;;;1954:241;;2058:2;2046:9;2037:7;2033:23;2029:32;2026:2;;;2074:1;2071;2064:12;2026:2;2109:1;2126:53;2171:7;2162:6;2151:9;2147:22;2126:53;;;2116:63;;2088:97;2020:175;;;;;2202:309;;2340:2;2328:9;2319:7;2315:23;2311:32;2308:2;;;2356:1;2353;2346:12;2308:2;2391:1;2408:87;2487:7;2478:6;2467:9;2463:22;2408:87;;;2398:97;;2370:131;2302:209;;;;;2518:297;;2650:2;2638:9;2629:7;2625:23;2621:32;2618:2;;;2666:1;2663;2656:12;2618:2;2701:1;2718:81;2791:7;2782:6;2771:9;2767:22;2718:81;;;2708:91;;2680:125;2612:203;;;;;2822:420;;;2970:2;2958:9;2949:7;2945:23;2941:32;2938:2;;;2986:1;2983;2976:12;2938:2;3021:1;3038:81;3111:7;3102:6;3091:9;3087:22;3038:81;;;3028:91;;3000:125;3156:2;3174:52;3218:7;3209:6;3198:9;3194:22;3174:52;;;3164:62;;3135:97;2932:310;;;;;;3249:101;3316:28;3338:5;3316:28;;;3311:3;3304:41;3298:52;;;3357:107;3428:30;3452:5;3428:30;;;3423:3;3416:43;3410:54;;;3471:110;3544:31;3569:5;3544:31;;;3539:3;3532:44;3526:55;;;3588:181;;3690:2;3679:9;3675:18;3667:26;;3704:55;3756:1;3745:9;3741:17;3732:6;3704:55;;;3661:108;;;;;3776:189;;3882:2;3871:9;3867:18;3859:26;;3896:59;3952:1;3941:9;3937:17;3928:6;3896:59;;;3853:112;;;;;3972:193;;4080:2;4069:9;4065:18;4057:26;;4094:61;4152:1;4141:9;4137:17;4128:6;4094:61;;;4051:114;;;;;4172:256;;4234:2;4228:9;4218:19;;4272:4;4264:6;4260:17;4371:6;4359:10;4356:22;4335:18;4323:10;4320:34;4317:62;4314:2;;;4392:1;4389;4382:12;4314:2;4412:10;4408:2;4401:22;4212:216;;;;;4435:92;;4515:5;4508:13;4501:21;4490:32;;4484:43;;;;4534:78;;4602:5;4591:16;;4585:27;;;;4619:79;;4688:5;4677:16;;4671:27;;;;4705:128;;4785:42;4778:5;4774:54;4763:65;;4757:76;;;;4840:79;;4909:5;4898:16;;4892:27;;;;4926:95;;5005:10;4998:5;4994:22;4983:33;;4977:44;;;",
+            "sources": [
+                "/Metacoin.sol"
+            ]
         }
     }
-}
+}
\ No newline at end of file
diff --git a/packages/metacoin/contracts/Metacoin.sol b/packages/metacoin/contracts/Metacoin.sol
index 6b6814b21..ac212b32e 100644
--- a/packages/metacoin/contracts/Metacoin.sol
+++ b/packages/metacoin/contracts/Metacoin.sol
@@ -11,6 +11,11 @@ contract Metacoin {
         uint256 amount;
     }
 
+    struct NestedTransferData {
+        TransferData transferData;
+        uint32 callback;
+    }
+
     function Metacoin() public {
         balances[msg.sender] = 10000;
     }
@@ -22,4 +27,14 @@ contract Metacoin {
         Transfer(msg.sender, transferData.to, transferData.amount);
         return true;
     }
+
+    function transfer(TransferData transferData, uint32 callback) public returns (int) {
+        transfer(transferData);
+        return callback;
+    }
+
+    function transfer(NestedTransferData nestedTransferData) public returns (int) {
+        return transfer(nestedTransferData.transferData, nestedTransferData.callback);
+    }
+
 }
diff --git a/packages/metacoin/package.json b/packages/metacoin/package.json
index 1177513a7..867f23192 100644
--- a/packages/metacoin/package.json
+++ b/packages/metacoin/package.json
@@ -18,7 +18,7 @@
         "coverage:report:html": "istanbul report html && open coverage/index.html",
         "coverage:report:lcov": "istanbul report lcov",
         "test:circleci": "yarn test:coverage",
-        "compile": "node ../deployer/lib/src/cli.js compile --contracts Metacoin --contracts-dir contracts --artifacts-dir artifacts"
+        "compile": "node ../deployer/lib/src/cli.js compile --contracts Metacoin --contract-dirs contracts --artifacts-dir artifacts"
     },
     "author": "",
     "license": "Apache-2.0",
diff --git a/packages/metacoin/test/metacoin_test.ts b/packages/metacoin/test/metacoin_test.ts
index 73537d342..4a2307444 100644
--- a/packages/metacoin/test/metacoin_test.ts
+++ b/packages/metacoin/test/metacoin_test.ts
@@ -36,12 +36,12 @@ describe('Metacoin', () => {
         });
     });
     describe('#transfer', () => {
-        it(`should successfully transfer tokens`, async () => {
+        it(`should successfully transfer tokens (via transfer_1)`, async () => {
             const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
             const amount = INITIAL_BALANCE.div(2);
             const oldBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
             expect(oldBalance).to.be.bignumber.equal(0);
-            const txHash = await metacoin.transfer.sendTransactionAsync(
+            const txHash = await metacoin.transfer_1.sendTransactionAsync(
                 {
                     to: ZERO_ADDRESS,
                     amount,
@@ -58,5 +58,57 @@ describe('Metacoin', () => {
             const newBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
             expect(newBalance).to.be.bignumber.equal(amount);
         });
+
+        it(`should successfully transfer tokens (via transfer_2)`, async () => {
+            const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
+            const amount = INITIAL_BALANCE.div(2);
+            const oldBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
+            expect(oldBalance).to.be.bignumber.equal(0);
+            const callback = 59;
+            const txHash = await metacoin.transfer_2.sendTransactionAsync(
+                {
+                    to: ZERO_ADDRESS,
+                    amount,
+                },
+                callback,
+                { from: devConstants.TESTRPC_FIRST_ADDRESS },
+            );
+            const txReceipt = await web3Wrapper.awaitTransactionMinedAsync(txHash);
+            const transferLogs = txReceipt.logs[0] as LogWithDecodedArgs<TransferContractEventArgs>;
+            expect(transferLogs.args).to.be.deep.equal({
+                _to: ZERO_ADDRESS,
+                _from: devConstants.TESTRPC_FIRST_ADDRESS,
+                _value: amount,
+            });
+            const newBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
+            expect(newBalance).to.be.bignumber.equal(amount);
+        });
+
+        it(`should successfully transfer tokens (via transfer_3)`, async () => {
+            const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
+            const amount = INITIAL_BALANCE.div(2);
+            const oldBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
+            expect(oldBalance).to.be.bignumber.equal(0);
+            const callback = 59;
+            const txHash = await metacoin.transfer_3.sendTransactionAsync(
+                {
+                    transferData: {
+                        to: ZERO_ADDRESS,
+                        amount,
+                    },
+                    callback,
+                },
+                { from: devConstants.TESTRPC_FIRST_ADDRESS },
+            );
+            const txReceipt = await web3Wrapper.awaitTransactionMinedAsync(txHash);
+            const transferLogs = txReceipt.logs[0] as LogWithDecodedArgs<TransferContractEventArgs>;
+            expect(transferLogs.args).to.be.deep.equal({
+                _to: ZERO_ADDRESS,
+                _from: devConstants.TESTRPC_FIRST_ADDRESS,
+                _value: amount,
+            });
+            const newBalance = await metacoin.balances.callAsync(ZERO_ADDRESS);
+            expect(newBalance).to.be.bignumber.equal(amount);
+        });
     });
 });
diff --git a/packages/utils/src/abi_utils.ts b/packages/utils/src/abi_utils.ts
new file mode 100644
index 000000000..843b8589b
--- /dev/null
+++ b/packages/utils/src/abi_utils.ts
@@ -0,0 +1,74 @@
+import { AbiDefinition, AbiType, ConstructorAbi, ContractAbi, DataItem, MethodAbi } from '@0xproject/types';
+import * as _ from 'lodash';
+
+export const abiUtils = {
+    parseFunctionParam(param: DataItem): string {
+        if (param.type === 'tuple') {
+            // Parse out tuple types into {type_1, type_2, ..., type_N}
+            const tupleComponents = param.components;
+            const paramString = _.map(tupleComponents, component => this.parseFunctionParam(component));
+            const tupleParamString = `{${paramString}}`;
+            return tupleParamString;
+        }
+        return param.type;
+    },
+    getFunctionSignature(abi: MethodAbi): string {
+        const functionName = abi.name;
+        const parameterTypeList = abi.inputs.map((param: DataItem) => this.parseFunctionParam(param));
+        const functionSignature = `${functionName}(${parameterTypeList})`;
+        return functionSignature;
+    },
+    renameOverloadedMethods(inputContractAbi: ContractAbi): ContractAbi {
+        const contractAbi = _.cloneDeep(inputContractAbi);
+        const methodAbis = contractAbi.filter((abi: AbiDefinition) => abi.type === AbiType.Function) as MethodAbi[];
+        const methodAbisByOriginalIndex = _.transform(
+            methodAbis,
+            (result: Array<{ index: number; methodAbi: MethodAbi }>, methodAbi, i: number) => {
+                result.push({ index: i, methodAbi });
+            },
+            [],
+        );
+        // Sort method Abis into alphabetical order, by function signature
+        const methodAbisByOriginalIndexOrdered = _.sortBy(methodAbisByOriginalIndex, [
+            (entry: { index: number; methodAbi: MethodAbi }) => {
+                const functionSignature = this.getFunctionSignature(entry.methodAbi);
+                return functionSignature;
+            },
+        ]);
+        // Group method Abis by name (overloaded methods will be grouped together, in alphabetical order)
+        const methodAbisByName = _.transform(
+            methodAbisByOriginalIndexOrdered,
+            (result: { [key: string]: Array<{ index: number; methodAbi: MethodAbi }> }, entry) => {
+                (result[entry.methodAbi.name] || (result[entry.methodAbi.name] = [])).push(entry);
+            },
+            {},
+        );
+        // Rename overloaded methods to overloadedMethoName_1, overloadedMethoName_2, ...
+        const methodAbisRenamed = _.transform(
+            methodAbisByName,
+            (result: MethodAbi[], methodAbisWithSameName: Array<{ index: number; methodAbi: MethodAbi }>) => {
+                _.forEach(methodAbisWithSameName, (entry, i: number) => {
+                    if (methodAbisWithSameName.length > 1) {
+                        const overloadedMethodId = i + 1;
+                        const sanitizedMethodName = `${entry.methodAbi.name}_${overloadedMethodId}`;
+                        const indexOfExistingAbiWithSanitizedMethodNameIfExists = _.findIndex(
+                            methodAbis,
+                            methodAbi => methodAbi.name === sanitizedMethodName,
+                        );
+                        if (indexOfExistingAbiWithSanitizedMethodNameIfExists >= 0) {
+                            const methodName = entry.methodAbi.name;
+                            throw new Error(
+                                `Failed to rename overloaded method '${methodName}' to '${sanitizedMethodName}'. A method with this name already exists.`,
+                            );
+                        }
+                        entry.methodAbi.name = sanitizedMethodName;
+                    }
+                    // Add method to list of ABIs in its original position
+                    result.splice(entry.index, 0, entry.methodAbi);
+                });
+            },
+            [...Array(methodAbis.length)],
+        );
+        return contractAbi;
+    },
+};
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index debcce746..0da4b265d 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -5,3 +5,4 @@ export { intervalUtils } from './interval_utils';
 export { BigNumber } from './configured_bignumber';
 export { AbiDecoder } from './abi_decoder';
 export { logUtils } from './log_utils';
+export { abiUtils } from './abi_utils';
diff --git a/yarn.lock b/yarn.lock
index 84decde70..d0760cd78 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6,6 +6,41 @@
   version "0.3.9"
   resolved "https://registry.yarnpkg.com/8fold-marked/-/8fold-marked-0.3.9.tgz#bb89c645612f8ccfaffac1ca6e3c11f168c9cf59"
 
+"@0xproject/dev-utils@^0.2.1":
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/@0xproject/dev-utils/-/dev-utils-0.2.1.tgz#a54465376fd7c8cf58781b02b1790d74fb51e91b"
+  dependencies:
+    "@0xproject/subproviders" "^0.7.0"
+    "@0xproject/types" "^0.3.1"
+    "@0xproject/utils" "^0.4.1"
+    ethereumjs-util "^5.1.2"
+    lodash "^4.17.4"
+    request-promise-native "^1.0.5"
+    web3 "^0.20.0"
+    web3-provider-engine "^13.0.1"
+
+"@0xproject/subproviders@^0.7.0":
+  version "0.7.0"
+  resolved "https://registry.yarnpkg.com/@0xproject/subproviders/-/subproviders-0.7.0.tgz#ce3379a85649773e5c08f5fc3239e8ed07f13361"
+  dependencies:
+    "@0xproject/assert" "^0.2.0"
+    "@0xproject/types" "^0.3.1"
+    "@0xproject/utils" "^0.4.1"
+    "@ledgerhq/hw-app-eth" "^4.3.0"
+    "@ledgerhq/hw-transport-u2f" "^4.3.0"
+    bn.js "^4.11.8"
+    es6-promisify "^5.0.0"
+    ethereumjs-tx "^1.3.3"
+    ethereumjs-util "^5.1.1"
+    hdkey "^0.7.1"
+    lodash "^4.17.4"
+    semaphore-async-await "^1.5.1"
+    web3 "^0.20.0"
+    web3-provider-engine "^13.0.1"
+    web3-typescript-typings "^0.10.0"
+  optionalDependencies:
+    "@ledgerhq/hw-transport-node-hid" "^4.3.0"
+
 "@0xproject/tslint-config@0.4.13":
   version "0.4.13"
   resolved "https://registry.yarnpkg.com/@0xproject/tslint-config/-/tslint-config-0.4.13.tgz#98c71c5ae5e80315a23eda0134cc9f6f4438cac2"
@@ -15,6 +50,40 @@
     tslint-eslint-rules "^4.1.1"
     tslint-react "^3.2.0"
 
+"@0xproject/types@^0.3.1":
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/@0xproject/types/-/types-0.3.1.tgz#9a75be6d3a2d41b7ecbd9105c3fdc09f3e3ec297"
+  dependencies:
+    bignumber.js "~4.1.0"
+    web3 "^0.20.0"
+    web3-typescript-typings "^0.10.0"
+
+"@0xproject/types@^0.4.2":
+  version "0.4.2"
+  resolved "https://registry.yarnpkg.com/@0xproject/types/-/types-0.4.2.tgz#83d6ebef60f41e6209acb2656b1d68ff79367ca5"
+  dependencies:
+    bignumber.js "~4.1.0"
+
+"@0xproject/typescript-typings@^0.0.2":
+  version "0.0.2"
+  resolved "https://registry.yarnpkg.com/@0xproject/typescript-typings/-/typescript-typings-0.0.2.tgz#b549ea3c81ce2d81b99f05583bdf7c411a3ca90c"
+  dependencies:
+    "@0xproject/types" "^0.4.2"
+    bignumber.js "~4.1.0"
+
+"@0xproject/utils@^0.4.1":
+  version "0.4.4"
+  resolved "https://registry.yarnpkg.com/@0xproject/utils/-/utils-0.4.4.tgz#bce4f7a5a46570a69911f4a4ade5d49016330087"
+  dependencies:
+    "@0xproject/types" "^0.4.2"
+    "@0xproject/typescript-typings" "^0.0.2"
+    "@types/node" "^8.0.53"
+    bignumber.js "~4.1.0"
+    ethers-contracts "^2.2.1"
+    js-sha3 "^0.7.0"
+    lodash "^4.17.4"
+    web3 "^0.20.0"
+
 "@ledgerhq/hw-app-eth@^4.3.0":
   version "4.7.3"
   resolved "https://registry.yarnpkg.com/@ledgerhq/hw-app-eth/-/hw-app-eth-4.7.3.tgz#d352e19658ae296532e522c53c8ec2a1a77b64e5"
@@ -285,7 +354,13 @@
   dependencies:
     redux "*"
 
-"@types/request@2.47.0":
+"@types/request-promise-native@^1.0.2":
+  version "1.0.14"
+  resolved "https://registry.yarnpkg.com/@types/request-promise-native/-/request-promise-native-1.0.14.tgz#20f2ba136e6f29c2ea745c60767738d434793d31"
+  dependencies:
+    "@types/request" "*"
+
+"@types/request@*", "@types/request@2.47.0":
   version "2.47.0"
   resolved "https://registry.yarnpkg.com/@types/request/-/request-2.47.0.tgz#76a666cee4cb85dcffea6cd4645227926d9e114e"
   dependencies:
@@ -3562,7 +3637,7 @@ ethereumjs-util@^4.0.1, ethereumjs-util@^4.3.0, ethereumjs-util@^4.4.0:
     rlp "^2.0.0"
     secp256k1 "^3.0.1"
 
-ethereumjs-util@^5.0.0, ethereumjs-util@^5.0.1, ethereumjs-util@^5.1.1, ethereumjs-util@^5.1.3, ethereumjs-util@^5.1.5:
+ethereumjs-util@^5.0.0, ethereumjs-util@^5.0.1, ethereumjs-util@^5.1.1, ethereumjs-util@^5.1.2, ethereumjs-util@^5.1.3, ethereumjs-util@^5.1.5:
   version "5.1.5"
   resolved "https://registry.yarnpkg.com/ethereumjs-util/-/ethereumjs-util-5.1.5.tgz#2f02575852627d45622426f25ee4a0b5f377f27a"
   dependencies:
@@ -8870,6 +8945,20 @@ request-ip@~1.2.3:
   version "1.2.3"
   resolved "https://registry.yarnpkg.com/request-ip/-/request-ip-1.2.3.tgz#66988f0e22406ec4af630d19b573fe4b447c3b49"
 
+request-promise-core@1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/request-promise-core/-/request-promise-core-1.1.1.tgz#3eee00b2c5aa83239cfb04c5700da36f81cd08b6"
+  dependencies:
+    lodash "^4.13.1"
+
+request-promise-native@^1.0.5:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/request-promise-native/-/request-promise-native-1.0.5.tgz#5281770f68e0c9719e5163fd3fab482215f4fda5"
+  dependencies:
+    request-promise-core "1.1.1"
+    stealthy-require "^1.1.0"
+    tough-cookie ">=2.3.3"
+
 request@2.81.0:
   version "2.81.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.81.0.tgz#c6928946a0e06c5f8d6f8a9333469ffda46298a0"
@@ -9751,6 +9840,10 @@ static-extend@^0.1.1:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/statuses/-/statuses-1.4.0.tgz#bb73d446da2796106efcc1b601a253d6c46bd087"
 
+stealthy-require@^1.1.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/stealthy-require/-/stealthy-require-1.1.1.tgz#35b09875b4ff49f26a777e509b3090a3226bf24b"
+
 stream-browserify@^2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/stream-browserify/-/stream-browserify-2.0.1.tgz#66266ee5f9bdb9940a4e4514cafb43bb71e5c9db"
@@ -10323,7 +10416,7 @@ touch@^3.1.0:
   dependencies:
     nopt "~1.0.10"
 
-tough-cookie@~2.3.0, tough-cookie@~2.3.3:
+tough-cookie@>=2.3.3, tough-cookie@~2.3.0, tough-cookie@~2.3.3:
   version "2.3.4"
   resolved "https://registry.yarnpkg.com/tough-cookie/-/tough-cookie-2.3.4.tgz#ec60cee38ac675063ffc97a5c18970578ee83655"
   dependencies:
@@ -11267,7 +11360,7 @@ web3-shh@1.0.0-beta.33:
     web3-core-subscriptions "1.0.0-beta.33"
     web3-net "1.0.0-beta.33"
 
-web3-typescript-typings@^0.10.2:
+web3-typescript-typings@^0.10.0, web3-typescript-typings@^0.10.2:
   version "0.10.2"
   resolved "https://registry.yarnpkg.com/web3-typescript-typings/-/web3-typescript-typings-0.10.2.tgz#a9903815d2a8a0dbd73fd5db374070de0bd30497"
   dependencies: