diff --git a/package.json b/package.json
index de5f2f2b9..d107254a7 100644
--- a/package.json
+++ b/package.json
@@ -9,9 +9,12 @@
     "auto-build": "node ./admin/cmds/reset-build.js && npm run build -- -w",
     "bootstrap": "node ./admin/cmds/reset-build.js && node ./admin/cmds/update-depgraph && lerna bootstrap --hoist",
     "build": "tsc --build ./tsconfig.project.json",
+    "build-cjs": "node ./admin/cmds/set-option cjs && npm run build",
+    "build-esm": "node ./admin/cmds/set-option esm && npm run build",
+    "build-all": "npm run build-esm && npm run build-cjs",
     "clean": "node ./admin/cmds/reset-build.js && tsc --build --clean ./tsconfig.project.json",
     "_dist_prepare": "npm run clean && npm run bootstrap && npm run build && node ./admin/cmds/update-exports.js",
-    "_dist_ethers": "rollup -c && rollup -c --configMinify && rollup -c --configModule && rollup -c --configModule --configMinify",
+    "_dist_ethers": "rollup -c && rollup -c --configMinify && rollup -c --configModule && rollup -c --configModule --configMinify && rollup -c rollup-wordlists.config.js",
     "_dist_tests": "rollup -c --configTest && rollup -c --configTest --configMinify && rollup -c --configTest --configModule && rollup -c --configTest --configModule --configMinify",
     "_test_prepare": "npm run _dist_prepare && npm run _dist_tests",
     "_test_node": "cd packages/tests && mocha --no-colors --reporter ./reporter ./lib/test-*.js",
@@ -25,6 +28,12 @@
     "old-test-aion-node": "cd packages/aion-tests && mocha --no-colors --reporter ../tests/tests/reporter ./tests/test-*.js",
     "update-versions": "npm run _dist_prepare && node ./admin/cmds/update-versions",
     "publish-all": "node ./admin/cmds/publish",
+    "_distMinLangAll": "node ./admin/cmds/set-option.js browser-lang-all && rollup -c --configMinify && rollup -c --configMinify --configModule && mv ./packages/ethers/dist/ethers.umd.min.js ./packages/ethers/dist/ethers-all.umd.min.js && mv ./packages/ethers/dist/ethers.esm.min.js ./packages/ethers/dist/ethers-all.esm.min.js",
+    "_distMinLangEn": "node ./admin/cmds/set-option.js browser-lang-en && rollup -c --configMinify && rollup -c --configMinify --configModule",
+    "_dist": "npm run build-all && npm run _distMinLangAll && npm run _distMinLangEn && rollup -c && rollup -c --configModule",
+    "_distTestBrowserEsm": "rollup -c rollup-tests.config.js --configModule",
+    "_distTestBrowserUmd": "rollup -c rollup-tests.config.js",
+    "_distTestBrowser": "npm run _distTestBrowserEsm && npm run _distTestBrowserUmd",
     "lock-versions": "node ./admin/cmds/lock-versions",
     "build-docs": "flatworm docs.wrm docs",
     "sync-github": "node ./admin/cmds/cache-github"
@@ -41,12 +50,14 @@
     "libnpm": "2.0.1",
     "mocha": "^5.2.0",
     "mocha-phantomjs-core": "2.1.2",
-    "scrypt-js": "2.0.4",
+    "scrypt-js": "3.0.0",
     "semver": "^5.6.0",
     "tar": "4.4.8",
     "typescript": "3.6.2",
     "rollup": "1.20.1",
+    "rollup-plugin-node-builtins": "2.1.2",
     "rollup-plugin-commonjs": "10.0.2",
+    "rollup-plugin-node-globals": "1.4.0",
     "rollup-plugin-json": "4.0.0",
     "rollup-plugin-node-resolve": "5.2.0",
     "rollup-plugin-terser": "5.1.1",
diff --git a/packages/testcases/src.ts/browser-fs.json b/packages/testcases/src.ts/browser-fs.json
index bb8f6e57f..8bf22653f 100644
--- a/packages/testcases/src.ts/browser-fs.json
+++ b/packages/testcases/src.ts/browser-fs.json
@@ -1 +1 @@
-{ "dirs": [ "./easyseed-bip39", "./testcases", "./wordlists" ] }
+{ "dirs": [ "./input/easyseed-bip39", "./testcases", "./input/wordlists" ] }
diff --git a/packages/testcases/src.ts/browser.ts b/packages/testcases/src.ts/browser.ts
index 1b342ff3f..421968684 100644
--- a/packages/testcases/src.ts/browser.ts
+++ b/packages/testcases/src.ts/browser.ts
@@ -4,13 +4,19 @@ import path from 'path';
 
 import zlib from "browserify-zlib";
 
+import { randomBytes, randomHexString, randomNumber } from "./random";
+export { randomBytes, randomHexString, randomNumber };
+
 import * as data from "./browser-fs.json";
 
-
+const Cache: { [ filename: string ]: any } = { };
 export function loadTests(tag: string): any {
     let filename = 'testcases/' + tag + ".json.gz";
-    console.log("loading:", filename);
-    return JSON.parse(zlib.gunzipSync(new Buffer((<any>data)[filename], "base64")).toString());
+    if (Cache[filename] == null) {
+        console.log("loading:", filename);
+        Cache[filename] = JSON.parse(zlib.gunzipSync(new Buffer((<any>data)[filename], "base64")).toString());
+    }
+    return Cache[filename];
 }
 
 export function loadData(filename: string): Buffer {
diff --git a/packages/testcases/src.ts/index.ts b/packages/testcases/src.ts/index.ts
index 1d949fd75..6815b063f 100644
--- a/packages/testcases/src.ts/index.ts
+++ b/packages/testcases/src.ts/index.ts
@@ -4,9 +4,8 @@ import fs from 'fs';
 import path from 'path';
 import zlib from 'browserify-zlib';
 
-import { arrayify, concat, hexlify } from "@ethersproject/bytes";
-import { keccak256 } from "@ethersproject/keccak256";
-import { toUtf8Bytes } from "@ethersproject/strings";
+import { randomBytes, randomHexString, randomNumber } from "./random";
+export { randomBytes, randomHexString, randomNumber };
 
 export module TestCase {
     export type HDWalletNode = {
@@ -93,28 +92,3 @@ export function loadData(filename: string): Buffer {
    return fs.readFileSync(path.resolve(__dirname, filename));
 }
 
-export function randomBytes(seed: string, lower: number, upper?: number): Uint8Array {
-    if (!upper) { upper = lower; }
-
-    if (upper === 0 && upper === lower) { return new Uint8Array(0); }
-
-    let result = arrayify(keccak256(toUtf8Bytes(seed)));
-    while (result.length < upper) {
-        result = concat([result, keccak256(result)]);
-    }
-
-    let top = arrayify(keccak256(result));
-    let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
-
-    return result.slice(0, lower + Math.floor((upper - lower) * percent));
-}
-
-export function randomHexString(seed: string, lower: number, upper?: number): string {
-    return hexlify(randomBytes(seed, lower, upper));
-}
-
-export function randomNumber(seed: string, lower: number, upper: number): number {
-    let top = randomBytes(seed, 3);
-    let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
-    return lower + Math.floor((upper - lower) * percent);
-}
diff --git a/packages/testcases/src.ts/random.ts b/packages/testcases/src.ts/random.ts
new file mode 100644
index 000000000..61ba0bd61
--- /dev/null
+++ b/packages/testcases/src.ts/random.ts
@@ -0,0 +1,29 @@
+"use strict";
+
+import { ethers } from "ethers";
+
+export function randomBytes(seed: string, lower: number, upper?: number): Uint8Array {
+    if (!upper) { upper = lower; }
+
+    if (upper === 0 && upper === lower) { return new Uint8Array(0); }
+
+    let result = ethers.utils.arrayify(ethers.utils.keccak256(ethers.utils.toUtf8Bytes(seed)));
+    while (result.length < upper) {
+        result = ethers.utils.concat([result, ethers.utils.keccak256(result)]);
+    }
+
+    let top = ethers.utils.arrayify(ethers.utils.keccak256(result));
+    let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
+
+    return result.slice(0, lower + Math.floor((upper - lower) * percent));
+}
+
+export function randomHexString(seed: string, lower: number, upper?: number): string {
+    return ethers.utils.hexlify(randomBytes(seed, lower, upper));
+}
+
+export function randomNumber(seed: string, lower: number, upper: number): number {
+    let top = randomBytes(seed, 3);
+    let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
+    return lower + Math.floor((upper - lower) * percent);
+}
diff --git a/packages/tests/lib.esm/browser.d.ts b/packages/tests/lib.esm/browser.d.ts
deleted file mode 100644
index 73d65f131..000000000
--- a/packages/tests/lib.esm/browser.d.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import * as accounts from "./test-account";
-import * as contract from "./test-contract";
-import * as contractInterface from "./test-contract-interface";
-import * as hdnode from "./test-hdnode";
-import * as providers from "./test-providers";
-import * as utils from "./test-utils";
-import * as wallet from "./test-wallet";
-import * as wordlists from "./test-wordlists";
-export { accounts, contract, contractInterface, hdnode, providers, utils, wallet, wordlists, };
diff --git a/packages/tests/lib.esm/browser.js b/packages/tests/lib.esm/browser.js
deleted file mode 100644
index 08419c74f..000000000
--- a/packages/tests/lib.esm/browser.js
+++ /dev/null
@@ -1,11 +0,0 @@
-'use strict';
-import * as accounts from "./test-account";
-import * as contract from "./test-contract";
-import * as contractInterface from "./test-contract-interface";
-import * as hdnode from "./test-hdnode";
-import * as providers from "./test-providers";
-import * as utils from "./test-utils";
-import * as wallet from "./test-wallet";
-import * as wordlists from "./test-wordlists";
-//    build: require('./test-build'),
-export { accounts, contract, contractInterface, hdnode, providers, utils, wallet, wordlists, };
diff --git a/packages/tests/lib/browser.d.ts b/packages/tests/lib/browser.d.ts
deleted file mode 100644
index 73d65f131..000000000
--- a/packages/tests/lib/browser.d.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import * as accounts from "./test-account";
-import * as contract from "./test-contract";
-import * as contractInterface from "./test-contract-interface";
-import * as hdnode from "./test-hdnode";
-import * as providers from "./test-providers";
-import * as utils from "./test-utils";
-import * as wallet from "./test-wallet";
-import * as wordlists from "./test-wordlists";
-export { accounts, contract, contractInterface, hdnode, providers, utils, wallet, wordlists, };
diff --git a/packages/tests/lib/browser.js b/packages/tests/lib/browser.js
deleted file mode 100644
index f0c4effcd..000000000
--- a/packages/tests/lib/browser.js
+++ /dev/null
@@ -1,25 +0,0 @@
-'use strict';
-var __importStar = (this && this.__importStar) || function (mod) {
-    if (mod && mod.__esModule) return mod;
-    var result = {};
-    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
-    result["default"] = mod;
-    return result;
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-var accounts = __importStar(require("./test-account"));
-exports.accounts = accounts;
-var contract = __importStar(require("./test-contract"));
-exports.contract = contract;
-var contractInterface = __importStar(require("./test-contract-interface"));
-exports.contractInterface = contractInterface;
-var hdnode = __importStar(require("./test-hdnode"));
-exports.hdnode = hdnode;
-var providers = __importStar(require("./test-providers"));
-exports.providers = providers;
-var utils = __importStar(require("./test-utils"));
-exports.utils = utils;
-var wallet = __importStar(require("./test-wallet"));
-exports.wallet = wallet;
-var wordlists = __importStar(require("./test-wordlists"));
-exports.wordlists = wordlists;
diff --git a/packages/tests/package.json b/packages/tests/package.json
index 8c87a6468..49b56a3fd 100644
--- a/packages/tests/package.json
+++ b/packages/tests/package.json
@@ -1,16 +1,7 @@
 {
-  "name": "@ethersproject/tests",
-  "version": "5.0.0-beta.142",
-  "description": "Testing package for ethers.",
-  "main": "./lib/index.js",
+  "author": "Richard Moore <me@ricmoo.com>",
   "browser": {
-    "@ethersproject/ethers": "./tests/browser-ethers.js"
-  },
-  "scripts": {
-    "dist-phantomjs": "browserify -g @ethersproject/testcases/scripts/browser-fs.js -s tests ./tests/browser.js -o ./dist/tests.js",
-    "test": "if [ \"$RUN_PHANTOMJS\" = \"1\" ]; then npm run-script test-phantomjs; else npm run-script test-node; fi",
-    "test-node": "mocha --no-colors --reporter tests/reporter tests/test-*.js",
-    "test-phantomjs": "npm run dist-phantomjs && phantomjs --web-security=false ../../node_modules/mocha-phantomjs-core/mocha-phantomjs-core.js ./test.html ./tests/reporter.js"
+    "ethers": "./lib/browser-ethers.js"
   },
   "dependencies": {
     "@ethersproject/testcases": ">=5.0.0-beta.131",
@@ -18,17 +9,21 @@
     "ethers": ">=5.0.0-beta.156",
     "mocha-phantomjs-core": "2.1.2"
   },
+  "description": "Testing package for ethers.",
   "devDependencies": {
     "browserify": "16.2.3",
     "mocha": "^5.2.0",
     "web3-providers-http": "1.0.0-beta.35"
   },
+  "ethereum": "donations.ethers.eth",
   "keywords": [
     "Ethereum",
     "ethers"
   ],
-  "author": "Richard Moore <me@ricmoo.com>",
   "license": "MIT",
+  "main": "./lib/index.js",
+  "module": "./lib.esm/index.js",
+  "name": "@ethersproject/tests",
   "publishConfig": {
     "access": "public"
   },
@@ -36,8 +31,10 @@
     "type": "git",
     "url": "git://github.com/ethers-io/ethers.js.git"
   },
-  "module": "./lib.esm/index.js",
+  "scripts": {
+    "test": "exit 1"
+  },
+  "tarballHash": "0xe35d27339acf100689bdafbc29234a5e2469164ae6badd271dab620931d2c2d0",
   "types": "./lib/index.d.ts",
-  "ethereum": "donations.ethers.eth",
-  "tarballHash": "0x016eddde4135966b3c9a3343aa29579816661d677a01dbc3933db9ee392de4e5"
+  "version": "5.0.0-beta.143"
 }
diff --git a/packages/tests/src.ts/browser-ethers.ts b/packages/tests/src.ts/browser-ethers.ts
index 1a0893491..dfb7c2795 100644
--- a/packages/tests/src.ts/browser-ethers.ts
+++ b/packages/tests/src.ts/browser-ethers.ts
@@ -2,5 +2,8 @@
 
 console.log("Using global.ethers");
 
-module.exports = (<any>global).ethers;
-console.log("FOO");
+const anyGlobal = (window as any);
+
+const ethers = anyGlobal.ethers;
+
+export { ethers }
diff --git a/packages/tests/src.ts/browser.ts b/packages/tests/src.ts/browser.ts
deleted file mode 100644
index 43dc5a1b3..000000000
--- a/packages/tests/src.ts/browser.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-'use strict';
-
-import * as accounts from "./test-account";
-import * as contract from "./test-contract";
-import * as contractInterface from "./test-contract-interface";
-import * as hdnode from "./test-hdnode";
-import * as providers from "./test-providers";
-import * as utils from "./test-utils";
-import * as wallet from "./test-wallet";
-import * as wordlists from "./test-wordlists";
-
-//    build: require('./test-build'),
-
-export {
-    accounts,
-    contract,
-    contractInterface,
-    hdnode,
-    providers,
-    utils,
-    wallet,
-    wordlists,
-}
diff --git a/packages/tests/src.ts/index.ts b/packages/tests/src.ts/index.ts
new file mode 100644
index 000000000..8b35a4566
--- /dev/null
+++ b/packages/tests/src.ts/index.ts
@@ -0,0 +1,14 @@
+"use strict";
+
+import "./test-account";
+import "./test-contract";
+import "./test-contract-interface";
+import "./test-hdnode";
+import "./test-providers";
+import "./test-utils";
+import "./test-wallet";
+import "./test-wordlists";
+
+import { Reporter } from "./reporter";
+
+export { Reporter }
diff --git a/packages/tests/src.ts/test-contract.json b/packages/tests/src.ts/test-contract.json
new file mode 100644
index 000000000..37ae109ce
--- /dev/null
+++ b/packages/tests/src.ts/test-contract.json
@@ -0,0 +1,20 @@
+{
+ "deployer": "0xE78e48deF8A432Ed0e9287d5678496E759e8A564",
+ "source": "pragma solidity ^0.4.20;\npragma experimental ABIEncoderV2;\n\ncontract TestContract {\n    struct TestStruct {\n        address p0;\n        uint256 p1;\n    }\n\n    struct TestStructParent {\n        address p0;\n        uint256 p1;\n        TestStruct child;\n    }\n\n    event Test(address p0, uint256 p2);\n    event TestP0(address indexed p0, uint256 p2);\n    event TestP0P1(address indexed p0, uint256 indexed p2);\n\n    event TestAnon(address p0, uint256 p2) anonymous;\n    event TestAnonP0(address indexed p0, uint256 p2) anonymous;\n    event TestAnonP0P1(address indexed p0, uint256 indexed p2) anonymous;\n\n    event TestIndexedString(string indexed p2, uint256 p1);\n\n    event TestV2(TestStruct indexed p0, TestStruct p1);\n    event TestV2Nested(TestStructParent indexed p0, TestStructParent p1);\n\n    /*\n    event TestV2Array(TestStruct indexed p0[2], TestStruct p1[2]);\n    event TestV2NestedArray(TestStructParent indexed p0[2], TestStructParent p1[2]);\n\n    event TestV2DynamicArray(TestStruct indexed p0[], TestStruct p1[]);\n    event TestV2NestedDynamicArray(TestStructParent indexed p0[], TestStructParent p1[]);\n    */\n\n    event TestHash(string name, bytes32 hash);\n\n    function testEvents(address p0, uint256 p1, string p2) public {\n\n        Test(p0, p1);\n        TestP0(p0, p1);\n        TestP0P1(p0, p1);\n\n        TestAnon(p0, p1);\n        TestAnonP0(p0, p1);\n        TestAnonP0P1(p0, p1);\n\n        TestIndexedString(p2, p1);\n\n        TestStruct memory testStruct;\n        testStruct.p0 = p0;\n        testStruct.p1 = p1;\n\n        TestStructParent memory testStructParent;\n        testStructParent.p0 = address(uint160(p0) + 1);\n        testStructParent.p1 = p1 + 1;\n        testStructParent.child = testStruct;\n\n        TestV2(testStruct, testStruct);\n        TestV2Nested(testStructParent, testStructParent);\n\n        TestHash(\"TestStructKeccak256\", keccak256(testStruct));\n        TestHash(\"TestStructParentKeccak256\", keccak256(testStructParent));\n    }\n\n    function testV2(TestStructParent p0) public pure returns (TestStructParent result) {\n        p0.p0 = address(uint160(p0.p0) + 0xf0);\n        p0.p1 += 0xf0;\n        p0.child.p0 = address(uint160(p0.child.p0) + 0x0f);\n        p0.child.p1 += 0x0f;\n\n        return p0;\n    }\n\n    function testSingleResult(uint32 p0) public pure returns (uint32 r0) {\n        r0 = p0 + 1;\n    }\n\n    function testMultiResult(uint32 p0) public pure returns (uint32 r0, uint32 r1) {\n        r0 = p0 + 1;\n        r1 = p0 + 2;\n    }\n}\n",
+ "optimize": 1,
+ "timestamp": 1528239748494,
+ "bytecode": "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",
+ "compiler": "0.4.20+commit.3155dd80",
+ "functionHashes": {
+  "testEvents(address,uint256,string)": "babf8901",
+  "testMultiResult(uint32)": "61096af3",
+  "testSingleResult(uint32)": "132414eb",
+  "testV2((address,uint256,(address,uint256)))": "70e4a0e6"
+ },
+ "interface": "[{\"constant\":true,\"inputs\":[{\"name\":\"p0\",\"type\":\"uint32\"}],\"name\":\"testSingleResult\",\"outputs\":[{\"name\":\"r0\",\"type\":\"uint32\"}],\"payable\":false,\"stateMutability\":\"pure\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"p0\",\"type\":\"uint32\"}],\"name\":\"testMultiResult\",\"outputs\":[{\"name\":\"r0\",\"type\":\"uint32\"},{\"name\":\"r1\",\"type\":\"uint32\"}],\"payable\":false,\"stateMutability\":\"pure\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"name\":\"child\",\"type\":\"tuple\"}],\"name\":\"p0\",\"type\":\"tuple\"}],\"name\":\"testV2\",\"outputs\":[{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"name\":\"child\",\"type\":\"tuple\"}],\"name\":\"result\",\"type\":\"tuple\"}],\"payable\":false,\"stateMutability\":\"pure\",\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"},{\"name\":\"p2\",\"type\":\"string\"}],\"name\":\"testEvents\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"Test\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"TestP0\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":true,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"TestP0P1\",\"type\":\"event\"},{\"anonymous\":true,\"inputs\":[{\"indexed\":false,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"TestAnon\",\"type\":\"event\"},{\"anonymous\":true,\"inputs\":[{\"indexed\":true,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"TestAnonP0\",\"type\":\"event\"},{\"anonymous\":true,\"inputs\":[{\"indexed\":true,\"name\":\"p0\",\"type\":\"address\"},{\"indexed\":true,\"name\":\"p2\",\"type\":\"uint256\"}],\"name\":\"TestAnonP0P1\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"name\":\"p2\",\"type\":\"string\"},{\"indexed\":false,\"name\":\"p1\",\"type\":\"uint256\"}],\"name\":\"TestIndexedString\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"indexed\":true,\"name\":\"p0\",\"type\":\"tuple\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"indexed\":false,\"name\":\"p1\",\"type\":\"tuple\"}],\"name\":\"TestV2\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"name\":\"child\",\"type\":\"tuple\"}],\"indexed\":true,\"name\":\"p0\",\"type\":\"tuple\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"},{\"components\":[{\"name\":\"p0\",\"type\":\"address\"},{\"name\":\"p1\",\"type\":\"uint256\"}],\"name\":\"child\",\"type\":\"tuple\"}],\"indexed\":false,\"name\":\"p1\",\"type\":\"tuple\"}],\"name\":\"TestV2Nested\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":false,\"name\":\"name\",\"type\":\"string\"},{\"indexed\":false,\"name\":\"hash\",\"type\":\"bytes32\"}],\"name\":\"TestHash\",\"type\":\"event\"}]",
+ "runtimeBytecode": "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",
+ "transactionHash": "0x19d1edeaa4f9b40cd0f08e8896bba04d1e74b97ddf4dabaa36e852512edf189d",
+ "contractAddress": "0x94d28bB6cd09f0488039a1870FbDB496Bc6ce98B",
+ "blockHash": "0xa5d83b96fb8002004d31ab6a5e20c48f6928169dae8bc70257b115f950e9d39c",
+ "blockNumber": 2411314
+}
\ No newline at end of file
diff --git a/packages/tests/src.ts/test-contract.ts b/packages/tests/src.ts/test-contract.ts
index 893484652..beffd92de 100644
--- a/packages/tests/src.ts/test-contract.ts
+++ b/packages/tests/src.ts/test-contract.ts
@@ -4,12 +4,13 @@ import assert from "assert";
 
 import { ethers } from "ethers";
 
+import contractData from "./test-contract.json";
 
 const provider = new ethers.providers.InfuraProvider('rinkeby');
 
+
 const contract = (function() {
-    let data = require('../contracts/test-contract.json');
-    return new ethers.Contract(data.contractAddress, data.interface, provider);
+    return new ethers.Contract(contractData.contractAddress, contractData.interface, provider);
 })();
 
 function equals(name: string, actual: any, expected: any): void {
diff --git a/packages/tests/src.ts/test-providers.ts b/packages/tests/src.ts/test-providers.ts
index 3cfee58b9..0fa04e404 100644
--- a/packages/tests/src.ts/test-providers.ts
+++ b/packages/tests/src.ts/test-providers.ts
@@ -2,7 +2,7 @@
 
 import assert from "assert";
 
-const Web3HttpProvider = require("web3-providers-http");
+import Web3HttpProvider from "web3-providers-http";
 
 import { ethers } from "ethers";
 
diff --git a/packages/tests/test-esm.html b/packages/tests/test-esm.html
new file mode 100644
index 000000000..a1bd6ba31
--- /dev/null
+++ b/packages/tests/test-esm.html
@@ -0,0 +1,45 @@
+<!doctype html>
+<html>
+    <head>
+        <title>Ethers Test Suite</title>
+        <meta charset="UTF-8">
+        <link href="../../node_modules/mocha/mocha.css" rel="stylesheet" />
+        <style type="text/css">
+        </style>
+    </head>
+
+    <body>
+        <div id="mocha"></div>
+        <script src="../../node_modules/mocha/mocha.js"></script>
+        <script src="../shims/dist/index.min.js"></script>
+
+        <!-- Inject the mocha describe and it functions -->
+        <script type="text/javascript">
+            // Inject the mocha describe and it functions
+            mocha.setup({ ui: 'bdd' });
+        </script>
+
+        <script type="module">
+           // Load the browser dist ethers package
+           import { ethers } from "../ethers/dist/ethers-all.esm.min.js";
+           console.log("ETH", ethers);
+           window.ethers = ethers;
+        </script>
+
+        <script type="module">
+           // Our test cases; compiled by browserify
+           import { Reporter } from "./dist/tests.esm.js";
+
+            mocha.reporter(Reporter);
+
+            // Use this to focus on specific test cases
+            //mocha.grep(new RegExp('easyseed-es')).run();
+
+            mocha.run();
+        </script>
+
+        <!-- Run the test cases! -->
+        <script type="text/javascript">
+        </script>
+    </body>
+</html>
diff --git a/packages/tests/test.html b/packages/tests/test-umd.html
similarity index 100%
rename from packages/tests/test.html
rename to packages/tests/test-umd.html
diff --git a/rollup-tests.config.js b/rollup-tests.config.js
new file mode 100644
index 000000000..bc9c5979a
--- /dev/null
+++ b/rollup-tests.config.js
@@ -0,0 +1,89 @@
+"use strict";
+
+import path from "path"
+import fs from "fs";
+
+import builtins from 'rollup-plugin-node-builtins';
+import resolve from 'rollup-plugin-node-resolve';
+import commonjs from 'rollup-plugin-commonjs';
+import json from 'rollup-plugin-json';
+import _globals from "rollup-plugin-node-globals";
+
+const undef = "module.exports = undefined;";
+const empty = "module.exports = {};";
+
+import { createFilter } from 'rollup-pluginutils';
+
+function replacer(libPath, options = {}) {
+    const filter = createFilter(options.include, options.exclude);
+
+    return {
+        name: "file-replacer",
+        resolveId(id, importee) {
+            if (id == "ethers") {
+                return path.resolve(importee.match(/^(.*\/packages\/)/)[1], `./tests/${ libPath }/browser-ethers.js`);
+            }
+            //return null;
+        },
+        transform(code, id) {
+            if (id.match(/\/browser-fs\.json$/)) {
+                const config = JSON.parse(code);
+                const data = { "_": { name: "browser-fs", config: config } };
+                config.dirs.forEach((dirname) => {
+                    let fulldirname = path.resolve(path.dirname(id), "..", dirname);
+                    fs.readdirSync(fulldirname).forEach((filename) => {
+                        const key = path.join(dirname, filename);
+                        const content = fs.readFileSync(path.resolve(fulldirname, filename));
+                        data[key] = content.toString("base64");
+                        console.log(`Added ${ key } (${ content.length } bytes)`);
+                    });
+                });
+
+                return {
+                     code: JSON.stringify(data),
+                     map: { mappings: '' }
+                };
+            }
+
+            return null;
+        }
+    };
+}
+
+export default commandLineArgs => {
+    let buildModule = commandLineArgs.configModule;
+
+    let input = "./packages/tests/lib/index.js"
+    let format = "umd";
+    let mainFields = [ "browser", "main" ];
+    let libPath = "lib";
+
+    if (buildModule) {
+        input = "./packages/tests/lib.esm/index.js";
+        format = "esm";
+        mainFields = [ "browser", "module", "main" ];
+        libPath = "lib.esm";
+    }
+
+    const plugins = [
+        replacer(libPath),
+        json(),
+        commonjs({ }),
+        builtins(),
+        resolve({
+            mainFields: mainFields
+        }),
+        _globals(),
+    ];
+
+    return {
+      input: input,
+      output: {
+        file: ("./packages/tests/dist/tests." + format + ".js"),
+        format: format,
+        name: "testing"
+      },
+      treeshake: false,
+      plugins: plugins
+  };
+}