Remove bad SafeCast test

Co-authored-by: Andrew B Coathup <28278242+abcoathup@users.noreply.github.com>

.circleci/config.yml

@@ -1,84 +0,0 @@
-version: 2
-# 2.1 does not yet support local run
-# unless with workaround. For simplicity just use it.
-# https://github.com/CircleCI-Public/circleci-cli/issues/79
-
-aliases:
-  - &defaults
-    docker:
-      - image: circleci/node:10
-
-  - &cache_key_node_modules
-    key: v1-node_modules-{{ checksum "package-lock.json" }}
-
-jobs:
-  dependencies:
-    <<: *defaults
-    steps:
-      - checkout
-      - restore_cache:
-          <<: *cache_key_node_modules
-      - run:
-          name: Install npm dependencies and prepare
-          command: |
-            if [ ! -d node_modules ]; then
-              npm ci
-            else
-              npm run prepare
-            fi
-      - persist_to_workspace:
-          root: .
-          paths:
-            - node_modules
-            - build
-      - save_cache:
-          paths:
-            - node_modules
-          <<: *cache_key_node_modules
-
-  lint:
-    <<: *defaults
-    steps:
-      - checkout
-      - attach_workspace:
-          at: .
-      - run:
-          name: Linter
-          command: npm run lint
-  test:
-    <<: *defaults
-    steps:
-      - checkout
-      - attach_workspace:
-          at: .
-      - run:
-          name: Unit tests
-          command: npm run test
-
-  coverage:
-    <<: *defaults
-    steps:
-      - checkout
-      - attach_workspace:
-          at: .
-      - run:
-          name: Unit tests with coverage report
-          command: npm run coverage
-
-      # TODO(xinbenlv, #1839): run SOLC_NIGHTLY to be run but allow it to fail.
-
-workflows:
-  version: 2
-  everything:
-    jobs:
-      - dependencies
-      - lint:
-          requires:
-            - dependencies
-      - test:
-          requires:
-            - dependencies
-      - coverage:
-          requires:
-            - dependencies
-

.eslintrc

@@ -18,6 +18,8 @@
     "contract": false,
     "assert": false,
     "web3": false,
+    "usePlugin": false,
+    "extendEnvironment": false,
   },
   "rules": {
 

.github/workflows/test.yml

@@ -0,0 +1,43 @@
+name: Test
+
+on:
+  push:
+    branches: [master]
+  pull_request: {}
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 10.x
+      - uses: actions/cache@v2
+        id: cache
+        with:
+          path: '**/node_modules'
+          key: npm-v2-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: npm-v2-
+      - run: npm ci
+        if: steps.cache.outputs.cache-hit != 'true'
+      - run: npm run lint
+      - run: npm run test
+
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 10.x
+      - uses: actions/cache@v2
+        id: cache
+        with:
+          path: '**/node_modules'
+          key: npm-v2-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: npm-v2-
+      - run: npm ci
+        if: steps.cache.outputs.cache-hit != 'true'
+      - run: npm run coverage
+      - uses: codecov/codecov-action@v1

.gitignore

@@ -50,3 +50,10 @@ contracts/README.md
 
 # temporary artifact from solidity-coverage
 allFiredEvents
+.coverage_artifacts
+.coverage_cache
+.coverage_contracts
+
+# buidler
+cache
+artifacts

.solcover.js

@@ -4,5 +4,8 @@ module.exports = {
     compileCommand: 'npm run compile',
     skipFiles: [
         'mocks',
-    ]
+    ],
+    providerOptions: {
+        default_balance_ether: '10000000000000000000000000',
+    },
 }

CONTRIBUTING.md

@@ -44,13 +44,6 @@ npm test
 npm run lint
 ```
 
-or you can simply run CircleCI locally
-```bash
-circleci local execute --job build
-circleci local execute --job test
-```
-*Note*: requires installing CircleCI and docker locally on your machine.
-
 5) Go to [github.com/OpenZeppelin/openzeppelin-contracts](https://github.com/OpenZeppelin/openzeppelin-contracts) in your web browser and issue a new pull request.
 
 *IMPORTANT* Read the PR template very carefully and make sure to follow all the instructions. These instructions

README.md

@@ -2,7 +2,6 @@
 
 [![Docs](https://img.shields.io/badge/docs-%F0%9F%93%84-blue)](https://docs.openzeppelin.com/contracts)
 [![NPM Package](https://img.shields.io/npm/v/@openzeppelin/contracts.svg)](https://www.npmjs.org/package/@openzeppelin/contracts)
-[![Build Status](https://circleci.com/gh/OpenZeppelin/openzeppelin-contracts.svg?style=shield)](https://circleci.com/gh/OpenZeppelin/openzeppelin-contracts)
 [![Coverage Status](https://codecov.io/gh/OpenZeppelin/openzeppelin-contracts/graph/badge.svg)](https://codecov.io/gh/OpenZeppelin/openzeppelin-contracts)
 
 **A library for secure smart contract development.** Build on a solid foundation of community-vetted code.

buidler.config.js

@@ -0,0 +1,20 @@
+const fs = require('fs');
+const path = require('path');
+
+usePlugin('solidity-coverage');
+usePlugin('@nomiclabs/buidler-truffle5');
+
+for (const f of fs.readdirSync(path.join(__dirname, 'buidler'))) {
+  require(path.join(__dirname, 'buidler', f));
+}
+
+module.exports = {
+  networks: {
+    buidlerevm: {
+      blockGasLimit: 10000000,
+    },
+  },
+  solc: {
+    version: '0.6.12',
+  },
+};

buidler/env-contract.js

@@ -0,0 +1,10 @@
+extendEnvironment(env => {
+  const { contract } = env;
+
+  env.contract = function (name, body) {
+    // remove the default account from the accounts list used in tests, in order
+    // to protect tests against accidentally passing due to the contract
+    // deployer being used subsequently as function caller
+    contract(name, accounts => body(accounts.slice(1)));
+  };
+});

contracts/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@openzeppelin/contracts",
-  "version": "3.2.0",
   "description": "Secure Smart Contract library for Solidity",
+  "version": "3.2.0",
   "files": [
     "**/*.sol",
     "/build/contracts/*.json",

docs/modules/ROOT/nav.adoc

@@ -1,4 +1,8 @@
 * xref:index.adoc[Overview]
+* xref:extending-contracts.adoc[Extending Contracts]
+* xref:upgrade-safe.adoc[Using with Upgrades]
+
+* xref:releases-stability.adoc[Releases & Stability]
 
 * xref:access-control.adoc[Access Control]
 
@@ -12,8 +16,4 @@
 * xref:gsn.adoc[Gas Station Network]
 ** xref:gsn-strategies.adoc[Strategies]
 
-* xref:extending-contracts.adoc[Extending Contracts]
-
 * xref:utilities.adoc[Utilities]
-
-* xref:releases-stability.adoc[Releases & Stability]

docs/modules/ROOT/pages/upgrade-safe.adoc

@@ -0,0 +1,71 @@
+= Using with Upgrades
+
+If your contract is going to be deployed with upgradeability, such as using the xref:upgrades-plugins::index.adoc[OpenZeppelin Upgrades Plugins], you will need to use the Upgrade Safe variant of OpenZeppelin Contracts.
+
+This variant is available as a separate package called `@openzeppelin/contracts-upgrade-safe`, which is hosted in the repository https://github.com/OpenZeppelin/openzeppelin-contracts-upgrade-safe[OpenZeppelin/openzeppelin-contracts-upgrade-safe].
+
+It follows all of the rules for xref:upgrades-plugins::writing-upgradeable.adoc[Writing Upgradeable Contracts]: constructors are replaced by initializer functions, state variables are initialized in initializer functions, and we additionally check for storage incompatibilities across minor versions.
+
+== Overview
+
+=== Installation
+
+```console
+$ npm install @openzeppelin/contracts-upgrade-safe
+```
+
+=== Usage
+
+The package replicates the structure of the main OpenZeppelin Contracts package, but every file and contract has the suffix `UpgradeSafe`.
+
+```diff
+-import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
++import "@openzeppelin/contracts-upgrade-safe/token/ERC721/ERC721UpgradeSafe.sol";
+ 
+-contract MyCollectible is ERC721 {
++contract MyCollectible is ERC721UpgradeSafe {
+```
+
+Constructors are replaced by internal initializer functions following the naming convention `+__{ContractName}_init+`. Since these are internal, you must always define your own public initializer function and call the parent initializer of the contract you extend.
+
+```diff
+-    constructor() ERC721("MyCollectible", "MCO") public {
++    function initialize() initializer public {
++        __ERC721_init("MyCollectible", "MCO");
+     }
+```
+
+CAUTION: Use with multiple inheritance requires special attention. See the section below titled <<multiple-inheritance>>.
+
+Once this contract is set up and compiled, you can deploy it using the xref:upgrades-plugins::index.adoc[Upgrades Plugins]. The following snippet shows an example deployment script using Hardhat.
+
+```js
+// scripts/deploy-my-collectible.js
+const { ethers, upgrades } = require("hardhat");
+
+async function main() {
+  const MyCollectible = await ethers.getContractFactory("MyCollectible");
+
+  const mc = await upgrades.deployProxy(MyCollectible);
+
+  await mc.deployed();
+  console.log("MyCollectible deployed to:", mc.address);
+}
+
+main();
+```
+
+== Further Notes
+
+[[multiple-inheritance]]
+=== Multiple Inheritance
+
+Initializer functions are not linearized by the compiler like constructors. Because of this, each `+__{ContractName}_init+` function embeds the linearized calls to all parent initializers. As a consequence, calling two of these `init` functions can potentially initialize the same contract twice.
+
+The function `+__{ContractName}_init_unchained+` found in every contract is the initializer function minus the calls to parent initializers, and can be used to avoid the double initialization problem, but doing this manually is not recommended. We hope to be able to implement safety checks for this in future versions of the Upgrades Plugins.
+
+=== Storage Gaps
+
+You may notice that every contract includes a state variable named `+__gap+`. This is empty reserved space in storage that is put in place in Upgrade Safe contracts. It allows us to freely add new state variables in the future without compromising the storage compatibility with existing deployments.
+
+It isn't safe to simply add a state variable because it "shifts down" all of the state variables below in the inheritance chain. This makes the storage layouts incompatible, as explained in xref:upgrades-plugins::writing-upgradeable.adoc#modifying-your-contracts[Writing Upgradeable Contracts]. The size of the `+__gap+` array is calculated so that the amount of storage used by a contract always adds up to the same number (in this case 50 storage slots).

package.json

@@ -1,17 +1,16 @@
 {
   "name": "openzeppelin-solidity",
-  "version": "3.2.0",
   "description": "Secure Smart Contract library for Solidity",
+  "version": "3.2.0",
   "files": [
     "/contracts/**/*.sol",
     "/build/contracts/*.json",
     "!/contracts/mocks",
-    "!/contracts/examples",
     "/test/behaviors"
   ],
   "scripts": {
-    "compile": "scripts/compile.sh",
-    "coverage": "scripts/coverage.sh",
+    "compile": "buidler compile",
+    "coverage": "buidler coverage",
     "docs": "oz-docs",
     "docs:watch": "npm run docs watch contracts 'docs/*.hbs'",
     "prepare-docs": "scripts/prepare-docs.sh",
@@ -20,12 +19,12 @@
     "lint:js": "eslint --ignore-path .gitignore .",
     "lint:js:fix": "eslint --ignore-path .gitignore . --fix",
     "lint:sol": "solhint --max-warnings 0 \"contracts/**/*.sol\"",
-    "prepublish": "rimraf build contracts/build",
+    "prepublish": "rimraf build contracts/build artifacts",
     "prepare": "npm run compile",
-    "prepack": "node scripts/remove-ignored-artifacts.js",
+    "prepack": "scripts/prepack.sh",
     "release": "scripts/release/release.sh",
     "version": "scripts/release/version.sh",
-    "test": "mocha --exit --recursive"
+    "test": "buidler test"
   },
   "repository": {
     "type": "git",
@@ -46,12 +45,13 @@
   },
   "homepage": "https://openzeppelin.com/contracts/",
   "devDependencies": {
-    "@openzeppelin/cli": "^2.8.2",
+    "@nomiclabs/buidler": "^1.4.8",
+    "@nomiclabs/buidler-truffle5": "^1.3.4",
+    "@nomiclabs/buidler-web3": "^1.3.4",
     "@openzeppelin/docs-utils": "^0.1.0",
     "@openzeppelin/gsn-helpers": "^0.2.3",
     "@openzeppelin/gsn-provider": "^0.1.10",
-    "@openzeppelin/test-environment": "^0.1.4",
-    "@openzeppelin/test-helpers": "^0.5.6",
+    "@openzeppelin/test-helpers": "^0.5.9",
     "chai": "^4.2.0",
     "eslint": "^6.5.1",
     "eslint-config-standard": "^14.1.1",
@@ -60,15 +60,14 @@
     "eslint-plugin-node": "^10.0.0",
     "eslint-plugin-promise": "^4.2.1",
     "eslint-plugin-standard": "^4.0.1",
-    "ethereumjs-util": "^7.0.1",
-    "ganache-core-coverage": "https://github.com/OpenZeppelin/ganache-core-coverage/releases/download/2.5.3-coverage/ganache-core-coverage-2.5.3.tgz",
+    "ethereumjs-util": "^7.0.7",
     "lodash.startcase": "^4.4.0",
     "lodash.zip": "^4.2.0",
     "micromatch": "^4.0.2",
     "mocha": "^8.0.1",
     "rimraf": "^3.0.2",
-    "solhint": "^3.0.0",
-    "solidity-coverage": "github:rotcivegaf/solidity-coverage#5875f5b7bc74d447f3312c9c0e9fc7814b482477",
+    "solhint": "^3.2.0",
+    "solidity-coverage": "^0.7.11",
     "solidity-docgen": "^0.5.3"
   },
   "dependencies": {}

scripts/compile.sh

@@ -1,9 +0,0 @@
-#!/usr/bin/env sh
-
-if [ "$SOLC_NIGHTLY" = true ]; then
-  docker pull ethereum/solc:nightly
-fi
-
-export OPENZEPPELIN_NON_INTERACTIVE=true
-
-npx oz compile

scripts/coverage.sh

@@ -1,25 +0,0 @@
-#!/usr/bin/env bash
-
-set -o errexit -o pipefail
-
-# Executes cleanup function at script exit.
-trap cleanup EXIT
-
-cleanup() {
-  # Delete the symlink created to the allFiredEvents file solidity-coverage creates
-  rm -f allFiredEvents
-}
-
-log() {
-  echo "$*" >&2
-}
-
-# The allFiredEvents file is created inside coverageEnv, but solidity-coverage
-# expects it to be at the top level. We create a symlink to fix this
-ln -s coverageEnv/allFiredEvents allFiredEvents
-
-OZ_TEST_ENV_COVERAGE=true npx solidity-coverage || log "Test run failed"
-
-if [ "$CI" = true ]; then
-  curl -s https://codecov.io/bash | bash -s -- -C "$CIRCLE_SHA1"
-fi

scripts/prepack.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# cross platform `mkdir -p`
+node -e 'fs.mkdirSync("build/contracts", { recursive: true })'
+
+cp artifacts/*.json build/contracts
+
+node scripts/remove-ignored-artifacts.js

scripts/remove-ignored-artifacts.js

@@ -23,20 +23,19 @@ const ignorePatternsSubtrees = ignorePatterns
   .concat(ignorePatterns.map(pat => path.join(pat, '**/*')))
   .map(p => p.replace(/^\//, ''));
 
+const solcOutput = readJSON('cache/solc-output.json');
+
 const artifactsDir = 'build/contracts';
 
 let n = 0;
 
-for (const artifact of fs.readdirSync(artifactsDir)) {
-  const fullArtifactPath = path.join(artifactsDir, artifact);
-  const { sourcePath: fullSourcePath } = readJSON(fullArtifactPath);
-  const sourcePath = path.relative('.', fullSourcePath);
-
+for (const sourcePath in solcOutput.contracts) {
   const ignore = match.any(sourcePath, ignorePatternsSubtrees);
-
   if (ignore) {
-    fs.unlinkSync(fullArtifactPath);
-    n += 1;
+    for (const contract in solcOutput.contracts[sourcePath]) {
+      fs.unlinkSync(path.join(artifactsDir, contract + '.json'));
+      n += 1;
+    }
   }
 }
 

test-environment.config.js

@@ -1,22 +0,0 @@
-const { GSNDevProvider } = require('@openzeppelin/gsn-provider');
-
-module.exports = {
-  accounts: {
-    ether: 1e6,
-  },
-
-  contracts: {
-    type: 'truffle',
-  },
-
-  setupProvider: (baseProvider) => {
-    const { accounts } = require('@openzeppelin/test-environment');
-
-    return new GSNDevProvider(baseProvider, {
-      txfee: 70,
-      useGSN: false,
-      ownerAddress: accounts[8],
-      relayerAddress: accounts[9],
-    });
-  },
-};

test/GSN/Context.behavior.js

@@ -1,8 +1,6 @@
-const { contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectEvent } = require('@openzeppelin/test-helpers');
 
-const ContextMock = contract.fromArtifact('ContextMock');
+const ContextMock = artifacts.require('ContextMock');
 
 function shouldBehaveLikeRegularContext (sender) {
   describe('msgSender', function () {

test/GSN/Context.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 require('@openzeppelin/test-helpers');
 
-const ContextMock = contract.fromArtifact('ContextMock');
-const ContextMockCaller = contract.fromArtifact('ContextMockCaller');
+const ContextMock = artifacts.require('ContextMock');
+const ContextMockCaller = artifacts.require('ContextMockCaller');
 
 const { shouldBehaveLikeRegularContext } = require('./Context.behavior');
 
-describe('Context', function () {
+contract('Context', function (accounts) {
   const [ sender ] = accounts;
 
   beforeEach(async function () {

test/GSN/ERC721GSNRecipientMock.test.js

@@ -1,20 +1,23 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { constants, expectEvent } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 const gsn = require('@openzeppelin/gsn-helpers');
 const { fixSignature } = require('../helpers/sign');
+const { setGSNProvider } = require('../helpers/set-gsn-provider');
 const { utils: { toBN } } = require('web3');
 
-const ERC721GSNRecipientMock = contract.fromArtifact('ERC721GSNRecipientMock');
+const ERC721GSNRecipientMock = artifacts.require('ERC721GSNRecipientMock');
 
-describe('ERC721GSNRecipient (integration)', function () {
+contract('ERC721GSNRecipient (integration)', function (accounts) {
   const [ signer, sender ] = accounts;
 
   const name = 'Non Fungible Token';
   const symbol = 'NFT';
   const tokenId = '42';
 
+  before(function () {
+    setGSNProvider(ERC721GSNRecipientMock, accounts);
+  });
+
   beforeEach(async function () {
     this.token = await ERC721GSNRecipientMock.new(name, symbol, signer);
   });

test/GSN/GSNRecipient.test.js

@@ -1,20 +1,24 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { balance, BN, constants, ether, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const gsn = require('@openzeppelin/gsn-helpers');
+const { setGSNProvider } = require('../helpers/set-gsn-provider');
 
 const { expect } = require('chai');
 
-const GSNRecipientMock = contract.fromArtifact('GSNRecipientMock');
-const ContextMockCaller = contract.fromArtifact('ContextMockCaller');
+const GSNRecipientMock = artifacts.require('GSNRecipientMock');
+const ContextMockCaller = artifacts.require('ContextMockCaller');
 
 const { shouldBehaveLikeRegularContext } = require('./Context.behavior');
 
-describe('GSNRecipient', function () {
+contract('GSNRecipient', function (accounts) {
   const [ payee, sender, newRelayHub ] = accounts;
 
+  before(function () {
+    setGSNProvider(GSNRecipientMock, accounts);
+    setGSNProvider(ContextMockCaller, accounts);
+  });
+
   beforeEach(async function () {
     this.recipient = await GSNRecipientMock.new();
   });

test/GSN/GSNRecipientERC20Fee.test.js

@@ -1,20 +1,25 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { ether, expectEvent } = require('@openzeppelin/test-helpers');
 const gsn = require('@openzeppelin/gsn-helpers');
+const { setGSNProvider } = require('../helpers/set-gsn-provider');
 
 const { expect } = require('chai');
 
-const GSNRecipientERC20FeeMock = contract.fromArtifact('GSNRecipientERC20FeeMock');
-const ERC20 = contract.fromArtifact('ERC20');
-const IRelayHub = contract.fromArtifact('IRelayHub');
+const GSNRecipientERC20FeeMock = artifacts.require('GSNRecipientERC20FeeMock');
+const ERC20 = artifacts.require('ERC20');
+const IRelayHub = artifacts.require('IRelayHub');
 
-describe('GSNRecipientERC20Fee', function () {
+contract('GSNRecipientERC20Fee', function (accounts) {
   const [ sender ] = accounts;
 
   const name = 'FeeToken';
   const symbol = 'FTKN';
 
+  before(function () {
+    setGSNProvider(GSNRecipientERC20FeeMock, accounts);
+    setGSNProvider(ERC20, accounts);
+    setGSNProvider(IRelayHub, accounts);
+  });
+
   beforeEach(async function () {
     this.recipient = await GSNRecipientERC20FeeMock.new(name, symbol);
     this.token = await ERC20.at(await this.recipient.token());

test/GSN/GSNRecipientSignature.test.js

@@ -1,16 +1,19 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { expectEvent, expectRevert, constants } = require('@openzeppelin/test-helpers');
 const gsn = require('@openzeppelin/gsn-helpers');
 const { fixSignature } = require('../helpers/sign');
+const { setGSNProvider } = require('../helpers/set-gsn-provider');
 const { utils: { toBN } } = require('web3');
 const { ZERO_ADDRESS } = constants;
 
-const GSNRecipientSignatureMock = contract.fromArtifact('GSNRecipientSignatureMock');
+const GSNRecipientSignatureMock = artifacts.require('GSNRecipientSignatureMock');
 
-describe('GSNRecipientSignature', function () {
+contract('GSNRecipientSignature', function (accounts) {
   const [ signer, other ] = accounts;
 
+  before(function () {
+    setGSNProvider(GSNRecipientSignatureMock, accounts);
+  });
+
   beforeEach(async function () {
     this.recipient = await GSNRecipientSignatureMock.new(signer);
   });

test/access/AccessControl.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const AccessControlMock = contract.fromArtifact('AccessControlMock');
+const AccessControlMock = artifacts.require('AccessControlMock');
 
-describe('AccessControl', function () {
+contract('AccessControl', function (accounts) {
   const [ admin, authorized, otherAuthorized, other, otherAdmin ] = accounts;
 
   const DEFAULT_ADMIN_ROLE = '0x0000000000000000000000000000000000000000000000000000000000000000';

test/access/Ownable.test.js

@@ -1,12 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
 const { constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const Ownable = contract.fromArtifact('OwnableMock');
+const Ownable = artifacts.require('OwnableMock');
 
-describe('Ownable', function () {
+contract('Ownable', function (accounts) {
   const [ owner, other ] = accounts;
 
   beforeEach(async function () {

test/cryptography/ECDSA.test.js

@@ -1,16 +1,14 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { expectRevert } = require('@openzeppelin/test-helpers');
 const { toEthSignedMessageHash, fixSignature } = require('../helpers/sign');
 
 const { expect } = require('chai');
 
-const ECDSAMock = contract.fromArtifact('ECDSAMock');
+const ECDSAMock = artifacts.require('ECDSAMock');
 
 const TEST_MESSAGE = web3.utils.sha3('OpenZeppelin');
 const WRONG_MESSAGE = web3.utils.sha3('Nope');
 
-describe('ECDSA', function () {
+contract('ECDSA', function (accounts) {
   const [ other ] = accounts;
 
   beforeEach(async function () {

test/cryptography/MerkleProof.test.js

@@ -1,5 +1,3 @@
-const { contract } = require('@openzeppelin/test-environment');
-
 require('@openzeppelin/test-helpers');
 
 const { MerkleTree } = require('../helpers/merkleTree.js');
@@ -7,9 +5,9 @@ const { keccakFromString, bufferToHex } = require('ethereumjs-util');
 
 const { expect } = require('chai');
 
-const MerkleProofWrapper = contract.fromArtifact('MerkleProofWrapper');
+const MerkleProofWrapper = artifacts.require('MerkleProofWrapper');
 
-describe('MerkleProof', function () {
+contract('MerkleProof', function (accounts) {
   beforeEach(async function () {
     this.merkleProof = await MerkleProofWrapper.new();
   });

test/helpers/set-gsn-provider.js

@@ -0,0 +1,15 @@
+const { GSNDevProvider } = require('@openzeppelin/gsn-provider');
+
+function setGSNProvider (Contract, accounts) {
+  const baseProvider = Contract.currentProvider;
+  Contract.setProvider(
+    new GSNDevProvider(baseProvider, {
+      txfee: 70,
+      useGSN: false,
+      ownerAddress: accounts[8],
+      relayerAddress: accounts[9],
+    }),
+  );
+};
+
+module.exports = { setGSNProvider };

test/helpers/sign.js

@@ -1,5 +1,3 @@
-const { web3 } = require('@openzeppelin/test-environment');
-
 function toEthSignedMessageHash (messageHex) {
   const messageBuffer = Buffer.from(messageHex.substring(2), 'hex');
   const prefix = Buffer.from(`\u0019Ethereum Signed Message:\n${messageBuffer.length}`);

test/introspection/ERC165.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
 const { shouldSupportInterfaces } = require('./SupportsInterface.behavior');
 
-const ERC165Mock = contract.fromArtifact('ERC165Mock');
+const ERC165Mock = artifacts.require('ERC165Mock');
 
-describe('ERC165', function () {
+contract('ERC165', function (accounts) {
   beforeEach(async function () {
     this.mock = await ERC165Mock.new();
   });

test/introspection/ERC165Checker.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC165CheckerMock = contract.fromArtifact('ERC165CheckerMock');
-const ERC165NotSupported = contract.fromArtifact('ERC165NotSupported');
-const ERC165InterfacesSupported = contract.fromArtifact('ERC165InterfacesSupported');
+const ERC165CheckerMock = artifacts.require('ERC165CheckerMock');
+const ERC165NotSupported = artifacts.require('ERC165NotSupported');
+const ERC165InterfacesSupported = artifacts.require('ERC165InterfacesSupported');
 
 const DUMMY_ID = '0xdeadbeef';
 const DUMMY_ID_2 = '0xcafebabe';
@@ -14,7 +13,7 @@ const DUMMY_UNSUPPORTED_ID = '0xbaddcafe';
 const DUMMY_UNSUPPORTED_ID_2 = '0xbaadcafe';
 const DUMMY_ACCOUNT = '0x1111111111111111111111111111111111111111';
 
-describe('ERC165Checker', function () {
+contract('ERC165Checker', function (accounts) {
   beforeEach(async function () {
     this.mock = await ERC165CheckerMock.new();
   });

test/introspection/ERC1820Implementer.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { expectRevert, singletons } = require('@openzeppelin/test-helpers');
 const { bufferToHex, keccakFromString } = require('ethereumjs-util');
 
 const { expect } = require('chai');
 
-const ERC1820ImplementerMock = contract.fromArtifact('ERC1820ImplementerMock');
+const ERC1820ImplementerMock = artifacts.require('ERC1820ImplementerMock');
 
-describe('ERC1820Implementer', function () {
+contract('ERC1820Implementer', function (accounts) {
   const [ registryFunder, implementee, other ] = accounts;
 
   const ERC1820_ACCEPT_MAGIC = bufferToHex(keccakFromString('ERC1820_ACCEPT_MAGIC'));

test/math/Math.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { BN } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const MathMock = contract.fromArtifact('MathMock');
+const MathMock = artifacts.require('MathMock');
 
-describe('Math', function () {
+contract('Math', function (accounts) {
   const min = new BN('1234');
   const max = new BN('5678');
 

test/math/SafeMath.test.js

@@ -1,12 +1,11 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { BN, constants, expectRevert } = require('@openzeppelin/test-helpers');
 const { MAX_UINT256 } = constants;
 
 const { expect } = require('chai');
 
-const SafeMathMock = contract.fromArtifact('SafeMathMock');
+const SafeMathMock = artifacts.require('SafeMathMock');
 
-describe('SafeMath', function () {
+contract('SafeMath', function (accounts) {
   beforeEach(async function () {
     this.safeMath = await SafeMathMock.new();
   });

test/math/SignedSafeMath.test.js

@@ -1,13 +1,11 @@
-const { contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectRevert } = require('@openzeppelin/test-helpers');
 const { MAX_INT256, MIN_INT256 } = constants;
 
 const { expect } = require('chai');
 
-const SignedSafeMathMock = contract.fromArtifact('SignedSafeMathMock');
+const SignedSafeMathMock = artifacts.require('SignedSafeMathMock');
 
-describe('SignedSafeMath', function () {
+contract('SignedSafeMath', function (accounts) {
   beforeEach(async function () {
     this.safeMath = await SignedSafeMathMock.new();
   });

test/payment/PaymentSplitter.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { balance, constants, ether, expectEvent, send, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const PaymentSplitter = contract.fromArtifact('PaymentSplitter');
+const PaymentSplitter = artifacts.require('PaymentSplitter');
 
-describe('PaymentSplitter', function () {
+contract('PaymentSplitter', function (accounts) {
   const [ owner, payee1, payee2, payee3, nonpayee1, payer1 ] = accounts;
 
   const amount = ether('1');

test/payment/PullPayment.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { balance, ether } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const PullPaymentMock = contract.fromArtifact('PullPaymentMock');
+const PullPaymentMock = artifacts.require('PullPaymentMock');
 
-describe('PullPayment', function () {
+contract('PullPayment', function (accounts) {
   const [ payer, payee1, payee2 ] = accounts;
 
   const amount = ether('17');

test/payment/escrow/ConditionalEscrow.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { ether, expectRevert } = require('@openzeppelin/test-helpers');
 const { shouldBehaveLikeEscrow } = require('./Escrow.behavior');
 
-const ConditionalEscrowMock = contract.fromArtifact('ConditionalEscrowMock');
+const ConditionalEscrowMock = artifacts.require('ConditionalEscrowMock');
 
-describe('ConditionalEscrow', function () {
+contract('ConditionalEscrow', function (accounts) {
   const [ owner, payee, ...otherAccounts ] = accounts;
 
   beforeEach(async function () {

test/payment/escrow/Escrow.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 require('@openzeppelin/test-helpers');
 const { shouldBehaveLikeEscrow } = require('./Escrow.behavior');
 
-const Escrow = contract.fromArtifact('Escrow');
+const Escrow = artifacts.require('Escrow');
 
-describe('Escrow', function () {
+contract('Escrow', function (accounts) {
   const [ owner, ...otherAccounts ] = accounts;
 
   beforeEach(async function () {

test/payment/escrow/RefundEscrow.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { balance, constants, ether, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const RefundEscrow = contract.fromArtifact('RefundEscrow');
+const RefundEscrow = artifacts.require('RefundEscrow');
 
-describe('RefundEscrow', function () {
+contract('RefundEscrow', function (accounts) {
   const [ owner, beneficiary, refundee1, refundee2 ] = accounts;
 
   const amount = ether('54');

test/presets/ERC1155PresetMinterPauser.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC1155PresetMinterPauser = contract.fromArtifact('ERC1155PresetMinterPauser');
+const ERC1155PresetMinterPauser = artifacts.require('ERC1155PresetMinterPauser');
 
-describe('ERC1155PresetMinterPauser', function () {
+contract('ERC1155PresetMinterPauser', function (accounts) {
   const [ deployer, other ] = accounts;
 
   const firstTokenId = new BN('845');

test/presets/ERC20PresetMinterPauser.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC20PresetMinterPauser = contract.fromArtifact('ERC20PresetMinterPauser');
+const ERC20PresetMinterPauser = artifacts.require('ERC20PresetMinterPauser');
 
-describe('ERC20PresetMinterPauser', function () {
+contract('ERC20PresetMinterPauser', function (accounts) {
   const [ deployer, other ] = accounts;
 
   const name = 'MinterPauserToken';

test/presets/ERC721PresetMinterPauserAutoId.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC721PresetMinterPauserAutoId = contract.fromArtifact('ERC721PresetMinterPauserAutoId');
+const ERC721PresetMinterPauserAutoId = artifacts.require('ERC721PresetMinterPauserAutoId');
 
-describe('ERC721PresetMinterPauserAutoId', function () {
+contract('ERC721PresetMinterPauserAutoId', function (accounts) {
   const [ deployer, other ] = accounts;
 
   const name = 'MinterAutoIDToken';

test/proxy/Initializable.test.js

@@ -1,13 +1,11 @@
-const { contract } = require('@openzeppelin/test-environment');
-
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
 const { assert } = require('chai');
 
-const InitializableMock = contract.fromArtifact('InitializableMock');
-const SampleChild = contract.fromArtifact('SampleChild');
+const InitializableMock = artifacts.require('InitializableMock');
+const SampleChild = artifacts.require('SampleChild');
 
-describe('Initializable', function () {
+contract('Initializable', function (accounts) {
   describe('basic testing without inheritance', function () {
     beforeEach('deploying', async function () {
       this.contract = await InitializableMock.new();

test/proxy/ProxyAdmin.test.js

@@ -1,15 +1,13 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ImplV1 = contract.fromArtifact('DummyImplementation');
-const ImplV2 = contract.fromArtifact('DummyImplementationV2');
-const ProxyAdmin = contract.fromArtifact('ProxyAdmin');
-const TransparentUpgradeableProxy = contract.fromArtifact('TransparentUpgradeableProxy');
+const ImplV1 = artifacts.require('DummyImplementation');
+const ImplV2 = artifacts.require('DummyImplementationV2');
+const ProxyAdmin = artifacts.require('ProxyAdmin');
+const TransparentUpgradeableProxy = artifacts.require('TransparentUpgradeableProxy');
 
-describe('ProxyAdmin', function () {
+contract('ProxyAdmin', function (accounts) {
   const [proxyAdminOwner, newAdmin, anotherAccount] = accounts;
 
   before('set implementations', async function () {

test/proxy/TransparentUpgradeableProxy.behaviour.js

@@ -1,22 +1,20 @@
-const { contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert, expectEvent, constants } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 const { toChecksumAddress, keccak256 } = require('ethereumjs-util');
 
 const { expect } = require('chai');
 
-const Proxy = contract.fromArtifact('Proxy');
-const Implementation1 = contract.fromArtifact('Implementation1');
-const Implementation2 = contract.fromArtifact('Implementation2');
-const Implementation3 = contract.fromArtifact('Implementation3');
-const Implementation4 = contract.fromArtifact('Implementation4');
-const MigratableMockV1 = contract.fromArtifact('MigratableMockV1');
-const MigratableMockV2 = contract.fromArtifact('MigratableMockV2');
-const MigratableMockV3 = contract.fromArtifact('MigratableMockV3');
-const InitializableMock = contract.fromArtifact('InitializableMock');
-const DummyImplementation = contract.fromArtifact('DummyImplementation');
-const ClashingImplementation = contract.fromArtifact('ClashingImplementation');
+const Proxy = artifacts.require('Proxy');
+const Implementation1 = artifacts.require('Implementation1');
+const Implementation2 = artifacts.require('Implementation2');
+const Implementation3 = artifacts.require('Implementation3');
+const Implementation4 = artifacts.require('Implementation4');
+const MigratableMockV1 = artifacts.require('MigratableMockV1');
+const MigratableMockV2 = artifacts.require('MigratableMockV2');
+const MigratableMockV3 = artifacts.require('MigratableMockV3');
+const InitializableMock = artifacts.require('InitializableMock');
+const DummyImplementation = artifacts.require('DummyImplementation');
+const ClashingImplementation = artifacts.require('ClashingImplementation');
 
 const IMPLEMENTATION_LABEL = 'eip1967.proxy.implementation';
 const ADMIN_LABEL = 'eip1967.proxy.admin';
@@ -409,7 +407,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy (createPro
       await proxy.upgradeTo(instance4.address, { from: proxyAdminAddress });
       const proxyInstance4 = new Implementation4(proxy.address);
 
-      const data = '';
+      const data = '0x';
       await web3.eth.sendTransaction({ to: proxy.address, from: anotherAccount, data });
 
       const res = await proxyInstance4.getValue();
@@ -423,7 +421,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy (createPro
       const instance2 = await Implementation2.new();
       await proxy.upgradeTo(instance2.address, { from: proxyAdminAddress });
 
-      const data = '';
+      const data = '0x';
       await expectRevert.unspecified(
         web3.eth.sendTransaction({ to: proxy.address, from: anotherAccount, data }),
       );

test/proxy/TransparentUpgradeableProxy.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const shouldBehaveLikeUpgradeableProxy = require('./UpgradeableProxy.behaviour');
 const shouldBehaveLikeTransparentUpgradeableProxy = require('./TransparentUpgradeableProxy.behaviour');
 
-const TransparentUpgradeableProxy = contract.fromArtifact('TransparentUpgradeableProxy');
+const TransparentUpgradeableProxy = artifacts.require('TransparentUpgradeableProxy');
 
-describe('TransparentUpgradeableProxy', function () {
+contract('TransparentUpgradeableProxy', function (accounts) {
   const [proxyAdminAddress, proxyAdminOwner] = accounts;
 
   const createProxy = async function (logic, admin, initData, opts) {

test/proxy/UpgradeableProxy.behaviour.js

@@ -1,11 +1,9 @@
-const { contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert } = require('@openzeppelin/test-helpers');
 const { toChecksumAddress, keccak256 } = require('ethereumjs-util');
 
 const { expect } = require('chai');
 
-const DummyImplementation = contract.fromArtifact('DummyImplementation');
+const DummyImplementation = artifacts.require('DummyImplementation');
 
 const IMPLEMENTATION_LABEL = 'eip1967.proxy.implementation';
 

test/proxy/UpgradeableProxy.test.js

@@ -1,10 +1,8 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const shouldBehaveLikeUpgradeableProxy = require('./UpgradeableProxy.behaviour');
 
-const UpgradeableProxy = contract.fromArtifact('UpgradeableProxy');
+const UpgradeableProxy = artifacts.require('UpgradeableProxy');
 
-describe('UpgradeableProxy', function () {
+contract('UpgradeableProxy', function (accounts) {
   const [proxyAdminOwner] = accounts;
 
   const createProxy = async function (implementation, _admin, initData, opts) {

test/setup.js

@@ -1,6 +1,6 @@
-const { defaultSender, web3 } = require('@openzeppelin/test-environment');
 const { deployRelayHub } = require('@openzeppelin/gsn-helpers');
 
 before('deploy GSN RelayHub', async function () {
+  const [defaultSender] = await web3.eth.getAccounts();
   await deployRelayHub(web3, { from: defaultSender });
 });

test/token/ERC1155/ERC1155.behavior.js

@@ -1,5 +1,3 @@
-const { contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
@@ -7,7 +5,7 @@ const { expect } = require('chai');
 
 const { shouldSupportInterfaces } = require('../../introspection/SupportsInterface.behavior');
 
-const ERC1155ReceiverMock = contract.fromArtifact('ERC1155ReceiverMock');
+const ERC1155ReceiverMock = artifacts.require('ERC1155ReceiverMock');
 
 function shouldBehaveLikeERC1155 ([minter, firstTokenHolder, secondTokenHolder, multiTokenHolder, recipient, proxy]) {
   const firstTokenId = new BN(1);

test/token/ERC1155/ERC1155.test.js

@@ -1,14 +1,12 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
 const { shouldBehaveLikeERC1155 } = require('./ERC1155.behavior');
-const ERC1155Mock = contract.fromArtifact('ERC1155Mock');
+const ERC1155Mock = artifacts.require('ERC1155Mock');
 
-describe('ERC1155', function () {
+contract('ERC1155', function (accounts) {
   const [operator, tokenHolder, tokenBatchHolder, ...otherAccounts] = accounts;
 
   const initialURI = 'https://token-cdn-domain/{id}.json';

test/token/ERC1155/ERC1155Burnable.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC1155BurnableMock = contract.fromArtifact('ERC1155BurnableMock');
+const ERC1155BurnableMock = artifacts.require('ERC1155BurnableMock');
 
-describe('ERC1155Burnable', function () {
+contract('ERC1155Burnable', function (accounts) {
   const [ holder, operator, other ] = accounts;
 
   const uri = 'https://token.com';

test/token/ERC1155/ERC1155Holder.test.js

@@ -1,12 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
 const { BN } = require('@openzeppelin/test-helpers');
 
-const ERC1155Holder = contract.fromArtifact('ERC1155Holder');
-const ERC1155Mock = contract.fromArtifact('ERC1155Mock');
+const ERC1155Holder = artifacts.require('ERC1155Holder');
+const ERC1155Mock = artifacts.require('ERC1155Mock');
 
 const { expect } = require('chai');
 
-describe('ERC1155Holder', function () {
+contract('ERC1155Holder', function (accounts) {
   const [creator] = accounts;
   const uri = 'https://token-cdn-domain/{id}.json';
   const multiTokenIds = [new BN(1), new BN(2), new BN(3)];

test/token/ERC1155/ERC1155Pausable.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC1155PausableMock = contract.fromArtifact('ERC1155PausableMock');
+const ERC1155PausableMock = artifacts.require('ERC1155PausableMock');
 
-describe('ERC1155Pausable', function () {
+contract('ERC1155Pausable', function (accounts) {
   const [ holder, operator, receiver, other ] = accounts;
 
   const uri = 'https://token.com';

test/token/ERC20/ERC20.test.js

@@ -1,5 +1,3 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { expect } = require('chai');
 const { ZERO_ADDRESS } = constants;
@@ -10,10 +8,10 @@ const {
   shouldBehaveLikeERC20Approve,
 } = require('./ERC20.behavior');
 
-const ERC20Mock = contract.fromArtifact('ERC20Mock');
-const ERC20DecimalsMock = contract.fromArtifact('ERC20DecimalsMock');
+const ERC20Mock = artifacts.require('ERC20Mock');
+const ERC20DecimalsMock = artifacts.require('ERC20DecimalsMock');
 
-describe('ERC20', function () {
+contract('ERC20', function (accounts) {
   const [ initialHolder, recipient, anotherAccount ] = accounts;
 
   const name = 'My Token';

test/token/ERC20/ERC20Burnable.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN } = require('@openzeppelin/test-helpers');
 
 const { shouldBehaveLikeERC20Burnable } = require('./behaviors/ERC20Burnable.behavior');
-const ERC20BurnableMock = contract.fromArtifact('ERC20BurnableMock');
+const ERC20BurnableMock = artifacts.require('ERC20BurnableMock');
 
-describe('ERC20Burnable', function () {
+contract('ERC20Burnable', function (accounts) {
   const [ owner, ...otherAccounts ] = accounts;
 
   const initialBalance = new BN(1000);

test/token/ERC20/ERC20Capped.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, ether, expectRevert } = require('@openzeppelin/test-helpers');
 const { shouldBehaveLikeERC20Capped } = require('./behaviors/ERC20Capped.behavior');
 
-const ERC20Capped = contract.fromArtifact('ERC20CappedMock');
+const ERC20Capped = artifacts.require('ERC20CappedMock');
 
-describe('ERC20Capped', function () {
+contract('ERC20Capped', function (accounts) {
   const [ minter, ...otherAccounts ] = accounts;
 
   const cap = ether('1000');

test/token/ERC20/ERC20Pausable.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC20PausableMock = contract.fromArtifact('ERC20PausableMock');
+const ERC20PausableMock = artifacts.require('ERC20PausableMock');
 
-describe('ERC20Pausable', function () {
+contract('ERC20Pausable', function (accounts) {
   const [ holder, recipient, anotherAccount ] = accounts;
 
   const initialSupply = new BN(100);

test/token/ERC20/ERC20Snapshot.test.js

@@ -1,11 +1,9 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
-const ERC20SnapshotMock = contract.fromArtifact('ERC20SnapshotMock');
+const ERC20SnapshotMock = artifacts.require('ERC20SnapshotMock');
 
 const { expect } = require('chai');
 
-describe('ERC20Snapshot', function () {
+contract('ERC20Snapshot', function (accounts) {
   const [ initialHolder, recipient, other ] = accounts;
 
   const initialSupply = new BN(100);

test/token/ERC20/SafeERC20.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
-const ERC20ReturnFalseMock = contract.fromArtifact('ERC20ReturnFalseMock');
-const ERC20ReturnTrueMock = contract.fromArtifact('ERC20ReturnTrueMock');
-const ERC20NoReturnMock = contract.fromArtifact('ERC20NoReturnMock');
-const SafeERC20Wrapper = contract.fromArtifact('SafeERC20Wrapper');
+const ERC20ReturnFalseMock = artifacts.require('ERC20ReturnFalseMock');
+const ERC20ReturnTrueMock = artifacts.require('ERC20ReturnTrueMock');
+const ERC20NoReturnMock = artifacts.require('ERC20NoReturnMock');
+const SafeERC20Wrapper = artifacts.require('SafeERC20Wrapper');
 
-describe('SafeERC20', function () {
+contract('SafeERC20', function (accounts) {
   const [ hasNoCode ] = accounts;
 
   describe('with address that has no contract code', function () {

test/token/ERC20/TokenTimelock.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, expectRevert, time } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC20Mock = contract.fromArtifact('ERC20Mock');
-const TokenTimelock = contract.fromArtifact('TokenTimelock');
+const ERC20Mock = artifacts.require('ERC20Mock');
+const TokenTimelock = artifacts.require('TokenTimelock');
 
-describe('TokenTimelock', function () {
+contract('TokenTimelock', function (accounts) {
   const [ beneficiary ] = accounts;
 
   const name = 'My Token';

test/token/ERC721/ERC721.test.js

@@ -1,5 +1,3 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
@@ -7,10 +5,10 @@ const { expect } = require('chai');
 
 const { shouldSupportInterfaces } = require('../../introspection/SupportsInterface.behavior');
 
-const ERC721Mock = contract.fromArtifact('ERC721Mock');
-const ERC721ReceiverMock = contract.fromArtifact('ERC721ReceiverMock');
+const ERC721Mock = artifacts.require('ERC721Mock');
+const ERC721ReceiverMock = artifacts.require('ERC721ReceiverMock');
 
-describe('ERC721', function () {
+contract('ERC721', function (accounts) {
   const [owner, newOwner, approved, anotherApproved, operator, other] = accounts;
 
   const name = 'Non Fungible Token';

test/token/ERC721/ERC721Burnable.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC721BurnableMock = contract.fromArtifact('ERC721BurnableMock');
+const ERC721BurnableMock = artifacts.require('ERC721BurnableMock');
 
-describe('ERC721Burnable', function () {
+contract('ERC721Burnable', function (accounts) {
   const [owner, approved] = accounts;
 
   const firstTokenId = new BN(1);

test/token/ERC721/ERC721Holder.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ERC721Holder = contract.fromArtifact('ERC721Holder');
-const ERC721Mock = contract.fromArtifact('ERC721Mock');
+const ERC721Holder = artifacts.require('ERC721Holder');
+const ERC721Mock = artifacts.require('ERC721Mock');
 
-describe('ERC721Holder', function () {
+contract('ERC721Holder', function (accounts) {
   const [ owner ] = accounts;
 
   const name = 'Non Fungible Token';

test/token/ERC721/ERC721Pausable.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC721PausableMock = contract.fromArtifact('ERC721PausableMock');
+const ERC721PausableMock = artifacts.require('ERC721PausableMock');
 
-describe('ERC721Pausable', function () {
+contract('ERC721Pausable', function (accounts) {
   const [ owner, receiver, operator ] = accounts;
 
   const name = 'Non Fungible Token';

test/token/ERC777/ERC777.behavior.js

@@ -1,10 +1,9 @@
-const { contract, web3 } = require('@openzeppelin/test-environment');
 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
 const { expect } = require('chai');
 
-const ERC777SenderRecipientMock = contract.fromArtifact('ERC777SenderRecipientMock');
+const ERC777SenderRecipientMock = artifacts.require('ERC777SenderRecipientMock');
 
 function shouldBehaveLikeERC777DirectSendBurn (holder, recipient, data) {
   shouldBehaveLikeERC777DirectSend(holder, recipient, data);

test/token/ERC777/ERC777.test.js

@@ -1,5 +1,3 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { BN, constants, expectEvent, expectRevert, singletons } = require('@openzeppelin/test-helpers');
 const { ZERO_ADDRESS } = constants;
 
@@ -19,10 +17,10 @@ const {
   shouldBehaveLikeERC20Approve,
 } = require('../ERC20/ERC20.behavior');
 
-const ERC777 = contract.fromArtifact('ERC777Mock');
-const ERC777SenderRecipientMock = contract.fromArtifact('ERC777SenderRecipientMock');
+const ERC777 = artifacts.require('ERC777Mock');
+const ERC777SenderRecipientMock = artifacts.require('ERC777SenderRecipientMock');
 
-describe('ERC777', function () {
+contract('ERC777', function (accounts) {
   const [ registryFunder, holder, defaultOperatorA, defaultOperatorB, newOperator, anyone ] = accounts;
 
   const initialSupply = new BN('10000');

test/utils/Address.test.js

@@ -1,13 +1,11 @@
-const { accounts, contract, web3 } = require('@openzeppelin/test-environment');
-
 const { balance, ether, expectRevert, send, expectEvent } = require('@openzeppelin/test-helpers');
 const { expect } = require('chai');
 
-const AddressImpl = contract.fromArtifact('AddressImpl');
-const EtherReceiver = contract.fromArtifact('EtherReceiverMock');
-const CallReceiverMock = contract.fromArtifact('CallReceiverMock');
+const AddressImpl = artifacts.require('AddressImpl');
+const EtherReceiver = artifacts.require('EtherReceiverMock');
+const CallReceiverMock = artifacts.require('CallReceiverMock');
 
-describe('Address', function () {
+contract('Address', function (accounts) {
   const [ recipient, other ] = accounts;
 
   beforeEach(async function () {
@@ -145,8 +143,8 @@ describe('Address', function () {
         }, []);
 
         await expectRevert(
-          this.mock.functionCall(this.contractRecipient.address, abiEncodedCall),
-          'Address: low-level call failed'
+          this.mock.functionCall(this.contractRecipient.address, abiEncodedCall, { gas: '90000' }),
+          'Address: low-level call failed',
         );
       }).timeout(5000);
 

test/utils/Arrays.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ArraysImpl = contract.fromArtifact('ArraysImpl');
+const ArraysImpl = artifacts.require('ArraysImpl');
 
-describe('Arrays', function () {
+contract('Arrays', function (accounts) {
   describe('findUpperBound', function () {
     context('Even number of elements', function () {
       const EVEN_ELEMENTS_ARRAY = [11, 12, 13, 14, 15, 16, 17, 18, 19, 20];

test/utils/Counters.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const CountersImpl = contract.fromArtifact('CountersImpl');
+const CountersImpl = artifacts.require('CountersImpl');
 
-describe('Counters', function () {
+contract('Counters', function (accounts) {
   beforeEach(async function () {
     this.counter = await CountersImpl.new();
   });

test/utils/Create2.test.js

@@ -1,13 +1,12 @@
-const { contract, accounts, web3 } = require('@openzeppelin/test-environment');
 const { balance, BN, ether, expectRevert, send } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const Create2Impl = contract.fromArtifact('Create2Impl');
-const ERC20Mock = contract.fromArtifact('ERC20Mock');
-const ERC1820Implementer = contract.fromArtifact('ERC1820Implementer');
+const Create2Impl = artifacts.require('Create2Impl');
+const ERC20Mock = artifacts.require('ERC20Mock');
+const ERC1820Implementer = artifacts.require('ERC1820Implementer');
 
-describe('Create2', function () {
+contract('Create2', function (accounts) {
   const [deployerAccount] = accounts;
 
   const salt = 'salt message';

test/utils/EnumerableMap.test.js

@@ -1,12 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
 const { BN, expectEvent } = require('@openzeppelin/test-helpers');
 const { expect } = require('chai');
 
 const zip = require('lodash.zip');
 
-const EnumerableMapMock = contract.fromArtifact('EnumerableMapMock');
+const EnumerableMapMock = artifacts.require('EnumerableMapMock');
 
-describe('EnumerableMap', function () {
+contract('EnumerableMap', function (accounts) {
   const [ accountA, accountB, accountC ] = accounts;
 
   const keyA = new BN('7891');

test/utils/EnumerableSet.test.js

@@ -1,12 +1,11 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
 const { BN } = require('@openzeppelin/test-helpers');
 
-const EnumerableAddressSetMock = contract.fromArtifact('EnumerableAddressSetMock');
-const EnumerableUintSetMock = contract.fromArtifact('EnumerableUintSetMock');
+const EnumerableAddressSetMock = artifacts.require('EnumerableAddressSetMock');
+const EnumerableUintSetMock = artifacts.require('EnumerableUintSetMock');
 
 const { shouldBehaveLikeSet } = require('./EnumerableSet.behavior');
 
-describe('EnumerableSet', function () {
+contract('EnumerableSet', function (accounts) {
   // AddressSet
   describe('EnumerableAddressSet', function () {
     const [ accountA, accountB, accountC ] = accounts;

test/utils/Pausable.test.js

@@ -1,12 +1,10 @@
-const { accounts, contract } = require('@openzeppelin/test-environment');
-
 const { expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const PausableMock = contract.fromArtifact('PausableMock');
+const PausableMock = artifacts.require('PausableMock');
 
-describe('Pausable', function () {
+contract('Pausable', function (accounts) {
   const [ pauser ] = accounts;
 
   beforeEach(async function () {

test/utils/ReentrancyGuard.test.js

@@ -1,12 +1,11 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const ReentrancyMock = contract.fromArtifact('ReentrancyMock');
-const ReentrancyAttack = contract.fromArtifact('ReentrancyAttack');
+const ReentrancyMock = artifacts.require('ReentrancyMock');
+const ReentrancyAttack = artifacts.require('ReentrancyAttack');
 
-describe('ReentrancyGuard', function () {
+contract('ReentrancyGuard', function (accounts) {
   beforeEach(async function () {
     this.reentrancyMock = await ReentrancyMock.new();
     expect(await this.reentrancyMock.counter()).to.be.bignumber.equal('0');

test/utils/SafeCast.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { BN, expectRevert } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const SafeCastMock = contract.fromArtifact('SafeCastMock');
+const SafeCastMock = artifacts.require('SafeCastMock');
 
-describe('SafeCast', async () => {
+contract('SafeCast', async (accounts) => {
   beforeEach(async function () {
     this.safeCast = await SafeCastMock.new();
   });
@@ -47,7 +46,6 @@ describe('SafeCast', async () => {
   describe('toUint256', () => {
     const maxInt256 = new BN('2').pow(new BN(255)).subn(1);
     const minInt256 = new BN('2').pow(new BN(255)).neg();
-    const maxUint256 = new BN('2').pow(new BN(256)).subn(1);
 
     it('casts 0', async function () {
       expect(await this.safeCast.toUint256(0)).to.be.bignumber.equal('0');
@@ -74,13 +72,6 @@ describe('SafeCast', async () => {
         'SafeCast: value must be positive'
       );
     });
-
-    it(`reverts when casting UINT256_MAX (${maxUint256})`, async function () {
-      await expectRevert(
-        this.safeCast.toUint256(maxUint256),
-        'SafeCast: value must be positive'
-      );
-    });
   });
 
   function testToInt (bits) {

test/utils/Strings.test.js

@@ -1,11 +1,10 @@
-const { contract } = require('@openzeppelin/test-environment');
 const { constants } = require('@openzeppelin/test-helpers');
 
 const { expect } = require('chai');
 
-const StringsMock = contract.fromArtifact('StringsMock');
+const StringsMock = artifacts.require('StringsMock');
 
-describe('Strings', function () {
+contract('Strings', function (accounts) {
   beforeEach(async function () {
     this.strings = await StringsMock.new();
   });