Test Environment

Blazing fast smart contract testing. One-line setup for an awesome testing experience.

  • Near-instant start up: have your code running in under 2s after typing npm test.

  • Test runner agnostic – from the familiarity of Mocha, to parallel tests using Jest or Ava!

  • Non-opinionated: use either @truffle/contract or web3-eth-contract as you see fit.

  • First class support for the OpenZeppelin Test Helpers.

  • Highly configurable: from gas limit and initial balance, to complex custom web3 providers and forking Mainnet state!

  • No global variables, no hacks.

Test Environment is the result of our learnings while developing the OpenZeppelin Contracts, combining best practices and the tools we’ve come to rely on over the years. We think you’ll love it!



$ npm install --save-dev @openzeppelin/test-environment


By including require('@openzeppelin/test-environment') in your test files, a local ganache-powered blockchain with unlocked accounts will be spun up, and all tools configured to work with it.

const { accounts, contract } = require('@openzeppelin/test-environment');
const [ owner ] = accounts;

const { expect } = require('chai');

const MyContract = contract.fromArtifact('MyContract'); // Loads a compiled contract

describe('MyContract', function () {
  it('deployer is owner', async function () {
    const myContract = await MyContract.new({ from: owner });
    expect(await myContract.owner()).to.equal(owner);

If you’re used to truffle test, this probably looks very familiar. Follow our guide on migrating from Truffle to have your project running with Test Environment in a breeze!

Note: if you’d rather not rely on truffle contracts and use web3 contract types directly, worry not: you can configure Test Environment to use the web3-eth-contract abstraction.

Learn More