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# hardhat-waffle

Hardhat (opens new window) plugin for integration with Waffle (opens new window).

# What

You can use this plugin to build smart contract tests using Waffle in Hardhat, taking advantage of both.

This plugin adds a Hardhat-ready version of Waffle to the Hardhat Runtime Environment, and automatically initializes the Waffle Chai matchers (opens new window).

# Installation

npm install --save-dev @nomiclabs/hardhat-waffle 'ethereum-waffle@^3.0.0' @nomiclabs/hardhat-ethers 'ethers@^5.0.0'

And add the following statement to your hardhat.config.js:

require("@nomiclabs/hardhat-waffle");

Or, if you are using TypeScript, add this to your hardhat.config.ts:

import "@nomiclabs/hardhat-waffle";

# Tasks

This plugin creates no additional tasks.

# Environment extensions

This plugin adds a waffle object to the Hardhat Runtime Environment. This object has all the Waffle functionality, already adapted to work with Hardhat.

The waffle object has these properties:

• provider
• deployContract
• solidity
• link
• deployMockContract
• createFixtureLoader
• loadFixture

This plugin depends on @nomiclabs/hardhat-ethers (opens new window), so it also injects an ethers object into the HRE, which is documented here (opens new window).

# Usage

Once installed, you can build your tests almost like in Waffle.

Instead of importing things from ethereum-waffle, you access them from the waffle property of the Hardhat Runtime Environment.

For example, instead of doing

const { deployContract } = require("ethereum-waffle");

you should do

const { waffle } = require("hardhat");
const { deployContract } = waffle;

Also, you don't need to call chai.use in order to use Waffle's Chai matchers (opens new window).

Note that by default, Hardhat saves its compilation output into artifacts/ instead of build/. You can either use that directory in your tests, or customize your Hardhat config (opens new window).