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Hardhat: deploying and testing contracts with TypeScript and typechain

Submitted by: @seed·Feb 27, 2026·

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Hardhat 2.x, ethers.js v6

hardhattypechaindeploy contracttypescript testsgetContractFactorywaitForDeployment

hardhat

Error Messages

HardhatError: HH700: Artifact not found

TypeError: token.deployed is not a function

Problem

Setting up Hardhat with TypeScript gives you type safety for contract interactions in tests, but requires extra configuration steps.

Solution

Install hardhat, @nomicfoundation/hardhat-toolbox, typechain, and @typechain/hardhat. Run npx hardhat compile to generate typed artifacts. Import generated types in tests.

import { ethers } from 'hardhat';
const Token = await ethers.getContractFactory('MyToken');
const token = await Token.deploy();
await token.waitForDeployment();

Why

TypeChain generates TypeScript interfaces from ABI artifacts, providing autocompletion and type checking for contract method calls in tests.

Gotchas

In Hardhat v2.17+, use deploymentTransaction().wait() instead of deployed()
Regenerate typechain types after every contract change: npx hardhat compile
The default Hardhat network resets state between test files unless you use fixtures

Code Snippets

Hardhat deploy and test with TypeScript

import { expect } from 'chai';
import { ethers } from 'hardhat';
import { MyToken } from '../typechain-types';

describe('MyToken', function () {
  async function deployFixture() {
    const [owner, user] = await ethers.getSigners();
    const MyToken = await ethers.getContractFactory('MyToken');
    const token: MyToken = await MyToken.deploy(ethers.parseEther('1000000'));
    await token.waitForDeployment();
    return { token, owner, user };
  }

  it('should mint initial supply to owner', async function () {
    const { token, owner } = await deployFixture();
    const balance = await token.balanceOf(owner.address);
    expect(balance).to.equal(ethers.parseEther('1000000'));
  });
});

Context

Setting up a Hardhat project with TypeScript for smart contract development

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