Enzyme React Adapters: enzyme-adapter-react-16 vs @wojtekmaj/enzyme-adapter-react-17

Both enzyme-adapter-react-16 and @wojtekmaj/enzyme-adapter-react-17 are official-style adapters that enable the Enzyme testing utility to work with specific versions of React. Enzyme itself is a JavaScript testing utility for React that lets you assert, manipulate, and traverse your React Components’ output. However, because Enzyme relies on internal React APIs that change between major versions, it requires version-specific adapters. Let’s compare these two adapters in depth.

🧪 Core Purpose: Bridging Enzyme to React Internals

enzyme-adapter-react-16 connects Enzyme to React 16’s rendering and lifecycle system. It uses the legacy react-test-renderer and React’s internal reconciler available in React 16.

// Setup for React 16
import Enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

Enzyme.configure({ adapter: new Adapter() });

@wojtekmaj/enzyme-adapter-react-17 does the same for React 17. This adapter was created by Wojciech Maj (a well-known contributor to the React ecosystem) because the official Enzyme team did not release a React 17 adapter before sunsetting active development.

// Setup for React 17
import Enzyme from 'enzyme';
import Adapter from '@wojtekmaj/enzyme-adapter-react-17';

Enzyme.configure({ adapter: new Adapter() });

Both adapters allow you to write tests like:

import { shallow } from 'enzyme';

const wrapper = shallow(<MyComponent />);
expect(wrapper.find('button')).toHaveLength(1);

⚠️ Maintenance Status and Official Support

enzyme-adapter-react-16 is published under the official enzyme organization on npm (airbnb/enzyme GitHub). However, as of 2021, the Enzyme project has been effectively deprecated. The repository is archived, and no new adapters are being developed by the original team.

@wojtekmaj/enzyme-adapter-react-17 is a community-maintained package that fills the gap left by the official team. It is widely adopted and works reliably with React 17, but it is not an official Airbnb/Enzyme release. The package documentation clearly states it exists because “Enzyme doesn’t officially support React 17 yet.”

🔴 Important: Neither adapter should be used in new projects. The Enzyme team recommends migrating to React Testing Library, which works seamlessly across React versions without adapters.

🔄 Compatibility with React Features

React 16 vs React 17 Differences

React 17 introduced a new JSX transform and minor event system changes, but no breaking component API changes. However, Enzyme’s deep integration with React internals means even subtle changes break compatibility.

• enzyme-adapter-react-16 will fail or behave unpredictably with React 17 due to changes in how events are attached and how the reconciler works.
• @wojtekmaj/enzyme-adapter-react-17 patches these incompatibilities and supports the new JSX runtime (though most Enzyme usage doesn’t depend on JSX transform details).

Example of a test that would break with the wrong adapter:

// MyComponent.jsx
function MyComponent({ onClick }) {
  return <button onClick={onClick}>Click me</button>;
}

// Test
const mockFn = jest.fn();
const wrapper = shallow(<MyComponent onClick={mockFn} />);
wrapper.find('button').simulate('click');
expect(mockFn).toHaveBeenCalled(); // May fail in React 17 with v16 adapter

The React 17 adapter correctly maps Enzyme’s .simulate() to React 17’s event system.

🛠️ Installation and Peer Dependencies

Both packages declare strict peer dependencies on their respective React versions.

For React 16:

npm install --save-dev enzyme enzyme-adapter-react-16 react@16 react-dom@16

For React 17:

npm install --save-dev enzyme @wojtekmaj/enzyme-adapter-react-17 react@17 react-dom@17

Attempting to use enzyme-adapter-react-16 with React 17 will result in npm/yarn warnings about unmet peer dependencies — and likely runtime errors.

📉 Long-Term Viability and Migration Path

Since Enzyme is no longer actively maintained, both adapters are end-of-life solutions. They exist only to support legacy codebases.

• If you’re on React 16, enzyme-adapter-react-16 is your only official option — but plan to migrate away from Enzyme.
• If you’ve upgraded to React 17, @wojtekmaj/enzyme-adapter-react-17 is the de facto standard community adapter — but again, treat it as a temporary bridge.

The recommended modern alternative is React Testing Library, which encourages testing behavior over implementation and works out-of-the-box with any React version:

// Modern equivalent with React Testing Library
import { render, screen, fireEvent } from '@testing-library/react';

render(<MyComponent onClick={mockFn} />);
fireEvent.click(screen.getByText('Click me'));
expect(mockFn).toHaveBeenCalled();

✅ When You Might Still Use These Adapters

Despite the deprecation, some teams remain on Enzyme due to:

• Large existing test suites that would be costly to rewrite
• Heavy reliance on Enzyme-specific features like .state(), .instance(), or deep rendering control
• Lack of bandwidth for migration

In those cases:

• Use enzyme-adapter-react-16 only if your app is locked on React 16.
• Use @wojtekmaj/enzyme-adapter-react-17 only if you’ve moved to React 17 and cannot migrate off Enzyme immediately.

But do not start new projects with either.

🆚 Summary: Key Differences

💡 Final Recommendation

These adapters solve a narrow, version-specific compatibility problem for a testing library that is no longer maintained. Your best move is to avoid both in new code. If you’re stuck maintaining an old Enzyme test suite:

• Match the adapter exactly to your React version.
• Treat any test instability as a sign to prioritize migration to React Testing Library.

Enzyme served the community well for years, but the ecosystem has moved on — and so should your testing strategy.