enzyme-on-rtl

Automated migration from Enzyme to React Testing Library.

![Test Status]()

---

The Problem

Enzyme is dead. Airbnb stopped maintaining it in 2021, and there's no React 18/19 adapter. Thousands of projects are stuck on unmaintained testing code.

Migrating manually takes weeks for large codebases. The patterns are repetitive but tedious.

enzyme-on-rtl automates the conversion.

---

The Solution

A command-line tool that converts Enzyme test patterns to React Testing Library equivalents:

``bash
npx enzyme-on-rtl convert MyComponent.test.tsx
`

$3

| Enzyme Pattern | React Testing Library |
|----------------|----------------------|
| mount() | render() |
| shallow() | render() |
| wrapper.find('.btn') | screen.getByTestId('btn') |
| wrapper.text() | textContent |
| wrapper.html() | innerHTML |
| wrapper.simulate('click') | userEvent.click() |
| wrapper.find('.btn').exists() | expect(screen.queryByTestId('btn')).not.toBeInTheDocument() |
| import { mount } from 'enzyme' | RTL imports + cleanup |

---

Installation

`bash


Global install (recommended for CLI use)

npm install -g enzyme-on-rtl

Or use via npx

npx enzyme-on-rtl@latest convert ./src
`

---

Usage

$3

`bash
enzyme-on-rtl convert MyComponent.test.tsx
`

$3

`bash
enzyme-on-rtl convert-dir ./src --output ./rtl-tests
`

$3

`bash
enzyme-on-rtl diff MyComponent.test.tsx
`

$3

`bash
enzyme-on-rtl list
`

$3

| Flag | Description |
|------|-------------|
| -o, --output | Output file or directory (default: overwrite) |
| -h, --help | Show help |
| -v, --version | Show version |

---

Example

Before (Enzyme):

`typescript
import { mount } from 'enzyme'
import Button from './Button'

describe('Button', () => {
it('calls onClick when clicked', () => {
const onClick = jest.fn()
const wrapper = mount()

wrapper.find('.submit-button').simulate('click')
expect(onClick).toHaveBeenCalled()
expect(wrapper.text()).toContain('Submitted')
})
})
`

After (React Testing Library):

`typescript
import { render, screen } from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import { cleanup } from '@testing-library/react'
import Button from './Button'

afterEach(() => cleanup())

describe('Button', () => {
it('calls onClick when clicked', async () => {
const onClick = jest.fn()
render(

)

const button = screen.getByTestId('submit-button')
await userEvent.click(button)
expect(onClick).toHaveBeenCalled()
expect(screen.getByText('Submitted')).toBeInTheDocument()
})
})
`

---

Patterns Supported

1. mount() → render()
2. shallow() → render()
3. .find(selector) → screen.getByTestId(), getByRole(), or getByText()
4. .text() → textContent
5. .html() → innerHTML
6. .simulate('click') → userEvent.click()
7. .simulate('change') → fireEvent.change()
8. .setProps() → Re-render comment
9. .state() → Custom state inspection comment
10. .instance() → Behavior testing comment
11. .find().exists() → expect(queryByTestId()).not.toBeInTheDocument()
12. Enzyme imports → RTL imports + cleanup

---

Development

`bash


Install dependencies

pnpm install

Run tests

pnpm test

Build for production

pnpm build

Run CLI

pnpm cli convert ./test-fixture.tsx
``

---

Why "enzyme-on-rtl"?

The name reflects the transition: Enzyme ON React Testing Library. Not just converting from Enzyme, but placing your tests ON a modern, supported testing foundation.

---

License

MIT © Peter W.

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Contributing

Issues and PRs welcome! This tool is early-stage — bug reports and pattern suggestions help a lot.