universal-test-renderer

Universal Test Renderer for React

A lightweight, JavaScript-only replacement for the deprecated React Test Renderer.

Why Use It?

• Pure JavaScript Testing - Test React components in Jest or Vitest without browser or native dependencies
• Universal - Can be used to simulate React Native or any other React renderer
• React 19 Ready - Modern alternative as React Test Renderer is now deprecated
• Lightweight - Minimal dependencies and small bundle size
• Type-safe - Written in TypeScript with full type definitions
• Flexible Configuration - Customizable reconciler options for different use cases

Installation

npm install -D universal-test-renderer

Basic Usage

import { act } from "react";
import { createRoot } from "universal-test-renderer";

test("example", () => {
  const renderer = createRoot();
  act(() => {
    renderer.render(<div>Hello!</div>);
  });

  expect(renderer.root?.toJSON()).toMatchInlineSnapshot(`
    <div>
      Hello!
    </div>
  `);
});

Key Differences from React Test Renderer

• Works at host component level only (no composite components)
• More flexible reconciler configuration options
• Uses act from the React package directly