Vitest Presets

This package provides Vitest configuration presets that mirror the functionality of jest-presets.

Usage

In your vitest.config.js:

import { defineConfig } from 'vitest/config'
import vitestPreset from 'config/vitest-presets/vitest/vitest-preset.js'

export default defineConfig({
  ...vitestPreset,
  // Add any additional overrides here
})

Migration from Jest

Key Differences

1. Globals: Vitest globals are opt-in. We've enabled them in the preset with globals: true.

2. Module Mocking: Use vi.mock() instead of jest.mock(). Mocks are hoisted automatically.

3. Transform Configuration: Vitest uses Vite's transform pipeline, so transformIgnorePatterns is replaced with optimizeDeps.include.

4. Module Mapping: Jest's moduleNameMapper is replaced with Vite's resolve.alias.

5. Setup Files: Jest's setupFilesAfterEnv becomes Vitest's setupFiles.

Configuration Mapping

| Jest | Vitest | |------|--------| | preset: 'ts-jest' | Not needed (TypeScript support is built-in) | | testEnvironment: 'jsdom' | test.environment: 'jsdom' | | moduleNameMapper | resolve.alias | | setupFilesAfterEnv | test.setupFiles | | transformIgnorePatterns | optimizeDeps.include | | collectCoverage | test.coverage.enabled | | coverageReporters | test.coverage.reporter | | globals | test.env |

Mocked Libraries

All mocks from jest-presets have been migrated:

• Chrome storage API (using mem-storage-area)
• React Native AsyncStorage
• Redux Persist
• Expo libraries (clipboard, blur, haptics, linear-gradient, screen-capture)
• Amplitude Analytics
• React Native Device Info
• NetInfo
• WalletConnect packages
• AppsFlyer

Features Not Migrated

1. SVG Transform: The jest-transformer-svg package needs a Vitest equivalent. For now, SVGs are handled through the alias system.

2. Babel Transform: Vitest uses Vite's transform pipeline which handles modern JavaScript/TypeScript natively. Babel-specific transforms may need custom Vite plugins.

3. Jest-specific mock packages: Some packages provide Jest-specific mocks (e.g., @react-native-community/netinfo/jest/netinfo-mock.js). These have been replaced with custom Vitest mocks in the setup file.

4. Statsig mocks: The Statsig SDK mocks that were importing from uniswap/src/features/gating/* have been removed to avoid cross-package dependencies.

Testing the Configuration

Run the included tests to verify the configuration:

cd config/vitest-presets
bun run test