vitest

> Base Vitest configuration with TypeScript-friendly defaults, v8 coverage and 80% thresholds.

✨ Features

• 📊 Coverage: v8 provider with 80% thresholds
• 🎯 Sensible defaults: Node environment, globals enabled, verbose reporter
• ⚡ Fast: thread pool by default
• 🔀 Dual format: ESM and CommonJS builds

📦 Installation

npm install --save-dev @jmlweb/vitest-config vitest @vitest/coverage-v8

@vitest/coverage-v8 is needed for --coverage; use the same version as vitest.

> 💡 Upgrading? See the Migration Guide.

🚀 Quick Start

vitest.config.ts

import { defineConfig } from 'vitest/config';
import baseConfig from '@jmlweb/vitest-config';

export default defineConfig({
  ...baseConfig,
});

Everything lives under test. A test key in your config replaces the whole base test block, so spread ...baseConfig.test into it, or use mergeConfig:

import { defineConfig, mergeConfig } from 'vitest/config';
import baseConfig from '@jmlweb/vitest-config';

export default mergeConfig(
  baseConfig,
  defineConfig({ test: { environment: 'jsdom' } }),
);

💡 Examples

Overrides

import { defineConfig } from 'vitest/config';
import baseConfig from '@jmlweb/vitest-config';

export default defineConfig({
  ...baseConfig,
  test: {
    ...baseConfig.test,
    environment: 'jsdom',
    setupFiles: ['./src/test/setup.ts'],
    testTimeout: 10000,
  },
});

Custom coverage thresholds

import { defineConfig } from 'vitest/config';
import baseConfig from '@jmlweb/vitest-config';

export default defineConfig({
  ...baseConfig,
  test: {
    ...baseConfig.test,
    coverage: {
      ...baseConfig.test?.coverage,
      thresholds: { lines: 90, functions: 90, branches: 85, statements: 90 },
    },
  },
});

Explicit imports, no thresholds

Import describe, it and expect yourself and report coverage without failing the run:

import { defineConfig } from 'vitest/config';
import baseConfig from '@jmlweb/vitest-config';

export default defineConfig({
  ...baseConfig,
  test: {
    ...baseConfig.test,
    globals: false,
    coverage: { ...baseConfig.test?.coverage, thresholds: {} },
  },
});

📋 Configuration Details

Setting	Value
globals	true
environment	'node'
testTimeout / hookTimeout	5000 / 10000 ms
pool	'threads'
reporters	['verbose']
include	**/*.{test,spec}.{ts,tsx,js,jsx}
exclude	node_modules, dist, build, dot-dirs, tool config files
coverage.provider	'v8'
coverage.thresholds	80 for lines, functions, branches, statements
coverage.include	src/**/*.{ts,tsx,js,jsx}
coverage.reporter	['text', 'json', 'html']

Coverage excludes *.d.ts, *.config.{ts,js}, dist, build, node_modules, coverage, and test/spec files.

🎯 When to Use

• ✅ Vitest-based TypeScript projects
• ✅ Enforced coverage with a shared baseline
• ✅ Node.js libraries, CLIs and APIs, or browser code with environment: 'jsdom'

Not for you if you use Jest: see @jmlweb/jest-config (maintenance mode).

🔧 Extending the Configuration

Spread baseConfig.test and override what you need (see Examples). Install jsdom or happy-dom yourself when you set environment to either.

📝 Usage with Scripts

{
  "scripts": {
    "test": "vitest",
    "test:run": "vitest run",
    "test:coverage": "vitest run --coverage",
    "test:typecheck": "vitest typecheck"
  }
}

npm test                  # watch mode
npm run test:coverage     # single run with coverage

Type checking is not part of the config: run vitest typecheck separately.

📋 Requirements

• Node.js >= 22.12.0
• Vitest >= 1.0.0 (config targets Vitest 4)

📦 Peer Dependencies

• vitest (>=1.0.0)

🔗 Related Packages

• @jmlweb/vite-config - Vite base config
• @jmlweb/tsconfig-base - TypeScript configuration
• @jmlweb/oxlint-config-base - Oxlint config
• @jmlweb/oxfmt-config-base - Oxfmt config
• @jmlweb/jest-config - Jest alternative (maintenance mode)

🔄 Migration Guide

2.x to 3.0

Breaking: Node.js >= 22.12.0 is required.

1. Upgrade Node.js to 22.12.0 or later.
2. Update: npm install --save-dev @jmlweb/vitest-config@latest

1.x to 2.0

Vitest 4: poolOptions.threads.minThreads and maxThreads are gone; Vitest manages the pool automatically.

See the Changelog for details.

📄 License

MIT