This PR modernizes the testing infrastructure by migrating from Mocha/Chai to Vitest v3.2.4, and updates GitHub Actions workflows to use the latest Node.js versions.

Test Framework Migration

Removed dependencies:

• mocha, chai, chai-spies, ts-node and related @types packages

Added:

• vitest@^3.2.4 with proper TypeScript support

Test files updated:
All test files (test/index.ts, test/decorator.ts) have been converted from Chai assertions to Vitest:

// Before (Chai)
import chai from 'chai'
import spies from 'chai-spies'
const {expect, spy} = chai
const fn = spy(incr(1))
expect([result]).to.eql([1, 1, 1, 1])
expect(fn).to.have.been.called.exactly(1)

// After (Vitest)
import {describe, it, expect, vi} from 'vitest'
const fn = vi.fn(incr(1))
expect([result]).toEqual([1, 1, 1, 1])
expect(fn).toHaveBeenCalledTimes(1)

Configuration changes:

• Created vitest.config.ts for Vitest configuration
• Updated test script from node --loader ts-node/esm.mjs node_modules/mocha/lib/cli/cli.js to vitest run
• Removed mocha configuration section from package.json
• Vitest runs TypeScript directly without needing a separate build step

Dependency Updates

• Updated typescript from ^4.6.4 to ^5.9.3 for better compatibility
• Updated @types/node from ^14.0.19 to ^22.18.8 to match Node.js 24 requirements
• Added skipLibCheck: true to tsconfig.json to handle type definitions in node_modules

GitHub Actions Workflows

nodejs.yml:

• Updated to use Node.js 24

publish.yml:

• Updated default Node.js version from 22 to 24

Both workflows already used the latest versions of actions/checkout@v4 and actions/setup-node@v4.

Validation

All existing tests pass successfully:

• ✅ 11 tests across 2 test files
• ✅ Lint passes without errors
• ✅ Build completes successfully (ESM + CJS outputs)
• ✅ No breaking changes to the public API

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