Convert test framework from Mocha/Chai to Vitest and update CI workflows

[Copilot]

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

Original prompt

This package currently uses chai and mocha to run tests. Convert it to use Vitest. Install vitest version ^3.2.4. Update test files to import describe/it/etc from vitest and use assertion helpers from vitest. Remove the pretest build script since vitest can run TypeScript directly. Run the tests with npm test and verify they pass. Remove all references to karma/chai/mocha.

Also update all github workflows to run with Node 24 by default, and include Node 22 in matrix runs (only if matrix is already configured, don't add it). Drop older versions. Update actions to use the latest version of actions/setup-node and actions/checkout. Add a step before running tests in CI which runs npx playwright install chromium.

Ensure lint and tests both pass. Remove any references to karma/mocha/chai from the lint config.

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[Copilot]

Pull Request Overview

This PR migrates the testing infrastructure from Mocha/Chai to Vitest v3.2.4 and updates CI workflows to use Node.js 24.

• Replaces Mocha/Chai test framework with Vitest for modern TypeScript testing
• Updates Node.js version to 24 in GitHub Actions workflows
• Removes outdated dependencies and configurations while adding Playwright support

Reviewed Changes

Copilot reviewed 6 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
vitest.config.ts	Adds Vitest configuration for TypeScript test execution
test/index.ts	Converts Chai assertions to Vitest syntax and spy functions
test/decorator.ts	Updates test assertions from Chai to Vitest format
package.json	Removes Mocha/Chai dependencies, adds Vitest, updates TypeScript and Node types
.github/workflows/publish.yml	Updates Node.js to v24 and adds Playwright installation
.github/workflows/nodejs.yml	Updates Node.js to v24 and adds Playwright installation

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[dgreif]

@copilot we actually don't need playwright since we aren't using browser mode. Remove all installs in ci

[Copilot]

Removed playwright install steps from both nodejs.yml and publish.yml workflows. (commit: will be included in next push)

[bteng22]

🙌