Migrate from Mocha to Vitest

[2nofa11]

Summary

Migrates the test framework from Mocha to Vitest to significantly improve test execution performance.

Closes #2787

Changes Made

060f779 - Initial Migration (Automated)

• Applied Codemod.com Mocha/Vitest recipe

3b667b0 - Manual Configuration & Integration Fixes

• Added vitest.config.ts with comprehensive test configuration:
  • Coverage provider set to v8
  • Configured include/exclude patterns
• Fixed integration tests to address Vitest worker limitations (vitest#1436):
  • Replaced process.chdir() usage with cwd option in cp.execSync() calls
  • Updated tests/integrations/eslint-plugin-import.js
  • Updated tests/integrations/flat-config.js
  • Replaced before/after hooks with beforeAll

ec06a3e - Global API Configuration

• Updated eslint.config.mjs to use vitest globals instead of mocha

Migration Details

• Test Coverage: All 11,059 tests pass without modification
• Compatibility: Maintains ESLint RuleTester compatibility
• Performance: 67% faster execution (74s → 24s)
• Configuration: Comprehensive vitest.config.ts with:
  • V8 coverage provider
  • HTML and LCOV reporting
  • Proper include/exclude patterns
  • Global API configuration

Test Plan

• All existing tests pass (11,059 tests)
• Integration tests work correctly
• Coverage reporting functional
• Performance improvement verified
• CI/CD pipeline validation needed

[changeset-bot]

⚠️ No Changeset found

Latest commit: 85cfbea

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[FloEdelmann]

While searching for mocha in the repo (https://github.com/search?q=repo%3Avuejs%2Feslint-plugin-vue%20mocha&type=code), I found two more occurrences that should probably be adapted, or just removed:

• tests/.eslintrc.json
• .vscode/launch.json

[FloEdelmann]

Looks good to me 🙂
Thank you! 🚀

[Copilot]

Pull Request Overview

Migrates the test framework from Mocha to Vitest to improve test execution performance and update related configurations.

• Added a vitest.config.ts with test and coverage settings
• Updated integration tests to use Vitest-compatible hooks and cwd options instead of process.chdir()
• Swapped out Mocha scripts, dependencies, and ESLint globals for Vitest equivalents; removed old VSCode launch config

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
vitest.config.ts	Introduce Vitest test and coverage configuration
tests/integrations/flat-config.js	Use beforeAll and cwd option for flat-config integration test
tests/integrations/eslint-plugin-import.js	Use beforeAll and cwd option for plugin-import integration test
tests/.eslintrc.json	Remove Mocha-specific ESLint config
package.json	Update scripts and dependencies from Mocha/nyc to Vitest
eslint.config.mjs	Switch ESLint globals from Mocha to Vitest
.vscode/launch.json	Remove outdated Mocha debug configuration

Comments suppressed due to low confidence (1)

[2nofa11]

@waynzh @FloEdelmann
Thank you for reviewing my PR 🚀
Your review helped me to create a better one 💯