babel-plugin-tester

Utilities for writing tests for Babel plugins and presets. Version 12.0.0 is current. The library supports Jest, Mocha, Jasmine, node:test, and Vitest. Key differentiators: automatic fixture file loading, built-in prettier formatting, snapshot-based testing, environment variable filtering (TEST_ONLY, TEST_SKIP), and async ResultFormatter. Breaking changes in v12 include dropping default exports, requiring Node.js >=20.18.0, and adopting prettier@3's async interface. Peer dependency on @babel/core >=7.22.0.