karma-rollup-plugin

A Karma preprocessor plugin that integrates Rollup for on-the-fly bundling and ES2015+ transpilation in test environments. Current version is 0.2.4 (stable, but rarely updated). It supports Rollup plugins, source maps (inline), and multiple ES versions via Babel or Buble. Compared to alternatives like karma-rollup-preprocessor, this plugin is simpler, more actively maintained at the time, and more aligned with the Rollup ecosystem. However, it lacks modern Rollup features and may not work with Rollup >=1.0.