rollup-plugin-by-output

A Rollup plugin (or plugin helper) that allows applying Rollup plugins conditionally based on output options (format, file, etc.). Version 1.0.1 is the latest stable release. It helps reduce duplicate config when Rollup has multiple outputs that need different plugins (e.g., minification only for UMD builds). Key differentiator: provides elegant helpers like `when`, `whenAll`, `prop`, `format`, and `file` to filter plugins per output. Unlike manual array configs, it keeps code DRY. Requires Node >=8.3.0.