rollup-plugin-memfs

A Rollup plugin that uses an in-memory filesystem (memfs) as the file system backend, enabling unit testing of Rollup builds without writing to disk. Current version is 4.0.1-alpha.0. It replaces Rollup's default file system with a memfs instance, allowing deterministic tests and fast iteration. Key differentiators: works with memfs v4, supports Promise-based memfs API, and is TypeScript-native. Compared to alternatives like rollup-plugin-mock-fs, this plugin integrates directly with memfs's Volume for fine-grained virtual file control.