memfs is an in-memory file system designed for Node.js, offering a lightweight and fast alternative to the standard fs module. Ideal for mocking file systems during testing or running code in isolated environments, memfs eliminates the need for actual disk I/O. It provides a familiar API compatible with Node.js's fs, making it easy to integrate into existing projects. Features include support for virtual directories, files, and symbolic links, along with customizable volume implementations. Use it for faster, more predictable tests and sandboxed code execution.
Memfs has had varied release frequency since 2015. Initial releases were in 2015-2018, with a period of high activity in 2017. There were relatively consistent releases between 2018-2021, but in between release counts are low. Release activity picked up in 2023 and peaked in July and August 2025, with 14 and 19 releases. There hasn't been any release this September, 2025.
Memfs npm package downloads show steady growth from March 2024 (43.6M) to August 2025 (89.8M). There's a clear upward trend, particularly in the first half of 2025. September 2025 downloads (24.9M) are incomplete and significantly lower, reflecting the partial month.
