streamich/memfs
Some data may be outdated — see provenance labels.
Node.js "fs" and browser "File System API" adapters and in-memory implementations 👍 observed · 2026-09-29
Health v2 · maintenance only
93/100
- Activity 96
- Release rhythm 84
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-10-22. Adoption (stars, forks) is never an input.
- gap_med: 0.0
- age_days: 4146
- days_rel: 29
- days_push: 29
- n_releases_24m: 109
Adoption not part of the score
2095 stars · 150 forks observed · 2026-09-29
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
memfs is a TypeScript library providing in-memory implementations of the Node.js `fs` module API and the browser File System Access API, plus adapters between the two. It lets code that expects a real filesystem run against a virtual one in tests, browsers, or sandboxed environments.
Use cases
- mock the node fs module in unit tests
- run node fs code in the browser
- use an in-memory filesystem for jest tests
- adapt between node fs and File System Access API
- test file-watching logic without touching disk
- snapshot and print virtual directory trees
When to choose
- you need to unit-test code that reads/writes files without hitting the real disk
- you want to run Node-style fs code in a browser or sandboxed environment
- you need fs/File System Access API interop adapters or OPFS file watching
When to avoid
- you need a persistent on-disk filesystem
- you need POSIX-perfect semantics like real permissions or hard links
- your project is not JavaScript/TypeScript
Facets
library · maturity active
file-system testing developer-tools developer-tools files testing web-development browser cross-platform in-memory-filesystem fs-mock opfs file-system-access-api typescript fs-adapters nodejs javascript
2 sources
- readme: https://github.com/streamich/memfs · fetched 2026-09-29 · 57e796d6ceab
- homepage: https://jsonjoy.com/libs/memfs · fetched 2026-08-29 · 3a190d979192
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| streamich/memfs | main | 93 |
For agents
Data as of 2026-10-19T08:05:51.212177+00:00 · Report a problem