google/jimfs
An in-memory file system for Java observed · 2026-08-28
Health v2 · maintenance only
87/100
- Activity 98
- Release rhythm 66
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.
- gap_med: 402
- age_days: 4699
- days_rel: 15
- days_push: 15
- n_releases_24m: 2
Adoption not part of the score
2557 stars · 293 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
Jimfs is an in-memory file system for Java 8+ that implements the java.nio.file abstract file system APIs. It lets code create and use virtual file systems with Unix- or Windows-style paths without touching the real disk.
Use cases
- unit test file I/O code without touching the real disk
- create a temporary in-memory file system for Java tests
- simulate unix or windows path semantics in tests
- test code that uses java.nio.file.Files and Path
- run file operations in a sandboxed virtual filesystem
When to choose
- you need to test java.nio.file-based code deterministically and fast
- you want a throwaway virtual file system with POSIX-style paths
- you need to simulate Windows or Unix path behavior on any OS
When to avoid
- you need persistence across process restarts
- you need real OS-level file system semantics like enforced permissions
- you are not on the JVM
Facets
library · maturity stable
file-system testing mocking developer-tools testing files jvm cross-platform in-memory-filesystem java-nio google unit-testing
1 source
- readme: https://github.com/google/jimfs · fetched 2026-08-28 · 55a05d7ab725
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| google/jimfs | main | 87 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem