sagemathincmemfs
This is a fork of https://www.npmjs.com/package/memfs, since there's a bunch of critical bugs and missing maintenance there, which might not be a priority for that project, but are definitely a priority for me (though I'm sending PR's). Upstream memfs has nearly 12 million downloads a week, so I can see why doing these changes would be really scary there!
Things I've done here include:
- update to newest jest, and increase maxWorkers for testing; fix an issue with one test
- update to newest typescript and node typings
- update target to es2020 from es5; this does make code run more efficiently and is much easier to debug if you want to directly edit node_modules
- fix the 13 security vulnerabilities revealed by npm audit
- upgrade prettier and switch to using the defaults
- switch to package-lock.json instead of yarn's lock
- fix chmodSync bug
- fix utimesSync bug
- fix realpathSync bug
See https://github.com/sagemathinc/memfs-js
Upstream description
In-memory file-system with Node's fs API.
- Node's
fsAPI implemented, see old API Status, missing list, missingopendir - Stores files in memory, in
Buffers - Throws sameish* errors as Node.js
- Has concept of i-nodes
- Implements hard links
- Implements soft links (aka symlinks, symbolic links)
- Permissions may* be implemented in the future
- Can be used in browser, see
memfs-webpack
Install
npm install --save memfsUsage
import { fs } from "memfs";
fs.writeFileSync("/hello.txt", "World!");
fs.readFileSync("/hello.txt", "utf8"); // World!Create a file system from a plain JSON:
import { fs, vol } from "memfs";
const json = {
"./README.md": "1",
"./src/index.js": "2",
"./node_modules/debug/index.js": "3",
};
vol.fromJSON(json, "/app");
fs.readFileSync("/app/README.md", "utf8"); // 1
vol.readFileSync("/app/src/index.js", "utf8"); // 2Export to JSON:
vol.writeFileSync("/script.sh", "sudo rm -rf *");
vol.toJSON(); // {"/script.sh": "sudo rm -rf *"}Use it for testing:
vol.writeFileSync("/foo", "bar");
expect(vol.toJSON()).toEqual({ "/foo": "bar" });Create as many filesystem volumes as you need:
import { Volume } from "memfs";
const vol = Volume.fromJSON({ "/foo": "bar" });
vol.readFileSync("/foo"); // bar
const vol2 = Volume.fromJSON({ "/foo": "bar 2" });
vol2.readFileSync("/foo"); // bar 2Use memfs together with unionfs to create one filesystem
from your in-memory volumes and the real disk filesystem:
import * as fs from "fs";
import { ufs } from "unionfs";
ufs.use(fs).use(vol);
ufs.readFileSync("/foo"); // barUse fs-monkey to monkey-patch Node's require function:
import { patchRequire } from "fs-monkey";
vol.writeFileSync("/index.js", 'console.log("hi world")');
patchRequire(vol);
require("/index"); // hi worldDocs
See also
spyfs- spies on filesystem actionsunionfs- creates a union of multiple filesystem volumeslinkfs- redirects filesystem pathsfs-monkey- monkey-patches Node'sfsmodule andrequirefunctionlibfs- real filesystem (that executes UNIX system calls) implemented in JavaScript
License
Unlicense - public domain.