hybridfs

Basically memfs, but you can mount directories from the native nodejs filesystem.
Install with:

npm i drinking-code/hybridfs

Use like:

import createHybridFs from 'hybridfs'

// create in-memory fs with "./node_modules" from the node:fs mounted to "/node_modules"
const hfs = createHybridFs([
    ['node_modules', '/node_modules']
])

hfs.writeFileSync('/foo', 'bar') // writes to the in-memory fs
console.log(
    hfs.readFileSync('/foo', 'utf8')
) // -> "bar"

Uses memfs' API (Node's fs API) for the file system.

Reference

createHybridFs(rewrites: (string | [string, string])[])

Create a hybrid file system. Accepts an array of mounts where one mount is either

• a string: "/foo" mounts "/foo" from the native filesystem to "/foo" in the in-memory filesystem; or
• an array of two strings: ["/foo", "/bar"] mounts "/foo" from the native filesystem to "/bar" in the in-memory filesystem.

Both types can be mixed in the array.

Returns a hybrid file system.