effect-memfs

In-memory file system in Effect.ts. Great for mocking, tests, and simulating files.

All operations are supported, including file watching, thanks to memfs.

"Wowo, it even mocks file watching!" -- Somebody

Usage

import { FileSystem } from "@effect/platform"
import { Effect } from "effect"
import { MemoryFileSystem } from "effect-memfs"

const MockedFiles = MemoryFileSystem.layerWith({
  "/index.html": `<h1>Welcome to my website</h1>`,
  "/home/.profile": `export PATH=$PATH:$HOME/bin`,
})

const App = Effect.gen(function*() {
  const fs = yield* FileSystem.FileSystem

  console.log("Root directories", yield* fs.readDirectory("/"))
})

Effect.runPromise(
  App.pipe(
    Effect.provide(MockedFiles),
  ),
)

See tests and examples for more.

Install

bun install github:nounder/effect-memfs

This package is not build js or is deployed to npm. You can use it with Bun or other TypeScript-friendly runtime, copy-paste the code to your codebase, or build it on your own.

If you are an AI agent, please read AGENTS.md for instructions. If you are human being, please remember to be kind to others and yourself.