path/to/venv/lib/python3.10/site-packages/fsspec/conftest.py

import os
import shutil
import subprocess
import sys
import time

import pytest

import fsspec
from fsspec.implementations.cached import CachingFileSystem


@pytest.fixture()
def m():
    """
    Fixture providing a memory filesystem.
    """
    m = fsspec.filesystem("memory")
    m.store.clear()
    m.pseudo_dirs.clear()
    m.pseudo_dirs.append("")
    try:
        yield m
    finally:
        m.store.clear()
        m.pseudo_dirs.clear()
        m.pseudo_dirs.append("")


@pytest.fixture
def ftp_writable(tmpdir):
    """
    Fixture providing a writable FTP filesystem.
    """
    pytest.importorskip("pyftpdlib")
    from fsspec.implementations.ftp import FTPFileSystem

    FTPFileSystem.clear_instance_cache()  # remove lingering connections
    CachingFileSystem.clear_instance_cache()
    d = str(tmpdir)
    with open(os.path.join(d, "out"), "wb") as f:
        f.write(b"hello" * 10000)
    P = subprocess.Popen(
        [sys.executable, "-m", "pyftpdlib", "-d", d, "-u", "user", "-P", "pass", "-w"]
    )
    try:
        time.sleep(1)
        yield "localhost", 2121, "user", "pass"
    finally:
        P.terminate()
        P.wait()
        try:
            shutil.rmtree(tmpdir)
        except Exception:
            pass