code: def test_dvcfs_no_subrepos(tmp_dir, dvc, scm):
      tmp_dir.scm_gen(
          {"dir": {"repo.txt": "file to confuse DVCFileSystem"}},
          commit="dir/repo.txt",
      )
      tmp_dir.dvc_gen({"lorem": "lorem"}, commit="add foo")
  
      subrepo = tmp_dir / "dir" / "repo"
      make_subrepo(subrepo, scm)
      with subrepo.chdir():
          subrepo.dvc_gen(
              {"foo": "foo", "dir1": {"bar": "bar"}}, commit="FOO"
          )
          subrepo.scm_gen({"ipsum": "ipsum"}, commit="BAR")
  
      # using fs that does not have dvcignore
      dvc._reset()
      fs = DVCFileSystem(repo=dvc)
      expected = [
          "/.dvcignore",
          "/.gitignore",
          "/lorem",
          "/lorem.dvc",
          "/dir",
          "/dir/repo.txt",
      ]
  
      actual = []
      for root, dirs, files in fs.walk("/", dvcfiles=True):
          for entry in dirs + files:
              actual.append(posixpath.join(root, entry))
  
      assert set(actual) == set(expected)
      assert len(actual) == len(expected)
  
      assert fs.isfile("lorem") is True
      assert fs.isfile("dir/repo/foo") is False
      assert fs.isdir("dir/repo") is False
      assert fs.isdir("dir") is True
  
      assert fs.isdvc("lorem") is True
      assert fs.isdvc("dir/repo/dir1") is False
  
      assert fs.exists("dir/repo.txt") is True
      assert fs.exists("repo/ipsum") is False
  
imports: import os
  import posixpath
  import shutil
  import pytest
  from fsspec.utils import tokenize
  from dvc.fs import localfs
  from dvc.fs.dvc import DVCFileSystem
  from dvc.testing.tmp_dir import make_subrepo
  from dvc_data.hashfile.build import build
  from dvc_data.hashfile.hash_info import HashInfo
label_desc: Use image node_id 21 for calling a global function with example usage: test_dvcfs_no_subrepos(tmp_dir, dvc, scm) without return types