code: def test_no_changes(mocker, capsys, opts, show, expected, dvc):
      args = parse_args(["diff", *opts, *show])
      cmd = args.func(args)
      mocker.patch("dvc.repo.Repo.diff", return_value={})
  
      assert cmd.run() == 0
      out, _ = capsys.readouterr()
      assert expected == out.strip()
  
file_path: dvc/tests/unit/command/test_diff.py
imports: import collections
  import os
  import pytest
  from dvc.cli import parse_args
  from dvc.commands.diff import _digest, _show_markdown
label_desc: Use image node_id 8 for calling a global function with example usage: test_no_changes(mocker, capsys, opts, show, expected, dvc) without return types