docstr: Return a list of all the files under git.
  
  .. note::
  
      This function raises a ValueError if the repo root does
      not have a ".git" folder. If git is not installed on the system,
      or cannot be found by subprocess, an IOError may also be raised.
code: def list_tracked_files():
      """
      Return a list of all the files under git.
  
      .. note::
  
          This function raises a ValueError if the repo root does
          not have a ".git" folder. If git is not installed on the system,
          or cannot be found by subprocess, an IOError may also be raised.
  
      """
      # Check the ".git" folder exists at the repo dir.
      if not (REPO_DIR / ".git").is_dir():
          raise ValueError(f"{REPO_DIR} is not a git repository.")
  
      output = subprocess.check_output(
          ["git", "ls-tree", "-z", "-r", "--name-only", "HEAD"],
          cwd=REPO_DIR,
      )
      output = output.rstrip(b"\0").split(b"\0")
      res = [fname.decode() for fname in output]
  
      return res
  
file_path: cartopy/lib/cartopy/tests/test_coding_standards.py
imports: from fnmatch import fnmatch
  import os
  from pathlib import Path
  import re
  import subprocess
  import pytest
  import cartopy
label_desc: Use image node_id 1 for calling the TestLicenseHeaders obj's underlying member method code with example usage: obj.list_tracked_files() and returns: res