lint/linters/whitespace.py

# Copyright 2022 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Provides utility for linting whitespace."""

import logging


def LintData(path: str, data: str) -> bool:
  """Run basic whitespace checks on |data|.

  Args:
    path: The name of the file (for diagnostics).
    data: The file content to lint.

  Returns:
    True if everything passed.
  """
  ret = True

  # Make sure files all have a trailing newline.
  if not data.endswith('\n'):
    ret = False
    logging.warning('%s: file needs a trailing newline', path)

  # Disallow leading & trailing blank lines.
  if data.startswith('\n'):
    ret = False
    logging.warning('%s: delete leading blank lines', path)
  if data.endswith('\n\n'):
    ret = False
    logging.warning('%s: delete trailing blank lines', path)

  for i, line in enumerate(data.splitlines(), start=1):
    if line.rstrip() != line:
      ret = False
      logging.warning('%s:%i: trim trailing whitespace: %s', path, i, line)

  return ret