ktlint.py

#!/usr/bin/env python3

#
# Copyright 2017, The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

"""Script that is used by developers to run style checks on Kotlin files."""

from __future__ import print_function

import argparse
import errno
import os
import subprocess
import sys

MAIN_DIRECTORY = os.path.normpath(os.path.dirname(__file__))
KTLINT_JAR = os.path.join(MAIN_DIRECTORY, 'ktlint-android-all.jar')
EDITOR_CONFIG = os.path.join(MAIN_DIRECTORY, '.editorconfig')
FORMAT_MESSAGE = '''
**********************************************************************
To format run:
{}/ktlint.py --format --file {}
**********************************************************************
'''


def main(args=None):
  parser = argparse.ArgumentParser()
  parser.add_argument('--file', '-f', nargs='*')
  parser.add_argument('--format', '-F', dest='format', action='store_true')
  parser.add_argument('--noformat', dest='format', action='store_false')
  parser.add_argument('--no-verify-format', dest='verify_format', action='store_false')
  parser.set_defaults(format=False, verify_format=True)
  args = parser.parse_args()
  kt_files = [f for f in args.file if f.endswith('.kt') or f.endswith('.kts')]
  if not kt_files:
    sys.exit(0)

  disabled_rules = ['indent', 'paren-spacing', 'curly-spacing', 'wrapping']

  # Disable more format-related rules if we shouldn't verify the format. This is usually
  # the case if files we are checking are already checked by ktfmt.
  if not args.verify_format:
      disabled_rules += ['final-newline', 'no-consecutive-blank-lines', 'import-ordering']

  ktlint_args = kt_files[:]
  ktlint_args += ['--editorconfig', EDITOR_CONFIG]
  ktlint_args += ['--disabled_rules=' + ','.join(disabled_rules)]

  # Automatically format files if requested.
  if args.format:
    ktlint_args += ['-F']

  ktlint_args += ['--android']

  ktlint_env = os.environ.copy()
  ktlint_env['JAVA_CMD'] = 'java'
  try:
    check = subprocess.Popen(['java', '-jar', KTLINT_JAR] + ktlint_args,
                             stdout=subprocess.PIPE, env=ktlint_env)
    stdout, _ = check.communicate()
    if stdout:
      print('prebuilts/ktlint found errors in files you changed:')
      print(stdout.decode('utf-8'))
      if (args.verify_format):
        print(FORMAT_MESSAGE.format(MAIN_DIRECTORY, ' '.join(kt_files)))
      sys.exit(1)
    else:
      sys.exit(0)
  except OSError as e:
    if e.errno == errno.ENOENT:
      print('Error running ktlint!')
      sys.exit(1)

if __name__ == '__main__':
  main()