old_contents: #!/usr/bin/env python
  # Copyright 2017 IBM Corp.
  #
  # All Rights Reserved.
  #
  # 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.
  
  from __future__ import nested_scopes, generators, division, absolute_import, \
      with_statement, print_function, unicode_literals
  
  import sys
  import subprocess
  
  
  def get_head_commit_message():
      return subprocess.check_output(['git', 'log', '-1', '--pretty=%B'])
  
  
  valid_subject_tags = [
      'feat:', 'fix:', 'docs:', 'style:', 'refactor:', 'test:', 'chore:',
      'Revert', 'Merge']
  no_errors = True
  errors = []
  
  for i, line in enumerate(get_head_commit_message().splitlines()):
      if i == 0:
          if line.split()[0] not in valid_subject_tags:
              no_errors = False
              errors.append("Subject line does not start with valid tag")
          if line.split()[0] not in ['Revert', 'Merge']:
              if line.split()[1][0].islower():
                  no_errors = False
                  errors.append("Subject line first word after tag is not "
                                "capitalized")
              if line.split()[-1][-1] == ".":
                  no_errors = False
                  errors.append("Subject line should not end with \".\"")
              if len(line) > 50:
                  no_errors = False
                  errors.append("Subject line > 50 characters long")
      elif i == 1:
          if line.strip() != '':
              no_errors = False
              errors.append("Line after subject should be blank")
      elif i > 1:
          if b".  " in line:
              no_errors = False
              errors.append("Body line #%d - period should be followed by "
                            "single space" % (i + 1))
          if len(line) > 72:
              no_errors = False
              errors.append("Body line #%d > 72 characters long" % (i + 1))
  
  if no_errors:
      sys.exit(0)
  else:
      for error in errors:
          print("Commit Message Style Error: %s" % error)
      sys.exit(1)
  
new_contents: #!/usr/bin/env python
  # Copyright 2018 IBM Corp.
  #
  # All Rights Reserved.
  #
  # 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.
  
  from __future__ import nested_scopes, generators, division, absolute_import, \
      with_statement, print_function, unicode_literals
  
  import sys
  import subprocess
  import re
  
  
  def get_head_commit_message():
      return subprocess.check_output(['git', 'log', '-1', '--pretty=%B'])
  
  
  valid_subject_tags = [
      'feat:', 'fix:', 'docs:', 'style:', 'refactor:', 'test:', 'chore:',
      'Revert', 'Merge']
  no_errors = True
  errors = []
  
  for i, line in enumerate(get_head_commit_message().splitlines()):
      if i == 0:
          if line.split()[0] not in valid_subject_tags:
              no_errors = False
              errors.append("Subject line does not start with valid tag")
          if line.split()[0] not in ['Revert', 'Merge']:
              if line.split()[1][0].islower():
                  no_errors = False
                  errors.append("Subject line first word after tag is not "
                                "capitalized")
              if line.split()[-1][-1] == ".":
                  no_errors = False
                  errors.append("Subject line should not end with \".\"")
              if len(re.sub(r' \(#\d+\)$', '', line)) > 50:
                  no_errors = False
                  errors.append("Subject line > 50 characters long")
      elif i == 1:
          if line.strip() != '':
              no_errors = False
              errors.append("Line after subject should be blank")
      elif i > 1:
          if b".  " in line:
              no_errors = False
              errors.append("Body line #%d - period should be followed by "
                            "single space" % (i + 1))
          if len(line) > 72:
              no_errors = False
              errors.append("Body line #%d > 72 characters long" % (i + 1))
  
  if no_errors:
      sys.exit(0)
  else:
      for error in errors:
          print("Commit Message Style Error: %s" % error)
      sys.exit(1)
  
subject: Allow pull request ref in commit subject (#47)