cq/scripts/slave/step/xml_check_step.py

"""Build step class for validating XML files."""

from __future__ import absolute_import
import collections
import os
import re
import xml.etree

from helpers import git_utils
from slave import base_step

_XML_PARSE_ERROR_MSG = 'This XML file failed to parse: {}'
_XML_ERROR_POSITION_PATTERN = r'line (?P<linenum>\d+), column \d+'


class XmlCheckStep(base_step.BaseStep):
  """Build step class for validating XML files."""

  def __init__(self, **kwargs):
    """Creates a XmlCheckStep instance.

    Args:
      **kwargs: Any additional args to pass to BaseStep.
    """
    base_step.BaseStep.__init__(self, name='xml check', **kwargs)

  def _parse_error_to_comment(self, err):
    comment = {'message': _XML_PARSE_ERROR_MSG.format(str(err))}
    match = re.search(_XML_ERROR_POSITION_PATTERN, str(err))
    if match:
      comment['line'] = match.group('linenum')
    return comment

  def run(self):
    """Attempts to parse all .xml files in the current commit.

    Sets a build property "review" with the output if there are any errors.

    Returns:
      True iff there were no parsing errors.
    """
    comments = collections.defaultdict(list)
    for xml_filename in self.changed_files(file_extensions=['.xml']):
      with open(os.path.join(self.directory, xml_filename)) as xml_file:
        try:
          xml.etree.ElementTree.parse(xml_file)
        except xml.etree.ElementTree.ParseError as err:
          comments[xml_filename].append(self._parse_error_to_comment(err))

    if comments:
      self.add_review({'comments': comments})
      return False

    # No Errors
    return True