new_contents: import re
  import subprocess
  from datetime import datetime
  
  
  def test_last_review_date():
      statement_file_path = "app/templates/views/accessibility_statement.html"
  
      # test local changes against master for a full diff of what will be merged
      statement_diff = subprocess.run([f"git diff --exit-code origin/master -- {statement_file_path}"],
                                      stdout=subprocess.PIPE, shell=True)
  
      # if statement has changed, test the review date was part of those changes
      if statement_diff.returncode == 1:
          raw_diff = statement_diff.stdout.decode('utf-8')
          today = datetime.now().strftime('%d %B %Y')
          with open(statement_file_path, 'r') as statement_file:
              current_review_date = re.search((r'This statement was prepared on 23 September 2020\. '
                                               r'It was last reviewed on (\d{1,2} [A-Z]{1}[a-z]+ \d{4})'),
                                              statement_file.read()).group(1)
  
          # guard against changes that don't need to update the review date
          if current_review_date != today:
              assert 'This statement was prepared on 23 September 2020. It was last reviewed on' in raw_diff
  
subject: Add test for accessibility statement last review