docs: def upsert_module_file(module_ident, fileid, filename):
      """Upsert a file associated with ``fileid`` with ``filename``
      as a module_files entry associated with content at ``module_ident``.
  
      """
      with db_connect() as db_conn:
          with db_conn.cursor() as cursor:
              cursor.execute("SELECT true FROM module_files "
                             "WHERE module_ident = %s "
                             "AND filename = %s",
                             (module_ident, filename,))
              try:
                  cursor.fetchone()[0]
              except (IndexError, TypeError):
                  cursor.execute("INSERT INTO module_files "
                                 "(module_ident, fileid, filename) "
                                 "VALUES (%s, %s, %s)",
                                 (module_ident, fileid, filename,))
              else:
                  cursor.execute("UPDATE module_files "
                                 "SET (fileid) = (%s) "
                                 "WHERE module_ident = %s AND filename = %s",
                                 (fileid, module_ident, filename,))