rally/tests/hacking/checks.py

# 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.

"""
Guidelines for writing new hacking checks

 - Use only for Rally specific tests. OpenStack general tests
   should be submitted to the common 'hacking' module.
 - Pick numbers in the range N3xx. Find the current test with
   the highest allocated number and then pick the next value.
 - Keep the test method code in the source file ordered based
   on the N3xx value.
 - List the new rule in the top level HACKING.rst file
 - Add test cases for each new rule to tests/test_hacking.py

"""

import re


re_assert_true_instance = re.compile(
    r"(.)*assertTrue\(isinstance\((\w|\.|\'|\"|\[|\])+, "
    r"(\w|\.|\'|\"|\[|\])+\)\)")
re_assert_equal_type = re.compile(
    r"(.)*assertEqual\(type\((\w|\.|\'|\"|\[|\])+\), "
    r"(\w|\.|\'|\"|\[|\])+\)")
re_assert_equal_end_with_none = re.compile(r"assertEqual\(.*?,\s+None\)$")
re_assert_equal_start_with_none = re.compile(r"assertEqual\(None,")
re_assert_true_false_with_in_or_not_in = re.compile(
    r"assert(True|False)\("
    r"(\w|[][.'\"])+( not)? in (\w|[][.'\",])+(, .*)?\)")
re_assert_true_false_with_in_or_not_in_spaces = re.compile(
    r"assert(True|False)\((\w|[][.'\"])+( not)? in [\[|'|\"](\w|[][.'\", ])+"
    r"[\[|'|\"](, .*)?\)")


def _parse_assert_mock_str(line):
    point = line.find('.assert_')

    if point != -1:
        end_pos = line[point:].find('(') + point
        return point, line[point + 1: end_pos], line[: point]
    else:
        return None, None, None


def check_assert_methods_from_mock(logical_line, filename):
    """Ensure that ``assert_*`` methods from ``mock`` library is used correctly

    N301 - base error number
    N302 - related to nonexistent "assert_called"
    N303 - related to nonexistent "assert_called_once"
    """

    correct_names = ["assert_any_call", "assert_called_once_with",
                     "assert_called_with", "assert_has_calls"]
    ignored_files = ["./tests/unit/test_hacking.py"]

    if filename.startswith("./tests") and filename not in ignored_files:
        pos, method_name, obj_name = _parse_assert_mock_str(logical_line)

        if pos:
            if method_name not in correct_names:
                error_number = "N301"
                msg = ("%(error_number)s:'%(method)s' is not present in `mock`"
                       " library. %(custom_msg)s For more details, visit "
                       "http://www.voidspace.org.uk/python/mock/ .")

                if method_name == "assert_called":
                    error_number = "N302"
                    custom_msg = ("Maybe, you should try to use "
                                  "'assertTrue(%s.called)' instead." %
                                  obj_name)
                elif method_name == "assert_called_once":
                    # For more details, see a bug in Rally:
                    #    https://bugs.launchpad.net/rally/+bug/1305991
                    error_number = "N303"
                    custom_msg = ("Maybe, you should try to use "
                                  "'assertEqual(1, %(obj_name)s.call_count)' "
                                  "or '%(obj_name)s.assert_called_once_with()'"
                                  " instead." % {"obj_name": obj_name})
                else:
                    custom_msg = ("Correct 'assert_*' methods: '%s'."
                                  % "', '".join(correct_names))

                yield (pos, msg % {
                    "error_number": error_number,
                    "method": method_name,
                    "custom_msg": custom_msg})


def check_import_of_logging(logical_line, filename):
    """Check correctness import of logging module

    N310
    """

    excluded_files = ["./rally/log.py", "./tests/unit/test_log.py"]

    forbidden_imports = ["from rally.openstack.common import log",
                         "import rally.openstack.common.log",
                         "import logging"]

    if filename not in excluded_files:
        for forbidden_import in forbidden_imports:
            if logical_line.startswith(forbidden_import):
                yield (0, "N310 Wrong module for logging is imported. Please "
                          "use `rally.log` instead.")


def no_translate_debug_logs(logical_line):
    """Check for 'LOG.debug(_('

    As per our translation policy,
    https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation
    we shouldn't translate debug level logs.

    * This check assumes that 'LOG' is a logger.
    * Use filename so we can start enforcing this in specific folders instead
      of needing to do so all at once.

    N311
    """
    if logical_line.startswith("LOG.debug(_("):
        yield(0, "N311 Don't translate debug level logs")


def assert_true_instance(logical_line):
    """Check for assertTrue(isinstance(a, b)) sentences

    N320
    """
    if re_assert_true_instance.match(logical_line):
        yield (0, "N320 assertTrue(isinstance(a, b)) sentences not allowed, "
                  "you should use assertIsInstance(a, b) instead.")


def assert_equal_type(logical_line):
    """Check for assertEqual(type(A), B) sentences

    N321
    """
    if re_assert_equal_type.match(logical_line):
        yield (0, "N321 assertEqual(type(A), B) sentences not allowed, "
                  "you should use assertIsInstance(a, b) instead.")


def assert_equal_none(logical_line):
    """Check for assertEqual(A, None) or assertEqual(None, A) sentences

    N322
    """
    res = (re_assert_equal_start_with_none.search(logical_line) or
           re_assert_equal_end_with_none.search(logical_line))
    if res:
        yield (0, "N322 assertEqual(A, None) or assertEqual(None, A) "
                  "sentences not allowed, you should use assertIsNone(A) "
                  "instead.")


def assert_true_or_false_with_in(logical_line):
    """Check assertTrue/False(A in/not in B) with collection contents

    Check for assertTrue/False(A in B), assertTrue/False(A not in B),
    assertTrue/False(A in B, message) or assertTrue/False(A not in B, message)
    sentences.

    N323
    """
    res = (re_assert_true_false_with_in_or_not_in.search(logical_line) or
           re_assert_true_false_with_in_or_not_in_spaces.search(logical_line))
    if res:
        yield (0, "N323 assertTrue/assertFalse(A in/not in B)sentences not "
                  "allowed, you should use assertIn(A, B) or assertNotIn(A, B)"
                  " instead.")


def factory(register):
    register(check_assert_methods_from_mock)
    register(check_import_of_logging)
    register(no_translate_debug_logs)
    register(assert_true_instance)
    register(assert_equal_type)
    register(assert_equal_none)
    register(assert_true_or_false_with_in)