Drop duplicate hacking check of thrid party mock

hacking now provides H216 check[1] to detect usage of third party mock
so the same check can be dropped from the local plugin.

[1] b921c4de513c9cc624d6ecf68e4f4493e6e72c0d

Change-Id: I0c6f86d1d47554f0127fc6a122f94ec8586964ec

HACKING.rst

@@ -19,7 +19,6 @@ Manila Specific Commandments
   with a sequence of key-value pairs.
 - [M337] Ensure to not use xrange().
 - [M338] Ensure to not use LOG.warn().
-- [M339] Ensure 'mock' is not imported/used. Use 'unittest.mock' instead.
 - [M354] Use oslo_utils.uuidutils to generate UUID instead of uuid4().
 - [M359] Validate that log messages are not translated.
 

manila/tests/hacking/checks.py

@@ -51,8 +51,6 @@ dict_constructor_with_list_copy_re = re.compile(r".*\bdict\((\[)?(\(|\[)")
 assert_no_xrange_re = re.compile(r"\s*xrange\s*\(")
 assert_True = re.compile(r".*assertEqual\(True, .*\)")
 no_log_warn = re.compile(r"\s*LOG.warn\(.*")
-third_party_mock = re.compile(r"^import.mock")
-from_third_party_mock = re.compile(r"^from.mock.import")
 
 
 class BaseASTChecker(ast.NodeVisitor):
@@ -284,14 +282,3 @@ def no_log_warn_check(logical_line):
     msg = ("M338: LOG.warn is deprecated, use LOG.warning.")
     if re.match(no_log_warn, logical_line):
         yield (0, msg)
-
-
-@core.flake8ext
-def no_third_party_mock(logical_line):
-    # We should only use unittest.mock, not the third party mock library that
-    # was needed for py2 support.
-    if (re.match(third_party_mock, logical_line) or
-            re.match(from_third_party_mock, logical_line)):
-        msg = ('M339: Unit tests should use the standard library "mock" '
-               'module, not the third party mock library.')
-        yield (0, msg)

manila/tests/test_hacking.py

@@ -247,16 +247,6 @@ class HackingTestCase(test.TestCase):
                """
         self._assert_has_no_errors(code, checks.check_uuid4)
 
-    @ddt.unpack
-    @ddt.data(
-        (1, 'import mock'),
-        (0, 'from unittest import mock'),
-        (1, 'from mock import patch'),
-        (0, 'from unittest.mock import patch'))
-    def test_no_third_party_mock(self, err_count, line):
-        self.assertEqual(err_count,
-                         len(list(checks.no_third_party_mock(line))))
-
     def test_no_log_warn_check(self):
         self.assertEqual(0, len(list(checks.no_log_warn_check(
             "LOG.warning('This should not trigger LOG.warn "

tox.ini

@@ -169,7 +169,6 @@ extension =
     M336 = checks:dict_constructor_with_list_copy
     M337 = checks:no_xrange
     M338 = checks:no_log_warn_check
-    M339 = checks:no_third_party_mock
     M354 = checks:check_uuid4
     M359 = checks:no_translate_logs
 paths = ./manila/tests/hacking