Remove hacking check N325

This hacking check was added back when the str()
function couldn't handle unicode characters.  With
Python3 this is no longer an issue.  As a result we
can now remove this check.

Change-Id: I926732062dbbd1242cd382e2593e07b4caf4ffec

HACKING.rst

@@ -10,8 +10,6 @@ Cinder Specific Commandments
 - [N314] Check for vi editor configuration in source files.
 - [N322] Ensure default arguments are not mutable.
 - [N323] Add check for explicit import of _() to ensure proper translation.
-- [N325] str() and unicode() cannot be used on an exception. Remove or use
-  six.text_type().
 - [N336] Must use a dict comprehension instead of a dict constructor with a
   sequence of key-value pairs.
 - [C301] timeutils.utcnow() from oslo_utils should be used instead of

cinder/tests/hacking/checks.py

@@ -167,53 +167,6 @@ def check_explicit_underscore_import(logical_line, filename):
         yield(0, "N323: Found use of _() without explicit import of _ !")
 
 
-class CheckForStrUnicodeExc(BaseASTChecker):
-    """Checks for the use of str() or unicode() on an exception.
-
-    This currently only handles the case where str() or unicode()
-    is used in the scope of an exception handler.  If the exception
-    is passed into a function, returned from an assertRaises, or
-    used on an exception created in the same scope, this does not
-    catch it.
-    """
-
-    CHECK_DESC = ('N325 str() and unicode() cannot be used on an '
-                  'exception.  Remove or use six.text_type()')
-
-    def __init__(self, tree, filename):
-        super(CheckForStrUnicodeExc, self).__init__(tree, filename)
-        self.name = []
-        self.already_checked = []
-
-    # Python 2
-    def visit_TryExcept(self, node):
-        for handler in node.handlers:
-            if handler.name:
-                self.name.append(handler.name.id)
-                super(CheckForStrUnicodeExc, self).generic_visit(node)
-                self.name = self.name[:-1]
-            else:
-                super(CheckForStrUnicodeExc, self).generic_visit(node)
-
-    # Python 3
-    def visit_ExceptHandler(self, node):
-        if node.name:
-            self.name.append(node.name)
-            super(CheckForStrUnicodeExc, self).generic_visit(node)
-            self.name = self.name[:-1]
-        else:
-            super(CheckForStrUnicodeExc, self).generic_visit(node)
-
-    def visit_Call(self, node):
-        if self._check_call_names(node, ['str', 'unicode']):
-            if node not in self.already_checked:
-                self.already_checked.append(node)
-                if isinstance(node.args[0], ast.Name):
-                    if node.args[0].id in self.name:
-                        self.add_error(node.args[0])
-        super(CheckForStrUnicodeExc, self).generic_visit(node)
-
-
 class CheckLoggingFormatArgs(BaseASTChecker):
     """Check for improper use of logging format arguments.
 
@@ -461,7 +414,6 @@ def factory(register):
     register(no_translate_logs)
     register(no_mutable_default_args)
     register(check_explicit_underscore_import)
-    register(CheckForStrUnicodeExc)
     register(CheckLoggingFormatArgs)
     register(CheckOptRegistrationArgs)
     register(check_datetime_now)

cinder/tests/unit/test_hacking.py

@@ -219,71 +219,6 @@ class HackingTestCase(test.TestCase):
                                 expected_errors=[(2, 19, 'C311'),
                                                  (3, 18, 'C311')])
 
-    def test_str_unicode_exception(self):
-
-        checker = checks.CheckForStrUnicodeExc
-        code = """
-               def f(a, b):
-                   try:
-                       p = str(a) + str(b)
-                   except ValueError as e:
-                       p = str(e)
-                   return p
-               """
-        errors = [(5, 16, 'N325')]
-        self._assert_has_errors(code, checker, expected_errors=errors)
-
-        code = """
-               def f(a, b):
-                   try:
-                       p = unicode(a) + str(b)
-                   except ValueError as e:
-                       p = e
-                   return p
-               """
-        self._assert_has_no_errors(code, checker)
-
-        code = """
-               def f(a, b):
-                   try:
-                       p = str(a) + str(b)
-                   except ValueError as e:
-                       p = unicode(e)
-                   return p
-               """
-        errors = [(5, 20, 'N325')]
-        self._assert_has_errors(code, checker, expected_errors=errors)
-
-        code = """
-               def f(a, b):
-                   try:
-                       p = str(a) + str(b)
-                   except ValueError as e:
-                       try:
-                           p  = unicode(a) + unicode(b)
-                       except ValueError as ve:
-                           p = str(e) + str(ve)
-                       p = e
-                   return p
-               """
-        errors = [(8, 20, 'N325'), (8, 29, 'N325')]
-        self._assert_has_errors(code, checker, expected_errors=errors)
-
-        code = """
-               def f(a, b):
-                   try:
-                       p = str(a) + str(b)
-                   except ValueError as e:
-                       try:
-                           p  = unicode(a) + unicode(b)
-                       except ValueError as ve:
-                           p = str(e) + unicode(ve)
-                       p = str(e)
-                   return p
-               """
-        errors = [(8, 20, 'N325'), (8, 33, 'N325'), (9, 16, 'N325')]
-        self._assert_has_errors(code, checker, expected_errors=errors)
-
     def test_check_no_log_audit(self):
         self.assertEqual(1, len(list(checks.check_no_log_audit(
             "LOG.audit('My test audit log')"))))