Add hacking check to ensure not use xrange()

Added hacking check to ensure not to use xrange.  Also,
fixed issues with EoF missing newline [W391].

Change-Id: Iba8d240c042e46cb34eb6ed057534d62efb6f903
Closes-Bug: #1538118

HACKING.rst

@@ -23,6 +23,7 @@ Octavia Specific Commandments
   assertEqual(A in B, False) or assertEqual(False, A in B) to the more
   specific assertIn/NotIn(A, B)
 - [O339] LOG.warn() is not allowed. Use LOG.warning()
+- [O340] Don't use xrange()
 
 Creating Unit Tests
 -------------------

octavia/hacking/checks.py

@@ -73,6 +73,8 @@ assert_not_equal_end_with_none_re = re.compile(
     r"(.)*assertNotEqual\(.+, None\)")
 assert_not_equal_start_with_none_re = re.compile(
     r"(.)*assertNotEqual\(None, .+\)")
+assert_no_xrange_re = re.compile(
+    r"\s*xrange\s*\(")
 
 
 def _directory_to_check_translation(filename):
@@ -209,6 +211,15 @@ def no_log_warn(logical_line):
         yield(0, "O339:Use LOG.warning() rather than LOG.warn()")
 
 
+def no_xrange(logical_line):
+    """Disallow 'xrange()'
+
+    O340
+    """
+    if assert_no_xrange_re.match(logical_line):
+        yield(0, "O340: Do not use xrange().")
+
+
 def factory(register):
     register(assert_true_instance)
     register(assert_equal_or_not_none)
@@ -220,3 +231,4 @@ def factory(register):
     register(no_mutable_default_args)
     register(assert_equal_in)
     register(no_log_warn)
+    register(no_xrange)

octavia/tests/unit/test_hacking.py

@@ -135,3 +135,10 @@ class HackingTestCase(base.BaseTestCase):
 
         self.assertEqual(0, len(list(checks.no_log_warn(
             "LOG.warning()"))))
+
+    def test_no_xrange(self):
+        self.assertEqual(1, len(list(checks.no_xrange(
+            "xrange(45)"))))
+
+        self.assertEqual(0, len(list(checks.no_xrange(
+            "range(45)"))))