[hacking] Ensure not to use LOG.warn

This patchs ensures not to use LOG.warn because LOG.warn deprecated
in Python 3 [1], use LOG.warning instead.

[1] https://docs.python.org/3/library/logging.html#logging.warning

TrivialFix

Change-Id: I50e44a89092e0ee15f5be294837a87c321427921

HACKING.rst

@@ -27,6 +27,7 @@ Manila Specific Commandments
   with a sequence of key-value pairs.
 - [M337] Ensure to not use xrange().
 - [M354] Use oslo_utils.uuidutils to generate UUID instead of uuid4().
+- [M338] Ensure to not use LOG.warn().
 
 LOG Translations
 ----------------

manila/hacking/checks.py

@@ -59,6 +59,7 @@ 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\(True, .*\)")
 assert_None = re.compile(r".*assertEqual\(None, .*\)")
+no_log_warn = re.compile(r"\s*LOG.warn\(.*")
 
 
 class BaseASTChecker(ast.NodeVisitor):
@@ -360,6 +361,19 @@ def check_uuid4(logical_line):
         yield (0, msg)
 
 
+def no_log_warn_check(logical_line):
+    """Disallow 'LOG.warn'
+
+    Deprecated LOG.warn(), instead use LOG.warning
+    ://bugs.launchpad.net/manila/+bug/1508442
+
+    M338
+    """
+    msg = ("M338: LOG.warn is deprecated, use LOG.warning.")
+    if re.match(no_log_warn, logical_line):
+        yield(0, msg)
+
+
 def factory(register):
     register(validate_log_translations)
     register(check_explicit_underscore_import)
@@ -373,3 +387,4 @@ def factory(register):
     register(validate_assertTrue)
     register(validate_assertIsNone)
     register(check_uuid4)
+    register(no_log_warn_check)

manila/tests/test_hacking.py

@@ -329,3 +329,15 @@ class HackingTestCase(test.TestCase):
                hex_uuid = uuid.uuid4().hex
                """
         self._assert_has_no_errors(code, checks.check_uuid4)
+
+    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 "
+            "hacking check.')"))))
+        self.assertEqual(1, len(list(checks.no_log_warn_check(
+            "LOG.warn('We should not use LOG.warn')"))))
+        foo = """
+            LOG.warn('Catch me too, please'
+            )
+            """
+        self.assertEqual(1, len(list(checks.no_log_warn_check(foo))))