Add translation_checks for i18n

This is the first patch to enable the translation checks.
These translation checks were taken from neutron_lib/hacking

Translation checks include:
 * validate_log_translation: Translate log messages
 * no_translate_debug_logs: Don't transate debug level logs
 * check_raised_localization_exception: Translate exception message

The pep8 tests will fail until all files meet the standards enforced
by these translaiton checks. So this patch is depenedent on the
following:

Depends-On: Ieb7e006de497c974756941608aea91f63e860dc5
Depends-On: I1d0649f240365b7f62b13af6edb1e8dbb5d06597
Depends-On: I48f95b3c090e9b6f91185c14113daae5bc621d0b
Depends-On: I5feafe8945960e34a8d0e038ad4617f39502f19b
Depends-On: If29f7b5df7f6958cec4b26f72babc47ca70f3706
Depends-On: Iddd738c2d9a7c9a57fcd445650d087123dbccfc4
Depends-On: Ifdf426684473fb05cae63877c334e6cf65aa5234
Depends-On: I94a341ba1fb4178e0c358c37ea31623d48938ec6
Depends-On: Ic8664bf105d601909c6efa5cf73db6c27adaf42e
Depends-On: I80f2ea6a20944cfbfdc79a8a71ad744f23aeaac1
Depends-On: If68b38ef5bdeba2fdc28f94d964ef8ce6d15c352
Depends-On: Ia54014fa8e44aacc7935bd73c1ee8d3139a19735
Depends-On: Iea58f4df337c79785dc7afe0e31bcfa7e231f374
Depends-On: I2b0313021fd9599bdaeb375358e8cf834581d493
Depends-On: I56972d16634654b8b71853d6aba10299cc9e2418
Depends-On: If632727fd29ec8d36c6890ebd156a46be70ba783
Depends-On: I1df8d4cba6a3a2ec23e8a1b2aa4ffc03c97b149e
Depends-On: I4070117b6335f4d85f35cc6473653c17d7c14bac
Depends-On: I83f2ccd623588af3fc5f94334b753cebcc3b6c18
Depends-On: I44ac13e9431018e18980e8ff7ff442c7fea68a13
Depends-On: I88284f61b5f37d78ad050a97c679f6bde23d832d
Depends-On: I6fb2bdcc4b83457e08b24599fb4a297ef6ec6c14

Change-Id: Ia2844799a2af8e020470d4c513ad55a51ec36ce1

HACKING.rst

@@ -0,0 +1,7 @@
+Trove Library Specific Commandments
+-------------------------------------
+
+- [T101] Validate that LOG messages, except debug ones, are translated
+- [T102] Validate that debug level logs are not translated
+- [T103] Exception messages should be translated
+

tox.ini

@@ -78,6 +78,10 @@ builtins = _
 exclude=.venv,.tox,.git,dist,doc,*egg,tools,etc,build,*.po,*.pot,integration
 filename=*.py,trove-*
 
+[hacking]
+import_exceptions = trove.common.i18n
+local-check-factory = trove.hacking.translation_checks.factory
+
 [testenv:api-ref]
 # This environment is called from CI scripts to test and publish
 # the API Ref to developer.openstack.org.

trove/hacking/translation_checks.py

@@ -0,0 +1,110 @@
+# 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.
+
+import re
+
+import pep8
+
+_all_log_levels = {
+    'critical': '_',
+    'error': '_',
+    'exception': '_',
+    'info': '_',
+    'reserved': '_',
+    'warning': '_',
+}
+_all_hints = set(_all_log_levels.values())
+
+
+def _regex_for_level(level, hint):
+    return r".*LOG\.%(level)s\(\s*((%(wrong_hints)s)\(|'|\")" % {
+        'level': level,
+        'wrong_hints': '|'.join(_all_hints - set([hint])),
+    }
+
+
+_log_translation_hint = re.compile(
+    '|'.join('(?:%s)' % _regex_for_level(level, hint)
+             for level, hint in _all_log_levels.items()))
+
+_log_string_interpolation = re.compile(
+    r".*LOG\.(error|warning|info|critical|exception|debug)\([^,]*%[^,]*[,)]")
+
+
+def _translation_is_not_expected(filename):
+    # Do not do these validations on tests
+    return any(pat in filename for pat in ["/tests/"])
+
+
+def validate_log_translations(logical_line, physical_line, filename):
+    """T101 - Log messages require translation hints.
+    :param logical_line: The logical line to check.
+    :param physical_line: The physical line to check.
+    :param filename: The file name where the logical line exists.
+    :returns: None if the logical line passes the check, otherwise a tuple
+    is yielded that contains the offending index in logical line and a
+    message describe the check validation failure.
+    """
+    if _translation_is_not_expected(filename):
+        return
+
+    if pep8.noqa(physical_line):
+        return
+
+    msg = "T101: Untranslated Log message."
+    if _log_translation_hint.match(logical_line):
+        yield (0, msg)
+
+
+def no_translate_debug_logs(logical_line, filename):
+    """T102 - Don't translate debug level logs.
+    Check for 'LOG.debug(_(' and 'LOG.debug(_Lx('
+    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.
+    :param logical_line: The logical line to check.
+    :param filename: The file name where the logical line exists.
+    :returns: None if the logical line passes the check, otherwise a tuple
+    is yielded that contains the offending index in logical line and a
+    message describe the check validation failure.
+    """
+    for hint in _all_hints:
+        if logical_line.startswith("LOG.debug(%s(" % hint):
+            yield(0, "T102 Don't translate debug level logs")
+
+
+def check_raised_localized_exceptions(logical_line, filename):
+    """T103 - Untranslated exception message.
+    :param logical_line: The logical line to check.
+    :param filename: The file name where the logical line exists.
+    :returns: None if the logical line passes the check, otherwise a tuple
+    is yielded that contains the offending index in logical line and a
+    message describe the check validation failure.
+    """
+    if _translation_is_not_expected(filename):
+        return
+
+    logical_line = logical_line.strip()
+    raised_search = re.compile(
+        r"raise (?:\w*)\((.*)\)").match(logical_line)
+    if raised_search:
+        exception_msg = raised_search.groups()[0]
+        if exception_msg.startswith("\"") or exception_msg.startswith("\'"):
+            msg = "T103: Untranslated exception message."
+            yield (logical_line.index(exception_msg), msg)
+
+
+def factory(register):
+    register(validate_log_translations)
+    register(no_translate_debug_logs)
+    register(check_raised_localized_exceptions)

trove/tests/unittests/hacking/test_translation_checks.py

@@ -0,0 +1,89 @@
+#    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.
+
+from trove.hacking import translation_checks as tc
+from trove.tests.unittests import trove_testtools
+
+
+class HackingTestCase(trove_testtools.TestCase):
+
+    def assertLinePasses(self, func, *args):
+        def check_callable(f, *args):
+            return next(f(*args))
+        self.assertRaises(StopIteration, check_callable, func, *args)
+
+    def assertLineFails(self, func, *args):
+        self.assertIsInstance(next(func(*args)), tuple)
+
+    def test_factory(self):
+        def check_callable(fn):
+            self.assertTrue(hasattr(fn, '__call__'))
+        self.assertIsNone(tc.factory(check_callable))
+
+    def test_log_translations(self):
+        expected_marks = {
+            'error': '_',
+            'info': '_',
+            'warning': '_',
+            'critical': '_',
+            'exception': '_',
+        }
+        logs = expected_marks.keys()
+        debug = "LOG.debug('OK')"
+        self.assertEqual(
+            0, len(list(tc.validate_log_translations(debug, debug, 'f'))))
+        for log in logs:
+            bad = 'LOG.%s("Bad")' % log
+            self.assertEqual(
+                1, len(list(tc.validate_log_translations(bad, bad, 'f'))))
+            ok = 'LOG.%s(_("OK"))' % log
+            self.assertEqual(
+                0, len(list(tc.validate_log_translations(ok, ok, 'f'))))
+            ok = "LOG.%s('OK')    # noqa" % log
+            self.assertEqual(
+                0, len(list(tc.validate_log_translations(ok, ok, 'f'))))
+            ok = "LOG.%s(variable)" % log
+            self.assertEqual(
+                0, len(list(tc.validate_log_translations(ok, ok, 'f'))))
+            # Do not do validations in tests
+            ok = 'LOG.%s("OK - unit tests")' % log
+            self.assertEqual(
+                0, len(list(tc.validate_log_translations(ok, ok,
+                                                         'f/tests/f'))))
+
+            for mark in tc._all_hints:
+                stmt = "LOG.%s(%s('test'))" % (log, mark)
+                self.assertEqual(
+                    0 if expected_marks[log] == mark else 1,
+                    len(list(tc.validate_log_translations(stmt, stmt, 'f'))))
+
+    def test_no_translate_debug_logs(self):
+        for hint in tc._all_hints:
+            bad = "LOG.debug(%s('bad'))" % hint
+            self.assertEqual(
+                1, len(list(tc.no_translate_debug_logs(bad, 'f'))))
+
+    def test_check_localized_exception_messages(self):
+        f = tc.check_raised_localized_exceptions
+        self.assertLineFails(f, "     raise KeyError('Error text')", '')
+        self.assertLineFails(f, ' raise KeyError("Error text")', '')
+        self.assertLinePasses(f, ' raise KeyError(_("Error text"))', '')
+        self.assertLinePasses(f, ' raise KeyError(_ERR("Error text"))', '')
+        self.assertLinePasses(f, " raise KeyError(translated_msg)", '')
+        self.assertLinePasses(f, '# raise KeyError("Not translated")', '')
+        self.assertLinePasses(f, 'print("raise KeyError("Not '
+                                 'translated")")', '')
+
+    def test_check_localized_exception_message_skip_tests(self):
+        f = tc.check_raised_localized_exceptions
+        self.assertLinePasses(f, "raise KeyError('Error text')",
+                              'neutron_lib/tests/unit/mytest.py')