Indented code which prints warnings for unrecognized os's.

Previous indentation level was causing the warning to print when
the OS name happened to be one of the preferred ("normalized") os
names, which is pretty much the opposite of intended behavior.

Testing Done:
Added test_osutil.py to make sure osutil.py is behaving properly.

CI went green: https://travis-ci.org/gmalmquist/pants/builds/77405988

Bugs closed: 2075

Reviewed at https://rbcommons.com/s/twitter/r/2713/

src/python/pants/util/osutil.py

@@ -42,8 +42,8 @@ def normalize_os_name(os_name):
     for proper_name, aliases in OS_ALIASES.items():
       if os_name in aliases:
         return proper_name
-  logger.warning('Unknown operating system name: {bad}, known names are: {known}'
-                 .format(bad=os_name, known=', '.join(sorted(known_os_names()))))
+    logger.warning('Unknown operating system name: {bad}, known names are: {known}'
+                   .format(bad=os_name, known=', '.join(sorted(known_os_names()))))
   return os_name
 
 

tests/python/pants_test/util/BUILD

@@ -9,6 +9,7 @@ target(
     ':fileutil',
     ':memo',
     ':meta',
+    ':osutil',
     ':strutil',
     ':xml_parser',
   ]
@@ -50,6 +51,14 @@ python_tests(
   ]
 )
 
+python_tests(
+  name = 'osutil',
+  sources = ['test_osutil.py'],
+  dependencies = [
+    'src/python/pants/util:osutil',
+  ]
+)
+
 python_tests(
   name = 'memo',
   sources = ['test_memo.py'],

tests/python/pants_test/util/test_osutil.py

@@ -0,0 +1,54 @@
+# coding=utf-8
+# Copyright 2014 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
+                        unicode_literals, with_statement)
+
+import logging
+import unittest
+from contextlib import contextmanager
+
+from pants.util.osutil import OS_ALIASES, known_os_names, normalize_os_name
+
+
+class OsutilTest(unittest.TestCase):
+
+  class WarningRecorder(object):
+    """Simple logging handler to record warnings."""
+
+    def __init__(self):
+      self.warning_list = []
+      self.level = logging.WARNING
+
+    def handle(self, record):
+      self.warning_list.append('{}: {}'.format(record.name, record.getMessage()))
+
+  @contextmanager
+  def warnings(self):
+    handler = self.WarningRecorder()
+    logging.getLogger('').addHandler(handler)
+    yield handler.warning_list
+
+  def test_alias_normalization(self):
+    for normal_os, aliases in OS_ALIASES.items():
+      for alias in aliases:
+        self.assertEqual(normal_os, normalize_os_name(alias))
+
+  def test_keys_in_aliases(self):
+    for key in OS_ALIASES.keys():
+      self.assertIn(key, known_os_names())
+
+  def test_no_warnings_on_known_names(self):
+    for name in known_os_names():
+      with self.warnings() as warning_list:
+        normalize_os_name(name)
+        self.assertEqual(0, len(warning_list),
+                         'Recieved unexpected warnings: {}'.format(warning_list))
+
+  def test_warnings_on_unknown_names(self):
+    name = 'I really hope no one ever names an operating system with this string.'
+    with self.warnings() as warning_list:
+      normalize_os_name(name)
+      self.assertEqual(1, len(warning_list),
+                       'Expected exactly one warning, but got: {}'.format(warning_list))