get_native_path_case() now preserves the trailing os.sep.path and work with non-existing path.

tools/isolate/trace_inputs_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import logging
 import os
 import unittest
 import sys
 
@@ skipping 46 matching lines @@
     self.assertEquals('$FOO/bar', actual.full_path)
     self.assertEquals(True, actual.tainted)
 
   def test_variable_rel(self):
     value = trace_inputs.Results.File('/usr', 'foo/bar', False)
     actual = value.replace_variables({'$FOO': 'foo'})
     self.assertEquals('$FOO/bar', actual.path)
     self.assertEquals(os.path.join('/usr', '$FOO/bar'), actual.full_path)
     self.assertEquals(True, actual.tainted)
 
-  if sys.platform == 'win32':
-    def test_native_case_windows(self):
-      windows_path = os.environ['SystemRoot']
+  def test_native_case_end_with_os_path_sep(self):
+    # Make sure the trailing os.path.sep is kept.
+    path = trace_inputs.get_native_path_case(ROOT_DIR) + os.path.sep
+    self.assertEquals(trace_inputs.get_native_path_case(path), path)
+
+  def test_native_case_non_existing(self):
+    # Make sure it doesn't throw on non-existing files.
+    non_existing = 'trace_input_test_this_file_should_not_exist'
+    path = os.path.expanduser('~/' + non_existing)
+    self.assertFalse(os.path.exists(path))
+    path = trace_inputs.get_native_path_case(ROOT_DIR) + os.path.sep
+    self.assertEquals(trace_inputs.get_native_path_case(path), path)
+
+  if sys.platform in ('darwin', 'win32'):
+    def test_native_case_not_sensitive(self):
+      # The home directory is almost guaranteed to have mixed upper/lower case
+      # letters on both Windows and OSX.
+      # This test also ensures that the output is independent on the input
+      # string case.
+      path = os.path.expanduser('~')
+      self.assertTrue(os.path.isdir(path))
+      # This test assumes the variable is in the native path case on disk, this
+      # should be the case. Verify this assumption:
+      self.assertEquals(path, trace_inputs.get_native_path_case(path))
       self.assertEquals(
-          trace_inputs.get_native_path_case(windows_path.lower()),
-          trace_inputs.get_native_path_case(windows_path.upper()))
+          trace_inputs.get_native_path_case(path.lower()),
+          trace_inputs.get_native_path_case(path.upper()))
+
+    def test_native_case_not_sensitive_non_existent(self):
+      # This test also ensures that the output is independent on the input
+      # string case.
+      non_existing = os.path.join(
+          'trace_input_test_this_dir_should_not_exist', 'really not', '')
+      path = os.path.expanduser(os.path.join('~', non_existing))
+      self.assertFalse(os.path.exists(path))
+      lower = trace_inputs.get_native_path_case(path.lower())
+      upper = trace_inputs.get_native_path_case(path.upper())
+      # Make sure non-existing element is not modified:
+      self.assertTrue(lower.endswith(non_existing.lower()))
+      self.assertTrue(upper.endswith(non_existing.upper()))
+      self.assertEquals(lower[:-len(non_existing)], upper[:-len(non_existing)])
 
   if sys.platform != 'win32':
     def test_symlink(self):
       # This test will fail if the checkout is in a symlink.
       actual = trace_inputs.split_at_symlink(None, ROOT_DIR)
       expected = (ROOT_DIR, None, None)
       self.assertEquals(expected, actual)
 
       actual = trace_inputs.split_at_symlink(
           None, os.path.join(ROOT_DIR, 'data', 'trace_inputs'))
@@ skipping 299 matching lines @@
           'size': -1,
         },
       ]
       self._test_lines(lines, '/home/foo_bar_user/src', files)
 
 
 if __name__ == '__main__':
   VERBOSE = '-v' in sys.argv
   logging.basicConfig(level=logging.DEBUG if VERBOSE else logging.ERROR)
   unittest.main()