Fix MockFileSystem.walk and add test.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py

 # Copyright (C) 2011 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #    * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #    * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 10 matching lines @@
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import unittest
 
-
+from webkitpy.common.host_mock import MockHost
 from webkitpy.common.system import filesystem_mock
 from webkitpy.common.system import filesystem_unittest
+from webkitpy.common.system.filesystem_mock import MockFileSystem
 
 
 class MockFileSystemTest(unittest.TestCase, filesystem_unittest.GenericFileSystemTests):
 
     def setUp(self):
         self.fs = filesystem_mock.MockFileSystem()
         self.setup_generic_test_dir()
 
     def tearDown(self):
         self.teardown_generic_test_dir()
@@ skipping 33 matching lines @@
                          'foo/',
                          'foo/.',
                          'foo/bar',
                          '/foo',
                          'foo/../bar',
                          'foo/../bar/baz',
                          '../foo')
 
     def test_relpath_win32(self):
         pass
+
+    def test_filesystem_walk(self):
+        mock_dir = 'foo'
+        mock_files = {'foo/bar/baz': '',
+                      'foo/a': '',
+                      'foo/b': '',
+                      'foo/c': ''}
+        host = MockHost()
+        host.filesystem = MockFileSystem(files=mock_files)
+        self.assertEquals(host.filesystem.walk(mock_dir), [('foo', ['bar'], ['a', 'b', 'c']), ('foo/bar', [], ['baz'])])
+
+    def test_filesystem_walk_deeply_nested(self):
+        mock_dir = 'foo'
+        mock_files = {'foo/bar/baz': '',
+                      'foo/bar/quux': '',
+                      'foo/a/x': '',
+                      'foo/a/y': '',
+                      'foo/a/z/lyrics': '',
+                      'foo/b': '',
+                      'foo/c': ''}
+        host = MockHost()
+        host.filesystem = MockFileSystem(files=mock_files)
+        self.assertEquals(host.filesystem.walk(mock_dir), [('foo', ['a', 'bar'], ['c', 'b']),
+                                                           ('foo/a', ['z'], ['x', 'y']),
+                                                           ('foo/a/z', [], ['lyrics']),
+                                                           ('foo/bar', [], ['quux', 'baz'])])