trace-viewer/third_party/tvcm/tvcm/fake_fs_unittest.py

# Copyright 2014 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 unittest
import os

from tvcm import fake_fs

class FakeFSUnittest(unittest.TestCase):
  def testBasic(self):
    fs = fake_fs.FakeFS()
    fs.AddFile('/blah/x', 'foobar')
    with fs:
      assert os.path.exists('/blah/x')
      self.assertEquals(
          'foobar',
          open('/blah/x', 'r').read())


  def testWithableOpen(self):
    fs = fake_fs.FakeFS()
    fs.AddFile('/blah/x', 'foobar')
    with fs:
      with open('/blah/x', 'r') as f:
        self.assertEquals('foobar', f.read())

  def testWalk(self):
    fs = fake_fs.FakeFS()
    fs.AddFile('/x/w2/w3/z3.txt', '')
    fs.AddFile('/x/w/z.txt', '')
    fs.AddFile('/x/y.txt', '')
    fs.AddFile('/a.txt', 'foobar')
    with fs:
      gen = os.walk('/')
      r = gen.next()
      self.assertEquals(('/', ['x'], ['a.txt']), r)

      r = gen.next()
      self.assertEquals(('/x', ['w', 'w2'], ['y.txt']), r)

      r = gen.next()
      self.assertEquals(('/x/w', [], ['z.txt']), r)

      r = gen.next()
      self.assertEquals(('/x/w2', ['w3'], []), r)

      r = gen.next()
      self.assertEquals(('/x/w2/w3', [], ['z3.txt']), r)

      self.assertRaises(StopIteration,
                        lambda: gen.next())