Docserver: refactor Servlet, ObjectStore, and ServerInstance architecture to

chrome/common/extensions/docs/server2/mock_file_system.py

+# Copyright 2013 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.
+
+from file_system import FileSystem
+
+class MockFileSystem(FileSystem):
+  '''Wraps a FileSystem to add simple mock behaviour - asserting how often
+  Stat/Read calls are being made to it. The Read/Stat implementations
+  themselves are provided by a delegate FileSystem.
+  '''
+  def __init__(self, file_system):
+    self._file_system = file_system
+    self._read_count = 0
+    self._stat_count = 0
+
+  #
+  # FileSystem implementation.
+  #
+
+  def Read(self, paths, binary=False):
+    self._read_count += 1
+    return self._file_system.Read(paths, binary=binary)
+
+  def Stat(self, path):
+    self._stat_count += 1
+    return self._file_system.Stat(path)
+
+  def GetIdentity(self):
+    return self._file_system.GetIdentity()
+
+  def __str__(self):
+    return repr(self)
+
+  def __repr__(self):
+    return 'MockFileSystem(read_count=%s, stat_count=%s)' % (
+        self._read_count, self._stat_count)
+
+  #
+  # Testing methods.
+  #
+
+  def GetReadCount(self):
+    return self._read_count
+
+  def GetStatCount(self):
+    return self._stat_count
+
+  def CheckAndReset(self, stat_count=0, read_count=0):
+    '''Returns a tuple (success, error). Use in tests like:
+    self.assertTrue(*object_store.CheckAndReset(...))
+    '''
+    errors = []
+    for desc, expected, actual in (
+        ('read_count', read_count, self._read_count),
+        ('stat_count', stat_count, self._stat_count)):
+      if actual != expected:
+        errors.append('%s: expected %s got %s' % (desc, expected, actual))
+    try:
+      return (len(errors) == 0, ', '.join(errors))
+    finally:
+      self.Reset()
+
+  def Reset(self):
+    self._read_count = 0
+    self._stat_count = 0