[recipe_modules/file] add real file module to engine.

recipe_modules/path/examples/full.py

 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 DEPS = [
   'path',
   'platform',
   'properties',
   'step',
 ]
@@ skipping 37 matching lines @@
   assert api.path.exists(file_path)
 
   realpath = api.path.realpath(file_path)
   assert api.path.exists(realpath)
 
   home_path = api.path.join(api.path.expanduser('~'), 'file')
   api.step('touch my home', ['touch', home_path])
   api.path.mock_add_paths(home_path)
   assert api.path.exists(home_path)
 
+  # can mock copy paths. See the file module to do this for real.
+  copy1 = api.path['start_dir'].join('copy1')
+  copy2 = api.path['start_dir'].join('copy2')
+  api.step('rm copy2 (initial)', ['rm', '-rf', copy2])
+
+  api.step('mkdirs', ['mkdir', '-p', copy1.join('foo', 'bar')])
+  api.path.mock_add_paths(copy1.join('foo', 'bar'))
+  api.step('cp copy1 copy2', ['cp', '-a', copy1, copy2])
+  api.path.mock_copy_paths(copy1, copy2)
+  assert api.path.exists(copy2.join('foo', 'bar'))
+
+  # can mock remove paths. See the file module to do this for real.
+  api.step('rm copy2/foo', ['rm', '-rf', copy2.join('foo')])
+  api.path.mock_remove_paths(str(copy2)+api.path.sep)
+  assert not api.path.exists(copy2.join('foo', 'bar'))
+  assert not api.path.exists(copy2.join('foo'))
+  assert api.path.exists(copy2)
+
+  api.step('rm copy2', ['rm', '-rf', copy2])
+  api.path.mock_remove_paths(copy2)
+  assert not api.path.exists(copy2)
+
   # Convert strings to Paths
   paths_to_convert =  [
     api.path['start_dir'].join('some', 'thing'),
     api.path['start_dir'],
     api.path.resource("module_resource.py"),
     api.path.resource(),
     api.resource("recipe_resource.py"),
     api.resource(),
   ]
   for p in paths_to_convert:
@@ skipping 37 matching lines @@
 
     yield (api.test('%s_luci' % platform) +
            api.platform.name(platform) +
            api.properties(**{
               '$recipe_engine/path': {
                 'cache_dir': '/c',
                 'temp_dir': '/t'
               },
            }) +
            api.path.exists(api.path['tmp_base']))