First cut of testing infrastructure for recipes.

scripts/slave/recipe_util.py

 # Copyright (c) 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.
 
 """This module holds utilities which make writing recipes easier."""
 
+import contextlib as _contextlib
 import os as _os
 
 # e.g. /b/build/slave/<slave-name>/build
 SLAVE_BUILD_ROOT = _os.path.abspath(_os.getcwd())
 # e.g. /b
 ROOT = _os.path.abspath(_os.path.join(SLAVE_BUILD_ROOT, _os.pardir, _os.pardir,
                                       _os.pardir, _os.pardir))
 # e.g. /b/build_internal
 BUILD_INTERNAL_ROOT = _os.path.join(ROOT, 'build_internal')
 # e.g. /b/build
@@ skipping 33 matching lines @@
 The actual checkout root is filled in by annotated_run after the recipe
 completes, and is dependent on the implementation of 'root()' in
 annotated_checkout for the checkout type that you've selected.
 
 NOTE: In order for this function to work, your recipe MUST use the 'checkout'
 functionality provided by annotated_run.
 """  # pylint: disable=W0105
 checkout_path = _path_method('checkout_path', "%(CheckoutRootPlaceholder)s")
 
 
+@_contextlib.contextmanager
+def mock_paths():
+  path_base_names = ['depot_tools', 'build_internal', 'build', 'slave_build',
+                     'root']
+  g = globals()
+  tokens = {}
+  path_funcs = {}
+  try:
+    for name in path_base_names:
+      token_name = (name+"_root").upper()
+      token_val = '[%s]' % token_name
+      path_func_name = (name+"_path")

[Isaac (away), 2013/05/14 21:34:27]

did pylint really pass on this?  Maybe use gpylint and ignore the excessive
stuff?

+
+      if token_name in g:
+        tokens[token_name] = g[token_name]
+        g[token_name] = token_val
+
+      if path_func_name in g:
+        path_funcs[path_func_name] = g[path_func_name]
+        g[path_func_name] = _path_method(path_func_name, token_val)
+    yield
+  finally:
+    g.update(tokens)
+    g.update(path_funcs)
+
+
 def deep_set(obj, key_vals):
   """Take an object (a dict or list), and a list of key/value pairs to set,
   and transform it by replacing items in obj at the key locations with the
   respective values.
 
   keys are strings in the form of: (str|int)[.(str|int)]*
 
   Example:
     obj = {'some': {'deep': {'list': [1, 2, 3, 4, 5, 6]}}}
     key_vals = [("some.deep.list.3", 'foobar')]
@@ skipping 178 matching lines @@
         '-e', 'commit-bot@chromium.org'])
 
   def git_step(self, *args):
     name = 'git '+args[0]
     # Distinguish 'git config' commands by the variable they are setting.
     if args[0] == 'config' and not args[1].startswith('-'):
       name += " "+args[1]
     return self.step(name, [
         'git', '--work-tree', checkout_path(),
                '--git-dir', checkout_path('.git')]+list(args))