Reland "Make gclient ready for the Blink (DEPS to main project)"

testing_support/fake_repos.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Generate fake repositories for testing."""
 
 import atexit
 import datetime
 import errno
@@ skipping 368 matching lines @@
         '--port=%d' % self.git_port]
     if self.host == '127.0.0.1':
       cmd.append('--listen=' + self.host)
     self.check_port_is_free(self.git_port)
     self.gitdaemon = subprocess2.Popen(
         cmd,
         cwd=self.root_dir,
         stdout=subprocess2.PIPE,
         stderr=subprocess2.PIPE)
     wait_for_port_to_bind(self.host, self.git_port, self.gitdaemon)
     self.populateGit()

[Primiano Tucci (use gerrit), 2015/02/09 21:32:04]

Moving the git commits operations before starting the git daemon, in order to
reduce potential sources of flakiness.
Rationale: the flake experienced in
https://codereview.chromium.org/753543006/#msg18 shows that the "gclient sync"
command didn't pull the commit that was made in fake repo.
The way the test works today is by doing commits directly on the repo using the
git CLI (not pushing them) *after* the server has been started.
I wonder whether doing this, i.e. making raw commits under the git daemon feet, 
causes a race (e.g., if the git server keeps some cache of the refs).
Starting the server *after* the git repo has been populated seems more reliable
to me.

     self.git_dirty = False
     return True
 
   def _commit_svn(self, tree):
     self._genTree(self.svn_checkout, tree)
     commit_svn(self.svn_checkout, self.USERS[0][0], self.USERS[0][1])
     if self.svn_revs and self.svn_revs[-1]:
       new_tree = self.svn_revs[-1].copy()
       new_tree.update(tree)
     else:
@@ skipping 421 matching lines @@
     self._commit_git('repo_2', {
         'DEPS': self.DEPS_git_pre % {'git_base': self.git_base},
         'myfile': 'svn/trunk/src@1'
     })
     self._commit_git('repo_2', {
         'DEPS': self.DEPS_post % {'git_base': self.git_base},
         'myfile': 'svn/trunk/src@2'
     })
 
 
+class FakeRepoBlinkDEPS(FakeReposBase):
+  """Simulates the Blink DEPS transition in Chrome."""
+
+  NB_GIT_REPOS = 2
+  DEPS_pre = 'deps = {"src/third_party/WebKit": "%(git_base)srepo_2",}'
+  DEPS_post = 'deps = {}'
+
+  def populateGit(self):
+    # Blink repo.
+    self._commit_git('repo_2', {
+        'OWNERS': 'OWNERS-pre',
+        'Source/exists_always': '_ignored_',
+        'Source/exists_before_but_not_after': '_ignored_',
+    })
+
+    # Chrome repo.
+    self._commit_git('repo_1', {
+        'DEPS': self.DEPS_pre % {'git_base': self.git_base},
+        'myfile': 'myfile@1',
+        '.gitignore': '/third_party/WebKit',
+    })
+    self._commit_git('repo_1', {
+        'DEPS': self.DEPS_post % {'git_base': self.git_base},
+        'myfile': 'myfile@2',
+        '.gitignore': '',
+        'third_party/WebKit/OWNERS': 'OWNERS-post',
+        'third_party/WebKit/Source/exists_always': '_ignored_',
+        'third_party/WebKit/Source/exists_after_but_not_before': '_ignored',
+    })
+
+  def populateSvn(self):
+    raise NotImplementedError()
+
+
 class FakeReposTestBase(trial_dir.TestCase):
   """This is vaguely inspired by twisted."""
   # Static FakeRepos instances. Lazy loaded.
   CACHED_FAKE_REPOS = {}
   # Override if necessary.
   FAKE_REPOS_CLASS = FakeRepos
 
   def setUp(self):
     super(FakeReposTestBase, self).setUp()
     if not self.FAKE_REPOS_CLASS in self.CACHED_FAKE_REPOS:
@@ skipping 88 matching lines @@
     fake.set_up_git()
     print('Fake setup, press enter to quit or Ctrl-C to keep the checkouts.')
     sys.stdin.readline()
   except KeyboardInterrupt:
     trial_dir.TrialDir.SHOULD_LEAK.leak = True
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))