Add script to update relevant changes to Node.js.

tools/release/update_node.py

+#!/usr/bin/env python
+# Copyright 2017 the V8 project 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 argparse
+import os
+import shutil
+import subprocess
+
+TARGET_SUBDIR = os.path.join("deps", "v8")
+REPOSITORIES = [ [""],
+                 ["testing", "gtest"],
+                 ["third_party", "jinja2"],
+                 ["third_party", "markupsafe"] ]
+
+def RunGclient(path):
+  assert os.path.isdir(path)
+  print ">> Running gclient sync"
+  subprocess.call("gclient sync --nohooks",
+                  cwd=path, shell=True, stdout=None)

[Michael Achenbach, 2017/03/10 13:35:06]

nit: stdout=None is the default, can be dropped.

[Yang, 2017/03/13 08:25:49]

Done.

+
+def UpdateTarget(repository, options):
+  source = os.path.join(options.v8_path, *repository)
+  target = os.path.join(options.node_path, TARGET_SUBDIR, *repository)
+  print ">> Updating target directory %s" % source

[Michael Achenbach, 2017/03/10 13:35:05]

nit - readability: it's a bit confusing to read "target directory" and then
print source var, though there's a target var as well...

[Yang, 2017/03/13 08:25:49]

You are right. It should print target first and source in the second line :)

+  print ">>     from active branch at %s" % target
+  git_commands = [

[Michael Achenbach, 2017/03/10 13:35:05]

Is there any assumption about the directory state, e.g. being a git repo already
or not? What if a previous run left this in a bad state?

[Yang, 2017/03/13 08:25:49]

Done.

+    "git init",                           # initialize target repo
+    "git remote add origin %s" % source,  # point to the source repo

[Michael Achenbach, 2017/03/10 13:35:06]

Does this work if the git repro in source folder uses git cache?

[Yang, 2017/03/13 08:25:49]

I'm not familiar with git cache. Isn't it provided by depot_tools? How would it
interfere with this?

[Michael Achenbach, 2017/03/13 10:33:23]

Not sure if everything works as expected when making a mirror from something
that itself uses a cache mirror. But I suggest we try and find out :)

+    "git fetch origin HEAD",              # sync to the current branch
+    "git reset --hard FETCH_HEAD",        # reset to the current branch
+    "git clean -fd"                       # delete removed files
+  ]
+  try:
+    for command in git_commands:
+      subprocess.call(command, cwd=target, shell=True, stdout=None)

[Michael Achenbach, 2017/03/10 13:35:06]

nit: drop stdout, like above

[Yang, 2017/03/13 08:25:49]

Done.

+  except:
+    print ">> Failed!"

[Michael Achenbach, 2017/03/10 13:35:06]

Do we need this?

[Yang, 2017/03/13 08:25:49]

Removed

+    raise
+  finally:
+    # Un-init git.
+    print ">> Cleaning up"
+    shutil.rmtree(os.path.join(target, ".git"))
+  print
+
+def UpdateGitIgnore(options):
+  file_name = os.path.join(options.node_path, TARGET_SUBDIR, ".gitignore")
+  assert os.path.isfile(file_name)
+  print ">> Updating .gitignore with lines"
+  with open(file_name, "a") as gitignore:

[Michael Achenbach, 2017/03/10 13:35:05]

Won't this append over and over again? What if the entries are already there?

[Yang, 2017/03/13 08:25:49]

Done.

+    for repository in REPOSITORIES:
+      sub_repo = "/".join(repository)
+      if not sub_repo is "":
+        line = "!/" + sub_repo
+        print line
+        gitignore.write(line + "\n")
+
+def ParseOptions():
+  parser = argparse.ArgumentParser(description="Update V8 in Node.js")
+  parser.add_argument("v8_path", help="Path to V8 checkout")
+  parser.add_argument("node_path", help="Path to Node.js checkout")
+  parser.add_argument("--gclient", dest="gclient",
+                      action="store_true", help="Run gclient sync")
+  options = parser.parse_args()
+  assert os.path.isdir(options.v8_path)
+  options.v8_path = os.path.abspath(options.v8_path)
+  assert os.path.isdir(options.node_path)
+  options.node_path = os.path.abspath(options.node_path)
+  return options
+
+def Main():
+  options = ParseOptions()
+  if options.gclient:
+    RunGclient(options.v8_path)
+  [UpdateTarget(repo, options) for repo in REPOSITORIES]

[Michael Achenbach, 2017/03/10 13:35:05]

I'm having a one-line fetish too, but maybe here it'd be more clear that this is
a procedure and not a pure function by writing it imperative:
for repo in REPOSITORIES:
  UpdateTarget(repo, options)

[Yang, 2017/03/13 08:25:49]

Done.

+  UpdateGitIgnore(options)
+
+if __name__ == "__main__":
+  Main()