Refactoring: Extract git checks in push and merge scripts.

tools/push-to-trunk/merge_to_branch.py

 #!/usr/bin/env python
 # Copyright 2014 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
@@ skipping 73 matching lines @@
       self.Die("Please specify a branch to merge to")
 
     self.CommonPrepare()
     self.PrepareBranch()
 
 
 class CreateBranch(Step):
   MESSAGE = "Create a fresh branch for the patch."
 
   def RunStep(self):
-    args = "checkout -b %s svn/%s" % (self.Config(BRANCHNAME),
-                                      self["merge_to_branch"])
-    if self.Git(args) is None:
-      self.die("Creating branch %s failed." % self.Config(BRANCHNAME))
+    self.Git("checkout -b %s svn/%s" % (self.Config(BRANCHNAME),
+                                        self["merge_to_branch"]))
 
 
 class SearchArchitecturePorts(Step):
   MESSAGE = "Search for corresponding architecture ports."
 
   def RunStep(self):
     self["full_revision_list"] = list(OrderedDict.fromkeys(self._options.args))
     port_revision_list = []
     for revision in self["full_revision_list"]:
       # Search for commits which matches the "Port rXXX" pattern.
@@ skipping 111 matching lines @@
       TextToFile(text, self.Config(VERSION_FILE))
     else:
       self.Editor(self.Config(VERSION_FILE))
     self.ReadAndPersistVersion("new_")
 
 
 class CommitLocal(Step):
   MESSAGE = "Commit to local branch."
 
   def RunStep(self):
-    if self.Git("commit -a -F \"%s\"" % self.Config(COMMITMSG_FILE)) is None:
-      self.Die("'git commit -a' failed.")
+    self.Git("commit -a -F \"%s\"" % self.Config(COMMITMSG_FILE))
 
 
 class CommitRepository(Step):
   MESSAGE = "Commit to the repository."
 
   def RunStep(self):
-    if self.Git("checkout %s" % self.Config(BRANCHNAME)) is None:
-      self.Die("Cannot ensure that the current branch is %s"
-               % self.Config(BRANCHNAME))
+    self.Git("checkout %s" % self.Config(BRANCHNAME))
     self.WaitForLGTM()
-    if self.Git("cl presubmit", "PRESUBMIT_TREE_CHECK=\"skip\"") is None:
-      self.Die("Presubmit failed.")
-
-    if self.Git("cl dcommit -f --bypass-hooks",
-                retry_on=lambda x: x is None) is None:
-      self.Die("Failed to commit to %s" % self._status["merge_to_branch"])
+    self.Git("cl presubmit", "PRESUBMIT_TREE_CHECK=\"skip\"")
+    self.Git("cl dcommit -f --bypass-hooks", retry_on=lambda x: x is None)
 
 
 class PrepareSVN(Step):
   MESSAGE = "Determine svn commit revision."
 
   def RunStep(self):
     if self._options.revert_bleeding_edge:
       return
-    if self.Git("svn fetch") is None:
-      self.Die("'git svn fetch' failed.")
+    self.Git("svn fetch")
     args = ("log -1 --format=%%H --grep=\"%s\" svn/%s"
             % (self["new_commit_msg"], self["merge_to_branch"]))
     commit_hash = self.Git(args).strip()
     if not commit_hash:
       self.Die("Unable to map git commit to svn revision.")
     self["svn_revision"] = self.Git(
         "svn find-rev %s" % commit_hash).strip()
     print "subversion revision number is r%s" % self["svn_revision"]
 
 
@@ skipping 99 matching lines @@
 def Main():
   parser = BuildOptions()
   (options, args) = parser.parse_args()
   if not ProcessOptions(options, args):
     parser.print_help()
     return 1
   RunMergeToBranch(CONFIG, MergeToBranchOptions(options, args))
 
 if __name__ == "__main__":
   sys.exit(Main())