Git support in presubmit tests.

Expand presubmit_support and gclient_scm to support
getting basic status and changed files from a Git
checkout.

BUG=5339
TEST=presubmit_support.py works from a git checkout,
gcl presubmit works from a svn checkout
Review URL: http://codereview.chromium.org/242140

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@28092 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -23,6 +23,7 @@ import xml.dom.minidom
 import gclient_utils
 
 SVN_COMMAND = "svn"
+GIT_COMMAND = "git"
 
 
 ### SCM abstraction layer
@@ -442,6 +443,62 @@ class SVNWrapper(SCMWrapper):
     RunSVNAndFilterOutput(command, path, False, False, filterer.Filter)
 
 
+# -----------------------------------------------------------------------------
+# Git utils:
+
+
+def CaptureGit(args, in_directory=None, print_error=True):
+  """Runs git, capturing output sent to stdout as a string.
+
+  Args:
+    args: A sequence of command line parameters to be passed to git.
+    in_directory: The directory where git is to be run.
+
+  Returns:
+    The output sent to stdout as a string.
+  """
+  c = [GIT_COMMAND]
+  c.extend(args)
+
+  # *Sigh*:  Windows needs shell=True, or else it won't search %PATH% for
+  # the git.exe executable, but shell=True makes subprocess on Linux fail
+  # when it's called with a list because it only tries to execute the
+  # first string ("git").
+  stderr = None
+  if not print_error:
+    stderr = subprocess.PIPE
+  return subprocess.Popen(c,
+                          cwd=in_directory,
+                          shell=sys.platform.startswith('win'),
+                          stdout=subprocess.PIPE,
+                          stderr=stderr).communicate()[0]
+
+
+def CaptureGitStatus(files, upstream_branch='origin'):
+  """Returns git status.
+
+  @files can be a string (one file) or a list of files.
+
+  Returns an array of (status, file) tuples."""
+  command = ["diff", "--name-status", "-r", "%s.." % upstream_branch]
+  if not files:
+    pass
+  elif isinstance(files, basestring):
+    command.append(files)
+  else:
+    command.extend(files)
+
+  status = CaptureGit(command).rstrip()
+  results = []
+  if status:
+    for statusline in status.split('\n'):
+      m = re.match('^(\w)\t(.+)$', statusline)
+      if not m:
+        raise Exception("status currently unsupported: %s" % statusline)
+      results.append(('%s      ' % m.group(1), m.group(2)))
+  return results
+
+
 # -----------------------------------------------------------------------------
 # SVN utils:
 

presubmit_support.py

@@ -389,7 +389,7 @@ class AffectedFile(object):
   def AbsoluteLocalPath(self):
     """Returns the absolute path of this file on the local disk.
     """
-    return normpath(os.path.join(self._local_root, self.LocalPath()))
+    return os.path.abspath(os.path.join(self._local_root, self.LocalPath()))
 
   def IsDirectory(self):
     """Returns true if this object is a directory."""
@@ -562,7 +562,8 @@ class Change(object):
       files = []
     self._name = name
     self._full_description = description
-    self._local_root = local_root
+    # Convert root into an absolute path.
+    self._local_root = os.path.abspath(local_root)
     self.issue = issue
     self.patchset = patchset
     self.scm = ''
@@ -764,6 +765,12 @@ class PresubmitExecuter(object):
     Return:
       A list of result objects, empty if no problems.
     """
+
+    # Change to the presubmit file's directory to support local imports.
+    main_path = os.getcwd()
+    os.chdir(os.path.dirname(presubmit_path))
+
+    # Load the presubmit script into context.
     input_api = InputApi(self.change, presubmit_path, self.committing)
     context = {}
     exec script_text in context
@@ -789,6 +796,8 @@ class PresubmitExecuter(object):
     else:
       result = ()  # no error since the script doesn't care about current event.
 
+    # Return the process to the original working directory.
+    os.chdir(main_path)
     return result
 
 
@@ -939,7 +948,7 @@ def Main(argv):
         options.files = ParseFiles(args, options.recursive)
       else:
         # Grab modified files.
-        raise NotImplementedException()  # TODO(maruel) Implement.
+        options.files = gclient_scm.CaptureGitStatus([options.root])
   elif os.path.isdir(os.path.join(options.root, '.svn')):
     change_class = SvnChange
     if not options.files:
@@ -947,12 +956,15 @@ def Main(argv):
         options.files = ParseFiles(args, options.recursive)
       else:
         # Grab modified files.
-        files = gclient_scm.CaptureSVNStatus([options.root])
+        options.files = gclient_scm.CaptureSVNStatus([options.root])
   else:
     # Doesn't seem under source control.
     change_class = Change
   if options.verbose:
-    print "Found %d files." % len(options.files)
+    if len(options.files) != 1:
+      print "Found %d files." % len(options.files)
+    else:
+      print "Found 1 file."
   return not DoPresubmitChecks(change_class(options.name,
                                             options.description,
                                             options.root,

tests/presubmit_unittest.py

@@ -53,12 +53,16 @@ def CheckChangeOnUpload(input_api, output_api):
     self.mox.StubOutWithMock(presubmit, 'random')
     self.mox.StubOutWithMock(presubmit, 'sys')
     presubmit._ASKED_FOR_FEEDBACK = False
+    presubmit.os.path.commonprefix = os_path_commonprefix
+    self.fake_root_dir = self.RootDir()
     # Special mocks.
     def MockAbsPath(f):
       return f
+    def MockChdir(f):
+      return None
     presubmit.os.path.abspath = MockAbsPath
-    presubmit.os.path.commonprefix = os_path_commonprefix
-    self.fake_root_dir = self.RootDir()
+    presubmit.os.getcwd = self.RootDir
+    presubmit.os.chdir = MockChdir
     self.mox.StubOutWithMock(presubmit.gclient_scm, 'CaptureSVNInfo')
     self.mox.StubOutWithMock(presubmit.gcl, 'GetSVNFileProperty')
     self.mox.StubOutWithMock(presubmit.gcl, 'ReadFile')