gclient_scm: add test for unsupported scm

gclient_scm: use a map for deciding whether or not the scm is supported

gclient_scm: add a checks for unsupported scm and unimplemented method

git_scm: pull out svn code into SVNWrapper

gclient_scm: create a create_scm factory method

Use a factory method to abstract SCMWrapper creation. This method
will eventually return the correct subclass of SCMWrapper. Initially,
there will only be SVNWrapper.

Review URL: http://codereview.chromium.org/215022

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@26823 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -555,7 +555,7 @@ class GClient(object):
                 raise Error(
                     "relative DEPS entry \"%s\" must begin with a slash" % d)
               # Create a scm just to query the full url.
-              scm = gclient_scm.SCMWrapper(solution["url"], self._root_dir,
+              scm = gclient_scm.CreateSCM(solution["url"], self._root_dir,
                                            None)
               url = scm.FullUrlForRelativeUrl(url)
         if d in deps and deps[d] != url:
@@ -672,7 +672,7 @@ class GClient(object):
       entries[name] = url
       if run_scm:
         self._options.revision = revision_overrides.get(name)
-        scm = gclient_scm.SCMWrapper(url, self._root_dir, name)
+        scm = gclient_scm.CreateSCM(url, self._root_dir, name)
         scm.RunCommand(command, self._options, args, file_list)
         file_list = [os.path.join(name, file.strip()) for file in file_list]
         self._options.revision = None
@@ -698,7 +698,7 @@ class GClient(object):
         entries[d] = url
         if run_scm:
           self._options.revision = revision_overrides.get(d)
-          scm = gclient_scm.SCMWrapper(url, self._root_dir, d)
+          scm = gclient_scm.CreateSCM(url, self._root_dir, d)
           scm.RunCommand(command, self._options, args, file_list)
           self._options.revision = None
 
@@ -715,7 +715,7 @@ class GClient(object):
         entries[d] = url
         if run_scm:
           self._options.revision = revision_overrides.get(d)
-          scm = gclient_scm.SCMWrapper(url, self._root_dir, d)
+          scm = gclient_scm.CreateSCM(url, self._root_dir, d)
           scm.RunCommand(command, self._options, args, file_list)
           self._options.revision = None
 

gclient_scm.py

@@ -28,6 +28,20 @@ SVN_COMMAND = "svn"
 ### SCM abstraction layer
 
 
+# Factory Method for SCM wrapper creation
+
+def CreateSCM(url=None, root_dir=None, relpath=None, scm_name='svn'):
+  # TODO(maruel): Deduce the SCM from the url.
+  scm_map = {
+    'svn' : SVNWrapper,
+  }
+  if not scm_name in scm_map:
+    raise gclient_utils.Error('Unsupported scm %s' % scm_name)
+  return scm_map[scm_name](url, root_dir, relpath, scm_name)
+
+
+# SCMWrapper base class
+
 class SCMWrapper(object):
   """Add necessary glue between all the supported SCM.
 
@@ -36,7 +50,6 @@ class SCMWrapper(object):
   once another SCM is supported."""
   def __init__(self, url=None, root_dir=None, relpath=None,
                scm_name='svn'):
-    # TODO(maruel): Deduce the SCM from the url.
     self.scm_name = scm_name
     self.url = url
     self._root_dir = root_dir
@@ -55,21 +68,21 @@ class SCMWrapper(object):
     if file_list is None:
       file_list = []
 
-    commands = {
-      'cleanup':  self.cleanup,
-      'export':   self.export,
-      'update':   self.update,
-      'revert':   self.revert,
-      'status':   self.status,
-      'diff':     self.diff,
-      'pack':     self.pack,
-      'runhooks': self.status,
-    }
+    commands = ['cleanup', 'export', 'update', 'revert',
+                'status', 'diff', 'pack', 'runhooks']
 
     if not command in commands:
       raise gclient_utils.Error('Unknown command %s' % command)
 
-    return commands[command](options, args, file_list)
+    if not command in dir(self):
+      raise gclient_utils.Error('Command %s not implemnted in %s wrapper' % (
+          command, self.scm_name))
+
+    return getattr(self, command)(options, args, file_list)
+
+
+class SVNWrapper(SCMWrapper):
+  """ Wrapper for SVN """
 
   def cleanup(self, options, args, file_list):
     """Cleanup working copy."""
@@ -255,6 +268,9 @@ class SCMWrapper(object):
     # "svn up --revision BASE" achieve the same effect.
     RunSVNAndGetFileList(['update', '--revision', 'BASE'], path, file_list)
 
+  def runhooks(self, options, args, file_list):
+    self.status(options, args, file_list)
+
   def status(self, options, args, file_list):
     """Display status information."""
     path = os.path.join(self._root_dir, self.relpath)