Implemented index.reset method including test

Author: Byron

lib/git/index.py

@@ -528,13 +528,13 @@ def update(self):
 		
 		Note:
 			This is a possibly dangerious operations as it will discard your changes
-			to index.endtries
+			to index.entries
 			
 		Returns
 			self
 		"""
 		del(self.entries)
-		self.entries
+		# allows to lazily reread on demand
 		return self
 
 	def write_tree(self):
@@ -623,7 +623,7 @@ def commit(self, message=None, parent_commits=None,  **kwargs):
 		raise NotImplementedError("todo")
 
 	@default_index
-	def reset(self, commit='HEAD', working_tree=False, **kwargs):
+	def reset(self, commit='HEAD', working_tree=False, paths=None, **kwargs):
 		"""
 		Reset the index to reflect the tree at the given commit. This will not
 		adjust our HEAD reference as opposed to HEAD.reset.
@@ -636,11 +636,23 @@ def reset(self, commit='HEAD', working_tree=False, **kwargs):
 		``working_tree``
 			If True, the files in the working tree will reflect the changed index.
 			If False, the working tree will not be touched
+			Please note that changes to the working copy will be discarded without 
+			warning !
 			
 		``**kwargs``
 			Additional keyword arguments passed to git-reset
+			
+		Returns
+			self
 		"""
-		raise NotImplementedError("todo: use git-read-tree if there is no working tree to update")
+		head = self.repo.head
+		prev_commit = head.commit
+		
+		# reset to get the tree/working copy
+		head.reset(commit, index=True, working_tree=working_tree, paths=paths, **kwargs)
+		# put the head back 
+		head.reset(prev_commit, index=False, working_tree=False)
+		return self
 
 	@default_index
 	def diff(self, other=diff.Diffable.Index, paths=None, create_patch=False, **kwargs):

test/git/test_index.py

@@ -146,7 +146,33 @@ def test_index_file_diffing(self, rw_repo):
 		# against something unusual
 		self.failUnlessRaises(ValueError, index.diff, int)
 
-		self.fail( "Test IndexFile.reset" )
+		# adjust the index to match an old revision
+		cur_branch = rw_repo.active_branch
+		cur_commit = cur_branch.commit
+		rev_head_parent = 'HEAD~1'
+		assert index.reset(rev_head_parent) is index
+		
+		assert cur_branch == rw_repo.active_branch
+		assert cur_commit == rw_repo.head.commit
+		
+		# there must be differences towards the working tree which is in the 'future'
+		assert index.diff(None)
+		
+		# reset the working copy as well to current head,to pull 'back' as well
+		new_data = "will be reverted"
+		file_path = os.path.join(rw_repo.git.git_dir, "CHANGES")
+		fp = open(file_path, "w")
+		fp.write(new_data)
+		fp.close()
+		index.reset(rev_head_parent, working_tree=True)
+		assert not index.diff(None)
+		assert cur_branch == rw_repo.active_branch
+		assert cur_commit == rw_repo.head.commit
+		fp = open(file_path)
+		try:
+			assert fp.read() != new_data
+		finally:
+			fp.close()
 
 	@with_rw_repo('0.1.6')
 	def test_index_mutation(self, rw_repo):