GIT - How to switch Branch without carrying changes and viceversa

Question

recently we moved from TFS to GIT so I am still learning how to use this amazing tool.

At the moment I am working in a very simple structure like the following one:

main -------------------------------------- 01 ----------
\                                           /
 dev ----------------------- 01 ---------- 02 ----------
  \                          /             /
   feat/login ------ 01 --- 02 --- 03 --- 04 --- 05 ---

• Developers work on feature/something and every tot hours they check-in and trigger a build with tests
• When the feature is stable they merge back into dev which will contains 1 or more checkins from feature/something
• When the whole feature is ready, they merge the feature from dev into main

The questions are the following:

• If I start to work from feat/login, if I do git checkout dev I don't get the latest code from dev but also my latest local file changed in feat/login. How can I checkout dev without carry over the local changes not commited from my previous branch?
• Assuming a developer made a mistake, how can I rollback to a previous check-in 01 in dev and push it so that the latest check-in 02 is not the last one anymore?

Answer 1

1) Stash your changes, checkout to another branch, make some changes there and come back to your original branch and apply/pop your stash.

$ git stash
$ git checkout dev

# do something in you dev branch

$ git checkout feat/login
$ git stash apply

You can view your stash list using the command $ git stash list

2) It seems like you want to revert back the changes. I recommend you to not play with git history as a beginner. Anyways, if you do want to try it out here's a good answer how to do it. As Lasse said it's better to create another commit that reverts the effect of the one you want to undo.

Answer 2

Another feature that you may use, is git worktree (https://git-scm.com/docs/git-worktree) which allows you to have working copies of multiple branches at the same time, so e.g. lets assume you are on master:

git worktree add -b dev ../dev origin/dev
git worktree add -b feat_login ../feat_login origin/feat/login

will give you 2 additional working copies in ../dev and ../feat_login that contain a working copy of the dev and feat_login branch.

I find this feature especially useful in projects were I have to switch between branches very often.