![gnugen logo](assets/gnugen_white_trans.svg) # just do *git* *Collaborative Workflow*

## Slides Available at: [gnugen.ch/en/guides/](https://gnugen.ch/en/guides/)

## Please help us improve! There will be a short survey at the end of the presentation

## Table of contents * [About gnugen](#about-gnugen) * [Collaborative workflow](#collaborative-workflow) * [Useful commands](#useful-commands) * [Best practices](#best-practices) * [Command Summary and Reference](#commands) * [Some practice](#some-practice)

# About gnugen

Who are we?

Promote free/libre software on the EPFL campus

free/libre software

Four fundamental freedoms

freedom to use: freely run parts of a program or not
freedom to study the source code
freedom to share the program
freedom to improve the program

free/libre software

But why?

Respect for the user
Accessible, inclusive
Privacy
Many more...

# collaborative workflow

This is why!

by https://github.com/pushpankq/Git-Commands-

What is 'origin/main' ?


							$ git status
							On branch main
							Your branch is up to date with 'origin/main'.

The remote

### publish your commits to the remote ``` bash $ git push ```

### get the commits from the remote ``` bash $ git pull ```

but...

```bash $ git pull error: cannot pull: You have unstaged changes. error: Please commit or stash them. ```

remember to commit your changes first

### Multiple remotes #### until now ```bash $ git remote -v origin https://gitlab.epfl.ch/... (fetch) origin https://gitlab.epfl.ch/... (push) ``` #### add a remote ```bash $ git remote add another_origin https://github.com/... $ git remote -v origin https://gitlab.epfl.ch/... (fetch) origin https://gitlab.epfl.ch/... (push) another_origin https://github.com/... (fetch) another_origin https://github.com/... (push) ```

### Multiple remotes You have to specify the remote #### pull ```bash $ git pull another_origin main ``` #### push ```bash $ git push another_origin main ```

### What if someone has changed the remote before you ? ```bash $ git push error: failed to push some refs to 'https://gitlab.epfl.ch/...' ```

NOT the thing to do: ~~git push --force~~

## get latest changes from the remote branch

### Rebase your commits on top of the remote If you don't have new commits yet ```bash $ git stash push $ git pull $ git stash pop // solve the conflicts $ git add name_of_file_changed.txt $ git commit -m "the commit message" $ git push ```

### Rebase your commits on top of the remote If you have done commits already ```bash $ git pull --rebase // solve the conflicts $ git rebase --continue //if you had conflicts $ git push ``` Tip: Some code editors help you solve conflicts

##### unsolved conflicts ```python <<< HEAD def f(self): a = 0 while a < 256: a += 1 print(a) ======= def f(self): x = 0 while x < 256: x += 1 print("Hello World") >>> the_new_branch ``` ##### solved conflicts ```python def f(self): x = 0 while x < 256: x += 1 print(x) ```

## Merge your feature branch into main

Rebase branch


							$ git checkout feature
							$ git rebase main
							// if there are conflicts, solve them and continue with: 
							// git rebase --continue
							$ git push --force // --force is necessary here

Before rebase

After rebase

Pull/merge requests


							$ git checkout feature
							$ git rebase main
							// if there are conflicts, solve them and continue with: 
							// git rebase --continue
							$ git push --force
							// finally create pull/merge request on github/gitlab
							// the remote server merges main and feature after approval

The goal is to allow other developers to review your code before it's added to the project's main branch

Pull/merge requests

Manually merge main


							$ git checkout feature
							$ git rebase main
							// if there are conflicts, solve them and continue with: 
							// git rebase --continue
							$ git push --force // --force is ok since on feature branch
							$ git checkout main
							$ git merge feature
							$ git push // do NOT --force on main branch

Avoid manual merge, use pull/merge requests

# Useful commands

Add some changes to the last commit ```bash $ git commit --amend ``` Restore a file from the last commit ```bash $ git restore file_name ``` Print the history of commits ```bash $ git log --graph --oneline ``` Print changes between your file and the last commit ```bash $ git diff file_name ```

### Jump to a specific commit use the commit hash ```bash $ git checkout 68aef35 ``` or the commit position from the last commit ```bash $ git checkout HEAD~3 ```

### Tag the last commit allow to easily find a specific commit ```bash $ git tag -a v1.2 -m "message for this version" $ git tag v1.2 $ git checkout v1.2 ``` you have to explicitly push the tags ```bash $ git push --tags ``` github and gitlab can do predefined actions when a tag is pushed

### reset ```bash $ git reset HEAD~2 ``` - Go back x commits behind without changing the files - Use "--soft" to keep the changes staged - Don't use "--hard" because it overwrites the files

# Best practices

Do not

use push --force (until required)
work on the same branch
work on main

Do

small commits
meaningful commit names
use as many branches as necessary
use merge/pull requests
add branch protection to main in github/gitlab

# Command Summary and Reference

Summary of basic commands

git add, git commit: create a commit
git status, git diff, git show: show status and changes

Handling branches

checkout
merge
rebase

Using git with other people

pull
push
remote
tag

Handling small mistakes

commit --amend
reset HEAD~
restore

Look at the history

log
diff
checkout

# Some practice

## Practice on the EPFL GitLab - we prepared a lab! - setup of git and gitlab/github on your computer - we will help you with any git related issues

## Some practice using our lab - instructions on how to setup GitLab and git on your computer - exercises to practice the collaborative workflow - available on: [gnugen.ch/en/guides/](https://gnugen.ch/en/guides/)

But first

Thank you!

just do git

Slides and Lab: gnugen.ch/en/guides/

Survey: