sashokbg/git-training-usecases

Git Training Use Cases

This repository is a list of git usecases that are commonly encountered during devleopment. Its primary goal is to show you how you can get into a delicate situation and train you how to solve it.

Usage

Each test case is associated with a POSIX shell script that prepares a local repository located in the workspace directory.

Normally you will do the following for most use-cases:

1. Run the associate .sh script
2. cd workspace/<use_case_name>
3. Solve the problem using git commands

Technical Notes

• Each script will clean the workspace and you will get a fresh start

• A remote repository is configured in the .git-repos directory by using the file:// protocol. This means that "git remote -v" will output something like /home/alexander/git-training-usecases/.git-repos/.

• If you don't have global username and email configured default values will be put for you in the workspace repos.

• Git "lg" and "s" aliases are configured to use a pretty print git history and for status. Usage: "git lg" and "git s"

• As a best practice and for security reasons you can run the exercises in a docker image:

  docker run --rm --name git-exercises -v $(pwd):/git -it sashokbg/git-exercises /bin/zsh
  

• Note that after running with docker you may need to manually clean the workspace and .git-repos directories with "sudo".

• Some test cases run interactive rebases and generate a "fake_editor.sh" script that simulates the user input. This works using the GIT_EDITOR and GIT_SEQUENCE_EDITOR env variables.

TODO

• Add assertion shells scripts for all use cases to validate the solution
• Add git snensitive shell PS1 for the docker image
• Add collapsible hints and explanations for each case

Use Cases

Use Case: Abort a merge

I accidentally typed the git merge feat command and now I am prompted a message for the merge. I want to abort this merge.

Traps:

- If you close the file or save and close the merge will happen

Run:

./abort_a_merge.sh
cd workspace/abort_a_merge

Use Case: Merge a feat into main with no merge commit

I finished working on my feature And I want to merge my code to main But I do not want to generate a merge commit In order to keep history clean and linear

Run:

./no_merge_to_main.sh
cd workspace/no_merge_to_main

Use Case: Get Most Recent Code from Main

I work on a "feature" branch And a colleague of mine did a fix that is on "main" branch I want to "get" my colleague's code on my branch.

Run:

./get_most_recent_code_from_main.sh
cd workspace/get_most_recent_code_from_main

Use Case: Undoing a bad commit that is pushed

I did a bad commit introducing a bug that got into production and is on "main" I want to quickly revert so that we can redeploy last version

Run:

./undo_pushed_commit.sh
cd workspace/undo_pushed_commit

Use Case: Undoing a range of pushed bad commit

I did a 3 bad commits introducing a bug that got into production and is on "main" I want to quickly revert them.

Run:

./undo_pushed_range_commits.sh
cd workspace/undo_pushed_range_commit

Use Case: Detached Head

I did a wrong checkout And now my HEAD is in "detached" state

Run:

./detached_head.sh
cd workspace/detached_head

Use Case: Redo last commit

I did a commit but I want to add some files to it. I want to push my code to the remote

Run:

./redo_last_commit.sh
cd workspace/redo_last_commit

Attention trap ahead !

Use Case: Clean a WIP commit

I worked on a feature And I had to quickly change a branch so I performed a "WIP" commit at one point. I want to clean this WIP commit before opening my merge request.

Solve for:

• I want to rename the wip commit
• I want to drop the wip commit
• I want to rename the wip AND the last commit to have (first, second, third, fourth)
• I want to fuse the wip commit with the previous commit
• I want to fuse the wip commit with the next commit

Run:

./clean_wip_commit.sh
cd workspace/clean_wip_commit

Use Case: Too many commits

I worked on a feature and did too many commits I wish to fuse them together before opening a merge request.

Run:

./too_many_commits.sh
cd workspace/too_many_commits

Use Case: Edit a previous commit (not last)

I did two commits: one for backend and then one for frontend But I forgot to add one file in the backend commit

Run:

./edit_second_to_last_commit.sh
cd workspace/edit_second_to_last_commit

Use Case: Quickly change branch

I am working on a feature and have not yet commited But I need to quickly change branch to main to fix an urgent issue.

Run:

./quickly_change_branch.sh
cd workspace/quickly_change_branch

Use Case: A non-tracked file is changed on another branch

I have a non-tracked file called file2.txt This file exists in the "main" branch When I try to checkout "main" I encountered the following error

error: The following untracked working tree files would be overwritten by checkout:
	file.txt
Please move or remove them before you switch branches.
Aborting

Run:

./non_tracked_file_checkout.sh
cd workspace/non_tracked_file_checkout

Use Case: Revert a Rebase

I squashed some commits But have not yet pushed to origin I want to revert my squash

Run:

./revert_squash.sh
cd workspace/revert_squash

Use Case: Revert a Rebase That was Pushed

I squashed some commits Then I pushed with --force I want to revert my squash

Run:

./revert_squash_pushed.sh
cd workspace/revert_squash_pushed

Use Case: Accidental merge from main

I worked on a feature and I wanted to rebase upon main But instead I did a merge

Run:

./accidental_merge.sh
cd workspace/accidental_merge

Use Case: Rebase Conflict Resolution

I edited the text1.txt file I want to rebase my feat branch onto main But another user edited the same file on main

Run:

./rebase_conflict.sh
cd workspace/rebase_conflict

Use Case: Split a commit

I did one big commit that has too many changes I want to split it into three commits "split: 1", "split: 2" and "split: 3"

Run:

./split_commit.sh
cd workspace/split_commit

Use Case: Branch merged upon itself

Me and a colleague worked on the same branch They commited a change on file1.txt I do a pull of the branch But and it generates a merge

Run:

./pull_generates_merge.sh
cd workspace/pull_generates_merge

Use Case: Multiple Origins - Get Second Remote Main

I forked a repository from a remote Someone has pushed some new code to the original remote in branch main I want to get the latest changes from the original remote (The second remote is found at .git-repos/

Hint: Use the file:// protocol for the second remote and point at /.git-repos/multiple_remotes_get_main-upstream.git

Run:

./multiple_remotes_update_main.sh
cd workspace/multiple_remotes_update_main

Use Case: Take File Version from Another Branch

I am working on a branch feat And I want to get the version of file "file1.txt" from the "feat/other" branch

Run:

./take_file_another_branch.sh
cd workspace/take_file_another_branch

Use Case: Preview my stash

I have some files in my stash I want to see the state of "file1.txt" in my stash

Run:

./stash_fun.sh
cd workspace/stash_fun

Use Case: I want new GIT repo from current branch

I want to transfer current branch to new GIT repository as a new project

Use Case: I want to ignore a directory but something is off

I want to ignore the dist directory

Run:

./ignore_dist.sh
cd workspace/ignore_dist

Use Case: I want to send a piece of code to another repo

I work on a repository that uses the same code as another repo I want to send my last commit to a colleague that is working on the other repo

Run:

./send_code_from_here.sh
cd workspace/send_code_from_here

Use Case: Create a branch results in "refs/heads/..." exists

I try to create a branch called "feat/my_feat" But it results in an error "refs/heads/my_feat" exists. Cannot create ...

Run:

./checkout_error_ref_exists.sh
cd workspace/checkout_error_ref_exists

Use Case: I see the commits of my colleague in my PR

I did some wrong operation And now I see the commits of my colleague as part of my PR

Run:

./foreign_commits_on_my_branch.sh
cd workspace/foreign_commits_on_my_branch

Use Case: Pulling from another repository fails

A colleague works on another repository that is not related to mine and have pushed a commit called "other commit". I want to get the content of their commit on my repo.

I added the second repository as a remote and pulled

And I receive the following error when trying merge

fatal: refusing to merge unrelated histories

Run:

./cannot_merge_unreleated_history.sh
cd workspace/cannot_merge_unreleated_history.sh

Use Case: I need to generate a report with commits from a branch