ROLLBACK_WALKTHROUGH.md

ROLLBACK/REVERTING

Quick walkthrough of reverting different types of commits.

NOTES:

• It's possible to rollback and cherry pick from the reflog.

Create repo

mkdir -p ./git_testing && cd ./git_testing
git init

Creating history

while IFS=, read -r operation value1 value2 value3
do
    case $operation in
        CREATE)
            filename=$value3
            echo "Creating $filename" 
            # add example files to master
            echo "$value1" > "$filename"
        ;;           
        APPEND)
            filename=$value3
            echo "Appending $filename" 
            # add example files to master
            echo "$value1" >> "$filename"        
            echo "$value2" >> "$filename"        
        ;;           
        COMMIT)
            commit=$value1
            echo "Committing $commit" 
            git add .
            git status
            git commit -m "$commit"
            git log --oneline
        ;;           
        *)
            echo "Unrecognised ${i}"
        ;;
    esac

done << EOF
CREATE,first line,"",./filename1.txt
CREATE,first line,"",./filename2.txt
CREATE,new line,"",./filename1.txt
CREATE,third file,"",./filename3.txt
APPEND,third file,"",./filename3.txt
APPEND,third file,"",./filename3.txt
COMMIT,first commit,"",""
CREATE,first line,"",./filename4.txt
COMMIT,second commit,"",""
APPEND,appending lines,"",./filename4.txt
COMMIT,third commit,"",""
APPEND,appending more lines,"",./filename4.txt
COMMIT,fourth commit,"",""
EOF

Reverting changes

# show the individual commits
git show head~3 --name-only 

# revert second commit
git revert head~3 

Rollback the last commit

Rollback in the current local branch. Recently used this to rollback a merge from master into my working feature branch. Rollback the merge and reapply the changes after the merge.

# pop the last commit off and move the changed files into staging
git reset head~1    

Rollback on default branch using a MR/PR.

# create a new branch
git checkout -b reverting

# revert commit 
git revert head|commitid

# push and create an MR
git push 

# or switch to main and merge the commit in
git switch main
git merge reverting