revert a merge in git code example

Example 1: undo a git merge

git reset --hard HEAD~1
git reset --hard <commit_sha>

Example 2: git undo merge

git reset --hard HEAD~1

Example 3: undo merge

// find the commit hash
git log --oneline

git revert -m 1 [commit-hash]

// https://www.datree.io/resources/git-undo-merge