Git Utility (ZSH) - Clean merged branches

git-clean.zsh

# Git Helper: Clean merged branches
# Checks for merged branches against the currently checkout branch. Lists and confirms for deletion.
# To protect branches from ever being deleted, add them to DO_NOT_DELETE. Protected branches will be skipped.
# usage: git-clean
function git-clean() {
    local DO_NOT_DELETE=(
        master
        develop
    )
    local mergedBranches=()

    echo -e "\n\e[34mChecking current branch...\e[0m"
    local currentBranch=$(git branch --show-current)
    echo "  $currentBranch"

    DO_NOT_DELETE+=($currentBranch)

    echo -e "\n\e[34mLooking for merged branches...\e[0m"
    mergedBranches+=$(git branch --merged | awk "/^[^*]/ {print}")

    # Detect branches that have been squashed before merging
    # @see https://github.com/not-an-aardvark/git-delete-squashed
    # Disabled because this is slow and should be covered by checking for branches deleted upstream
    # mergedBranches+=$(git for-each-ref refs/heads/ "--format=%(refname:short)" |
    #     while read branch;
    #         do mergeBase=$(git merge-base $currentBranch $branch) &&
    #         [[ $(git cherry $currentBranch $(git commit-tree $(git rev-parse $branch^{tree}) -p $mergeBase -m _)) == "-"* ]] &&
    #         echo $branch;
    #     done)

    echo -e "\n\e[34mLooking for branches deleted upstream...\e[0m"
    mergedBranches+=$(git branch -vv | awk '/: gone\]/ {print $1}')

    # Remove duplicates
    mergedBranches=$(echo $mergedBranches | sort -u)

    local queuedBranches=()
    local protectedBranches=()
    for branch in $(echo $mergedBranches)
    do
        # Trim leading whitespace
        branch=$(echo $branch | sed 's/^ *//')

        if [ $branch = "*" ]; then
            # Skip
        elif [ ${DO_NOT_DELETE[(Ie)$branch]} -gt "0" ]; then
            echo "  \e[32mSkipping\e[0m $branch"
            protectedBranches+=($branch)
        else
            queuedBranches+=($branch)
        fi
    done

    if [ -z "$queuedBranches" ]; then
        echo -e "\n\e[32mNothing to do here!\e[0m"
    else
        branchesCount="${#queuedBranches}"
        pluralBranches=$([ $branchesCount != "1" ] && echo "$branchesCount branches" || echo "branch")

        echo -e "\n\e[93mRemove the following $pluralBranches?\e[0m (Y/N)"

        for branch in $queuedBranches
        do
            echo "  $branch"
        done

        echo "\n"
        read -q $'confirm?> '
        if [ "$confirm" = "y" ]; then
            echo -e "\n\e[34mCleaning branches...\e[0m\n"

            echo $queuedBranches | xargs -n 1 git branch -D # FORCE delete (squashed branches)

            echo -e "\n\e[32mAll Done!\e[0m\n"
        else
            echo -e "\n\n\e[33mCanceled\e[0m\n"
            return
        fi
    fi
}