git-fixup

#!/bin/zsh

# git rev-list 'HEAD^..HEAD'

if (( ! $+commands[git-deps] )); then
    echo 'Required dependency git-deps was not found in path.' >&2
    exit
fi

if git diff --cached --quiet; then
    echo 'No staged changes.' >&2
    exit
fi

git commit -m 'git-fixup temporary commit' --quiet
if (( $? )); then
    echo 'Failed committing index.' >&2
fi

typeset -a deps
deps=( ${(f)"$(git deps -e master HEAD)"} )

if (( $#deps == 1 )); then
    echo "Index depends on one commit only:"
    git log -n 1 --oneline $deps[1]
    echo "Creating fixup commit:"
    git commit --amend --fixup=$deps[1] --quiet
    git log -n 1 --oneline HEAD
elif (( $#deps == 0 )); then
    echo "Index does not depend on any commit (just amend?)" >&2
    git reset --soft 'HEAD^'
else
    echo "Index depends on more than one commit in this branch:" >&2
    for b in $deps; do
        echo $b
        git log -n 1 --oneline $b
    done
    git reset --soft 'HEAD^'
fi