gemfile_locks

#!/bin/bash

# Ignore file-only checkouts
[[ $3 -ne 1 ]] && exit 0

git_root=$(git rev-parse --show-toplevel)
root=$git_root
[[ -d "$root/vmdb" ]] && root="$root/vmdb"
gemfile_lock="$root/Gemfile.lock"

# Ignore backups when Gemfile.lock is committed
git ls-files --error-unmatched "$gemfile_lock" >/dev/null 2>&1
[[ $? -eq 0 ]] && echo "Skip backup" && exit 0

from_branch=$(git branch --points-at $1 | rev | cut -d ' ' -f1 | rev)
to_branch=$(git branch --points-at $2 | rev | cut -d ' ' -f1 | rev)

# Ignore "git checkout" without args
[[ "$from_branch" == "$to_branch" ]] && exit 0

lockfiles="$git_root/.lockfiles"
mkdir -p $lockfiles

lockfile="Gemfile.lock.$from_branch"
cp "$gemfile_lock" "$lockfiles/$lockfile"
echo "Gemfile.lock saved to $lockfile"

lockfile="Gemfile.lock.$([[ -f "$lockfiles/Gemfile.lock.$to_branch" ]] && echo $to_branch || echo master)"
cp "$lockfiles/$lockfile" "$gemfile_lock"
echo "Gemfile.lock restored to $lockfile"