migration_version_at_ref

#!/usr/bin/env bash

# Useful when you want to git bisect in a rails app and know
# you need to `bin/rake db:migrate VERSION="SOMETHING"` before
# you check out the next commit so the database is in the right
# state, but you don't know what SOMETHING is.

# Usage:
#
# $ migration_version_at_ref <REF>

ref="$1"

git ls-tree --name-only "$ref:db/migrate" | tail -n 1 | cut -f 1 -d '_'