Run rails migration commands via aliases with auto-completion for version numbers (via fzf)

fzf_migrations

#!/bin/bash                        

# TDLR; run rails migration commands via aliases with auto-completion for version numbers (via fzf)
#
#   brew install fzf
#   curl https://gist.githubusercontent.com/matthutchinson/6c1bc7681b323d4d2ef5d5a55626a5cf/raw/fzf_migrations > ~/.fzf_migrations
#   source ~/.fzf_migrations
#  
# Then run these commands to migrate:
#   
#   rdbm  # bundle exec rake db:migrate (no auto-completion)
#   rdbmu # bundle exec rake db:migrate:up
#   rdbmd # bundle exec rake db:migrate:down
#   rdbmr # bundle exec rake db:migrate:redo
# 
# [Read more](https://github.com/junegunn/fzf) about fzf 
# I have other useful fuzzy find helpers [here](https://github.com/matthutchinson/workbench/blob/master/fuzzy_finder) (for git, bash etc.)

# helper to echo and execute a command
function _echo_and_execute() {
  echo $1
  eval $1
}

# fzf (with preview) a rails migration and pass it as the command VERSION
function _fzf_rails_migration() {
  echo $(ls ./db/migrate/ | fzf --preview 'head -20 ./db/migrate/{}' | xargs | cut -d '_' -f 1 | xargs | tr -d '\n')
}

function rdbm() {
  if [ ! -d "./db/migrate" ]; then
    echo "Opps, you're not in a Rails directory"
  else
    if [ $# -eq 0 ]; then
      _echo_and_execute "bundle exec rake db:migrate"
    else
      migrate_version=$(_fzf_rails_migration)
      if [ ! -z $migrate_version ]; then
        _echo_and_execute "$*$migrate_version"
      fi
    fi
  fi
}

# db migrate up/down/redo with VERSION
alias rdbmu="rdbm bundle exec rake db:migrate:up VERSION="
alias rdbmd="rdbm bundle exec rake db:migrate:down VERSION="
alias rdbmr="rdbm bundle exec rake db:migrate:redo VERSION="