git_rails

#!/bin/bash

function help {
  echo -e "\nUsage:"
  echo -e "\tgit-rails [-d] [-v] [-y] [src_ref] [dest_ref]"
  echo -e "\tgit-rails -h"
  echo "Flags:"
  echo -e "\t-d\tdry-run: display pending changes and exit"
  echo -e "\t-v\tverbose: display pending changes, prompt to continue, display command output"
  echo -e "\t-y\tauto-confirm: in verbose mode, apply pending changes without prompting"
  echo
  echo -e "\tsrc_ref\t\tBranch/ref you're coming from; defaults to ORIG_HEAD"
  echo
  echo -e "\tdest_ref\tBranch/ref you're ending at; defaults to HEAD"
  echo -e "\t\t\tUse with care; see README for more details"
  echo
  echo -e "Web: https://github.com/brysgo/git-rails"
  echo
  exit 0
}

dry_run=0
verbose=0
confirm=0
out_target="/dev/null"

optspec=":vdyh-:"
while getopts "$optspec" optchar; do
  case "${optchar}" in
    -)
      case "${OPTARG}" in
        dry-run | dry_run)
          dry_run=1
          verbose=1
          ;;
        verbose)
          verbose=1
          confirm=1
          out_target="/dev/stdout"
          ;;
        auto-confirm | auto_confirm)
          confirm_opt=0
          ;;
        help)
          help
          ;;
      esac;;
    d)
      dry_run=1
      verbose=1
      ;;
    v)
      verbose=1
      confirm=1
      out_target="/dev/stdout"
      ;;
    y)
      confirm_opt=0
      ;;
    h)
      help
      ;;
  esac
done
if [ "$verbose" -eq 1 -a ! -z "$confirm_opt" ]; then
  confirm=$confirm_opt
fi
shift $((OPTIND -1))

old_ref=$1
new_ref=$2

if [ -z "$old_ref" ]; then
  old_ref=`git rev-parse ORIG_HEAD`
fi

if [ -z "$new_ref" ]; then
  new_ref=`git rev-parse HEAD`
fi

# CHECK IF WE NEED TO DO A BUNDLE
bundle_changed=`git diff $old_ref $new_ref -- Gemfile.lock`

# CHECK IF WE NEED TO SPIN SOME YARN
yarn_changed=`git diff $old_ref $new_ref -- yarn.lock`

migrations=`git diff --name-status $old_ref $new_ref -- db/migrate | grep '^[AD]'`

if [ "$verbose" -eq 1 ]; then
  if [ ! -z "$bundle_changed" -o ! -z "$yarn_changed" ]; then
    echo -e "\nPrep needed:"
    if [ ! -z "$bundle_changed" ]; then
      echo -e "\t- bundle"
    fi
    if [ ! -z "$yarn_changed" ]; then
      echo -e "\t- yarn"
    fi
  fi
  if [ ! -z "$migrations" ]; then
    echo -e "\nMigrations needed:\n${migrations}"
  fi
  if [ -z "$bundle_changed" -a -z "$yarn_changed" -a -z "$migrations" ]; then
    echo -e "\nNo changes necessary\n"
    exit 0
  fi
  echo
  if [ "$dry_run" -eq 1 ]; then
    exit 0
  elif [ "$confirm" -eq 1 ]; then
    read -p "Continue? [Yn]: " confirm
    [[ $confirm =~ ^[Nn] ]] && echo && exit 0
  fi
fi

# okay, now actually run whatever's needed
if [ ! -z "$bundle_changed" ]; then
  echo "Your Gemfile.lock has changed, running bundle"
  bundle
fi

if [ ! -z "$yarn_changed" ]; then
  echo "Your yarn.lock has changed, running yarn"
  yarn
fi

if [ ! -z "$migrations" ]; then
  echo "Running migrations!"
  for migration in $migrations
  do
    # CHECK THE MIGRATION TYPE AND CONTINUE TO THE FILENAME
    if [ $migration == "D" ]; then
      migration_type="down"
      continue
    elif [ $migration == "A" ]; then
      migration_type="up"
      continue
    fi

    # BUILD THE MIGRATION COMMAND FROM THE VERSION AND TYPE
    version=`echo "$migration" | grep -o 'db/migrate/.*' | cut -d'_' -f1 | cut -d'/' -f3`
    migrate_command="ActiveRecord::Migrator.run(:$migration_type, 'db/migrate', $version) rescue nil"

    # APPEND OR PREPREND TO THE COMMAND LIST DEPENDING ON MIGRATION TYPE
    if [[ $migration_type == "down" ]]; then
      # CHECKOUT DOWN MIGRATION AND SAVE PATH FOR CLEANUP
      git checkout "$old_ref" -- ":/$migration"
      migration_cleanup="$migration_cleanup $(git ls-files :/$migration)"
      migrate_commands="$migrate_command;$migrate_commands"
    else
      migrate_commands="$migrate_commands;$migrate_command"
    fi
  done

  # RUN THE MIGRATIONS (AND TEST PREPARE)
  {
    echo "$migrate_commands" | bundle exec rails runner /dev/stdin
  } > $out_target

  # CLEAN UP DOWN MIGRATIONS
  if [ ! -z "$migration_cleanup" ]; then
    git reset $new_ref -- $migration_cleanup
    rm $migration_cleanup
  fi
fi