Git post checkout hook

place this in: .git/hooks/post-checkout

Upon switching branches, this will (as necessary):

• bundle install
• yarn install
• migrate or rollback any migrations relevant (or not relevant) to the branch, and checkout db/schema.rb
• git submodule update

If your repo does not have the submodule, run:

• git submodule update --init
• cd app/javascript/ui/shared
• git checkout shape

You can also decline the updates e.g. if you are just making a quick branch update don't want to rollback migrations (and lose data).

# modified from https://gist.github.com/brysgo/9980344

CHECKING_OUT_BRANCH=$3
OLD_BRANCH=$1
NEW_BRANCH=$2

if [ $CHECKING_OUT_BRANCH -eq 1 ]
  then
    FILES_CHANGED=`git diff $OLD_BRANCH $NEW_BRANCH --name-status`
    MIGRATIONS_REMOVED=`echo "$FILES_CHANGED" | egrep 'D\tdb/migrate/([0-9]+)' | sort -r`
    MIGRATIONS_ADDED=`echo "$FILES_CHANGED" | egrep 'A\tdb/migrate/([0-9]+)'`

    exec < /dev/tty

    read -p "Do you want to proceed with automated branch changes? y/n" -n 1 -r
    echo    # (optional) move to a new line
    if [[ $REPLY =~ ^[Yy]$ ]]
    then
      # check if we need to do a bundle
      BUNDLE_CHANGED=`echo "$FILES_CHANGED" | egrep 'M\tGemfile.lock'`
      if [ ! -z "$BUNDLE_CHANGED" ]; then
        echo "Your Gemfile.lock has changed, running bundle"
        bundle
      fi

      # check if we need to do a yarn install
      PACKAGE_CHANGED=`echo "$FILES_CHANGED" | egrep 'M\tyarn.lock'`
      if [ ! -z "$PACKAGE_CHANGED" ]; then
        echo "Your yarn.lock has changed, running yarn"
        yarn
      fi

      if [ ! -z "$MIGRATIONS_REMOVED" ]; then
        echo "Rolling back missing migrations"
        for migration in $MIGRATIONS_REMOVED
        do
          if [ $migration == "D" ]; then
            continue
          fi
          git checkout "$OLD_BRANCH" -- "$migration"
          VERSION=`echo "$migration" | cut -d'_' -f1 | cut -d'/' -f3`
          bundle exec rake db:migrate:down VERSION="$VERSION"
          git reset
          rm "$migration"
        done
        bundle exec rake db:test:prepare
        git checkout db/schema.rb
      fi

      if [ ! -z "$MIGRATIONS_ADDED" ]; then
        echo "New migrations have been added running migrations"
        bundle exec rake db:migrate db:test:prepare
      fi
    fi

    # always check out the branch's correct version of the submodule
    git submodule update app/javascript/ui/shared
fi