thoughtbot--shoulda-matchers/script/update_gem_in_all_appraisals

#!/bin/bash

SUPPORTED_VERSIONS=$(<script/SUPPORTED_VERSIONS)
gem="$1"

update-gem-for-version() {
  local version="$1"
  (export RBENV_VERSION=$version; bundle update "$gem" && bundle exec appraisal update "$gem")
}

for version in $SUPPORTED_VERSIONS; do
  echo
  echo "*** Updating $gem for $version ***"
  update-gem-for-version $version
done