Shell script to only run rubocop on changed files

rubocop_changed.sh

#!/bin/bash

set -e

run() {
  echo "CHANGED_FILES=$(echo $CHANGED_FILES | tr ' ' ,)"
  eval $1
}

# Load changed files.
IFS=$'\n'
CHANGED_FILES=($(git diff $TRAVIS_COMMIT_RANGE --name-only | grep '\.rb$' | tr '\n' ' '))

if [ ${#CHANGED_FILES[@]} -eq 0 ]
then
  echo "No ruby files touched so nothing to cop"
else
  run "bundle exec rubocop $CHANGED_FILES"
fi