Replace spec_helper with rails_helper

#!/bin/bash

# get a list of files which contain "require" AND "spec_helper" on a single line
# excluding spec/rails_helper.rb (we want "require 'spec_helper'" to exist here)
declare -a files=$(git grep -E "require.*spec_helper" | cut -d ':' -f 1 | grep -v 'spec/rails_helper.rb')

# loop through files and replace "spec_helper" with "rails_helper"
for i in $files; do
  sed -i '' -e 's/spec_helper/rails_helper/' $i
done