check_changes.rb

require 'json'

impact_map = JSON.parse(File.read('impact_map.json'))
response = JSON.parse(`curl -s -H "authorization: Bearer #{ENV['GITHUB_TOKEN']}" -X GET -G #{ENV['PULL_REQUEST']}/files`)
impacted_files = response.map { |file| file['filename'] }

impact_map.select! do |test, related_source_files|
  related_source_files.any? { |file| impacted_files.include?(file) }
end

puts impact_map.keys.join(',')