Searches for a certain set of files, and injects the same line into each line at a matching place

Add_line_at_matching_line.rb

def inject_model_fixtures(filepath)
  content = File.read(filepath).split("\n")

  block_start = content.find_index{|l| l =~ /^RSpec.describe/}
  
  return false if block_start.nil?

  content.insert(block_start + 1, "  include_context 'model_fixtures'")

  File.open(filepath, 'wb') { |file| file.write(content.join("\n")) }

  true
end

files = `ag junk_account -l`.split("\n")

files.each do |file|
  puts "Couldn't find Rspec block for #{file}" unless inject_model_fixtures(file)
end