Gem update script. Put this in bin/gem_update and chmod +x bin/gem_update. Thanks to https://www.honeybadger.io/blog/capturing-stdout-stderr-from-shell-commands-via-ruby/

gem_update.rb

#!/usr/bin/env ruby
require "open3"

puts "Create new branch? (press y to continue)"
print "> "

if gets.chomp.casecmp?("y")
  system("git checkout master")
  system("git branch -D gems/outdated")
  system("git checkout -b gems/outdated")
end

# Build list
puts "Fetching gems...\n"
to_update, _status, = Open3.capture2("bundle outdated --strict --parseable")
gems = to_update.split("\n")
gems.shift
to_review = gems.each_with_object({}) do |g, h|
  gem = g.scan(/(?<name>.*?) \(newest (?<new_version>.*?), installed (?<old_version>.*?)\)/).pop
  h[gem[0]] = { new_version: gem[1], old_version: gem[2] }
end

# Confirm
puts "List of gems to update:\n"
to_review.each { |g, v| puts "#{g} (#{v[:old_version]} => #{v[:new_version]})" }

puts "Ok to update? (press y to continue)"
print "> "

if gets.chomp.casecmp?("y")
  # Execute
  puts "Updating gems\n"
  to_review.each { |g, v| system(%Q{bundle update #{g} && git commit --all -m "Gems: Update #{g} to #{v[:new_version]}" --no-verify}) }
  puts
  puts "Finished! Don't forget to run tests!"
else
  # Bail
  puts "Canceling"
  exit
end