Easy migrate to new rspec expect syntax

rspec_expect.rb

#!/usr/bin/env ruby
dir = ARGV[0]

regexps = [
    {from: /(\s+)(.+?)\.should ==/, to: '\1expect(\2).to eq'},
    {from: /(\s+)(.+?)\.should =~ \[/, to: '\1expect(\2).to match_array ['},
    {from: 'be_true', to: 'be_truthy'},
    {from: 'be_false', to: 'be_falsey'},
    {from: /(\s+)(.+?)\.should(?:(_)?(not)?) be_(\w+)/, to: '\1expect(\2).\4\3to be_\5'},
    {from: /(\s+)(.+?)\.should(?:(_)?(not)?)_(\w+)/, to: '\1expect(\2).\4\3to \5'},
    {from: /(\s+)(.+?)\.should (?:have|has)\((\d+)\)[.\w]*/, to: '\1expect(\2.length).to eq \3'},
    {from: /(\s+)(.+?)\.stub/, to: '\1allow(\2).to receive'}
]

Dir["#{dir}/**/*_spec.rb"].each do |path|
  puts path
  data = File.read(path)
  regexps.each { |regexp| data.gsub!(regexp[:from], regexp[:to]) }
  File.write(path, data)
end

puts 'DONE!'