#!/usr/bin/env ruby

def usage(msg = nil)
  puts "Error: #{msg}\n" if msg
  puts "Usage: #{File.basename(__FILE__)} test files"
  puts
  puts "Will convert a existing test files with names like "
  puts
  puts "  def test_should_do_stuff"
  puts "    ..."
  puts "  end"
  puts
  puts "to one using the new syntax: "
  puts
  puts "  should \"be super cool\" do"
  puts "    ..."
  puts "  end"
  puts
  puts "Will run the tests before and after, ensuring that they don't break, and that the test counts"
  puts "are consistent"
  puts
  puts "A copy of the old file will be left under /tmp/ in case this script just seriously screws up"
  puts
  exit (msg ? 2 : 0)
end

require 'fileutils'

usave if ARGV.empty?
usage("This system doesn't have a /tmp directory.  wtf?") unless File.directory?('/tmp')

def run_tests(file)
  puts "  running..."
  test_output = `ruby #{file}`
  unless $?.success?
    puts "Tests failed for #{file}"
    exit 2
  end
  count = test_output.grep(/ assertions, /).first.split[0]
  #puts "#{count} tests"
  return count
end

def make_tempfile(file)
  tmpfile = "/tmp/#{File.basename(file)}"
  puts "  copying to #{tmpfile}"
  FileUtils.cp(file, tmpfile)
  return tmpfile
end

def convert_contents(tmpfile)
  contents = File.read(tmpfile)
  contents.gsub!(/def test_(\S*)/) do |match|
    parts = $1.split('_')
    if parts.first == 'should'
      parts.shift
    else
      puts "  Needs renaming: should #{parts.join(' ')}"
      parts.unshift("RENAME ME:")
    end
    "should \"#{parts.join(' ')}\" do"
  end
  return contents
end

def write_file(file, contents)
  puts "  writing new version"
  File.open(file, 'w') { |f| f.write(contents) }
end

ARGV.each do |file|
  unless File.exists?(file)
    puts "Can't find #{file}"
    next
  end

  puts "Converting #{file}"

  old_count = run_tests(file)

  tf = make_tempfile(file)
  write_file(file, convert_contents(tf))

  new_count = run_tests(file)

  if new_count != old_count
    puts "ERROR: #{old_count} tests before conversion, #{new_count} after.  Something's wrong."
    exit 2
  end
end