Use Google's undocumented spellcheck API to make spelling correction suggestions.

spellcheck.rb

# Unfortunately, Google doesn't return the actual string it is suggesting
# replacements for, so this got a little complicated. Fork and improve!

require 'httparty'
require 'nokogiri'

# > Spellcheck.correct("Ths is a tst")
# => "This is a test"
# > Spellcheck.correct("My nme is Robrt Whtney")
# => "My name is Robert Whitney"
# > Spellcheck.correct("Chnky Bacn")
# => "Chunky Bacon"

module Spellcheck
  def self.correct(text)
    resp = self.get_corrections(text)

    result = Nokogiri.XML(resp.body).xpath('spellresult').first

    chars_checked = result['charschecked'].to_i
    corrections = result.xpath('c')
    text_array = text.split(" ")

    corrections.each do |correction|
      offset = correction['o'].to_i
      length = correction['l'].to_i

      mispelled_word = text[offset..(offset+length)].strip
      corrected_word = correction.text.split(" ").first

      text_array[text_array.index(mispelled_word)] = corrected_word
    end

    text_array.join(" ")
  end

  # Returns possible spelling corrections as xml
  #
  # <spellresult error="0" clipped="0" charschecked="12">  
  #   <c o="0" l="3" s="1">This Th's Thus Th HS</c>  
  #   <c o="9" l="3" s="1">test tat ST St st</c>  
  # </spellresult> 
  #
  # o    -  The offset from the start of the text of the word
  # l    -  Length of misspelled word
  # s    -  Confidence of the suggestion
  # text -  Tab delimited list of suggestions
  #
  def self.get_corrections(text)
    HTTParty.post(
      'https://www.google.com/tbproxy/spell?lang=en&hl=en',
      body: "<spellrequest textalreadyclipped='0' ignoredups='0' ignoredigits='1' ignoreallcaps='1'>  
              <text>#{text}</text>  
            </spellrequest>"
    )
  end
end

It nows renders a 404 😞

Me too get 404, it's really die