Script to parse the HSBC mortgage rate page

check-hsbc-tracker-rate.rb

#!/usr/bin/env ruby
#
# Script to parse the HSBC mortgage rate page
# to see if they have chanegd the 2 Year Term Tracker Fee Saver
# 
# Subtracts the Bank of England rate from the HSBC advertised rates
# 

require 'net/http'
require 'nokogiri'
require 'bigdecimal'
require 'uri'

EXPECTED_RATE = BigDecimal('0.84')


boe_rate_uri = URI('https://www.bankofengland.co.uk/boeapps/database/Bank-Rate.asp')
hsbc_rates_uri = URI('https://www.hsbc.co.uk/mortgages/existing-customers/switch/rates/')


boe_html = Net::HTTP.get(boe_rate_uri)
boe_doc = Nokogiri::HTML.parse(boe_html)

boe_base_rate = boe_doc.at('.featured-stat/.stat-figure').inner_text
if boe_base_rate =~ /(\d+\.?\d*)\s*%?/
  boe_base_rate = BigDecimal($1)
else
  raise "Failed to get bank of England base rate: #{boe_base_rate}"
end




hsbc_html = Net::HTTP.get(hsbc_rates_uri)
hsbc_doc = Nokogiri::HTML.parse(hsbc_html)

rates = {}
hsbc_doc.search('table.desktop').each do |table|
  caption = table.at('caption')
  next if caption.nil?

  if caption.inner_text =~ /60% Maximum Loan to Value/
    table.search('tr').each do |row|
      cells = row.search('td,th')
      next if cells.empty?
      
      name,rate = cells.map {|e| e.inner_text.strip}
      name.gsub!(/[^\w\s]+/, '')
      next if name == 'Mortgage'
      if rate =~ /(\d+\.?\d*)\s*%?/
        rates[name] = BigDecimal($1)
      end
    end
  end
end


tracker_count = rates.keys.select {|k| k =~ /Tracker/i}.count
if tracker_count != 4
  puts "Number of HSBC tracker rates isn't 4:"
  rates.each_pair do |name, value|
    if name =~ /tracker/i
      puts ' ' + name + ': ' + value.to_s('F') + '%'
    end
  end
end

tracker_fee_saver = rates['2 Year Term Tracker Fee Saver']
rate_above = tracker_fee_saver - boe_base_rate
if rate_above != EXPECTED_RATE
  puts "HSBC Tracker rate has changed to: #{rate_above.to_s('F')} (used to be #{EXPECTED_RATE.to_s('F')})"
end