Gist showing an issue with Xero API that returns xml instead of Json when there is a validation error

xml-returned-instead-of-json-when-validation-error.rb

require 'rubygems'
require 'bundler/setup'
require 'xero_gateway'

YOUR_OAUTH_CONSUMER_KEY = ''
YOUR_OAUTH_CONSUMER_SECRET = ''
PATH_TO_YOUR_PRIVATE_KEY = 'privatekey.pem'
url = "https://api.xero.com/payroll.xro/1.0/Employees"

options = {
    :signature_method => 'RSA-SHA1',
    :private_key_file => PATH_TO_YOUR_PRIVATE_KEY
}

client   = XeroGateway::OAuth.new(YOUR_OAUTH_CONSUMER_KEY, YOUR_OAUTH_CONSUMER_SECRET, options)
client.authorize_from_access(YOUR_OAUTH_CONSUMER_KEY, YOUR_OAUTH_CONSUMER_SECRET)
headers = {'charset' => 'utf-8'}
headers['Content-Type'] ||= "application/x-www-form-urlencoded"
# we are asking for JSON
headers['Accept'] ||= 'application/json'


uri   = URI.parse(url)

b = Builder::XmlMarkup.new
body = b.Employees {
  b.Employee {
    b.LastName SecureRandom.uuid
    b.FirstName SecureRandom.uuid
    b.WorkLocations 'super wrong'
  }
  b.Employee {
    b.LastName SecureRandom.uuid
    b.FirstName SecureRandom.uuid
    b.WorkLocations 'super wrong'
  }
}

response = client.put(uri.request_uri, { :xml => body }, headers)

result = response.plain_body.force_encoding("UTF-8")
p result
# this fail because result is not JSON but xml
# "<Response xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\"><ErrorNumber>0</ErrorNumber><Type>Error</Type><Message>WorkLocations is not a valid element in Employee</Message></Response>"
# parsed = JSON.parse result
# p parsed
# p parsed["ValidationErrors"]