compel_hash_validation.rb

object = {
  first_name: 'Joaquim',
  birth_date: '1989-0',
  address: {
    line_one: 'Lisboa',
    post_code: '1100',
    country_code: 'PT'
  }
}

schema = Compel.hash.keys({
  first_name: Compel.string.required,
  last_name: Compel.string.required,
  birth_date: Compel.datetime,
  address: Compel.hash.keys({
    line_one: Compel.string.required,
    line_two: Compel.string.default('-'),
    post_code: Compel.string.format(/^\d{4}-\d{3}$/).required,
    country_code: Compel.string.in(['PT', 'GB']).default('PT')
  })
})

schema.validate(object)

=> <Compel::Result:0x007f82a1b053f8
 @errors=
  {"last_name"=>["is required"],
   "birth_date"=>["'1989-0' is not a parsable datetime with format: %FT%T"],
   "address"=>{"post_code"=>["must match format ^\\d{4}-\\d{3}$"]}},
 @valid=false,
 @value=
  {"first_name"=>"Joaquim",
   "birth_date"=>"1989-0",
   "address"=>{"line_one"=>"Lisboa", "post_code"=>"1100", "country_code"=>"PT", "line_two"=>"-"},
   "errors"=>
    {"last_name"=>["is required"],
     "birth_date"=>["'1989-0' is not a parsable datetime with format: %FT%T"],
     "address"=>{"post_code"=>["must match format ^\\d{4}-\\d{3}$"]}}}>