Animal Shelter Data Export

Problem/Feature Description

An animal shelter management company runs a Rails application that tracks animals across multiple shelter locations. They use a third-party data warehouse API (already integrated with Auth, Client, and Fetcher layers in the codebase) to store and query shelter records. A new requirement has arrived: the application needs to query animals records from the warehouse, exposing only the fields tag_number, name, species_id, shelter_id, and intake_date. There must also be a way to look up a single animal by its tag_number.

The existing integration module is app/services/shelter_api/ and already contains auth.rb, client.rb, and fetcher.rb. You need to add the missing transformation and domain layers so the application can request and use animal data safely. A particular concern is that the warehouse API returns many more fields than are needed — leaking internal API schema details into the application domain would make refactoring painful.

Output Specification

Add the Builder and Domain Entity layers to the existing shelter_api integration. Also write specs for the new components.

Expected output files:

• app/services/shelter_api/builder.rb
• app/services/shelter_api/animal.rb (domain entity)
• spec/services/shelter_api/builder_spec.rb
• spec/services/shelter_api/animal_spec.rb
• spec/factories/shelter_api/animal_response.rb (FactoryBot hash factory for API response test data)

Input Files

The following files are provided as inputs. Extract them before beginning.

=============== FILE: app/services/shelter_api/client.rb =============== module ShelterApi class Client include HTTParty

MISSING_CONFIGURATION_ERROR = 'Missing required configuration'
DEFAULT_TIMEOUT = 30
DEFAULT_RETRIES = 3

class Error < StandardError; end

def self.default
  token = Auth.default.token
  host = Rails.configuration.secrets[:shelter_api_host]
  new(token:, host:)
end

def initialize(token:, host:, timeout: DEFAULT_TIMEOUT, max_retries: DEFAULT_RETRIES)
  raise Error, MISSING_CONFIGURATION_ERROR if [token, host].any?(&:blank?)
  @token = token
  @host = host
  @timeout = timeout
  @max_retries = max_retries
end

def execute_query(payload)
  response = self.class.post(
    "#{@host}/api/query",
    headers: { 'Authorization' => "Bearer #{@token}", 'Content-Type' => 'application/json' },
    body: payload.to_json,
    timeout: @timeout
  )
  JSON.parse(response.body)
rescue JSON::ParserError, HTTParty::Error => e
  raise Error, "Request failed: #{e.message}"
end

end end

=============== FILE: app/services/shelter_api/fetcher.rb =============== module ShelterApi class Fetcher MAX_RETRIES = 3 RETRY_DELAY_IN_SECONDS = 2

def initialize(client, data_builder:, default_query:)
  @client = client
  @data_builder = data_builder
  @default_query = default_query
end

def execute_query(query = @default_query)
  retries = 0
  begin
    raw_response = @client.execute_query(query)
    @data_builder.build(raw_response)
  rescue ShelterApi::Client::Error => e
    retries += 1
    if retries < MAX_RETRIES
      sleep(RETRY_DELAY_IN_SECONDS ** retries)
      retry
    end
    raise
  end
end
alias query execute_query

end end