Logistics

• Secret code is:
• Masks may be off if you are tripple vaxed and healthy
• How did it go with Authentication?

Background

• Service testing is key when building a Service Oriented Architecure
• It is exactly analogous to End-to-end testing or integration testing
• It supplements basics of Unit Testing
• It’s an extension of testing in general
• Concurrent software is the most difficult kind to reason about

External APIs

• External APIS - Web APIs provided to you by another company altogether
• You don’t control it. The response time may vary dramatically from test to test
• You might need tokens or log ins. There may be quotas (maximum number of calls)
• The service may not be free
• You need to make sure that your code behaves correctly no matter what that service does
• You cannot fix bugs in the service, all you can do is respond in a safe way
• However: We are focused here on *internal” service APIs
• Since you control that the considerations are different

How Services are put together

• By definition what makes it a service is that is accessed over HTTP
• The functionality is invoked via a URL (or queue – for later)
• And it produces results by returning JSON (or XML – for later)
• We happen to be using Sinatra for dispatching HTTP routes and returning JSON
• Usually it’s a good idea to provide a ruby library to invoke the service
• Keep the app server aspect (e.g. sinatra) as thin as possible
• Create your functionality from POROs (Poro Service Objects)

Unit Testing Services directly

• It’s no different from any other automated test
• Either it invokes the actual URL:

require "faraday"
require "json"

url = "http://dummy.restapiexample.com/api/v1/employees"
data = Faraday.get(url).body
result = JSON.parse(data, symbolize_names: true)
assert_equal :success, result[:status]

• Or it uses your own provided API library

require_relative xxx
result = get_employees
assert_equal :success, result[:status]

Additional material

• Demo TDD
• Mocking
• Test Data
• Why does testing matter?

Thank you. Questions?  (random Image from picsum.photos)