How to mock OAuth2 authentication flow in RSpec? - ruby

Question

I am quite new to using RSpec but would like to start testing the (thus far, quite basic) API that I have created, but I am absolutely stumped as to how I can go about mocking the authorization flow of OAuth2, using the oauth and quickbooks-ruby gems. I have researched into this quite extensively today, and am coming up empty handed on any results. Any resources or suggestions would be hugely appreciated.
I am unsure how to even begin approaching actually writing tests, so I don't have any RSpec stuff written yet, but below is shown the two endpoints that I would like to somehow mock, to give an idea of my aim.
get '/callback' do
redirect_uri = "http://localhost:4567/callback"
resp = qbo_client.auth_code.get_token(params[:code], redirect_uri: redirect_uri)
redirect to("/")
end
get '/auth' do
redirect_uri = 'http://localhost:4567/callback'
code_url = qbo_client.auth_code.authorize_url(redirect_uri: redirect_uri, response_type: "code", state: SecureRandom.hex(12), scope: "com.intuit.quickbooks.accounting")
redirect code_url
end
Basically, for a user to authenticate, they hit the /auth endpoint which redirects to Quickbooks for OAuth authorization, this sends the authorization code to the callback endpoint which is then traded for an access token.
I am unsure how to simulate obtaining and exchanging the authorization code, primarily. My best guess at this point is to use a fixture representing the auth-code, mock the exchange with webmock or some comparable tool, but I am very unsure if this is the right approach.

Answer 1

To test the OAuth2 flow in your API, you will need to simulate the responses from the authorization server and ensure that your code handles them correctly. One way to do this is by using a library like VCR or WebMock to record and replay HTTP interactions between your API and the authorization server.
Here is an example of how you could use VCR to record and replay requests to the Quickbooks API:
Install VCR gem() and configure VCR in your spec_helper.rb file:
require 'vcr'
VCR.configure do |config|
config.cassette_library_dir = 'spec/vcr_cassettes'
config.hook_into :webmock
end
RSpec.configure do |config|
config.around(:each) do |example|
VCR.use_cassette("#{example.full_description.parameterize.underscore}") do
example.run
end
end
end
Use the VCR.use_cassette block to wrap your API requests in your test:
describe 'GET /auth' do
it 'redirects to Quickbooks for OAuth authorization' do
VCR.use_cassette('quickbooks_oauth_authorize') do
get '/auth'
expect(last_response).to be_redirect
end
end
end
describe 'GET /callback' do
it 'trades the authorization code for an access token' do
VCR.use_cassette('quickbooks_oauth_token') do
get '/callback', code: '123456'
expect(last_response).to be_redirect
end
end
end
When you run your tests, VCR will record the HTTP interactions and save them to a YAML file in the spec/vcr_cassettes directory. On subsequent test runs, VCR will replay the interactions from the cassette file instead of making real HTTP requests to the authorization server. This allows you to test the OAuth2 flow in a predictable and repeatable way.
In the example above, I used quickbooks_oauth_authorize and quickbooks_oauth_token as the names of the cassette files, but you can use any name that makes sense for your test. You can also pass additional options to the VCR.use_cassette block to customize how VCR records and replays the interactions, such as record: :new_episodes to append new interactions to an existing cassette file.
I hope this helps you get started with testing the OAuth2 flow in your API using RSpec and VCR. Good luck!