Include Rack/Test to perform API Testing

Start testing your REST API in RSpec.

In other to get the awesome functionality of writing restful routes like
‘/users.json’ instead of the usual :update for example:

# spec/controller/whatever.rb

describe ... do
  patch '/users.json' {key: 'value}
  expect(response).to be_success
end

You’ll need to use Rack/Test

First, in your Gemfile:

# Gemfile
...
gem "rack-test", require: "rack/test"

Then, in your spec/spec_helper.rb, Add the following in the outer block:

# spec/spec_helper.rb

module ApiHelper
  require 'rack/test'
  include Rack::Test::Methods

  def app
    Rails.application
  end
end

# and inside the RSpec config block
RSpec.configure do |config|
  config.include ApiHelper
end

And you’re done.

Now you can do this in your tests!

  get '/users'

Note

In Rack::Test, the response object is not response (like in
ActionController::TestCase::Behavior) but last_response.

References: