RSpec test for handling known IP addresses

Question

I want to replace the array of ips with a method (like known_ips or just ips) but I don't know how.

I'll use this known_ips somewhere else.

describe WelcomeController, type: :controller do
  [
    {
      ip: '73.53.61.23',
      location_name: 'Seattle, Washington, US'
    }, {
      ip: '8.26.157.16',
      location_name: 'San Francisco, California, US'
    }, {
      ip: '174.112.13.21',
      location_name: 'Mississauga, Ontario, CA'
    }
  ].each do |params|
    it 'geolocalizes the visitor based on the ip' do
      allow_any_instance_of(ActionDispatch::Request).to receive(:remote_ip).and_return params[:ip]
      get :index
      expect(controller.current_location.name).to eq params[:location_name]
    end
  end
end

Answer 1

I'll use this known_ips somewhere else.

I'm guessing that "somewhere" will still be in a test file. If so you can put this in support file (which is a common patern in RSpec).

# spec/support/ip_list.rb
IP_LIST = [
  # easily to recognize that IP address is first and the location name the second, but you can use your code that uses Hash here
  ['73.53.61.23',   'Seattle, Washington, US'],
  ['8.26.157.16',   'San Francisco, California, US'],
  ['174.112.13.21', 'Mississauga, Ontario, CA']
]

Then on spec_helper.rb (see this example)

# spec/spec_helper.rb
# after the last require
Dir[Rails.root.join("spec/support/**/*.rb")].each { |f| require f }

And in your actual test:

describe WelcomeController, type: :controller do
  it 'geolocalizes the visitor based on the ip' do
    IP_LIST.each do |(ip, location_name)|
      expect(controller.request).to receive(:remote_ip).and_return ip
      get :index
      expect(controller.current_location.name).to eq location_name
    end
  end
end

Note that I nested IP_LIST.each inside the it block, I don't think you need to create one it for each test. This is a personal opinion, I'm not sure what is the best practices here.