my_api_spec_using_before.rb

require 'rails_helper'

RSpec.describe 'My API' do
  let(:request) do
    lambda do
      get '/my_api/value-cannot-be-routed-due-to-route-constraints'
    end
  end

  context 'when action_dispatch.show_exceptions is false (default behavior on test env)' do
    it 'raise a routing error' do
      expect { request.call }.to raise_error(ActionController::RoutingError)
    end
  end
  
  context 'when action_dispatch.show_exceptions is true' do
    before do
      Rails.application.config.action_dispatch.show_exceptions = true
    end
    
    it 'return a 404' do
      request.call
      expect(response.status).to eq(404)
    end
  end
end