Initial Benchmark

a.rb

require 'test_helper'
require 'benchmark/ips'

class UserFlowTest < ActionDispatch::IntegrationTest
  def test_index
    get 'http://example.com/users'
    assert_equal 200, response.status
  end
end

class UserFlowTest2 < ActionController::TestCase
  tests UsersController

  def test_index
    get :index
    assert_equal 200, response.status
  end
end

Benchmark.ips(30) do |bm|
  bm.report 'Integration Test' do
    Minitest.run_one_method(UserFlowTest, 'test_index')
  end

  bm.report 'Functional Test' do
    Minitest.run_one_method(UserFlowTest2, 'test_index')
  end
end

index.html.erb

<h1>Listing users</h1>

<table>
  <thead>
    <tr>
      <th colspan="3"></th>
    </tr>
  </thead>

  <tbody>
    <% @users.each do |user| %>
      <tr>
        <td><%= link_to 'Show', user %></td>
        <td><%= link_to 'Edit', edit_user_path(user) %></td>
        <td><%= link_to 'Destroy', user, method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>

<br>

<%= link_to 'New User', new_user_path %>

route.rb

Rails.application.routes.draw do
  resources :users
end

z

# Before https://github.com/rails/rails/commit/4fd144dd4bb0e1ede5a4857c178138088353a3d1 on May 13

Calculating -------------------------------------
    Integration Test        34 i/100ms
     Functional Test        43 i/100ms
-------------------------------------------------
    Integration Test      352.6 (±7.7%) i/s -      10540 in  30.075333s
     Functional Test      445.1 (±7.4%) i/s -      13287 in  30.018357s

# After on June 12

Calculating -------------------------------------
    Integration Test        37 i/100ms
     Functional Test        46 i/100ms
-------------------------------------------------
    Integration Test      367.0 (±4.1%) i/s -      11026 in  30.095082s
     Functional Test      453.8 (±3.1%) i/s -      13616 in  30.031817s