controller.rb

class UsersController < ApplicationController
  def show
    raise ActiveRecord::RecordNotFound
  end
end

functional_test.rb

require 'test_helper'

class UsersControllerTest < ActionController::TestCase
  test "exception behavior" do
    get :show, id: 1
  end
end

integration_test.rb

require 'test_helper'

class RootTest < ActionDispatch::IntegrationTest
  test "exception behavior" do
    get "/users/1"
  end
end

Functional

rails_master » ruby -Itest test/controllers/users_controller_test.rb
Run options: --seed 29368

# Running:

E

Finished in 0.022488s, 44.4682 runs/s, 0.0000 assertions/s.

  1) Error:
UsersControllerTest#test_exception_behavior:
ActiveRecord::RecordNotFound: ActiveRecord::RecordNotFound
    app/controllers/users_controller.rb:3:in `show'
    test/controllers/users_controller_test.rb:5:in `block in <class:UsersControllerTest>'

1 runs, 0 assertions, 0 failures, 1 errors, 0 skips

Integration

rails_master » ruby -Itest test/integration/root_test.rb
Run options: --seed 24369

# Running:

E

Finished in 0.050185s, 19.9263 runs/s, 0.0000 assertions/s.

  1) Error:
RootTest#test_exception_behavior:
ActiveRecord::RecordNotFound: ActiveRecord::RecordNotFound
    app/controllers/users_controller.rb:3:in `show'
    test/integration/root_test.rb:5:in `block in <class:RootTest>'

1 runs, 0 assertions, 0 failures, 1 errors, 0 skips