Why does this test pass? And from the book does not pass?

Question

Software testing

#product.yml
one:
  title: MyString
  description: MyText
  image_url: MyString
  price: 99.99

two:
  title: MyString
  description: MyText
  image_url: MyString
  price: 99.99
ruby:
  title: Programming Ruby 1.9
  description: MyText
  image_url: MyString.png
  price: www

require 'test_helper'
class StoreControllerTest < ActionController::TestCase
  test "should get index" do
    get :index
    assert_response :success
    assert_select '#columns #side a', minimum: 4
    assert_select '#main .entry', 3
    assert_select 'h3', 'Programming Ruby 1.9'
    assert_select '.price', /[\d]+\.\d\d/
  end
end

Everything is fine here with the exhaust:

Run options: --seed 45596
# Running:
............
Finished in 0.478399s, 25.0837 runs/s, 81.5220 assertions/s.
12 runs, 39 assertions, 0 failures, 0 errors, 0 skips

But why???
But like in the book

one:
  title: MyString
  description: MyText
  image_url: MyString
  price: 99.99

two:
  title: MyString
  description: MyText
  image_url: MyString
  price: 99.99
ruby:
  title: Programming Ruby 1.9
  description: MyText
  image_url: MyString.png
  price: 99.99

require 'test_helper'

class StoreControllerTest < ActionController::TestCase
  test "should get index" do
    get :index
    assert_response :success
    assert_select '#columns #side a', minimum: 4
    assert_select '#main .entry', 3
    assert_select 'h3', 'Programming Ruby 1.9'
    assert_select '.price', /\$[,\d]+\.\d\d/
  end
end

Test fails:

Run options: --seed 3724
# Running:
...........F
Finished in 0.483193s, 24.8348 runs/s, 80.7131 assertions/s.
  1) Failure:
StoreControllerTest#test_should_get_index [/home/beerdy/Dev/depot/test/controllers/store_controller_test.rb:10]:
<(?-mix:\$[,\d]+\.\d\d)> expected but was
<99.99>..
Expected 0 to be >= 1.
12 runs, 39 assertions, 1 failures, 0 errors, 0 skips

Why is that????

Answer 1

In the first case, the regular expression [\d]+\.\d\dcaptures the price in the format "number.number".
In the second case, the regular expression \$[,\d]+\.\d\drequires a dollar sign before the price, like "$number.number". To pass the test in the second case, you need to add a dollar sign to the price or change the regular expression to[\d]+\.\d\d