Hound ExUnit: assert_raise seems to considerably slow down the test suite

Question

I've added the following test for a phoenix application:

navigate_to("/")

registration_page_link = find_element(:class, "header__button__register")
registration_page_link |> click()

form                   = find_element(:class, "form__register")
email_field            = find_within_element(form, :class, "input--email")
first_name_field       = find_within_element(form, :class, "input--first_name")
last_name_field        = find_within_element(form, :class, "input--last_name")
password_field         = find_within_element(form, :class, "input--password")
confirm_password_field = find_within_element(form, :class, "input--confirm_password")
submit_button          = find_within_element(form, :class, "form__submit")

email_field            |> fill_field("[email protected]")
first_name_field       |> fill_field("John")
last_name_field        |> fill_field("Doe")
password_field         |> fill_field("12345678")
confirm_password_field |> fill_field("12345678")
submit_button          |> submit_element()

alert      = find_element(:class, "alert--success")
alert_text = visible_text(alert)
name       = find_element(:class, "header__user_name")
name_text  = visible_text(name)

assert alert_text  == "Congratulations John! You have successfuly registered."
assert name_text   == "John D."
assert_raise Hound.NoSuchElementError, ~r/No element found for class/, fn ->
  find_element(:class, "header__button__register")
end

It tests that the user can register with valid credentials.
If I comment out the last assertion, the test take 0.7 seconds to run.
If I try with the last assertion alone, the test takes 6.1 seconds to run.

How come this assertion runs so much slower ? Is there a better way to test that an element does not appear on the page anymore ?

What if you pass 0 as the third argument: find_element(:class, "header__button__register", 0)? — Dogbert

Dogbert Dogbert · Accepted Answer · 2018-02-04T15:02:36

find_element's third argument is the number of retries which defaults to 5 and is the number of times Hound tries to find the element with a gap of retry_time milliseconds which defaults to 250. Since the page is already loaded by the earlier find_element calls, you can speed up this assertion by setting number of retries to 0:

assert_raise Hound.NoSuchElementError, ~r/No element found for class/, fn ->
  find_element(:class, "header__button__register", 0)
end

Hound ExUnit: assert_raise seems to considerably slow down the test suite

1 Answers