coen.bakker

coen.bakker

I am testing a feature that uses an scroll event listener. I am using the event listener inside a JS hook.

Basically this.

mounted() {
  this.el.addEventListener('scroll', () => {
    ...
    this.pushEvent("scroll_changed", ...)
  })
}

I am using Wallaby to test this feature, and I have set up Wallaby to scroll to a certain location during the test. And using take_screenshot() I have confirmed the page indeed gets scrolled to the right location.

feature "", %{session, session} do
  user = ...

  session
  |> log_in_user(user)
  |> visit(~p"/read/#{story.id}")
  |> scroll_into_view(@resume_location)
end

def scroll_into_view(session, selector) do
  execute_script(
    session,
    """
    document.querySelector(arguments[0]).scrollIntoView({
      behavior: 'auto',
      block: 'center',
      inline: 'center'
    })
    """,
    [selector]
  )
end

I expect to handle the “scroll_changed” event during testing. Outside of testing I always receive the event. During testing I don’t receive the event.

This IO.inspect() never gets printed.

def handle_event("scroll_changed",_, socket) do
  IO.inspect("received!")
end

I also tried using touch_scroll instead of execute_script.

Any idea what could explain this behaviour?

Where Next? Top

Trending in Questions Top

katta
I having some trouble figuring out if I have set myself too strict of standards for my production server. Currently I can handle 75% of r...
New
brecabral
Documentation While reading the Scoped Routes section, I noticed that the documentation currently refers to a problem without explainin...
New
nseaSeb
Hello, I know there is an approach for handling lists that allows for optimized traversal, but I can’t recall the specific method (somet...
New
kpanic
Hi everyone, I am toying with the idea of building a “match maker” for giving personal help to people that wants to start coding. I sta...
New
velrest
So my question is quite simple and i have found no conclusive answer on forum, google or AI. Should we use :erlang.float for Integer to ...
New
asweet-confluent
I recently noticed that Elixir’s Logger defaults its primary log level to :debug when no :logger, :level application configuration is pre...
New
apz
I’m new to elixir and just tried to install the elixirLS extension for VScode(ium) and it is throwing some errors that I would like help ...
New

Other Trending Topics Top

GenericJam
Edit: 2026 May 15 - This post is archived. Mob is alive!! Main docs: mob v0.7.11 — Documentation A bit of explanation for the slightly c...
New
JesseHerrick
Hey, I’m Jesse and I’m the main contributor behind Dexter, a full-featured, lightning-fast Elixir LSP optimized for large codebases. It s...
New
mudasobwa
I am happy to introduce the very α version of the new programming language compiled to BEAM. Welcome Cure. It has literally three kille...
New
garrison
Hobbes is a low-level distributed database for the Elixir programming language. Hobbes provides a simple, safe, and scalable storage lay...
New
mhanberg
Hi everyone! The first release candidate for the Expert language server project is now available! We’ve published a press release detai...
New
budgie
A little off-topic, but I feel like people here have a good head on their shoulders. I used to be quite good at making software. Was luc...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews