`bind:value` with function bindings don't work well with the input caret when value is changed in set

[paulovieira]

Describe the bug

Not sure if this is a bug, but it's a bit annoying.

Consider this scenario:

• the original value from an <input type="text"> is changed in set (as in the example from the docs),
• the caret is not at the end

Then after set is called, the caret will be positioned at the end.

The expectation here would be to have a "on-the-fly correction" of the value being typed. The caret should not change position.

Reproduction

Minimal example here: https://svelte.dev/playground/7a2879030b22491f90b27fb825076ae3?version=5.9.1

Type any lowercase letter the beginning. After that I would expect that the caret would be at second position (not at the final position)

Logs

No response

System Info

Brave.

Severity

annoyance

[harrisi]

This doesn't seem like Svelte's responsibility. You can achieve this behavior yourself with something like this: repl.

I will say that it would be nice here if you could get a reference to the element itself without having to wire it up yourself.

[trueadm]

I think we can probably improve on this by restoring selection. I've put up a PR.

[harrisi]

The only reason I thought this doesn't seem like Svelte's responsibility is because a site could want to do any wacky stuff, like jump over every other character, or wrap around after n characters or whatever. This is probably a sane enough default that is desirable most of the time though.

It does add additional events if anything is watching for selectionchange and also adds their own logic. But that seems fine most of the time.

[trueadm]

@harrisi I don't believe selectionchange fires for changes to input selection, as it has its own selection model outside of document selection.