Allow serialize to overwrite value instead of creating an array

[leonbeon]

I'm using Svelte to conditionally hide and insert form elements (using their #if directive). When doing this, serializing the form appends a value to the key in the serialized object, creating an array instead. This seems to be somewhat intended behaviour.

Quoting the docs:

This results in an object with name/value pairs that map to each form control. If more than one form control shares the same name, the values will be passed as an array, e.g. { name: ['value1', 'value2'] }.

Since I'm not actively creating a new element but instead re-creating the same one, I would love an option to allow overwriting the value in the serialized object instead of creating an array (maybe on a per-key basis)?

One workaround is to visually hide the element using display: none. I made a pen to illustrate the difference: https://codepen.io/leonbeon/pen/MWxoLMm. As you can see, the value for test3 is replaced with an array when re-adding the DOM element.