Unclearable NaN value in NumberInput example

[vasilii-kovalev]

Steps to reproduce:

1. Go to https://sveltekit.now.sh/#NumberInput
2. Focus on the input element and clear the value by pressing Backspace button

Actual behavior: NaN value is displayed and can't be cleared/changed even with increase/decrease buttons (arrows).

Expected behavior: value is cleared.

[vasilii-kovalev]

It seems that's because isFinite('') is true:

ui/src/components/NumberInput/NumberInput.svelte

Lines 25 to 27 in 41a6cd9

	function isValidValue(value) {
	return isFinite(value) || /^-?[0-9.]+$/.test(value);
	}

so it is casted to float:

ui/src/components/NumberInput/NumberInput.svelte

Lines 33 to 35 in 41a6cd9

	function makeNumber(value) {
	return isValidValue(value) ? parseFloat(value) : value;
	}

Actually, unit tests could help to catch this issue. I personally know about Svelte Testing Library, maybe there is something else.