Alpine Test $watch
Alpine supports watching for when a component’s property changes through a method called $watch().
You can "watch" a component property using the $watch magic method. For example
<div x-data="watcher()" x-init="initWatcher">
<p>
<label>Dollar: </label>
<input type="text" x-model="dollar" />
</p>
<p>
<label>Naira: </label>
<input type="text" x-model="naira" />
</p>
</div>