Laravel Jetstream Livewire to Vue with Inertia Code Conversion

Question

I've been following this awesome repository but I'm having a hard time converting this code (line 42 in the repo) to Vue with Inertia:

<select name="roles[]" id="roles" class="form-multiselect block rounded-md shadow-sm mt-1 block w-full" multiple="multiple">
         @foreach($roles as $id => $role)
              <option value="{{ $id }}"{{ in_array($id, old('roles', [])) ? ' selected' : '' }}>{{ $role }}</option>
         @endforeach
</select>

Same code in the controller but for accessing the roles value in Vue, I have declared roles as props:

props: {
     roles: Object,
},

Then for the select:

<select name="roles[]" id="roles" class="form-multiselect block rounded-md shadow-sm mt-1 block w-full" multiple="multiple">
     <option v-for="role in roles" :key="role" :value="role">{{ role }}</option>
</select>

How do I set the selected attribute in the select input by getting the old values? Any help is much appreciated. Thanks!