koel/resources/assets/js/components/ui/SidebarMenuToggleButton.vue

<template>
  <button @click.prevent.stop="toggleSidebar">
    <Icon :icon="faBars" />
  </button>
</template>

<script lang="ts" setup>
import { faBars } from '@fortawesome/free-solid-svg-icons'
import { eventBus } from '@/utils'

const toggleSidebar = () => eventBus.emit('TOGGLE_SIDEBAR')
</script>