pos/pos_container/templates/templates.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
    Copyright 2019 Coop IT Easy SCRLfs
    	    Robin Keunen <robin@coopiteasy.be>
    License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->

<odoo>
    <template id="assets_frontend" inherit_id="point_of_sale.assets">
        <xpath expr="." position="inside">
            <link href="/pos_container/static/src/css/container.css" rel="stylesheet"/>
            <script type="text/javascript" src="/pos_container/static/src/js/models_and_db.js"/>
            <script type="text/javascript" src="/pos_container/static/src/js/container.js"/>
            <script type="text/javascript" src="/pos_container/static/src/js/tests.js"/>
        </xpath>
    </template>
</odoo>