ServiceNow UI Action Open Relationship record from Related List Entry

OpenRelationship.UIAction.script.js

// type: sys_ui_action
// name: Open Relationship
// table: sys_ui_related_list_entry
// onclick: _<ui_action_sys_id>() eg: _7d3f6d1947e2b6105295e49b506d43e9()
// condition: current.related_list.toString().startsWith("REL:") && current.related_list.toString().length === 36
// flags: client, show update, form link, list context menu

async function _7d3f6d1947e2b6105295e49b506d43e9() {
    let table, id;
    if (globalThis.g_list && globalThis.g_sysId) {
        table = globalThis.g_list.getTableName();
        id = globalThis.g_sysId;
    } else if (globalThis.g_form) {
        table = globalThis.g_form.getTableName();
        id = globalThis.g_form.getUniqueValue();
    } else return jslog("Unable to determine table & sys_id");

    const field = "related_list";
    const rl = (
        await (
            await fetch(
                "/api/now/table/" +
                    table +
                    "/" +
                    id +
                    "?sysparm_fields=" +
                    field,
                {
                    headers: {
                        "X-UserToken": window.g_ck,
                    },
                },
            )
        ).json()
    ).result?.[field];

    if (typeof rl === "string" && rl.startsWith("REL:") && rl.length === 36) {
        window.open("/sys_relationship.do?sys_id=" + rl.slice(-32));
    }
}