Fails to serialize certain functions using serializeFunction in the template

[rchl]

Versions

• nuxt: v2.14.12
• node: v14

Reproduction

https://codesandbox.io/s/serializefunction-bug-3elqy?file=/pages/index.vue

Steps to reproduce

From a template, call

<%
const obj = {
  fn () { const x = rule => rule }
};
const serialized = serializeFunction(obj.fn)
%>
<%= serialized %>

What is Expected?

That the serialized function starts with a function keyword.

What is actually happening?

The serialized function starts with a fn identifier.