fetch() can't handle Blob as body

[belden]

This client code:

const jsonString = JSON.stringify({my: 'payload'});
const blob = new Blob([jsonString], {type: 'text/plain;charset=utf-8'});
navigator.sendBeacon('https://my-dev-server', blob);

triggers a TypeError in zombie, originating here

zombie/src/fetch.js

Line 208 in e6cf0f8

else if (bodyInit)