meteor/packages/fetch/tests/main.js

import { Tinytest } from "meteor/tinytest";

Tinytest.add("fetch - sanity", function (test) {
  test.equal(typeof fetch, "function");
});

Tinytest.addAsync("fetch - asset", function (test) {
  return fetch(
    Meteor.absoluteUrl("/packages/local-test_fetch/tests/asset.json")
  ).then(res => {
    if (! res.ok) throw res;
    return res.json();
  }).then(json => {
    test.equal(json.word, "oyez");
    test.equal(json.times, 3);
  });
});