This is a testharness.js-based test.
[FAIL] Global object's setter throws when called on incompatible object
  assert_throws_js: function "() => { Reflect.set(globalThis, "onoffline", onoffline, notGlobalObject); }" threw object "ReferenceError: onoffline is not defined" ("ReferenceError") expected instance of function "function TypeError() { [native code] }" ("TypeError")
[FAIL] Global object's getter works when called on null / undefined
  onoffline is not defined
[FAIL] Global object's setter works when called on null / undefined
  assert_true: expected true got false
Harness: the test ran to completion.