This is a testharness.js-based test.
[FAIL] URL: Setting <file://localhost/>.protocol = 'http' Can’t switch from file URL with no host
  assert_equals: expected "file:///" but got "http://localhost/"
[FAIL] URL: Setting <file://y/>.host = 'x:123'
  assert_equals: expected "file://y/" but got "file://x/"
[FAIL] URL: Setting <file://y/>.host = 'loc%41lhost'
  assert_equals: expected "file:///" but got "file://localhost/"
[FAIL] URL: Setting <file://y/>.hostname = 'loc%41lhost'
  assert_equals: expected "file:///" but got "file://localhost/"
[FAIL] URL: Setting <file://localhost/>.port = '12'
  assert_equals: expected "file:///" but got "file://localhost/"
Harness: the test ran to completion.