assertInvalid("http://a..b/", "Invalid URL host: \"a..b\"")
    assertInvalid("http://.a/", "Invalid URL host: \".a\"")
    assertInvalid("http://../", "Invalid URL host: \"..\"")
  }

  @Test
  fun hostnameTelephone() {
    // https://www.gosecure.net/blog/2020/10/27/weakness-in-java-tls-host-verification/

    // Map the single character telephone symbol (℡) to the string "tel".