*/
internal fun String.toCanonicalHost(): String? {
  val host: String = this

  // If the input contains a :, it’s an IPv6 address.
  if (":" in host) {
    // If the input is encased in square braces "[...]", drop 'em.
    val inetAddressByteArray =
      (
        if (host.startsWith("[") && host.endsWith("]")) {
          decodeIpv6(host, 1, host.length - 1)
        } else {

        '`'.code,
        '{'.code,
        '|'.code,
        '}'.code,
      )
      .test(UrlComponentEncodingTester.Component.HOST)
  }

  @Test
  fun hostIpv6() {
    // Square braces are absent from host()...
    assertThat(parse("http://[::1]/").host).isEqualTo("::1")

    // ... but they're included in toString().
    assertThat(parse("http://[::1]/").toString()).isEqualTo("http://[::1]/")

  integrity sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==
  dependencies:
    balanced-match "^1.0.0"

braces@^3.0.2, braces@~3.0.2:
  version "3.0.2"
  resolved "https://registry.yarnpkg.com/braces/-/braces-3.0.2.tgz#3454e1a462ee8d599e236df336cd9ea4f8afe107"

   *
   *  * A regular host name, like `android.com`.
   *
   *  * An IPv4 address, like `127.0.0.1`.
   *
   *  * An IPv6 address, like `::1`. Note that there are no square braces.
   *
   *  * An encoded IDN, like `xn--n3h.net`.
   *
   * | URL                   | `host()`        |
   * | :-------------------- | :-------------- |
   * | `http://android.com/` | `"android.com"` |

      "plan 1 TLS connected",
    )

    taskFaker.assertNoMoreTasks()
  }

  /**
   * This test performs two races:
   *
   *  * The first race is between plan0 and plan1, with a 250 ms head start for plan0.
   *  * The second race is between plan2 and plan3, with a 250 ms head start for plan2.
   *
   * We get plan0 and plan1 from the route planner.

   * - Both request discover no existing connection. They both make a connection.
   * - The first request "wins the race".
   * - The second request discovers it "lost the race" and closes the connection it just opened.
   * - The second request uses the coalesced connection from request1.
   * - The coalesced connection is violently closed after servicing the first request.