companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {
      override fun lookup(hostname: String): List<InetAddress> {
        try {

    var routeSelector = newRouteSelector(address)
    dns[PROXY_A_HOST] = dns.allocate(1)
    dns[PROXY_B_HOST] = dns.allocate(1)

    // Mark the ProxyA route as failed.
    val selection = routeSelector.next()
    dns.assertRequests(PROXY_A_HOST)
    val route = selection.next()
    assertRoute(route, address, proxyA, dns.lookup(PROXY_A_HOST, 0), PROXY_A_PORT)
    routeDatabase.failed(route)

/**
 * [DNS over HTTPS implementation][doh_spec].
 *
 * > A DNS API client encodes a single DNS query into an HTTP request
 * > using either the HTTP GET or POST method and the other requirements
 * > of this section.  The DNS API server defines the URI used by the
 * > request through the use of a URI Template.
 *
 * [doh_spec]: https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-13
 */

        continue
      }

      val dns = route?.address?.dns ?: defaultDns
      val auth =
        if (proxyAuthorization) {
          val proxyAddress = proxy.address() as InetSocketAddress
          Authenticator.requestPasswordAuthentication(
            proxyAddress.hostName,
            proxy.connectToInetAddress(url, dns),
            proxyAddress.port,
            url.scheme,

@Tag("Slowish")
class DnsOverHttpsTest {
  @RegisterExtension
  val platform = PlatformRule()

  @StartStop
  private val server = MockWebServer()

  private lateinit var dns: Dns
  private val cacheFs = FakeFileSystem()
  private val eventRecorder = EventRecorder()
  private val bootstrapClient =
    OkHttpClient
      .Builder()
      .protocols(listOf(Protocol.HTTP_2, Protocol.HTTP_1_1))

import okhttp3.OkHttpClient

/**
 * Temporary registry of known DNS over HTTPS providers.
 *
 * https://github.com/curl/curl/wiki/DNS-over-HTTPS
 */
object DohProviders {
  private fun buildGoogle(bootstrapClient: OkHttpClient): DnsOverHttps =
    DnsOverHttps
      .Builder()
      .client(bootstrapClient)
      .url("https://dns.google/dns-query".toHttpUrl())
      .bootstrapDnsHosts(getByIp("8.8.4.4"), getByIp("8.8.8.8"))

    server.useHttps(handshakeCertificates.sslSocketFactory())

    val dns =
      Dns {
        Dns.SYSTEM.lookup(server.hostName)
      }

    val client =
      clientTestRule
        .newClientBuilder()
        .sslSocketFactory(
          handshakeCertificates.sslSocketFactory(),
          handshakeCertificates.trustManager,
        ).dns(dns)
        .build()

    server.enqueue(MockResponse())

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns

/**
 * Internal Bootstrap DNS implementation for handling initial connection to DNS over HTTPS server.
 *
 * Returns hardcoded results for the known host.
 */
internal class BootstrapDns(
  private val dnsHostname: String,
  private val dnsServers: List<InetAddress>,
) : Dns {
  @Throws(UnknownHostException::class)

    return copy(writeTimeoutMillis = checkDuration("writeTimeout", timeout.toLong(), unit))
  }

  override fun withDns(dns: Dns): Interceptor.Chain {
    check(exchange == null) { "dns can't be adjusted in a network interceptor" }

    return copy(dns = dns)
  }

  override fun withSocketFactory(socketFactory: SocketFactory): Interceptor.Chain {

  @BeforeEach
  fun setUp() {
    socketFactory = SpecificHostSocketFactory(InetSocketAddress(server1.hostName, server1.port))

    client =
      clientTestRule
        .newClientBuilder()
        .dns(dns)
        .socketFactory(socketFactory)
        .eventListenerFactory(clientTestRule.wrap(eventRecorder))
        .build()
  }

  @RepeatedTest(100)
  fun http2OneBadHostOneGoodNoRetryOnConnectionFailure() {