* https://hc.apache.org/httpcomponents-client-5.0.x/httpclient5/examples/AsyncClientTlsAlpn.java
 *
 * Mainly intended to verify behaviour of popular clients across Android versions, similar
 * to observing Firefox or Chrome browser behaviour.
 */
class ApacheHttpClientHttp2Test {
  @Test
  fun testHttp2() {
    val client = HttpAsyncClients.createHttp2Default()

    client.use { client ->
      client.start()

    return result
  }
  synchronized(BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS) {
    for (i in 0 until BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS.size) {
      var format: DateFormat? = BROWSER_COMPATIBLE_DATE_FORMATS[i]
      if (format == null) {
        format =
          SimpleDateFormat(BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS[i], Locale.US).apply {

  private OAuthSessionFactory sessionFactory;

  /** Guarded by this. */
  private OAuthSession session;

  public SlackClient(SlackApi slackApi) {
    this.slackApi = slackApi;
  }

  /** Shows a browser URL to authorize this app to act as this user. */
  public void requestOauthSession(String scopes, String team) throws Exception {
    if (sessionFactory == null) {
      sessionFactory = new OAuthSessionFactory(slackApi);

Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020

    byte[] bytes = new byte[16];
    secureRandom.nextBytes(bytes);
    return ByteString.of(bytes);
  }

  private HttpUrl redirectUrl() {
    return mockWebServer.url("/oauth/");
  }

  /** When the browser hits the redirect URL, use the provided code to ask Slack for a session. */
  @Override public MockResponse dispatch(RecordedRequest request) {
    HttpUrl requestUrl = mockWebServer.url(request.getPath());

 * direct translation of the pseudocode presented there.
 *
 * Partner this class with [UTS #46] to implement IDNA2008 [RFC 5890] like most browsers do.
 *
 * [RFC 3492]: https://datatracker.ietf.org/doc/html/rfc3492
 * [RFC 5890]: https://datatracker.ietf.org/doc/html/rfc5890
 * [UTS #46]: https://www.unicode.org/reports/tr46/
 */
object Punycode {

  private var failFastResponse: MockResponse? = null

  @Throws(InterruptedException::class)
  override fun dispatch(request: RecordedRequest): MockResponse {
    // To permit interactive/browser testing, ignore requests for favicons.
    val requestLine = request.requestLine
    if (requestLine == "GET /favicon.ico HTTP/1.1") {
      logger.info("served $requestLine")

    assertThat(formEncode(8)).isEqualTo("%08")
    assertThat(formEncode(9)).isEqualTo("%09")
    // Browsers convert '\n' to '\r\n'
    assertThat(formEncode(10)).isEqualTo("%0A")
    assertThat(formEncode(11)).isEqualTo("%0B")
    assertThat(formEncode(12)).isEqualTo("%0C")
    // Browsers convert '\r' to '\r\n'
    assertThat(formEncode(13)).isEqualTo("%0D")
    assertThat(formEncode(14)).isEqualTo("%0E")

OkHttp depends on [Okio][okio] for high-performance I/O and the [Kotlin standard library][kotlin]. Both are small libraries with strong backward-compatibility.

We highly recommend you keep OkHttp up-to-date. As with auto-updating web browsers, staying current
with HTTPS clients is an important defense against potential security problems. [We
track][tls_history] the dynamic TLS ecosystem and adjust OkHttp to improve connectivity and
security.

    // 3) Caller specified but assuming the visible defaults in MODERN_CIPHER_SUITES are rejigged
    // to match legacy i.e. the platform/provider
    //
    // Opting for 2 here and keeping MODERN_TLS in line with secure browsers.
    cipherSuitesAsString.intersect(socketEnabledCipherSuites, CipherSuite.ORDER_BY_NAME)
  } else {
    socketEnabledCipherSuites
  }
}

internal fun MediaType?.chooseCharset(): Pair<Charset, MediaType?> {