testing everything. You can even copy & paste HTTP responses from your real web
server to create representative test cases. Or test that your code survives in
awkward-to-reproduce situations like 500 errors or slow-loading responses.


### Example

Use MockWebServer the same way that you use mocking frameworks like
[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.

  }

  @Test
  fun timeoutWritingRequest() {
    server.enqueue(MockResponse())
    val request =
      Request.Builder()
        .url(server.url("/"))
        .post(sleepingRequestBody(500))
        .build()
    val call = client.newCall(request)
    call.timeout().timeout(250, TimeUnit.MILLISECONDS)
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->

    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Give the server time to enact the socket policy if it's one that could happen after the
    // client has received the response.
    Thread.sleep(500)
    val response2 = getResponse(newRequest("/b"))
    response1.body.source().timeout().timeout(100, TimeUnit.MILLISECONDS)
    assertContent("This comes after a busted connection", response2)

  private val serverListener = WebSocketRecorder("server")
  private val random = Random(0)
  private var client =
    clientTestRule.newClientBuilder()
      .writeTimeout(Duration.ofMillis(500))
      .readTimeout(Duration.ofMillis(500))
      .addInterceptor(
        Interceptor { chain: Interceptor.Chain ->
          val response = chain.proceed(chain.request())
          // Ensure application interceptors never see a null body.

        .throttleBody((64 * 1024).toLong(), 125, TimeUnit.MILLISECONDS),
    ) // 500 Kbps
    server.start()
    val call =
      client.newCall(
        Request.Builder()
          .url(server.url("/"))
          .build(),
      )
    val response = call.execute()
    interruptLater(500)
    val responseBody = response.body.byteStream()
    val buffer = ByteArray(1024)

    client.listener.assertFailure(IOException::class.java, "source is closed")
    assertThat(client.closed).isTrue()
  }

  @Test
  fun pingOnInterval() {
    client.initWebSocket(random, pingIntervalMillis = 500)
    taskFaker.advanceUntil(ns(500L))
    server.processNextFrame() // Ping.
    client.processNextFrame() // Pong.
    taskFaker.advanceUntil(ns(1000L))
    server.processNextFrame() // Ping.

      throw RuntimeException("boom!")
    }

    queue.schedule("task", TimeUnit.MILLISECONDS.toNanos(200)) {
      log.put("normal task running")
      return@schedule -1L
    }

    queue.idleLatch().await(500, TimeUnit.MILLISECONDS)

    assertThat(log.take()).isEqualTo("failing task running")
    assertThat(log.take()).isEqualTo("uncaught exception: java.lang.RuntimeException: boom!")

  fun pingsTransmitted(
    protocol: Protocol,
    mockWebServer: MockWebServer,
  ) {
    setUp(protocol, mockWebServer)
    // Ping every 500 ms, starting at 500 ms.
    client =
      client.newBuilder()
        .pingInterval(Duration.ofMillis(500))
        .build()

    // Delay the response to give 1 ping enough time to be sent and replied to.
    server.enqueue(
      MockResponse.Builder()

    client =
      client.newBuilder()
        .callTimeout(250, TimeUnit.MILLISECONDS)
        .build()
    server.enqueue(
      MockResponse.Builder()
        .bodyDelay(500, TimeUnit.MILLISECONDS)
        .setHeader("content-type", "text/event-stream")
        .body("data: hey\n\n")
        .build(),
    )
    val source = newEventSource()

  }

  @Test
  fun fullCallTimeoutAppliesToSetup() {
    enableProtocol(Protocol.HTTP_2)
    server.enqueue(
      MockResponse.Builder()
        .headersDelay(500, TimeUnit.MILLISECONDS)
        .build(),
    )
    val request =
      Request.Builder()
        .url(server.url("/"))
        .post(AsyncRequestBody())
        .build()