```kotlin
testImplementation("com.squareup.okhttp3:mockwebserver3:5.3.0")
```

MockWebServer is used for firstly for internal testing, and for basic testing of apps using OkHttp client.
It is not a full featured HTTP testing library that is developed standalone. It is not being actively developed

policy:

```java
HandshakeCertificates serverCertificates = new HandshakeCertificates.Builder()
    .heldCertificate(localhostCertificate)
    .build();
MockWebServer server = new MockWebServer();
server.useHttps(serverCertificates.sslSocketFactory(), false);
```

`HandshakeCertificates` also works for clients where its job is to define which root certificates

package okhttp3

import app.cash.burst.Burst
import app.cash.burst.burstValues
import java.io.IOException
import java.util.Random
import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.testing.PlatformRule
import okio.ByteString.Companion.toByteString
import org.junit.jupiter.api.Assumptions.assumeTrue
import org.junit.jupiter.api.Test

import java.net.CookieManager
import java.net.CookiePolicy
import java.net.HttpCookie
import java.net.HttpURLConnection
import java.net.InetAddress
import java.net.URI
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.Cookie.Companion.parse
import okhttp3.HttpUrl.Companion.toHttpUrl
import okhttp3.java.net.cookiejar.JavaNetCookieJar
import org.junit.jupiter.api.Test

import java.util.Locale
import java.util.TimeZone
import java.util.concurrent.TimeUnit
import javax.net.ssl.HostnameVerifier
import javax.net.ssl.SSLSession
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.Headers.Companion.headersOf
import okhttp3.internal.buildCache
import okhttp3.java.net.cookiejar.JavaNetCookieJar
import okhttp3.okio.LoggingFilesystem

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManagerFactory;
import okhttp3.mockwebserver.Dispatcher;
import okhttp3.mockwebserver.MockResponse;
import okhttp3.mockwebserver.MockWebServer;
import okhttp3.mockwebserver.RecordedRequest;
import okio.Buffer;
import okio.Okio;

public class SampleServer extends Dispatcher {
  private final SSLContext sslContext;

import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.mockwebserver.MockResponse
import okhttp3.mockwebserver.MockWebServer
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.internal.TlsUtil

class DevServer {
  val handshakeCertificates = TlsUtil.localhost()

  val server =
    MockWebServer().apply {
      useHttps(handshakeCertificates.sslSocketFactory(), false)

      enqueue(

import java.util.concurrent.CountDownLatch
import java.util.concurrent.TimeUnit
import java.util.concurrent.atomic.AtomicReference
import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.TestUtil.repeat
import okhttp3.testing.Flaky
import okio.BufferedSink

import assertk.assertThat
import assertk.assertions.containsExactlyInAnyOrder
import assertk.assertions.isEmpty
import assertk.assertions.isNotEmpty
import javax.net.ssl.SSLSocket
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.testing.PlatformRule
import okhttp3.testing.PlatformVersion
import okio.ByteString.Companion.toByteString

import okhttp3.OkHttpClient
import okhttp3.OkHttpClientTestRule
import okhttp3.Request
import okhttp3.RequestBody
import okhttp3.Response
import okhttp3.mockwebserver.MockResponse
import okhttp3.mockwebserver.MockWebServer
import okhttp3.mockwebserver.SocketPolicy
import okhttp3.testing.PlatformRule
import okio.Buffer
import okio.BufferedSink
import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.BeforeEach