code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.grid.sessionmap;
  
  import static java.time.Duration.ofSeconds;
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  import static org.assertj.core.api.Assertions.assertThatNoException;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.time.Instant;
  import java.util.UUID;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.ImmutableCapabilities;
  import org.openqa.selenium.NoSuchSessionException;
  import org.openqa.selenium.events.EventBus;
  import org.openqa.selenium.events.local.GuavaEventBus;
  import org.openqa.selenium.grid.data.Session;
  import org.openqa.selenium.grid.data.SessionClosedEvent;
  import org.openqa.selenium.grid.sessionmap.local.LocalSessionMap;
  import org.openqa.selenium.grid.sessionmap.remote.RemoteSessionMap;
  import org.openqa.selenium.grid.testing.PassthroughHttpClient;
  import org.openqa.selenium.remote.SessionId;
  import org.openqa.selenium.remote.http.HttpClient;
  import org.openqa.selenium.remote.tracing.DefaultTestTracer;
  import org.openqa.selenium.remote.tracing.Tracer;
  import org.openqa.selenium.support.ui.FluentWait;
  import org.openqa.selenium.support.ui.Wait;
  
  /**
   * We test the session map by ensuring that the HTTP protocol is properly adhered to. If this is
   * true, then any implementations are interoperable, and we can breathe a sigh of relief.
   */
  class SessionMapTest {
  
    private SessionId id;
    private Session expected;
    private SessionMap local;
    private HttpClient client;
    private SessionMap remote;
    private EventBus bus;
  
    @BeforeEach
    public void setUp() throws URISyntaxException {
      id = new SessionId(UUID.randomUUID());
      expected =
          new Session(
              id,
              new URI("http://localhost:1234"),
              new ImmutableCapabilities(),
              new ImmutableCapabilities(),
              Instant.now());
  
      Tracer tracer = DefaultTestTracer.createTracer();
      bus = new GuavaEventBus();
  
      local = new LocalSessionMap(tracer, bus);
      client = new PassthroughHttpClient(local);
      remote = new RemoteSessionMap(tracer, client);
    }
  
    @Test
    void shouldBeAbleToAddASession() {
      assertTrue(remote.add(expected));
  
      assertThat(local.get(id)).isEqualTo(expected);
    }
  
    @Test
    void shouldBeAbleToRetrieveASessionUri() {
      local.add(expected);
  
      assertThat(remote.get(id)).isEqualTo(expected);
    }
  
    @Test
    void shouldThrowANoSuchSessionExceptionIfSessionCannotBeFound() {
      assertThatExceptionOfType(NoSuchSessionException.class).isThrownBy(() -> local.get(id));
      assertThatExceptionOfType(NoSuchSessionException.class).isThrownBy(() -> remote.get(id));
    }
  
    @Test
    void shouldAllowSessionsToBeRemoved() {
      local.add(expected);
  
      assertThat(remote.get(id)).isEqualTo(expected);
  
      remote.remove(id);
  
      assertThatExceptionOfType(NoSuchSessionException.class).isThrownBy(() -> local.get(id));
      assertThatExceptionOfType(NoSuchSessionException.class).isThrownBy(() -> remote.get(id));
    }
  
    /** This is because multiple areas within the grid may all try and remove a session. */
    @Test
    void removingASessionThatDoesNotExistIsNotAnError() {
      assertThatNoException().isThrownBy(() -> remote.remove(id));
    }
  
    @Test
    void shouldThrowAnExceptionIfGettingASessionThatDoesNotExist() {
      assertThatExceptionOfType(NoSuchSessionException.class).isThrownBy(() -> remote.get(id));
    }
  
    @Test
    void shouldAllowEntriesToBeRemovedByAMessage() {
      local.add(expected);
  
      bus.fire(new SessionClosedEvent(expected.getId()));
  
      Wait<SessionMap> wait = new FluentWait<>(local).withTimeout(ofSeconds(2));
      wait.until(
          sessions -> {
            try {
              sessions.get(expected.getId());
              return false;
            } catch (NoSuchSessionException e) {
              return true;
            }
          });
    }
  }
  