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.testing;
  
  import static java.net.HttpURLConnection.HTTP_NOT_FOUND;
  import static org.openqa.selenium.remote.Dialect.W3C;
  import static org.openqa.selenium.remote.http.Contents.utf8String;
  
  import java.io.UncheckedIOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.time.Instant;
  import java.util.UUID;
  import java.util.function.BiFunction;
  import org.openqa.selenium.Capabilities;
  import org.openqa.selenium.ImmutableCapabilities;
  import org.openqa.selenium.WebDriverException;
  import org.openqa.selenium.grid.data.CreateSessionRequest;
  import org.openqa.selenium.grid.data.Session;
  import org.openqa.selenium.grid.node.ActiveSession;
  import org.openqa.selenium.grid.node.BaseActiveSession;
  import org.openqa.selenium.grid.node.SessionFactory;
  import org.openqa.selenium.internal.Either;
  import org.openqa.selenium.remote.Dialect;
  import org.openqa.selenium.remote.SessionId;
  import org.openqa.selenium.remote.http.HttpHandler;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  
  public class TestSessionFactory implements SessionFactory {
  
    private final Capabilities stereotype;
    private final BiFunction<SessionId, Capabilities, Session> sessionGenerator;
  
    public TestSessionFactory(BiFunction<SessionId, Capabilities, Session> sessionGenerator) {
      this(new ImmutableCapabilities(), sessionGenerator);
    }
  
    public TestSessionFactory(
        Capabilities stereotype, BiFunction<SessionId, Capabilities, Session> sessionGenerator) {
      this.stereotype = ImmutableCapabilities.copyOf(stereotype);
      this.sessionGenerator = sessionGenerator;
    }
  
    @Override
    public Capabilities getStereotype() {
      return stereotype;
    }
  
    @Override
    public Either<WebDriverException, ActiveSession> apply(CreateSessionRequest sessionRequest) {
      SessionId id = new SessionId(UUID.randomUUID());
      Session session = sessionGenerator.apply(id, sessionRequest.getDesiredCapabilities());
  
      URL url;
      try {
        url = session.getUri().toURL();
      } catch (MalformedURLException e) {
        throw new UncheckedIOException(e);
      }
  
      Dialect downstream =
          sessionRequest.getDownstreamDialects().contains(W3C)
              ? W3C
              : sessionRequest.getDownstreamDialects().iterator().next();
  
      BaseActiveSession activeSession =
          new BaseActiveSession(
              session.getId(),
              url,
              downstream,
              W3C,
              stereotype,
              session.getCapabilities(),
              Instant.now()) {
            @Override
            public void stop() {
              // Do nothing
            }
  
            @Override
            public HttpResponse execute(HttpRequest req) throws UncheckedIOException {
              if (session instanceof HttpHandler) {
                return ((HttpHandler) session).execute(req);
              } else {
                // Do nothing.
                return new HttpResponse()
                    .setStatus(HTTP_NOT_FOUND)
                    .setContent(utf8String("No handler found for " + req));
              }
            }
          };
      return Either.right(activeSession);
    }
  
    @Override
    public boolean test(Capabilities capabilities) {
      return true;
    }
  }
  