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.gridui;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.openqa.selenium.grid.gridui.Urls.whereIs;
  import static org.openqa.selenium.json.Json.MAP_TYPE;
  import static org.openqa.selenium.remote.http.HttpMethod.GET;
  import static org.openqa.selenium.support.ui.ExpectedConditions.textToBe;
  import static org.openqa.selenium.support.ui.ExpectedConditions.visibilityOfAllElementsLocatedBy;
  import static org.openqa.selenium.support.ui.ExpectedConditions.visibilityOfElementLocated;
  import static org.openqa.selenium.testing.Safely.safelyCall;
  
  import com.google.common.collect.ImmutableMap;
  import java.time.Duration;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.By;
  import org.openqa.selenium.WebDriver;
  import org.openqa.selenium.WebElement;
  import org.openqa.selenium.grid.commands.Standalone;
  import org.openqa.selenium.grid.config.Config;
  import org.openqa.selenium.grid.config.MapConfig;
  import org.openqa.selenium.grid.config.MemoizedConfig;
  import org.openqa.selenium.grid.server.Server;
  import org.openqa.selenium.grid.web.Values;
  import org.openqa.selenium.net.PortProber;
  import org.openqa.selenium.remote.RemoteWebDriver;
  import org.openqa.selenium.remote.http.HttpClient;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  import org.openqa.selenium.support.ui.FluentWait;
  import org.openqa.selenium.support.ui.Wait;
  import org.openqa.selenium.support.ui.WebDriverWait;
  import org.openqa.selenium.testing.drivers.Browser;
  import org.openqa.selenium.testing.drivers.WebDriverBuilder;
  
  class OverallGridTest {
  
    private Server<?> server;
    private WebDriver driver;
    private WebDriver remoteWebDriver;
    private Wait<WebDriver> wait;
  
    @BeforeEach
    public void setup() {
      server = createStandalone();
  
      driver = new WebDriverBuilder().get();
  
      wait = new WebDriverWait(driver, Duration.ofSeconds(10));
    }
  
    @AfterEach
    public void tearDown() {
      safelyCall(() -> driver.quit());
      safelyCall(() -> remoteWebDriver.quit());
      safelyCall(() -> server.stop());
    }
  
    @Test
    void shouldReportConcurrencyZeroPercentWhenGridIsStartedWithoutLoad() {
      driver.get(whereIs(server, "/ui#/sessions"));
  
      WebElement concurrency =
          wait.until(
              visibilityOfElementLocated(By.cssSelector("div[data-testid='concurrency-usage']")));
  
      assertEquals("0%", concurrency.getText());
    }
  
    @Test
    void shouldShowOneNodeRegistered() {
      driver.get(whereIs(server, "/ui"));
  
      List<WebElement> nodeInfoIcons =
          wait.until(
              visibilityOfAllElementsLocatedBy(By.cssSelector("button[data-testid*='node-info-']")));
  
      assertEquals(1, nodeInfoIcons.size());
    }
  
    @Test
    void shouldIncrementSessionCountWhenSessionStarts() {
      remoteWebDriver = new RemoteWebDriver(server.getUrl(), Browser.detect().getCapabilities());
      driver.get(whereIs(server, "/ui#/sessions"));
  
      wait.until(textToBe(By.cssSelector("div[data-testid='session-count']"), "1"));
    }
  
    private Server<?> createStandalone() {
      int port = PortProber.findFreePort();
  
      Config config =
          new MemoizedConfig(
              new MapConfig(
                  ImmutableMap.of(
                      "server", Collections.singletonMap("port", port),
                      "node", ImmutableMap.of("detect-drivers", true, "selenium-manager", true))));
  
      Server<?> server = new Standalone().asServer(config).start();
  
      waitUntilReady(server);
  
      return server;
    }
  
    private void waitUntilReady(Server<?> server) {
      try (HttpClient client = HttpClient.Factory.createDefault().createClient(server.getUrl())) {
        new FluentWait<>(client)
            .withTimeout(Duration.ofSeconds(5))
            .until(
                c -> {
                  HttpResponse response = c.execute(new HttpRequest(GET, "/status"));
                  Map<String, Object> status = Values.get(response, MAP_TYPE);
                  return status != null && Boolean.TRUE.equals(status.get("ready"));
                });
      }
    }
  }
  