BiDi APIs

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Selenium is working with browser vendors to create the WebDriver BiDirectional Protocol as a means to provide a stable, cross-browser API that uses the bidirectional functionality useful for both browser automation generally and testing specifically. Before now, users seeking this functionality have had to rely on the Chrome DevTools Protocol, with all of its frustrations and limitations.

The traditional webdriver model of strict request/response commands will be supplemented with the ability to stream events from the user agent to the controlling software via WebSockets, better matching the evented nature of the browser DOM.

Because it’s a bad idea to tie your tests to a specific version of a specific browser, the Selenium project recommends using WebDriver BiDi wherever possible. However, until the spec is complete there are many useful things that the CDP offers. To help keep your tests independent and portable, Selenium offers some useful helper classes. At the moment, these use the CDP, but when we shall be using WebDriver Bidi as soon as possible

The following list of APIs will be growing as the Selenium project works through supporting real world use cases. If there is additional functionality you’d like to see, please raise a feature request.

Register Basic Auth

Some applications make use of browser authentication to secure pages. With Selenium, you can automate the input of basic auth credentials whenever they arise.

Predicate<URI> uriPredicate = uri -> uri.getHost().contains("your-domain.com");

((HasAuthentication) driver).register(uriPredicate, UsernameAndPassword.of("admin", "password"));
driver.get("https://your-domain.com/login");
# Please raise a PR to add code sample
NetworkAuthenticationHandler handler = new NetworkAuthenticationHandler()
{
    UriMatcher = (d) => d.Host.Contains("your-domain.com"),
    Credentials = new PasswordCredentials("admin", "password")
};

INetwork networkInterceptor = driver.Manage().Network;
networkInterceptor.AddAuthenticationHandler(handler);
await networkInterceptor.StartMonitoring();
require 'selenium-webdriver'

driver = Selenium::WebDriver.for :chrome

begin
  driver.devtools.new
  driver.register(username: 'username', password: 'password')
  driver.get '<your site url>'
ensure
  driver.quit
end
const {Builder} = require('selenium-webdriver');

(async function example() {
  try {
    let driver = await new Builder()
      .forBrowser('chrome')
      .build();

    const pageCdpConnection = await driver.createCDPConnection('page');
    await driver.register('username', 'password', pageCdpConnection);
    await driver.get('https://the-internet.herokuapp.com/basic_auth');
    await driver.quit();
  }catch (e){
    console.log(e)
  }
}())
val uriPredicate = Predicate { uri: URI ->
        uri.host.contains("your-domain.com")
    }
(driver as HasAuthentication).register(uriPredicate, UsernameAndPassword.of("admin", "password"))
driver.get("https://your-domain.com/login")

Mutation Observation

Mutation Observation is the ability to capture events via WebDriver BiDi when there are DOM mutations on a specific element in the DOM.

ChromeDriver driver = new ChromeDriver();

AtomicReference<DomMutationEvent> seen = new AtomicReference<>();
CountDownLatch latch = new CountDownLatch(1);
((HasLogEvents) driver).onLogEvent(domMutation(mutation -> {
    seen.set(mutation);
    latch.countDown();
}));

driver.get("https://www.google.com");
WebElement span = driver.findElement(By.cssSelector("span"));

((JavascriptExecutor) driver).executeScript("arguments[0].setAttribute('cheese', 'gouda');", span);

assertThat(latch.await(10, SECONDS), is(true));
assertThat(seen.get().getAttributeName(), is("cheese"));
assertThat(seen.get().getCurrentValue(), is("gouda"));

driver.quit();
  
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait

driver = webdriver.Chrome()
async with driver.log.mutation_events() as event:
    pages.load("dynamic.html")
    driver.find_element(By.ID, "reveal").click()
    WebDriverWait(driver, 5)\
        .until(EC.visibility_of(driver.find_element(By.ID, "revealed")))

assert event["attribute_name"] == "style"
assert event["current_value"] == ""
assert event["old_value"] == "display:none;"

  
List<DomMutationData> attributeValueChanges = new List<DomMutationData>();
DefaultWait<List<DomMutationData>> wait = new DefaultWait<List<DomMutationData>>(attributeValueChanges);
wait.Timeout = TimeSpan.FromSeconds(3);

IJavaScriptEngine monitor = new JavaScriptEngine(driver);
monitor.DomMutated += (sender, e) =>
{
    attributeValueChanges.Add(e.AttributeData);
};
await monitor.StartEventMonitoring();

driver.Navigate().GoToUrl("http://www.google.com");
IWebElement span = driver.FindElement(By.CssSelector("span"));

await monitor.EnableDomMutationMonitoring();
((IJavaScriptExecutor) driver).ExecuteScript("arguments[0].setAttribute('cheese', 'gouda');", span);

wait.Until((list) => list.Count > 0);
Console.WriteLine("Found {0} DOM mutation events", attributeValueChanges.Count);
foreach(var record in attributeValueChanges)
{
    Console.WriteLine("Attribute name: {0}", record.AttributeName);
    Console.WriteLine("Attribute value: {0}", record.AttributeValue);
}

await monitor.DisableDomMutationMonitoring();
  
require 'selenium-webdriver'
driver = Selenium::WebDriver.for :firefox
begin
  driver.on_log_event(:mutation) { |mutation| mutations.push(mutation) }
  driver.navigate.to url_for('dynamic.html')
  driver.find_element(id: 'reveal').click
  wait.until { mutations.any? }
  mutation = mutations.first
  expect(mutation.element).to eq(driver.find_element(id: 'revealed'))
  expect(mutation.attribute_name).to eq('style')
  expect(mutation.current_value).to eq('')
  expect(mutation.old_value).to eq('display:none;')
ensure
  driver.quit
end
  
const {Builder, until} = require('selenium-webdriver');
const assert = require("assert");

(async function example() {
  try {
    let driver = await new Builder()
      .forBrowser('chrome')
      .build();

    const cdpConnection = await driver.createCDPConnection('page');
    await driver.logMutationEvents(cdpConnection, event => {
      assert.deepStrictEqual(event['attribute_name'], 'style');
      assert.deepStrictEqual(event['current_value'], "");
      assert.deepStrictEqual(event['old_value'], "display:none;");
    });

    await driver.get('dynamic.html');
    await driver.findElement({id: 'reveal'}).click();
    let revealed = driver.findElement({id: 'revealed'});
    await driver.wait(until.elementIsVisible(revealed), 5000);
    await driver.quit();
  }catch (e){
    console.log(e)
  }
}())
  
# Please raise a PR to add code sample
  

Listen to console.log events

Listen to the console.log events and register callbacks to process the event.

ChromeDriver driver = new ChromeDriver();
DevTools devTools = driver.getDevTools();
devTools.createSession();
devTools.send(Log.enable());
devTools.addListener(Log.entryAdded(),
                           logEntry -> {
                               System.out.println("log: "+logEntry.getText());
                               System.out.println("level: "+logEntry.getLevel());
                           });
driver.get("http://the-internet.herokuapp.com/broken_images");
// Check the terminal output for the browser console messages.
driver.quit();
async def printConsoleLogs():
  chrome_options = webdriver.ChromeOptions()
  driver = webdriver.Chrome()
  driver.get("http://www.google.com")

  async with driver.bidi_connection() as session:
      log = Log(driver, session)
      from selenium.webdriver.common.bidi.console import Console
      async with log.add_listener(Console.ALL) as messages:
          driver.execute_script("console.log('I love cheese')")
      print(messages["message"])

  driver.quit()
IJavaScriptEngine monitor = new JavaScriptEngine(driver);
List<string> consoleMessages = new List<string>();
monitor.JavaScriptConsoleApiCalled += (sender, e) =>
{
    Console.WriteLine("Log: {0}", e.MessageContent);
};
await monitor.StartEventMonitoring();
require 'selenium-webdriver'

driver = Selenium::WebDriver.for :chrome
begin
  driver.get 'http://www.google.com'
  logs = []
  driver.on_log_event(:console) do |event|
    logs.push(event)
    puts logs.length
  end

  driver.execute_script('console.log("here")')

ensure
  driver.quit
end
const {Builder} = require('selenium-webdriver');
(async () => {
  try {
    let driver = new Builder()
      .forBrowser('chrome')
      .build();

    const cdpConnection = await driver.createCDPConnection('page');
    await driver.onLogEvent(cdpConnection, function (event) {
      console.log(event['args'][0]['value']);
    });
    await driver.executeScript('console.log("here")');
    await driver.quit();
  }catch (e){
    console.log(e);
  }
})()
fun kotlinConsoleLogExample() {
    val driver = ChromeDriver()
    val devTools = driver.devTools
    devTools.createSession()

    val logConsole = { c: ConsoleEvent -> print("Console log message is: " + c.messages)}
    devTools.domains.events().addConsoleListener(logConsole)

    driver.get("https://www.google.com")

    val executor = driver as JavascriptExecutor
    executor.executeScript("console.log('Hello World')")

    val input = driver.findElement(By.name("q"))
    input.sendKeys("Selenium 4")
    input.sendKeys(Keys.RETURN)
    driver.quit()
}

Listen to JS Exceptions

Listen to the JS Exceptions and register callbacks to process the exception details.

import org.openqa.selenium.*;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.devtools.DevTools;

public void jsExceptionsExample() {
    ChromeDriver driver = new ChromeDriver();
    DevTools devTools = driver.getDevTools();
    devTools.createSession();

    List<JavascriptException> jsExceptionsList = new ArrayList<>();
    Consumer<JavascriptException> addEntry = jsExceptionsList::add;
    devTools.getDomains().events().addJavascriptExceptionListener(addEntry);

    driver.get("<your site url>");

    WebElement link2click = driver.findElement(By.linkText("<your link text>"));
    ((JavascriptExecutor) driver).executeScript("arguments[0].setAttribute(arguments[1], arguments[2]);",
          link2click, "onclick", "throw new Error('Hello, world!')");
    link2click.click();

    for (JavascriptException jsException : jsExceptionsList) {
        System.out.println("JS exception message: " + jsException.getMessage());
        System.out.println("JS exception system information: " + jsException.getSystemInformation());
        jsException.printStackTrace();
    }
}
async def catchJSException():
  chrome_options = webdriver.ChromeOptions()
  driver = webdriver.Chrome()

  async with driver.bidi_connection() as session:
      driver.get("<your site url>")
      log = Log(driver, session)
      async with log.add_js_error_listener() as messages:
          # Operation on the website that throws an JS error
      print(messages)

  driver.quit()
List<string> exceptionMessages = new List<string>();
IJavaScriptEngine monitor = new JavaScriptEngine(driver);
monitor.JavaScriptExceptionThrown += (sender, e) =>
{
    exceptionMessages.Add(e.Message);
};

await monitor.StartEventMonitoring();

driver.Navigate.GoToUrl("<your site url>");

IWebElement link2click = driver.FindElement(By.LinkText("<your link text>"));
((IJavaScriptExecutor) driver).ExecuteScript("arguments[0].setAttribute(arguments[1], arguments[2]);",
      link2click, "onclick", "throw new Error('Hello, world!')");
link2click.Click();

foreach (string message in exceptionMessages)
{
    Console.WriteLine("JS exception message: {0}", message);
}
require 'selenium-webdriver'

driver = Selenium::WebDriver.for :chrome
begin
  driver.get '<your-site-url>'
  exceptions = []
  driver.on_log_event(:exception) do |event|
    exceptions.push(event)
    puts exceptions.length
  end

  # Actions causing JS exceptions

ensure
  driver.quit
end
# Please raise a PR to add code sample
fun kotlinJsErrorListener() {
    val driver = ChromeDriver()
    val devTools = driver.devTools
    devTools.createSession()

    val logJsError = { j: JavascriptException -> print("Javascript error: '" + j.localizedMessage + "'.") }
    devTools.domains.events().addJavascriptExceptionListener(logJsError)

    driver.get("https://www.google.com")

    val link2click = driver.findElement(By.name("q"))
    (driver as JavascriptExecutor).executeScript(
      "arguments[0].setAttribute(arguments[1], arguments[2]);",
      link2click, "onclick", "throw new Error('Hello, world!')"
    )
    link2click.click()

    driver.quit()
}

Network Interception

If you want to capture network events coming into the browser and you want manipulate them you are able to do it with the following examples.

## Collect Performance Metrics Collect various performance metrics while navigating the application.
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.devtools.DevTools;

public void performanceMetricsExample() {
    ChromeDriver driver = new ChromeDriver();
    DevTools devTools = driver.getDevTools();
    devTools.createSession();
    devTools.send(Performance.enable(Optional.empty()));
    List<Metric> metricList = devTools.send(Performance.getMetrics());

    driver.get("https://google.com");
    driver.quit();

    for(Metric m : metricList) {
        System.out.println(m.getName() + " = " + m.getValue());
    }
}
# Please raise a PR to add code sample
// File must contain the following using statements
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.DevTools;

// We must use a version-specific set of domains
using OpenQA.Selenium.DevTools.V94.Performance;

public async Task PerformanceMetricsExample()
{
    IWebDriver driver = new ChromeDriver();
    IDevTools devTools = driver as IDevTools;
    DevToolsSession session = devTools.GetDevToolsSession();
    await session.SendCommand<EnableCommandSettings>(new EnableCommandSettings());
    var metricsResponse =
        await session.SendCommand<GetMetricsCommandSettings, GetMetricsCommandResponse>(
            new GetMetricsCommandSettings());

    driver.Navigate().GoToUrl("http://www.google.com");
    driver.Quit();

    var metrics = metricsResponse.Metrics;
    foreach (Metric metric in metrics)
    {
        Console.WriteLine("{0} = {1}", metric.Name, metric.Value);
    }
}
require 'selenium-webdriver'

driver = Selenium::WebDriver.for :chrome

begin
  driver.get 'https://www.duckduckgo.com'
  driver.execute_cdp('Performance.enable', {})
  metrics = driver.execute_cdp('Performance.getMetrics', {})
  puts metrics
ensure
  driver.quit
end
await driver.get("https://www.duckduckgo.com");

await driver.sendAndGetDevToolsCommand('Performance.enable')

let result = await driver.sendAndGetDevToolsCommand('Performance.getMetrics')
console.log(result)

await driver.quit();
val driver = ChromeDriver()
val devTools = driver.devTools
devTools.createSession()
devTools.send(Performance.enable(Optional.empty()))
val metricList: List<Metric> = devTools.send(Performance.getMetrics())

driver["https://google.com"]
driver.quit()

for (m in metricList) {
    println(m.name.toString() + " = " + m.value)
}
    import org.openqa.selenium.WebDriver;
    import org.openqa.selenium.devtools.HasDevTools;
    import org.openqa.selenium.devtools.NetworkInterceptor;
    import org.openqa.selenium.remote.http.Contents;
    import org.openqa.selenium.remote.http.Filter;
    import org.openqa.selenium.remote.http.HttpResponse;
    import org.openqa.selenium.remote.http.Route;

    NetworkInterceptor interceptor = new NetworkInterceptor(
      driver,
      Route.matching(req -> true)
        .to(() -> req -> new HttpResponse()
          .setStatus(200)
          .addHeader("Content-Type", MediaType.HTML_UTF_8.toString())
          .setContent(utf8String("Creamy, delicious cheese!"))));

   driver.get("https://example-sausages-site.com");

    String source = driver.getPageSource();

    assertThat(source).contains("delicious cheese!");
# Currently unavailable in python due the inability to mix certain async and sync commands
require 'selenium-webdriver'

driver = Selenium::WebDriver.for :chrome
driver.intercept do |request, &continue|
    uri = URI(request.url)
    if uri.path.end_with?('one.js')
      uri.path = '/devtools_request_interception_test/two.js'
      request.url = uri.to_s
    end
    continue.call(request)
end
driver.navigate.to url_for('devToolsRequestInterceptionTest.html')
driver.find_element(tag_name: 'button').click
expect(driver.find_element(id: 'result').text).to eq('two')
const connection = await driver.createCDPConnection()
let url = fileServer.whereIs("/cheese")
let httpResponse = new HttpResponse(url)
httpResponse.addHeaders("Content-Type", "UTF-8")
httpResponse.body = "sausages"
await driver.onIntercept(connection, httpResponse, async function () {
  let body = await driver.getPageSource()
  assert.strictEqual(body.includes("sausages"), true, `Body contains: ${body}`)
})
driver.get(url)
val driver = ChromeDriver()
val interceptor = new NetworkInterceptor(
      driver,
      Route.matching(req -> true)
        .to(() -> req -> new HttpResponse()
          .setStatus(200)
          .addHeader("Content-Type", MediaType.HTML_UTF_8.toString())
          .setContent(utf8String("Creamy, delicious cheese!"))))

    driver.get(appServer.whereIs("/cheese"))

    String source = driver.getPageSource()