Add preference to enable CDP in Firefox by default

Related to SeleniumHQ#11736

Author: pujagani

dotnet/src/webdriver/Firefox/FirefoxOptions.cs

@@ -88,6 +88,9 @@ public FirefoxOptions()
             this.AddKnownCapabilityName(FirefoxOptions.FirefoxLegacyProfileCapability, "Profile property");
             this.AddKnownCapabilityName(FirefoxOptions.FirefoxLegacyBinaryCapability, "BrowserExecutableLocation property");
             this.AddKnownCapabilityName(FirefoxOptions.FirefoxEnableDevToolsProtocolCapability, "EnableDevToolsProtocol property");
+            // Firefox 129 onwards the CDP protocol will not be enabled by default. Setting this preference will enable it.
+            // https://fxdx.dev/deprecating-cdp-support-in-firefox-embracing-the-future-with-webdriver-bidi/.
+            this.SetPreference("remote.active-protocols", 2);
         }
 
         /// <summary>

java/src/org/openqa/selenium/firefox/FirefoxOptions.java

@@ -63,6 +63,10 @@ public FirefoxOptions() {
     setCapability(CapabilityType.BROWSER_NAME, FIREFOX.browserName());
     setAcceptInsecureCerts(true);
     setCapability("moz:debuggerAddress", true);
+    // Firefox 129 onwards the CDP protocol will not be enabled by default. Setting this preference
+    // will enable it.
+    // https://fxdx.dev/deprecating-cdp-support-in-firefox-embracing-the-future-with-webdriver-bidi/.
+    addPreference("remote.active-protocols", 2);
   }
 
   public FirefoxOptions(Capabilities source) {

javascript/node/selenium-webdriver/firefox.js

@@ -246,6 +246,9 @@ class Options extends Capabilities {
   constructor(other) {
     super(other)
     this.setBrowserName(Browser.FIREFOX)
+    // Firefox 129 onwards the CDP protocol will not be enabled by default. Setting this preference will enable it.
+    // https://fxdx.dev/deprecating-cdp-support-in-firefox-embracing-the-future-with-webdriver-bidi/.
+    this.setPreference('remote.active-protocols', 2)
   }
 
   /**

py/selenium/webdriver/firefox/options.py

@@ -41,6 +41,9 @@ def __init__(self) -> None:
         super().__init__()
         self._binary_location = ""
         self._preferences: dict = {}
+        # Firefox 129 onwards the CDP protocol will not be enabled by default. Setting this preference will enable it.
+        # https://fxdx.dev/deprecating-cdp-support-in-firefox-embracing-the-future-with-webdriver-bidi/.
+        self._preferences["remote.active-protocols"] = 2
         self._profile = None
         self.log = Log()
 

rb/lib/selenium/webdriver/firefox/options.rb

@@ -64,6 +64,9 @@ def initialize(log_level: nil, **opts)
 
           @options[:args] ||= []
           @options[:prefs] ||= {}
+          # Firefox 129 onwards the CDP protocol will not be enabled by default. Setting this preference will enable it.
+          # https://fxdx.dev/deprecating-cdp-support-in-firefox-embracing-the-future-with-webdriver-bidi/.
+          @options[:prefs]['remote.active-protocols'] = 2
           @options[:env] ||= {}
           @options[:log] ||= {level: log_level} if log_level