[java] Throwing warnings for non-W3C before creating session

java/src/org/openqa/selenium/PersistentCapabilities.java

@@ -53,8 +53,6 @@ public PersistentCapabilities setCapability(String name, Object value) {
     Require.nonNull("Name", name);
     Require.nonNull("Value", value);
 
-    W3CCapabilityKeysValidator.validateCapability(name);
-
     return new PersistentCapabilities(this, new ImmutableCapabilities(name, value));
   }
 

java/src/org/openqa/selenium/SharedCapabilitiesMethods.java

@@ -46,8 +46,6 @@ static boolean equals(Capabilities left, Capabilities right) {
   }
 
   static void setCapability(Map<String, Object> caps, String key, Object value) {
-    W3CCapabilityKeysValidator.validateCapability(key);
-
     if ("loggingPrefs".equals(key) && value instanceof Map) {
       LoggingPreferences prefs = new LoggingPreferences();
       @SuppressWarnings("unchecked") Map<String, String> prefsMap = (Map<String, String>) value;

java/src/org/openqa/selenium/remote/RemoteWebDriver.java

@@ -20,6 +20,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 
+import org.openqa.selenium.AcceptedW3CCapabilityKeys;
 import org.openqa.selenium.Alert;
 import org.openqa.selenium.Beta;
 import org.openqa.selenium.By;
@@ -74,6 +75,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.time.Duration;
+import java.util.Arrays;
 import java.util.Base64;
 import java.util.Collection;
 import java.util.Collections;
@@ -107,6 +109,26 @@ public class RemoteWebDriver implements WebDriver,
   PrintsPage,
   TakesScreenshot {
 
+  private static final List<String> IE_CAPABILITY_NAMES = Arrays.asList(
+    "browserAttachTimeout",
+    "elementScrollBehavior",
+    "enablePersistentHover",
+    "ie.enableFullPageScreenshot",
+    "ie.forceCreateProcessApi",
+    "ie.forceShellWindowsApi",
+    "ie.ensureCleanSession",
+    "ie.browserCommandLineSwitches",
+    "ie.usePerProcessProxy",
+    "ignoreZoomSetting",
+    "initialBrowserUrl",
+    "ignoreProtectedModeSettings",
+    "requireWindowFocus",
+    "ie.fileUploadDialogTimeout",
+    "nativeEvents",
+    "ie.useLegacyFileUploadDialogHandling",
+    "ie.edgechromium",
+    "ie.edgepath");
+
   // TODO: This static logger should be unified with the per-instance localLogs
   private static final Logger logger = Logger.getLogger(RemoteWebDriver.class.getName());
   private final ElementLocation elementLocation = new ElementLocation();
@@ -243,6 +265,21 @@ protected void setSessionId(String opaqueKey) {
   }
 
   protected void startSession(Capabilities capabilities) {
+    // Throwing warnings for non-W3C WebDriver compliant capabilities
+    List<String> invalid = capabilities.asMap().keySet()
+      .stream()
+      .filter(key -> !(new AcceptedW3CCapabilityKeys().test(key)))
+      .filter(key -> !IE_CAPABILITY_NAMES.contains(key))
+      .collect(Collectors.toList());
+
+    if (!invalid.isEmpty()) {
+      logger.log(Level.WARNING,
+                 () -> String.format("Support for Legacy Capabilities is deprecated; " +
+                                     "You are sending the following invalid capabilities: %s; " +
+                                     "Please update to W3C Syntax: https://www.selenium.dev/blog/2022/legacy-protocol-support/",
+                                     invalid));
+    }
+
     Response response = execute(DriverCommand.NEW_SESSION(singleton(capabilities)));
 
     if (response == null) {

java/src/org/openqa/selenium/remote/RemoteWebDriverBuilder.java

@@ -26,7 +26,6 @@
 import org.openqa.selenium.ImmutableCapabilities;
 import org.openqa.selenium.SessionNotCreatedException;
 import org.openqa.selenium.UsernameAndPassword;
-import org.openqa.selenium.W3CCapabilityKeysValidator;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebDriverInfo;
 import org.openqa.selenium.internal.Either;
@@ -201,14 +200,12 @@ public RemoteWebDriverBuilder setCapability(String capabilityName, Object value)
     Require.nonNull("Capability name", capabilityName);
     Require.nonNull("Capability value", value);
 
-    W3CCapabilityKeysValidator.validateCapability(capabilityName);
-
     Object previous = additionalCapabilities.put(capabilityName, value);
     if (previous != null) {
       LOG.log(
         getDebugLogLevel(),
-        String.format("Overwriting capability %s. Previous value %s, new value %s", capabilityName,
-                      previous, value));
+        () -> String.format("Overwriting capability %s. Previous value %s, new value %s",
+                            capabilityName, previous, value));
     }
 
     return this;