Fix tests and address comments

Author: pujagani

java/src/org/openqa/selenium/bidi/BUILD.bazel

@@ -60,7 +60,7 @@ genrule(
     name = "generate-bidi",
     srcs = ["//javascript/selenium-webdriver:create-bidi-src_schema"],
     outs = ["bidi-generated.srcjar"],
-    cmd = "$(execpath :bidi-client-generator) $(location //javascript/selenium-webdriver:create-bidi-src_schema) $@",
+    cmd = "\"$(execpath :bidi-client-generator)\" \"$(location //javascript/selenium-webdriver:create-bidi-src_schema)\" \"$@\"",
     tools = [":bidi-client-generator"],
 )
 

java/src/org/openqa/selenium/bidi/BiDiGenerator.java

@@ -820,7 +820,12 @@ private void appendRecordBody(
             appendConstructorAssignment(sb, f, domain, m + "  ", needsBuilder);
           }
           if (needsExtrasCapture) {
-            sb.append(m).append("  this.extensions = extensions;\n");
+            // Copy rather than alias: when this constructor is called from a Builder's build(),
+            // the argument is the Builder's own live, mutable map — a later addExtension() call
+            // on a reused Builder must not be able to mutate an already-built instance out from
+            // under it (the BiDi low-level behavioral contract requires a built/received instance
+            // to stay immutable).
+            sb.append(m).append("  this.extensions = new LinkedHashMap<>(extensions);\n");
           }
           sb.append(m).append("}\n\n");
         }

java/test/org/openqa/selenium/bidi/protocol/module/BrowsingContextModuleTest.java

@@ -160,8 +160,18 @@ void canListenToBrowsingContextDestroyedEvent() throws Exception {
     BrowsingContext browsingContext = new BrowsingContext(driver);
     String windowHandle = driver.switchTo().newWindow(WindowType.WINDOW).getWindowHandle();
 
+    // CONTEXT_DESTROYED can only be subscribed globally (Module.subscribe has no per-context
+    // overload), so an unrelated context closing during the test — e.g. a browser onboarding tab
+    // some grid nodes auto-close shortly after launch — can also complete this. Filter to the
+    // context this test closed instead of completing on the first event received.
     CompletableFuture<Info> future = new CompletableFuture<>();
-    browsingContext.subscribe(BrowsingContext.CONTEXT_DESTROYED, future::complete);
+    browsingContext.subscribe(
+        BrowsingContext.CONTEXT_DESTROYED,
+        info -> {
+          if (windowHandle.equals(info.getContext())) {
+            future.complete(info);
+          }
+        });
 
     driver.close();