From ecb5ace5f30b83808a13fdfd9932f5dce563b7cf Mon Sep 17 00:00:00 2001
From: Artur Signell <artur@vaadin.com>
Date: Fri, 5 Dec 2025 19:28:43 +0200
Subject: [PATCH] fix: allow non-Serializable beans in Element.callJsFunction

Element.callJsFunction was incorrectly using Serializable[] for
parameter storage and System.arraycopy to copy Object[] arguments.
This caused ArrayStoreException when passing non-Serializable objects
like plain beans or records.

Changed to use Object[] instead, matching the implementation pattern
used in Element.executeJs and Page.executeJs, which correctly support
all Jackson-serializable types including non-Serializable beans.

Added test to verify beans can be passed to callJsFunction.
---
 .../src/main/java/com/vaadin/flow/dom/Element.java   |  6 +++---
 .../java/com/vaadin/flow/dom/ElementJacksonTest.java | 12 ++++++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/flow-server/src/main/java/com/vaadin/flow/dom/Element.java b/flow-server/src/main/java/com/vaadin/flow/dom/Element.java
index 1cafe613a54..e1eb83ecdb9 100644
--- a/flow-server/src/main/java/com/vaadin/flow/dom/Element.java
+++ b/flow-server/src/main/java/com/vaadin/flow/dom/Element.java
@@ -1634,11 +1634,11 @@ public PendingJavaScriptResult callJsFunction(String functionName,
         String paramPlaceholderString = IntStream.range(1, arguments.length + 1)
                 .mapToObj(i -> "$" + i).collect(Collectors.joining(","));
         // Inject the element as $0
-        Serializable[] jsParameters;
+        Object[] jsParameters;
         if (arguments.length == 0) {
-            jsParameters = new Serializable[] { this };
+            jsParameters = new Object[] { this };
         } else {
-            jsParameters = new Serializable[arguments.length + 1];
+            jsParameters = new Object[arguments.length + 1];
             jsParameters[0] = this;
             System.arraycopy(arguments, 0, jsParameters, 1, arguments.length);
         }
diff --git a/flow-server/src/test/java/com/vaadin/flow/dom/ElementJacksonTest.java b/flow-server/src/test/java/com/vaadin/flow/dom/ElementJacksonTest.java
index f099e29e0fb..341b712f8ac 100644
--- a/flow-server/src/test/java/com/vaadin/flow/dom/ElementJacksonTest.java
+++ b/flow-server/src/test/java/com/vaadin/flow/dom/ElementJacksonTest.java
@@ -2342,6 +2342,18 @@ public void callFunctionTwoParams() {
         assertPendingJs(ui, "return $0.method($1,$2)", element, "foo", 123);
     }
 
+    @Test
+    public void callFunctionWithBean() {
+        UI ui = new MockUI();
+        Element element = ElementFactory.createDiv();
+        SimpleBean bean = new SimpleBean();
+        element.callJsFunction("method", bean);
+        ui.getElement().appendChild(element);
+        ui.getInternals().getStateTree().runExecutionsBeforeClientResponse();
+
+        assertPendingJs(ui, "return $0.method($1)", element, bean);
+    }
+
     @Test
     public void callFunctionOnProperty() {
         UI ui = new MockUI();