revert to default simplifiedElementCheck: false to prevent class removal issues.

Author: johanneswilm

browser/diffDOM.js

@@ -43,14 +43,19 @@ export function checkElementType(
 
     // Simplified check for primitive virtual DOMs without ownerDocument
     if (simplifiedCheck) {
-        return elementTypeNames.some((elementTypeName) => {
+        const simplifiedResult = elementTypeNames.some((elementTypeName) => {
             // Special case for basic element types
             if (elementTypeName === "Element") {
+                // Enhanced check that handles both virtual DOM objects and real DOM elements
                 return (
                     element.nodeType === 1 ||
                     (typeof element.nodeName === "string" &&
                         element.nodeName !== "#text" &&
-                        element.nodeName !== "#comment")
+                        element.nodeName !== "#comment") ||
+                    // Additional check for real DOM elements that might not have nodeType
+                    (element.tagName && typeof element.tagName === "string") ||
+                    // Check if it has DOM element-like properties (fallback)
+                    (element.setAttribute && typeof element.setAttribute === "function")
                 )
             }
             if (elementTypeName === "Text") {
@@ -60,20 +65,40 @@ export function checkElementType(
                 return element.nodeType === 8 || element.nodeName === "#comment"
             }
 
-            // For HTML element types, check nodeName
+            // For HTML element types, check nodeName or tagName
             if (
                 elementTypeName.startsWith("HTML") &&
                 elementTypeName.endsWith("Element")
             ) {
                 const tagName = elementTypeName.slice(4, -7).toLowerCase()
                 return (
-                    element.nodeName &&
-                    element.nodeName.toLowerCase() === tagName
+                    (element.nodeName &&
+                        element.nodeName.toLowerCase() === tagName) ||
+                    (element.tagName &&
+                        element.tagName.toLowerCase() === tagName)
                 )
             }
 
             return false
         })
+        
+        // If simplified check succeeds, return true
+        if (simplifiedResult) {
+            return true
+        }
+        
+        // Fallback to DOM-based check if simplified check fails and element has ownerDocument
+        if (element.ownerDocument) {
+            return elementTypeNames.some(
+                (elementTypeName) =>
+                    typeof element?.ownerDocument?.defaultView?.[elementTypeName] ===
+                        "function" &&
+                    element instanceof
+                        element.ownerDocument.defaultView[elementTypeName],
+            )
+        }
+        
+        return false
     }
 
     // DOM-based check
@@ -86,4 +111,4 @@ export function checkElementType(
             element instanceof
                 element.ownerDocument.defaultView[elementTypeName],
     )
-}
+}

browser/diffDOM.js.map

@@ -18,7 +18,7 @@ const DEFAULT_OPTIONS = {
     maxDepth: false, // False or a numeral. If set to a numeral, limits the level of depth that the the diff mechanism looks for differences. If false, goes through the entire tree.
     maxChildCount: 50, // False or a numeral. If set to a numeral, only does a simplified form of diffing of contents so that the number of diffs cannot be higher than the number of child nodes.
     valueDiffing: true, // Whether to take into consideration the values of forms that differ from auto assigned values (when a user fills out a form).
-    simplifiedElementCheck: true, // Whether to use simplified element type checking for primitive virtual DOMs without ownerDocument
+    simplifiedElementCheck: false, // Whether to use simplified element type checking for primitive virtual DOMs without ownerDocument
     // syntax: textDiff: function (node, currentValue, expectedValue, newValue)
     textDiff(
         node: textNodeType,