Bug Fix: isHTMLElement will return false when given 'splide__list"

dist/js/splide.cjs.js

@@ -68,8 +68,26 @@ function isNull(subject) {
   return subject === null;
 }
 
+function isInstanceOf(subject, typeName) {
+  if (subject === null) {
+    return false;
+  }
+
+  var p = subject.__proto__;
+
+  while (p !== null) {
+    if (p.constructor.name === typeName) {
+      return true;
+    }
+
+    p = p.__proto__;
+  }
+
+  return false;
+}
+
 function isHTMLElement(subject) {
-  return subject instanceof HTMLElement;
+  return isInstanceOf(subject, "HTMLElement");
 }
 
 function toArray(value) {

dist/js/splide.esm.js

@@ -63,8 +63,26 @@ function isNull(subject) {
   return subject === null;
 }
 
+function isInstanceOf(subject, typeName) {
+  if (subject === null) {
+    return false;
+  }
+
+  var p = subject.__proto__;
+
+  while (p !== null) {
+    if (p.constructor.name === typeName) {
+      return true;
+    }
+
+    p = p.__proto__;
+  }
+
+  return false;
+}
+
 function isHTMLElement(subject) {
-  return subject instanceof HTMLElement;
+  return isInstanceOf(subject, "HTMLElement");
 }
 
 function toArray(value) {

dist/js/splide.js

@@ -68,8 +68,26 @@ function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _d
     return subject === null;
   }
 
+  function isInstanceOf(subject, typeName) {
+    if (subject === null) {
+      return false;
+    }
+
+    var p = subject.__proto__;
+
+    while (p !== null) {
+      if (p.constructor.name === typeName) {
+        return true;
+      }
+
+      p = p.__proto__;
+    }
+
+    return false;
+  }
+
   function isHTMLElement(subject) {
-    return subject instanceof HTMLElement;
+    return isInstanceOf(subject, "HTMLElement");
   }
 
   function toArray(value) {

dist/js/utils/splide-utils.cjs.js

@@ -40,11 +40,24 @@ const isUndefined = apply(typeOf, "undefined");
 function isNull(subject) {
   return subject === null;
 }
+function isInstanceOf(subject, typeName) {
+  if (subject === null) {
+    return false;
+  }
+  let p = subject.__proto__;
+  while (p !== null) {
+    if (p.constructor.name === typeName) {
+      return true;
+    }
+    p = p.__proto__;
+  }
+  return false;
+}
 function isHTMLElement(subject) {
-  return subject instanceof HTMLElement;
+  return isInstanceOf(subject, "HTMLElement");
 }
 function isHTMLButtonElement(subject) {
-  return subject instanceof HTMLButtonElement;
+  return isInstanceOf(subject, "HTMLButtonElement");
 }
 
 function toArray(value) {

dist/js/utils/splide-utils.esm.js

@@ -36,11 +36,24 @@ const isUndefined = apply(typeOf, "undefined");
 function isNull(subject) {
   return subject === null;
 }
+function isInstanceOf(subject, typeName) {
+  if (subject === null) {
+    return false;
+  }
+  let p = subject.__proto__;
+  while (p !== null) {
+    if (p.constructor.name === typeName) {
+      return true;
+    }
+    p = p.__proto__;
+  }
+  return false;
+}
 function isHTMLElement(subject) {
-  return subject instanceof HTMLElement;
+  return isInstanceOf(subject, "HTMLElement");
 }
 function isHTMLButtonElement(subject) {
-  return subject instanceof HTMLButtonElement;
+  return isInstanceOf(subject, "HTMLButtonElement");
 }
 
 function toArray(value) {

src/js/utils/type/type.ts

@@ -72,6 +72,31 @@ export function isNull( subject: unknown ): subject is null {
   return subject === null;
 }
 
+/**
+ * Tests to see if the given TypeName appears anywhere
+ * in the prototype chain of the given subject.
+ * This is a lose version of the instanceof operator
+ * (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof)
+ * required when checking the type of elements that cross window and iframe bouderies.
+ * 
+ * @param subject 
+ * @param typeName 
+ * @returns `true` if 
+ */
+function isInstanceOf(subject: any, typeName: string) {
+  if (subject === null) {
+    return false;
+  }
+  let p = subject.__proto__;
+  while (p !== null) {
+    if (p.constructor.name === typeName) {
+      return true;
+    }
+    p = p.__proto__;
+  }
+  return false;
+}
+
 /**
  * Checks if the given subject is an HTMLElement or not.
  *
@@ -80,7 +105,7 @@ export function isNull( subject: unknown ): subject is null {
  * @return `true` if the subject is an HTMLElement instance, or otherwise `false`.
  */
 export function isHTMLElement( subject: unknown ): subject is HTMLElement {
-  return subject instanceof HTMLElement;
+  return isInstanceOf( subject, 'HTMLElement' );
 }
 
 /**
@@ -91,5 +116,5 @@ export function isHTMLElement( subject: unknown ): subject is HTMLElement {
  * @return `true` if the subject is an HTMLButtonElement, or otherwise `false`.
  */
 export function isHTMLButtonElement( subject: unknown ): subject is HTMLButtonElement {
-  return subject instanceof HTMLButtonElement;
+  return isInstanceOf( subject, 'HTMLButtonElement' );
 }