LibWeb: Const qualify HTMLCollection::length

Author: https://github.com/shannonbooth
Commit: https://github.com/SerenityOS/serenity/commit/15944c5b26
Pull-request: https://github.com/SerenityOS/serenity/pull/20656
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp

@@ -60,7 +60,7 @@ JS::MarkedVector<Element*> HTMLCollection::collect_matching_elements() const
 }
 
 // https://dom.spec.whatwg.org/#dom-htmlcollection-length
-size_t HTMLCollection::length()
+size_t HTMLCollection::length() const
 {
     // The length getter steps are to return the number of nodes represented by the collection.
     return collect_matching_elements().size();

Userland/Libraries/LibWeb/DOM/HTMLCollection.h

@@ -38,7 +38,7 @@ public:
 
     virtual ~HTMLCollection() override;
 
-    size_t length();
+    size_t length() const;
     Element* item(size_t index) const;
     Element* named_item(DeprecatedFlyString const& name) const;