LibWeb/IDB: Implement IDBObjectStore::indexNames

Libraries/LibWeb/IndexedDB/IDBObjectStore.cpp

@@ -153,4 +153,16 @@ WebIDL::ExceptionOr<GC::Ref<IDBIndex>> IDBObjectStore::create_index(String const
     return IDBIndex::create(realm, index, *this);
 }
 
+// https://w3c.github.io/IndexedDB/#dom-idbobjectstore-indexnames
+GC::Ref<HTML::DOMStringList> IDBObjectStore::index_names()
+{
+    // 1. Let names be a list of the names of the indexes in this's index set.
+    Vector<String> names;
+    for (auto const& [name, index] : m_indexes)
+        names.append(name);
+
+    // 2. Return the result (a DOMStringList) of creating a sorted name list with names.
+    return create_a_sorted_name_list(realm(), names);
+}
+
 }

Libraries/LibWeb/IndexedDB/IDBObjectStore.h

@@ -40,6 +40,7 @@ public:
     AK::HashMap<String, GC::Ref<Index>>& index_set() { return m_indexes; }
 
     WebIDL::ExceptionOr<GC::Ref<IDBIndex>> create_index(String const&, KeyPath, IDBIndexParameters options);
+    [[nodiscard]] GC::Ref<HTML::DOMStringList> index_names();
 
 protected:
     explicit IDBObjectStore(JS::Realm&, GC::Ref<ObjectStore>, GC::Ref<IDBTransaction>);

Libraries/LibWeb/IndexedDB/IDBObjectStore.idl

@@ -6,7 +6,7 @@
 interface IDBObjectStore {
     attribute DOMString name;
     readonly attribute any keyPath;
-    [FIXME] readonly attribute DOMStringList indexNames;
+    readonly attribute DOMStringList indexNames;
     [SameObject] readonly attribute IDBTransaction transaction;
     readonly attribute boolean autoIncrement;