8 files changed, 48 insertions, 0 deletions
diff --git a/Userland/Libraries/LibWeb/DOM/Document.h b/Userland/Libraries/LibWeb/DOM/Document.h
index 44f4512e2c..47e21b6938 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.h
+++ b/Userland/Libraries/LibWeb/DOM/Document.h
@@ -618,4 +618,7 @@ private:
     JS::GCPtr<HTML::HTMLBaseElement const> m_first_base_element_with_href_in_tree_order;
 };
 
+template<>
+inline bool Node::fast_is<Document>() const { return is_document(); }
+
 }
diff --git a/Userland/Libraries/LibWeb/DOM/Node.h b/Userland/Libraries/LibWeb/DOM/Node.h
index 172fc6a756..89cf7014df 100644
--- a/Userland/Libraries/LibWeb/DOM/Node.h
+++ b/Userland/Libraries/LibWeb/DOM/Node.h
@@ -85,6 +85,9 @@ public:
     virtual bool is_html_html_element() const { return false; }
     virtual bool is_html_anchor_element() const { return false; }
     virtual bool is_html_base_element() const { return false; }
+    virtual bool is_html_body_element() const { return false; }
+    virtual bool is_html_input_element() const { return false; }
+    virtual bool is_html_progress_element() const { return false; }
     virtual bool is_html_template_element() const { return false; }
     virtual bool is_browsing_context_container() const { return false; }
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLBodyElement.h b/Userland/Libraries/LibWeb/HTML/HTMLBodyElement.h
index dc3725a3dc..e20cb07daa 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLBodyElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLBodyElement.h
@@ -29,6 +29,9 @@ public:
 private:
     HTMLBodyElement(DOM::Document&, DOM::QualifiedName);
 
+    // ^DOM::Node
+    virtual bool is_html_body_element() const override { return true; }
+
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
 
     // ^HTML::GlobalEventHandlers
@@ -41,3 +44,8 @@ private:
 };
 
 }
+
+namespace Web::DOM {
+template<>
+inline bool Node::fast_is<HTML::HTMLBodyElement>() const { return is_html_body_element(); }
+}
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
index ee916ff5c5..2d85ed6409 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
@@ -125,6 +125,9 @@ public:
 private:
     HTMLInputElement(DOM::Document&, DOM::QualifiedName);
 
+    // ^DOM::Node
+    virtual bool is_html_input_element() const final { return true; }
+
     // ^DOM::EventTarget
     virtual void did_receive_focus() override;
     virtual void legacy_pre_activation_behavior() override;
@@ -166,3 +169,8 @@ private:
 };
 
 }
+
+namespace Web::DOM {
+template<>
+inline bool Node::fast_is<HTML::HTMLInputElement>() const { return is_html_input_element(); }
+}
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.h b/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.h
index 5417d3ff50..17905b6ee3 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLProgressElement.h
@@ -39,6 +39,9 @@ public:
 private:
     HTMLProgressElement(DOM::Document&, DOM::QualifiedName);
 
+    // ^DOM::Node
+    virtual bool is_html_input_element() const final { return true; }
+
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
 
     void progress_position_updated();
@@ -47,3 +50,8 @@ private:
 };
 
 }
+
+namespace Web::DOM {
+template<>
+inline bool Node::fast_is<HTML::HTMLProgressElement>() const { return is_html_progress_element(); }
+}
diff --git a/Userland/Libraries/LibWeb/Layout/ListItemBox.h b/Userland/Libraries/LibWeb/Layout/ListItemBox.h
index d3b79f3e3d..7f4598b398 100644
--- a/Userland/Libraries/LibWeb/Layout/ListItemBox.h
+++ b/Userland/Libraries/LibWeb/Layout/ListItemBox.h
@@ -25,9 +25,13 @@ public:
     void set_marker(JS::GCPtr<ListItemMarkerBox>);
 
 private:
+    virtual bool is_list_item_box() const override { return true; }
+
     virtual void visit_edges(Cell::Visitor&) override;
 
     JS::GCPtr<ListItemMarkerBox> m_marker;
 };
 
+template<>
+inline bool Node::fast_is<ListItemBox>() const { return is_list_item_box(); }
 }
diff --git a/Userland/Libraries/LibWeb/Layout/Node.h b/Userland/Libraries/LibWeb/Layout/Node.h
index 9e8319a402..271da99197 100644
--- a/Userland/Libraries/LibWeb/Layout/Node.h
+++ b/Userland/Libraries/LibWeb/Layout/Node.h
@@ -89,11 +89,14 @@ public:
     virtual bool is_viewport() const { return false; }
     virtual bool is_svg_box() const { return false; }
     virtual bool is_svg_geometry_box() const { return false; }
+    virtual bool is_svg_svg_box() const { return false; }
     virtual bool is_label() const { return false; }
     virtual bool is_replaced_box() const { return false; }
+    virtual bool is_list_item_box() const { return false; }
     virtual bool is_list_item_marker_box() const { return false; }
     virtual bool is_table_wrapper() const { return false; }
     virtual bool is_table() const { return false; }
+    virtual bool is_node_with_style_and_box_model_metrics() const { return false; }
 
     template<typename T>
     bool fast_is() const = delete;
@@ -219,9 +222,14 @@ protected:
     }
 
 private:
+    virtual bool is_node_with_style_and_box_model_metrics() const final { return true; }
+
     BoxModelMetrics m_box_model;
 };
 
+template<>
+inline bool Node::fast_is<NodeWithStyleAndBoxModelMetrics>() const { return is_node_with_style_and_box_model_metrics(); }
+
 inline Gfx::Font const& Node::font() const
 {
     if (m_has_style)
diff --git a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
index d63052879e..4e91029664 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGSVGBox.h
@@ -25,6 +25,12 @@ public:
     virtual JS::GCPtr<Painting::Paintable> create_paintable() const override;
 
     virtual void prepare_for_replaced_layout() override;
+
+private:
+    virtual bool is_svg_svg_box() const final { return true; }
 };
 
+template<>
+inline bool Node::fast_is<SVGSVGBox>() const { return is_svg_svg_box(); }
+
 }