feat: implement ShadowRoot::setHTMLUnsafe (#36240)

Implements #36166

---------

Signed-off-by: TG <ebiritg@gmail.com>

components/script/dom/element.rs

@@ -3025,28 +3025,8 @@ impl ElementMethods<crate::DomTypeHolder> for Element {
             DomRoot::from_ref(self.upcast())
         };
 
-        // Step 3. Unsafely set HTML given target, this, and compliantHTML.
-        // Let newChildren be the result of the HTML fragment parsing algorithm.
-        let new_children = ServoParser::parse_html_fragment(self, html, true, can_gc);
-
-        let context_document = {
-            if let Some(template) = self.downcast::<HTMLTemplateElement>() {
-                template.Content(can_gc).upcast::<Node>().owner_doc()
-            } else {
-                self.owner_document()
-            }
-        };
-
-        // Let fragment be a new DocumentFragment whose node document is contextElement's node document.
-        let frag = DocumentFragment::new(&context_document, can_gc);
-
-        // For each node in newChildren, append node to fragment.
-        for child in new_children {
-            frag.upcast::<Node>().AppendChild(&child, can_gc).unwrap();
-        }
-
-        // Replace all with fragment within target.
-        Node::replace_all(Some(frag.upcast()), &target, can_gc);
+        // Step 3. Unsafely set HTML given target, this, and compliantHTML
+        Node::unsafely_set_html(&target, self, html, can_gc);
     }
 
     /// <https://html.spec.whatwg.org/multipage/#dom-element-gethtml>

components/script/dom/node.rs

@@ -110,7 +110,7 @@ use crate::dom::pointerevent::{PointerEvent, PointerId};
 use crate::dom::processinginstruction::ProcessingInstruction;
 use crate::dom::range::WeakRangeVec;
 use crate::dom::raredata::NodeRareData;
-use crate::dom::servoparser::serialize_html_fragment;
+use crate::dom::servoparser::{ServoParser, serialize_html_fragment};
 use crate::dom::shadowroot::{IsUserAgentWidget, LayoutShadowRootHelpers, ShadowRoot};
 use crate::dom::stylesheetlist::StyleSheetListOwner;
 use crate::dom::svgsvgelement::{LayoutSVGSVGElementHelpers, SVGSVGElement};
@@ -316,6 +316,34 @@ impl Node {
         }
     }
 
+    /// Implements the "unsafely set HTML" algorithm as specified in:
+    /// <https://html.spec.whatwg.org/multipage/#concept-unsafely-set-html>
+    pub fn unsafely_set_html(
+        target: &Node,
+        context_element: &Element,
+        html: DOMString,
+        can_gc: CanGc,
+    ) {
+        // Step 1. Let newChildren be the result of the HTML fragment parsing algorithm.
+        let new_children = ServoParser::parse_html_fragment(context_element, html, true, can_gc);
+
+        // Step 2. Let fragment be a new DocumentFragment whose node document is contextElement's node document.
+
+        let context_document = context_element.owner_document();
+        let fragment = DocumentFragment::new(&context_document, can_gc);
+
+        // Step 3. For each node in newChildren, append node to fragment.
+        for child in new_children {
+            fragment
+                .upcast::<Node>()
+                .AppendChild(&child, can_gc)
+                .unwrap();
+        }
+
+        // Step 4. Replace all with fragment within target.
+        Node::replace_all(Some(fragment.upcast()), target, can_gc);
+    }
+
     pub(crate) fn clean_up_style_and_layout_data(&self) {
         self.owner_doc().cancel_animations_for_node(self);
         self.style_data.borrow_mut().take();

components/script/dom/shadowroot.rs

@@ -453,6 +453,15 @@ impl ShadowRootMethods<crate::DomTypeHolder> for ShadowRoot {
         self.slot_assignment_mode
     }
 
+    /// <https://html.spec.whatwg.org/multipage/#dom-shadowroot-sethtmlunsafe>
+    fn SetHTMLUnsafe(&self, html: DOMString, can_gc: CanGc) {
+        // Step 2. Unsafely set HTMl given this, this's shadow host, and complaintHTML
+        let target = self.upcast::<Node>();
+        let context_element = self.Host();
+
+        Node::unsafely_set_html(target, &context_element, html, can_gc);
+    }
+
     // https://dom.spec.whatwg.org/#dom-shadowroot-onslotchange
     event_handler!(onslotchange, GetOnslotchange, SetOnslotchange);
 }