fix(dom): serialize XML innerHTML by document mode

moli-renderer-v8/src/native_bridge/element/content.rs

@@ -833,10 +833,16 @@ fn node_inner_text(
 }
 
 fn node_inner_html(runtime: &JsContextHost, handle: DomHandle) -> Option<String> {
-    let scripting_enabled_for_node = |node| runtime.node_document_scripting_enabled(node);
-    runtime
-        .dom_host()
-        .get_html(handle, &scripting_enabled_for_node, false, &[])
+    let dom_host = runtime.dom_host();
+    if dom_host
+        .node_document_is_html_document(handle)
+        .unwrap_or(true)
+    {
+        let scripting_enabled_for_node = |node| runtime.node_document_scripting_enabled(node);
+        dom_host.get_html(handle, &scripting_enabled_for_node, false, &[])
+    } else {
+        crate::xml_serializer::serialize_native_inner_html(dom_host, handle)
+    }
 }
 
 fn is_element_or_shadow_root_receiver(runtime: &JsContextHost, handle: DomHandle) -> bool {

moli-renderer-v8/src/script_vm/tests/dom_xhr/shadow_dom.rs

@@ -3340,6 +3340,59 @@ fn set_html_unsafe_preserves_declarative_shadow_roots() {
         "function|1|true|true|2|input|span|1|em|true|2|true|false|true|true|true|slot|true"
     );
 }
+
+#[test]
+fn set_html_unsafe_in_xml_documents_uses_xml_fragment_serialization() {
+    let mut vm = new_storage_test_vm("https://set-html-unsafe-xml.test/");
+
+    let result = vm
+        .eval(
+            r#"
+(() => {
+  const markup = '<p><foo><b><i>test</b></i>';
+  const xml = document.implementation.createDocument(null, 'root', null);
+  xml.documentElement.setHTMLUnsafe(markup);
+
+  const svg = document.implementation.createDocument(
+    'http://www.w3.org/2000/svg',
+    'root',
+    null
+  );
+  svg.documentElement.setHTMLUnsafe(markup);
+
+  const liveSvg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
+  liveSvg.setHTMLUnsafe('<circle></circle>');
+
+  return [
+    xml.contentType,
+    xml.documentElement.innerHTML,
+    xml.documentElement.firstChild.namespaceURI,
+    svg.contentType,
+    svg.documentElement.innerHTML,
+    svg.documentElement.firstChild.namespaceURI,
+    liveSvg.innerHTML,
+    liveSvg.firstChild.namespaceURI
+  ].join('|');
+})()
+"#,
+        )
+        .expect("setHTMLUnsafe should serialize XML document fragments as XML");
+
+    assert_eq!(
+        result,
+        concat!(
+            "application/xml|",
+            "<p xmlns=\"http://www.w3.org/1999/xhtml\"><foo><b><i>test</i></b></foo></p>|",
+            "http://www.w3.org/1999/xhtml|",
+            "image/svg+xml|",
+            "<p xmlns=\"http://www.w3.org/1999/xhtml\"><foo><b><i>test</i></b></foo></p>|",
+            "http://www.w3.org/1999/xhtml|",
+            "<circle></circle>|",
+            "http://www.w3.org/2000/svg"
+        )
+    );
+}
+
 #[test]
 fn get_html_serializes_shadow_roots_when_requested() {
     let mut vm = new_storage_test_vm("https://shadow-get-html.test/");

moli-renderer-v8/src/xml_serializer.rs

@@ -109,6 +109,24 @@ pub(crate) fn serialize_native_handle(dom_host: &DomHost, handle: NativeNodeId)
     )
 }
 
+pub(crate) fn serialize_native_inner_html(
+    dom_host: &DomHost,
+    handle: NativeNodeId,
+) -> Option<String> {
+    let child_container = dom_host
+        .node(handle)?
+        .as_element()
+        .and_then(Element::template_contents)
+        .unwrap_or(handle);
+    let mut next_generated_prefix = 1;
+    Some(serialize_native_children(
+        dom_host,
+        child_container,
+        &NamespaceContext::default(),
+        &mut next_generated_prefix,
+    ))
+}
+
 fn serialize_native_node(
     dom_host: &DomHost,
     handle: NativeNodeId,