fix(dom): align insertAdjacentHTML sibling contexts

moli-renderer-v8/src/document_runtime/document_write.rs

@@ -36,6 +36,7 @@ enum DocumentWriteParserPumpInput<'a> {
 enum HtmlFragmentParserContextMode {
     Standard,
     RangeCreateContextualFragment,
+    SiblingInsertion,
 }
 
 struct DocumentWriteParserMutationOwner<'a, 'scope, 'pin> {
@@ -553,8 +554,11 @@ impl DocumentRuntime {
             .and_then(Node::local_name)
             .unwrap_or("body")
             .to_owned();
-        if context_mode == HtmlFragmentParserContextMode::RangeCreateContextualFragment
-            && context_namespace == "http://www.w3.org/1999/xhtml"
+        if matches!(
+            context_mode,
+            HtmlFragmentParserContextMode::RangeCreateContextualFragment
+                | HtmlFragmentParserContextMode::SiblingInsertion
+        ) && context_namespace == "http://www.w3.org/1999/xhtml"
             && context_local_name.eq_ignore_ascii_case("html")
         {
             context_local_name = "body".to_owned();
@@ -951,7 +955,13 @@ impl DocumentRuntime {
         html: &str,
         insert: impl FnOnce(&mut Self, &mut v8::PinScope<'_, '_>, *mut JsContextHost, DomHandle) -> bool,
     ) -> bool {
-        let Some(fragment) = self.build_fragment_from_html(
+        let scripting_enabled = unsafe { &*host_ptr }.document_scripting_enabled(document_handle);
+        let context_mode = if context_handle == target {
+            HtmlFragmentParserContextMode::Standard
+        } else {
+            HtmlFragmentParserContextMode::SiblingInsertion
+        };
+        let Some(fragment) = self.build_fragment_from_html_with_context_mode(
             scope,
             host_ptr,
             document_handle,
@@ -959,11 +969,13 @@ impl DocumentRuntime {
             html,
             true,
             HtmlFragmentCustomElementUpgradeTiming::AfterInsertion,
+            context_mode,
+            scripting_enabled,
+            false,
         ) else {
             return false;
         };
         let added_children = self.dom_host().child_handles(fragment).collect::<Vec<_>>();
-        let _ = target;
         let changed = insert(self, scope, host_ptr, fragment);
         if changed
             && !self.upgrade_inserted_html_fragment_custom_elements(

moli-renderer-v8/src/native_bridge/element/tree_mutation/callbacks.rs

@@ -297,15 +297,26 @@ pub(in crate::native_bridge) fn node_insert_adjacent_html_callback<'s>(
         position,
         InsertAdjacentPosition::BeforeBegin | InsertAdjacentPosition::AfterEnd
     );
-    if needs_parent
-        && unsafe { &*runtime_ptr }
+    if needs_parent {
+        let parent = unsafe { &*runtime_ptr }
             .dom_host()
             .node(target)
-            .and_then(Node::parent_node)
-            .is_none()
-    {
-        rv.set_undefined();
-        return;
+            .and_then(Node::parent_node);
+        let has_no_modifiable_parent = parent.is_none_or(|parent| {
+            unsafe { &*runtime_ptr }
+                .dom_host()
+                .node(parent)
+                .is_none_or(Node::is_document)
+        });
+        if has_no_modifiable_parent {
+            throw_dom_exception(
+                scope,
+                "NoModificationAllowedError",
+                7,
+                "The element has no modifiable parent for sibling insertion.",
+            );
+            return;
+        }
     }
     let Some(document_handle) =
         insert_adjacent_document_handle(unsafe { &*runtime_ptr }, target, position)

moli-renderer-v8/src/script_vm/tests/dom_xhr/dom/tree_mutations.rs

@@ -419,6 +419,82 @@ fn element_insert_adjacent_methods_parse_webidl_arguments() {
     );
 }
 
+#[test]
+fn insert_adjacent_html_enforces_sibling_context_rules() {
+    let mut vm = new_storage_test_vm("https://insert-adjacent-sibling-context.test/");
+
+    let result = vm
+        .eval(
+            r#"
+(() => {
+  const probe = callback => {
+    try {
+      callback();
+      return 'missing';
+    } catch (error) {
+      return `${error.name}:${error.code}`;
+    }
+  };
+  const sources = ['', 'text', '<!--comment-->', '<div></div>'];
+  const positions = ['beforebegin', 'afterend'];
+  const detached = document.createElement('div');
+  const root = document.documentElement ||
+    document.appendChild(document.createElement('html'));
+  const detachedErrors = positions.flatMap(position =>
+    sources.map(source => probe(() => detached.insertAdjacentHTML(position, source)))
+  );
+  const documentErrors = positions.flatMap(position =>
+    sources.map(source => probe(() => root.insertAdjacentHTML(position, source)))
+  );
+
+  while (root.firstChild) {
+    root.removeChild(root.firstChild);
+  }
+  root.insertAdjacentHTML(
+    'afterbegin',
+    '<head id="inside-head"></head><body id="inside-body"></body>'
+  );
+  const preservedInnerHtmlContext =
+    document.head?.id === 'inside-head' &&
+    document.body?.id === 'inside-body' &&
+    root.firstChild === document.head &&
+    root.lastChild === document.body;
+  const head = document.head ||
+    root.insertBefore(document.createElement('head'), root.firstChild);
+  const body = document.body || root.appendChild(document.createElement('body'));
+  head.insertAdjacentHTML('beforebegin', '<p id="before-head"></p>');
+  body.insertAdjacentHTML('afterend', '<p id="after-body"></p>');
+  const beforeHead = document.getElementById('before-head');
+  const afterBody = document.getElementById('after-body');
+
+  return JSON.stringify({
+    detachedErrors,
+    documentErrors,
+    preservedInnerHtmlContext,
+    counts: [
+      document.getElementsByTagName('html').length,
+      document.getElementsByTagName('head').length,
+      document.getElementsByTagName('body').length
+    ],
+    placement: [
+      beforeHead.nextSibling === head,
+      body.nextSibling === afterBody,
+      beforeHead.parentNode === root,
+      afterBody.parentNode === root
+    ]
+  });
+})()
+"#,
+        )
+        .expect("insertAdjacentHTML sibling context rules should evaluate");
+
+    assert_eq!(
+        result,
+        r#"{"detachedErrors":["NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7"],"documentErrors":["NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7","NoModificationAllowedError:7"],"preservedInnerHtmlContext":true,"counts":[1,1,1],"placement":[true,true,true,true]}"#
+    );
+}
+
+
 #[test]
 fn document_fragment_and_shadow_root_get_element_by_id_match_browser_lookup_boundaries() {
     let mut vm = new_storage_test_vm("https://fragment-shadow-get-by-id.test/");