fix(js): parse fragments in their insertion context

crates/obscura-js/src/ops.rs

@@ -391,7 +391,16 @@ fn op_dom_inner(state: &OpState, cmd: String, arg1: String, arg2: String) -> Str
                 dom.detach(child);
             }
             if !arg2.is_empty() {
-                let fragment = obscura_dom::parse_fragment(&arg2);
+                let context_name = dom
+                    .with_node(target, |node| match &node.data {
+                        NodeData::Element { name, .. } => Some(name.clone()),
+                        _ => None,
+                    })
+                    .flatten();
+                let fragment = match context_name {
+                    Some(name) => obscura_dom::parse_fragment_with_context(&arg2, name),
+                    None => obscura_dom::parse_fragment(&arg2),
+                };
                 let import_root = fragment.find_body_or_root();
                 dom.import_children_from(target, &fragment, import_root);
             }

crates/obscura-js/src/runtime.rs

@@ -1346,6 +1346,32 @@ mod tests {
         assert_eq!(out, serde_json::json!("SyntaxError"));
     }
 
+    #[test]
+    fn insert_adjacent_html_keeps_leading_comments_in_table_contexts() {
+        let mut rt = setup_runtime(
+            r#"<html><body><table><tbody id="tb"><tr id="row"></tr></tbody></table></body></html>"#,
+        );
+        let out = rt
+            .evaluate(
+                "(function(){var tb=document.getElementById('tb');tb.insertAdjacentHTML('beforeend','<!--m--><tr><td>v</td></tr>');var row=document.getElementById('row');row.insertAdjacentHTML('beforeend','<!--n--><td>x</td>');return Array.from(tb.childNodes).map(function(n){return n.nodeName}).join('|')+';'+Array.from(row.childNodes).map(function(n){return n.nodeName}).join('|');})()",
+            )
+            .unwrap();
+        assert_eq!(out, serde_json::json!("TR|#comment|TR;#comment|TD"));
+    }
+
+    #[test]
+    fn insert_adjacent_html_uses_the_insertion_element_as_context() {
+        let mut rt = setup_runtime(
+            r#"<html><body><div id="d"></div><table id="table"><tbody id="tb"></tbody></table></body></html>"#,
+        );
+        let out = rt
+            .evaluate(
+                "(function(){var d=document.getElementById('d');d.insertAdjacentHTML('beforeend','<tr><td>v</td></tr>');var table=document.getElementById('table');table.insertAdjacentHTML('beforeend','<tr><td>x</td></tr>');var tb=document.getElementById('tb');tb.insertAdjacentHTML('beforeend','<tr><td>y</td></tr>tail');return d.firstChild.nodeName+':'+d.textContent+';'+table.lastElementChild.tagName+';'+Array.from(tb.childNodes).map(function(n){return n.nodeName+(n.data?':'+n.data:'')}).join('|');})()",
+            )
+            .unwrap();
+        assert_eq!(out, serde_json::json!("#text:v;TBODY;TR|#text:tail"));
+    }
+
     #[test]
     fn test_document_title() {
         let mut rt = setup_runtime("<html><head><title>Test</title></head><body></body></html>");