feat(language-server): add tag folding and linked editing

packages/language-server/test/html-service.test.ts

@@ -3,6 +3,7 @@ import {
   htmlCompletions,
   htmlFoldingRanges,
   htmlHover,
+  htmlLinkedEditingRanges,
   htmlTagComplete,
 } from "../src/html-service.ts";
 
@@ -172,3 +173,25 @@ test("merging ranks WRNexus entries above HTML and drops exact collisions", () =
   const sorted = [...merged].sort((a, b) => (a.sortText ?? "").localeCompare(b.sortText ?? ""));
   expect(sorted[0]!.label).toBe("Card");
 });
+
+test("linked editing returns both the opening and closing tag names", () => {
+  const text = `page A {
+  view {
+    <div>x</div>
+  }
+}
+`;
+  const ranges = htmlLinkedEditingRanges(doc(text), positionOf(text, "<di"));
+  expect(ranges).not.toBeNull();
+  expect(ranges).toHaveLength(2);
+});
+
+test("linked editing returns null outside a view block", () => {
+  const text = `page A {
+  functions {
+    function go() { }
+  }
+}
+`;
+  expect(htmlLinkedEditingRanges(doc(text), positionOf(text, "func"))).toBeNull();
+});