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();
+});

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

@@ -305,3 +305,69 @@ test("didClose drops the region cache so a reopened document at the same version
   process.kill();
   await process.exited;
 });
+
+test("advertises and serves folding ranges and linked editing ranges over the wire", async () => {
+  const process = Bun.spawn(
+    ["bun", "run", fileURLToPath(new URL("../src/server.ts", import.meta.url))],
+    { stdin: "pipe", stdout: "pipe", stderr: "pipe" },
+  );
+  const uri = "file:///fold.wrn";
+  const text = `page A {
+  view {
+    <div>x</div>
+  }
+}
+`;
+  const reader = process.stdout.getReader();
+  let output = "";
+  async function readUntil(marker: string): Promise<void> {
+    while (!output.includes(marker)) {
+      const chunk = await reader.read();
+      if (chunk.done) break;
+      output += new TextDecoder().decode(chunk.value);
+    }
+  }
+
+  process.stdin.write(packet({ jsonrpc: "2.0", id: 1, method: "initialize", params: {} }));
+  await process.stdin.flush();
+  await readUntil('"id":1');
+  const initReply = output.slice(output.indexOf('"id":1'));
+  expect(initReply).toContain('"foldingRangeProvider":true');
+  expect(initReply).toContain('"linkedEditingRangeProvider":true');
+
+  process.stdin.write(
+    packet({
+      jsonrpc: "2.0",
+      method: "textDocument/didOpen",
+      params: { textDocument: { uri, version: 1, text } },
+    }),
+  );
+  process.stdin.write(
+    packet({
+      jsonrpc: "2.0",
+      id: 2,
+      method: "textDocument/foldingRange",
+      params: { textDocument: { uri } },
+    }),
+  );
+  await process.stdin.flush();
+  await readUntil('"id":2');
+  const foldReply = output.slice(output.indexOf('"id":2'));
+  expect(foldReply).toContain('"result":[');
+
+  process.stdin.write(
+    packet({
+      jsonrpc: "2.0",
+      id: 3,
+      method: "textDocument/linkedEditingRange",
+      params: { textDocument: { uri }, position: { line: 2, character: 6 } },
+    }),
+  );
+  await process.stdin.flush();
+  await readUntil('"id":3');
+  const linkedReply = output.slice(output.indexOf('"id":3'));
+  expect(linkedReply).toContain('"ranges"');
+
+  process.kill();
+  await process.exited;
+});