test(focus-announcer): cover empty and clipped render behavior (#311)

* test(focus-announcer): cover empty and clipped render behavior

* test(focus-announcer): address review feedback

Author: RtlZeroMemory

docs/widgets/focus-announcer.md

@@ -26,6 +26,8 @@ ui.focusAnnouncer({
 - Uses semantic labels when provided via `accessibleLabel`.
 - Includes `field` metadata in announcements (for example required/error context).
 - Renders `emptyText` when focus is `null`.
+- Renders nothing when both the computed announcement and `emptyText` are empty.
+- Draws a single line and clips long announcements to the available width with ellipsis.
 
 ## Example
 

packages/core/src/widgets/__tests__/basicWidgets.render.test.ts

@@ -3,7 +3,12 @@ import {
   parseDrawTextCommands as parseDecodedDrawTextCommands,
   parseInternedStrings,
 } from "../../__tests__/drawlistDecode.js";
-import { type DrawlistBuilder, type VNode, createDrawlistBuilder } from "../../index.js";
+import {
+  type DrawlistBuilder,
+  type VNode,
+  createDrawlistBuilder,
+  truncateWithEllipsis,
+} from "../../index.js";
 import { layout } from "../../layout/layout.js";
 import { renderToDrawlist } from "../../renderer/renderToDrawlist.js";
 import { commitVNodeTree } from "../../runtime/commit.js";
@@ -242,6 +247,33 @@ describe("basic widgets render to drawlist", () => {
     assert.equal(fallback.includes("No focus"), true);
   });
 
+  test("focusAnnouncer renders nothing when both announcement and fallback are empty", () => {
+    const commands = parseDrawTextCommands(
+      renderBytes(ui.focusAnnouncer(), { cols: 40, rows: 4 }, {}),
+    );
+    assert.equal(commands.length, 0);
+  });
+
+  test("focusAnnouncer clips long text to the available width", () => {
+    const announcement = "Email input ready";
+    const clippedAnnouncement = parseDrawTextCommands(
+      renderBytes(ui.focusAnnouncer(), { cols: 8, rows: 2 }, { focusAnnouncement: announcement }),
+    );
+    assert.deepEqual(
+      clippedAnnouncement.map((command) => command.text),
+      [truncateWithEllipsis(announcement, 8)],
+    );
+
+    const fallback = "No focus selected";
+    const clippedFallback = parseDrawTextCommands(
+      renderBytes(ui.focusAnnouncer({ emptyText: fallback }), { cols: 7, rows: 2 }, {}),
+    );
+    assert.deepEqual(
+      clippedFallback.map((command) => command.text),
+      [truncateWithEllipsis(fallback, 7)],
+    );
+  });
+
   test("input renders placeholder text when value is empty", () => {
     const strings = parseInternedStrings(
       renderBytes(