Add playground action regression coverage

Author: a-baran-orhan

playground/test/playground-actions.test.ts

@@ -0,0 +1,32 @@
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+import { describe, expect, it } from "vitest";
+
+const root = resolve(import.meta.dirname, "../..");
+const playground = readFileSync(resolve(root, "playground/play.html"), "utf8");
+const main = readFileSync(resolve(root, "playground/src/main.ts"), "utf8");
+
+describe("playground header actions", () => {
+  it("keeps both motion formats behind one Export menu", () => {
+    expect(playground).toContain('id="export-menu-button"');
+    expect(playground).toContain('aria-haspopup="menu"');
+    expect(playground).toContain('id="export-menu"');
+    expect(playground).toContain('id="download-bvh"');
+    expect(playground).toContain('id="download-gltf"');
+    expect(playground.match(/>Download BVH</g)).toBeNull();
+    expect(playground.match(/>Download glTF</g)).toBeNull();
+  });
+
+  it("links the GitHub action to the repository instead of issue creation", () => {
+    expect(playground).toContain('href="https://github.com/posecode-dev/posecode"');
+    expect(playground).not.toContain("posecode-dev/posecode/issues/new");
+    expect(playground).toContain("Open the Posecode repository on GitHub");
+  });
+
+  it("supports dismissal and keyboard navigation for the export menu", () => {
+    expect(main).toContain("function setExportMenu(open: boolean)");
+    expect(main).toContain('event.key === "ArrowDown"');
+    expect(main).toContain('event.key === "ArrowUp"');
+    expect(main).toContain('e.key === "Escape"');
+  });
+});