test: add coverage for list_pages after selected page is closed

Adds a test that verifies list_pages works correctly when the
currently selected page has been closed externally. This exercises
the definePageTool → defineTool change that removes the page-scoped
requirement from list_pages.

Ref #1138

Author: atian8179

tests/tools/pages.test.ts

@@ -53,6 +53,24 @@ describe('pages', () => {
         assert.ok(response.includePages);
       });
     });
+    it('list pages after selected page is closed', async () => {
+      await withMcpContext(async (response, context) => {
+        // Create a second page and select it.
+        const page2 = await context.newPage();
+        assert.strictEqual(context.getSelectedMcpPage(), page2);
+
+        // Close the selected page via puppeteer (simulating external close).
+        await page2.pptrPage.close();
+
+        // list_pages should still work even though the selected page is gone.
+        await listPages().handler(
+          {params: {}},
+          response,
+          context,
+        );
+        assert.ok(response.includePages);
+      });
+    });
     it(`list pages for extension pages with --category-extensions`, async t => {
       await withMcpContext(
         async (response, context) => {