buku: improve bukuserver tests

Closes #72512.

Signed-off-by: Sean Molenaar <1484494+SMillerDev@users.noreply.github.com>
Signed-off-by: Rylan Polster <rslpolster@gmail.com>

Formula/buku.rb

@@ -278,5 +278,15 @@ class Buku < Formula
     # Test bukuserver
     result = shell_output("#{bin}/bukuserver --version")
     assert_match version.to_s, result
+
+    port = free_port
+    fork do
+      exec "#{bin}/bukuserver run --host 127.0.0.1 --port #{port} 2>&1 >/dev/null"
+    end
+    sleep 5
+
+    result = shell_output("curl -s 127.0.0.1:#{port}/api/bookmarks")
+    assert_match "https://github.com/Homebrew/brew", result
+    assert_match "The missing package manager for macOS", result
   end
 end