tvbrowser: add simple test

This test starts tvbrowser with an Xvfb X server
and verifies that all expected windows are created.

pkgs/applications/misc/tvbrowser/default.nix

@@ -6,6 +6,7 @@
 , ant
 , jdk
 , makeWrapper
+, callPackage
 }:
 
 let
@@ -72,6 +73,8 @@ stdenv.mkDerivation rec {
     runHook postInstall
   '';
 
+  passthru.tests.startwindow = callPackage ./test.nix {};
+
   meta = with lib; {
     description = "Electronic TV Program Guide";
     homepage = "https://www.tvbrowser.org/";

pkgs/applications/misc/tvbrowser/test.nix

@@ -0,0 +1,40 @@
+{ lib
+, xvfb-run
+, tvbrowser
+, runCommand
+, writeShellApplication
+, xorg
+}:
+
+let
+  testScript = writeShellApplication {
+    name = "tvbrowser-test-script";
+    runtimeInputs = [ xorg.xwininfo tvbrowser ];
+    text = ''
+      function find_tvbrowser_windows {
+          for window_name in java tvbrowser-TVBrowser 'Setup assistant' ; do
+              grep -q "$window_name" "$1"  ||  return 1
+          done
+      }
+      tvbrowser &
+      for _ in {0..900} ; do
+          xwininfo -root -tree  \
+              | sed 's/.*0x[0-9a-f]* \"\([^\"]*\)\".*/\1/; t; d'  \
+              | tee window-names
+          echo
+          if find_tvbrowser_windows window-names ; then
+              break
+          fi
+          sleep 1
+      done
+      find_tvbrowser_windows window-names
+    '';
+  };
+in
+runCommand
+"tvbrowser-test"
+{ buildInputs = [ xvfb-run ]; }
+''
+  HOME=$PWD xvfb-run ${lib.getExe testScript}
+  touch ${placeholder "out"}
+''