Test that todosettings panel opens

todolist/fxui/src/main/resources/todolist/ui/TodoSettings.fxml

@@ -9,7 +9,7 @@
 <?import javafx.scene.control.ChoiceBox?>
 <?import javafx.collections.FXCollections?>
 
-<VBox xmlns:fx="http://javafx.com/fxml" fx:controller="todolist.ui.TodoSettingsController">
+<VBox fx:id="todoSettingsRoot" xmlns:fx="http://javafx.com/fxml" fx:controller="todolist.ui.TodoSettingsController">
     <Label text="Settings"/>
     <GridPane alignment="center" hgap="10" vgap="10">
         <!-- <padding><Insets top="25" right="25" bottom="25" left="25"/></padding> -->

todolist/fxui/src/test/java/todolist/ui/TodoAppTest.java

@@ -4,6 +4,7 @@ import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
+import javafx.stage.Window;
 import todolist.json.TodoPersistence;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.fail;
@@ -15,6 +16,7 @@ import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.testfx.framework.junit5.ApplicationTest;
+import org.testfx.util.WaitForAsyncUtils;
 
 public class TodoAppTest extends ApplicationTest {
 
@@ -55,4 +57,23 @@ public class TodoAppTest extends ApplicationTest {
   public void testSelectedTodoList_initial() {
     assertNotNull(this.controller.getSelectedTodoList());
   }
+
+  @Test
+  public void testTodoSettings() {
+    clickOn("#todoSettingsButton");
+    WaitForAsyncUtils.waitForFxEvents();
+    assertNotNull(findSceneRootWithId("todoSettingsRoot"));
+  }
+
+  private Parent findSceneRootWithId(String id) {
+    for (Window window : Window.getWindows()) {
+      if (window instanceof Stage && window.isShowing()) {
+        var root = window.getScene().getRoot();
+        if (id.equals(root.getId())) {
+          return root;
+        }
+      }
+    }
+    return null;
+  }
 }

todolist/fxui/src/test/resources/todolist/ui/TodoModel_test.fxml

@@ -3,10 +3,12 @@
 <?import javafx.scene.layout.VBox?>
 <?import javafx.scene.layout.HBox?>
 <?import javafx.scene.control.ComboBox?>
+<?import javafx.scene.control.Button?>
 
 <VBox xmlns:fx="http://javafx.com/fxml/1" fx:controller="todolist.ui.TodoModelController">
     <HBox>
         <ComboBox fx:id="todoListsView"/>
+        <Button fx:id="todoSettingsButton" onAction="#handleSettingsAction"/>
     </HBox>
     <fx:include fx:id="todoListView" source="TodoList_test.fxml"/>
 </VBox>