Merge branch 'add-test-templates' into 'master'

Add test templates

See merge request oysteikt/h20-tdt4100-project!5

.gitlab-ci.yml

@@ -3,15 +3,33 @@
 # and
 # https://gitlab.stud.idi.ntnu.no/tdt4140-staff/examples/-/blob/master/.gitlab-ci.yml
 
-image: maven:3.6.3-openjdk-15
+image: maven:3-openjdk-15-slim
 
 variables:
+
   # This will suppress any download for dependencies and plugins or upload messages which would clutter the console log.
   # `showDateTime` will show the passed time in milliseconds. You need to specify `--batch-mode` to make this work.
-  MAVEN_OPTS: "-Dhttps.protocols=TLSv1.2 -Dmaven.repo.local=$CI_PROJECT_DIR/.m2/repository -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true"
+  MAVEN_OPTS: " \
+    -Dhttps.protocols=TLSv1.2 \
+    -Dmaven.repo.local=$CI_PROJECT_DIR/.m2/repository \
+    -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN \
+    -Dorg.slf4j.simpleLogger.showDateTime=true \
+    -Djava.awt.headless=true"
+
   # As of Maven 3.3.0 instead of this you may define these options in `.mvn/maven.config` so the same config is used
   # when running from the command line.
-  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-at-end --show-version"
+  MAVEN_CLI_OPTS: " \
+  --batch-mode \
+  --errors \
+  --fail-at-end \
+  --show-version \
+  -Dprism.verbose=true \
+  -Dtestfx.robot=glass \
+  -Dtestfx.headless=true \
+  -Dglass.platform=Monocle \
+  -Dprism.order=sw \
+  -Dprism.text=t2k \
+  -Dtestfx.setup.timeout=60000"
 
 # Cache downloaded dependencies and plugins between builds.
 # To keep cache across branches add 'key: "$CI_JOB_NAME"'
@@ -38,6 +56,8 @@ unittest:
   stage: test
   needs: [build]
   script:
+    - "apt update"
+    - "apt install -y openjfx"
     - "mvn package $MAVEN_CLI_OPTS"
   artifacts:
     paths:
@@ -46,12 +66,15 @@ unittest:
     reports:
       junit:
         - target/surefire-reports/TEST-*.xml
-        - target/failsafe-reports/TEST-*.xml
+        # TODO: Separate unit tests and integration tests
+        # - target/failsafe-reports/TEST-*.xml
 
 generate-coverage:
   stage: docs
   script:
-    - 'mvn clean jacoco:prepare-agent test jacoco:report'
+    - "apt update"
+    - "apt install -y openjfx"
+    - 'mvn clean jacoco:prepare-agent test $MAVEN_CLI_OPTS jacoco:report'
     - 'cat target/site/jacoco/index.html'
   coverage: '/Total.*?([0-9]{1,3})%/'
   artifacts:

pom.xml

@@ -42,7 +42,6 @@
       <version>3.2.0-01</version>
     </dependency>
 
-
     <!-- JUnit 5 -->
     <dependency>
         <groupId>org.junit.jupiter</groupId>
@@ -65,6 +64,36 @@
       <scope>test</scope>
     </dependency>
 
+    <!-- Hamcrest - Matchers to help testing the JavaFX UI -->
+    <dependency>
+      <groupId>org.hamcrest</groupId>
+      <artifactId>hamcrest</artifactId>
+      <version>2.1</version>
+      <scope>test</scope>
+    </dependency>
+
+    <!-- Monocle - Headless UI testing in CI -->
+    <dependency>
+      <groupId>org.testfx</groupId>
+      <artifactId>openjfx-monocle</artifactId>
+      <version>jdk-12.0.1+2</version>
+      <scope>test</scope>
+    </dependency>
+
+    <!-- Mockito - Mocking Library for performing isolated unit tests -->
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-inline</artifactId>
+      <version>3.8.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <version>2.23.0</version>
+      <scope>test</scope>
+    </dependency>
+
     <!-- JavaDoc -->
     <dependency>
       <groupId>org.apache.maven.plugins</groupId>
@@ -133,7 +162,6 @@
         </executions>
       </plugin>
 
-
     </plugins>
   </build>
 </project>

src/main/java/app/Main.java

@@ -35,6 +35,7 @@ public class Main extends Application {
    */
   private void setupWindow(Stage window) {
     window.setTitle(TITLE);
+    if (window.getIcons().isEmpty())
       window.getIcons().add(new Image(getClass().getResourceAsStream(ICON_PATH)));
   }
 
@@ -53,6 +54,7 @@ public class Main extends Application {
    */
   private void createScene() {
     this.scene = new Scene(fxmlRoot);
+    this.scene.setUserData(this.fxmlLoader);
     Model.setScene(scene);
   }
 

src/main/java/app/MainController.java

@@ -66,6 +66,16 @@ public class MainController implements Initializable {
     return hostServices;
   }
 
+  //TODO: Document
+  public List<Controller> getInnerControllers() {
+    return List.of(
+      editorController,
+      filetreeController,
+      modelineController,
+      menubarController
+    );
+  }
+
   /**
    * Set a reference to the global Host Services API
    * 

src/main/java/app/controllers/EditorController.java

@@ -66,6 +66,11 @@ public class EditorController implements Initializable, Controller, FileManageme
     this.eventBus.register(this);
   }
 
+  // TODO: document
+  public CodeArea getEditor() {
+    return editor;
+  }
+
   /**
    * Applies highlighting to the editor.
    * 
@@ -146,21 +151,20 @@ public class EditorController implements Initializable, Controller, FileManageme
    * @throws FileNotFoundException
    */
   public void setEditorContent(String filePath) {
-    if (filePath == null) {
-      editor.clear();
-      editor.appendText("// New File");
-      return;
-    }
+    // if (filePath == null) {
+    //   editor.clear();
+    //   editor.appendText("// New File");
+    //   return;
+    // }
     try (Scanner sc = new Scanner(new File(filePath))) {
-      if (filePath.endsWith(".java") || filePath.endsWith(".md")) {
+      // if (filePath.endsWith(".java") || filePath.endsWith(".md")) {
         editor.clear();
         while (sc.hasNextLine()) {
-          editor.appendText(sc.nextLine());
-          editor.appendText("\n");
-        }
-      } else {
-        throw new FileNotFoundException();
+          editor.appendText(sc.nextLine() + "\n");
         }
+      // } else {
+      //   throw new FileNotFoundException();
+      // }
 
     } catch (FileNotFoundException ex) {
       Alert error = new Alert(AlertType.ERROR);
@@ -208,7 +212,7 @@ public class EditorController implements Initializable, Controller, FileManageme
    * Updates Code Area (read from file) whenever the FileSelected is changed
    */
   @Subscribe
-  private void handle(FileSelectedEvent event) {
+  public void handle(FileSelectedEvent event) {
       this.setEditorContent(event.getPath());
   }
 
@@ -226,7 +230,7 @@ public class EditorController implements Initializable, Controller, FileManageme
   }
 
   @Subscribe
-  private void handle(ToggleCommentEvent event) {
+  public void handle(ToggleCommentEvent event) {
     this.toggleComment();
   }
 

src/main/java/app/controllers/FiletreeController.java

@@ -9,6 +9,7 @@ import javafx.scene.image.ImageView;
 import javafx.scene.input.MouseEvent;
 
 import java.io.File;
+import java.io.IOException;
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -124,12 +125,26 @@ public class FiletreeController implements Initializable, Controller {
     String name = file.getName();
     String ext = (name.substring(file.getName().lastIndexOf(".") + 1, file.getName().length()));
 
-    if ("java".equals(ext))
-      createExtension(name, java, parent);
-    else if ("md".equals(ext))
-      createExtension(name, md, parent);
-    else
-      createExtension(name, placeholder, parent);
+    try {
+      createExtension(name, getIconForFile(file), parent);
+    } catch (Exception e) {
+      System.err.println("ICON NOT FOUND: " + file.getPath());
+    }
+
+    // if ("java".equals(ext))
+    //   createExtension(name, java, parent);
+    // else if ("md".equals(ext))
+    //   createExtension(name, md, parent);
+    // else
+    //   createExtension(name, placeholder, parent);
+  }
+
+  private Image getIconForFile(File file) throws IOException {
+    String mimeType = Files.probeContentType(file.toPath()).replace('/', '-');
+    String iconPath = (mimeType != null)
+      ? "/graphics/filetreeicons/" + mimeType + ".png"
+      : "/graphics/filetreeicons/file.png";
+    return new Image(getClass().getResourceAsStream(iconPath));
   }
 
   private void createExtension(String name, Image image, CheckBoxTreeItem<String> parent) {

src/main/java/app/events/Event.java

@@ -3,4 +3,4 @@ package app.events;
 /**
  * Base class for any type of event of the eventbus
  */
-abstract class Event {}
+public abstract class Event {}

src/main/java/app/service/LanguageOperations.java

@@ -13,7 +13,7 @@ import app.model.ProgrammingLanguage;
  * Common static operations that can be executed on any class
  * that implements {@link app.model.ProgrammingLanguage ProgrammingLanguage}
  */
-public class LanguageOperations {
+public final class LanguageOperations {
   
   /**
    * Use a matcher to find the styleclass of the next match

src/main/resources/fxml/Main.fxml

@@ -10,7 +10,8 @@
   prefHeight="400"
   xmlns="http://javafx.com/javafx/8.0.65"
   xmlns:fx="http://javafx.com/fxml/1"
-  fx:controller="app.MainController">
+  fx:controller="app.MainController"
+  fx:id="root">
 
   <top>
     <!-- Menubar -->

src/test/java/app/FxTestTemplate.java

@@ -0,0 +1,44 @@
+package app;
+
+import javafx.scene.Node;
+import javafx.stage.Stage;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.testfx.api.FxToolkit;
+import org.testfx.framework.junit5.ApplicationTest;
+import org.testfx.util.WaitForAsyncUtils;
+
+import java.util.concurrent.TimeoutException;
+
+public class FxTestTemplate extends ApplicationTest {
+
+  private Stage stage;
+
+  @BeforeEach
+  public void runAppToTests() throws Exception {
+    FxToolkit.registerPrimaryStage();
+    FxToolkit.setupApplication(Main::new);
+    FxToolkit.showStage();
+    WaitForAsyncUtils.waitForFxEvents(100);
+  }
+
+  @AfterEach
+  public void stopApp() throws TimeoutException {
+    FxToolkit.cleanupStages();
+  }
+
+  @Override
+  public void start(Stage primaryStage){
+    this.stage = primaryStage;
+    primaryStage.toFront();
+  }
+
+  public Stage getStage() {
+    return stage;
+  }
+
+  public <T extends Node> T find(final String query) {
+    /** TestFX provides many operations to retrieve elements from the loaded GUI. */
+    return lookup(query).query();
+  }
+}

src/test/java/app/MainTest.java

@@ -1,16 +1,74 @@
 package app;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.io.IOException;
 
-import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.Test;
+import org.junit.platform.commons.annotation.Testable;
 
-public class MainTest {
+import app.controllers.*;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import javafx.scene.layout.BorderPane;
+
+import app.testing.FxTestTemplate;
+
+
+@Testable
+public class MainTest extends FxTestTemplate {
 
     @Test
-  @DisplayName("Temp Test")
-  public void tempTest() {
-    assertEquals(1, 1);
+    @DisplayName("Check that the stage title is correct")
+    public void should_have_stage_title() {
+      assertEquals("Banana Editor", this.getStage().getTitle());
     }
 
+    @Test
+    @Order(1)
+    @DisplayName("Check that the stage has an icon")
+    public void should_have_stage_icon() {
+      assertEquals(1, this.getStage().getIcons().size());
+    }
+
+
+    @Test
+    @Order(2)
+    @DisplayName("Check that the root element is present")
+    public void should_have_root() {
+      BorderPane app = (BorderPane) find("#root");
+      assertNotNull(app);
+    }
+
+    @Test
+    @Order(3)
+    @DisplayName("Check that all subcontrollers are present")
+    public void should_have_subcontrollers() {
+      this
+        .getMainController()
+        .getInnerControllers()
+        .forEach((Controller controller) -> assertNotNull(controller));
+    }
+
+    @Test
+    @DisplayName("Check that the scene is correct")
+    public void should_have_scene() throws IOException {
+      assertNotNull(this.getStage().getScene());
+    }
+
+    @Test
+    @DisplayName("Check that the CSS is set")
+    public void should_have_css() {
+      List<String> expectedCSS = 
+        List.of("/styling/themes/monokai.css", "/styling/languages/java.css")
+          .stream()
+          .map(p -> getClass().getResource(p).toExternalForm())
+          .collect(Collectors.toList());
+      assertEquals(expectedCSS, this.getStage().getScene().getStylesheets());
+    }
 }

src/test/java/app/controllers/EditorControllerTest.java

@@ -0,0 +1,238 @@
+package app.controllers;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.fxmisc.richtext.CodeArea;
+import org.fxmisc.richtext.model.StyleSpans;
+
+import com.google.common.eventbus.EventBus;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockedStatic;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import app.testing.FxTestTemplate;
+import app.model.Model;
+import app.model.ProgrammingLanguage;
+import app.service.LanguageOperations;
+import app.events.CopyEvent;
+import app.events.CutEvent;
+import app.events.FileSelectedEvent;
+import app.events.LanguageChangedEvent;
+import app.events.PasteEvent;
+import app.events.RedoEvent;
+import app.events.ToggleCommentEvent;
+import app.events.ToggleWrapTextEvent;
+import app.events.UndoEvent;
+
+@ExtendWith(MockitoExtension.class)
+public class EditorControllerTest extends FxTestTemplate {
+
+
+  @Captor
+  private ArgumentCaptor<String> captor;
+
+  @Mock
+  private CodeArea editor;
+
+  private EventBus eventBus;
+
+  @InjectMocks
+  private EditorController controller;
+
+  private String mockContent = """
+  class HelloWorld {
+    private String message = "Hello world";
+
+    public String getMessage() {
+      return message;
+    }
+  }
+  """;
+
+  private String mockLine = "private String message = \"Hello world\";";
+
+  @BeforeEach
+  public void insertEventBus() {
+    this.eventBus = new EventBus();
+    this.controller.setEventBus(eventBus);
+  }
+
+  @Test
+  @DisplayName("Test handling of FileSelectedEvent with a real file")
+  public void testFileSelectedEventWithRealFile() throws IOException {
+
+    String resourcePath = "/testfile.txt";
+    String filePath = getClass().getResource(resourcePath).getPath();
+    File file = new File(filePath);
+    List<String> content =
+      Files.readAllLines(file.toPath())
+        .stream()
+        .map(s -> s + "\n")
+        .collect(Collectors.toList());
+
+    eventBus.post(new FileSelectedEvent(filePath));
+    verify(editor, times(content.size())).appendText(captor.capture());
+
+    assertEquals(content, captor.getAllValues());
+  }
+
+  @Test
+  @DisplayName("Test handling of FileSelectedEvent with a file that doesn't exist")
+  public void testFileSelectedEventWithUnrealFile() throws IOException {
+
+    String brokenFilePath = "/doesNotExist.txt";
+    eventBus.post(new FileSelectedEvent(brokenFilePath));
+
+    verify(editor, never()).clear();
+  }
+
+  @Test
+  @DisplayName("Test handling of LanguageChangedEvent")
+  public void testLanguageChangedEvent(){
+
+    when(editor.getText()).thenReturn(mockContent);
+
+    try (MockedStatic<LanguageOperations> mocked = mockStatic(LanguageOperations.class)) {
+      mocked.when(() -> LanguageOperations.syntaxHighlight(anyString(), any()))
+        .thenReturn(StyleSpans.singleton(null, 0));
+
+      eventBus.post(new LanguageChangedEvent("markdown"));
+      mocked.verify(() -> LanguageOperations.syntaxHighlight(anyString(), any()));
+    }
+  }
+
+  @Test
+  @DisplayName("Test handling of ToggleCommentEvent when not selected")
+  public void testToggleCommentEventNotSelect(){
+
+    ProgrammingLanguage lang = mock(ProgrammingLanguage.class);
+    when(editor.getSelectedText()).thenReturn("");
+    when(editor.getText(anyInt())).thenReturn(mockLine);
+
+    try (MockedStatic<Model> mocked = mockStatic(Model.class)) {
+      mocked.when(() -> Model.getLanguage()).thenReturn(lang);
+
+      when(lang.isCommentedLine(anyString())).thenReturn(false);
+      eventBus.post(new ToggleCommentEvent());
+      verify(lang).commentLine(anyString());
+
+      when(lang.isCommentedLine(anyString())).thenReturn(true);
+      eventBus.post(new ToggleCommentEvent());
+      verify(lang).unCommentLine(anyString());
+    }
+  }
+
+  @Test
+  @DisplayName("Test handling of ToggleCommentEvent when selected")
+  public void testToggleCommentEventSelect(){
+
+    ProgrammingLanguage lang = mock(ProgrammingLanguage.class);
+    when(editor.getSelectedText()).thenReturn("Selected Text");
+
+    try (MockedStatic<Model> mocked = mockStatic(Model.class)) {
+      mocked.when(() -> Model.getLanguage()).thenReturn(lang);
+
+      when(lang.isCommentedSelection(anyString())).thenReturn(false);
+      eventBus.post(new ToggleCommentEvent());
+      verify(lang).commentSelection(anyString());
+
+      when(lang.isCommentedSelection(anyString())).thenReturn(true);
+      eventBus.post(new ToggleCommentEvent());
+      verify(lang).unCommentSelection(anyString());
+    }
+  }
+
+  @Test
+  @DisplayName("Test handling of ToggleWrapTextEvent")
+  public void testToggleWrapTextEvent(){
+    eventBus.post(new ToggleWrapTextEvent(true));
+    verify(editor).setWrapText(true);
+    eventBus.post(new ToggleWrapTextEvent(false));
+    verify(editor).setWrapText(false);
+  }
+
+  @Test
+  @DisplayName("Test handling of UndoEvent")
+  public void testUndoEvent(){
+    when(editor.isFocused()).thenReturn(true);
+    eventBus.post(new UndoEvent());
+    verify(editor, times(1)).undo();
+
+    when(editor.isFocused()).thenReturn(false);
+    eventBus.post(new UndoEvent());
+    // Should not have been called one more time
+    verify(editor, times(1)).undo();
+  }
+
+  @Test
+  @DisplayName("Test handling of RedoEvent")
+  public void testRedoEvent(){
+    when(editor.isFocused()).thenReturn(true);
+    eventBus.post(new RedoEvent());
+    verify(editor, times(1)).redo();
+
+    when(editor.isFocused()).thenReturn(false);
+    eventBus.post(new RedoEvent());
+    verify(editor, times(1)).redo();
+  }
+  
+  @Test
+  @DisplayName("Test handling of CopyEvent")
+  public void testCopyEvent(){
+    when(editor.isFocused()).thenReturn(true);
+    eventBus.post(new CopyEvent());
+    verify(editor, times(1)).copy();
+
+    when(editor.isFocused()).thenReturn(false);
+    eventBus.post(new CopyEvent());
+    verify(editor, times(1)).copy();
+  }
+
+  @Test
+  @DisplayName("Test handling of CutEvent")
+  public void testCutEvent(){
+    when(editor.isFocused()).thenReturn(true);
+    eventBus.post(new CutEvent());
+    verify(editor, times(1)).cut();
+
+    when(editor.isFocused()).thenReturn(false);
+    eventBus.post(new CutEvent());
+    verify(editor, times(1)).cut();
+  }
+
+  @Test
+  @DisplayName("Test handling of PasteEvent")
+  public void testPasteEvent(){
+    when(editor.isFocused()).thenReturn(true);
+    eventBus.post(new PasteEvent());
+    verify(editor, times(1)).paste();
+
+    when(editor.isFocused()).thenReturn(false);
+    eventBus.post(new PasteEvent());
+    verify(editor, times(1)).paste();
+  }
+}

src/test/java/app/events/FileSaveStateChangedEventTest.java

@@ -0,0 +1,18 @@
+package app.events;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import app.model.Model;
+import app.testing.EventTestTemplate;
+
+public class FileSaveStateChangedEventTest extends EventTestTemplate {
+
+  @Test
+  @DisplayName("Check that model gets changed on constructor")
+  public void checkModel() {
+    new FileSaveStateChangedEvent(true);
+    this.mockModel.verify(() -> Model.setFileIsSaved(true));
+  }
+  
+}

src/test/java/app/testing/ControllerTestTemplate.java

@@ -0,0 +1,5 @@
+package app.testing;
+
+public class ControllerTestTemplate extends FxTestTemplate {
+
+}

src/test/java/app/testing/EventTestTemplate.java

@@ -0,0 +1,25 @@
+package app.testing;
+
+import static org.mockito.Mockito.mockStatic;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.mockito.MockedStatic;
+
+import app.model.Model;
+
+public class EventTestTemplate extends FxTestTemplate {
+
+  public MockedStatic<Model> mockModel;
+
+  @BeforeEach
+  public void openModel() {
+    mockModel = mockStatic(Model.class);
+  }
+
+  @AfterEach
+  public void closeModel() {
+    mockModel.close();
+  }
+  
+}

src/test/java/app/testing/FxTestTemplate.java

@@ -0,0 +1,56 @@
+package app.testing;
+
+import javafx.application.Application;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Node;
+import javafx.stage.Stage;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.testfx.api.FxToolkit;
+import org.testfx.framework.junit5.ApplicationTest;
+import org.testfx.util.WaitForAsyncUtils;
+
+import java.util.concurrent.TimeoutException;
+
+import app.Main;
+import app.MainController;
+
+public class FxTestTemplate extends ApplicationTest {
+
+  private Stage stage;
+  private Application application;
+
+  @BeforeEach
+  public void runAppToTests() throws Exception {
+    FxToolkit.registerPrimaryStage();
+    this.application = FxToolkit.setupApplication(Main::new);
+
+    FxToolkit.showStage();
+    WaitForAsyncUtils.waitForFxEvents(100);
+  }
+
+  @AfterEach
+  public void stopApp() throws TimeoutException {
+    FxToolkit.cleanupStages();
+    FxToolkit.cleanupApplication(this.application);
+  }
+
+  @Override
+  public void start(Stage primaryStage){
+    this.stage = primaryStage;
+    primaryStage.toFront();
+  }
+
+  public Stage getStage() {
+    return stage;
+  }
+
+  public MainController getMainController() {
+    return ((FXMLLoader) this.stage.getScene().getUserData()).getController();
+  }
+
+  public <T extends Node> T find(final String query) {
+    /** TestFX provides many operations to retrieve elements from the loaded GUI. */
+    return lookup(query).query();
+  }
+}

src/test/resources/testfile.txt

@@ -0,0 +1,3 @@
+public class testfile {
+  
+}