do not exit menu after wrong input

src/main/java/PasswordManager.java

@@ -1,4 +1,7 @@
+import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.Scanner;
 
 public class PasswordManager implements PasswordManagerInterface {
@@ -7,10 +10,11 @@ public class PasswordManager implements PasswordManagerInterface {
 
     public static void main(String[] args) {
         PasswordManager pm = new PasswordManager();
+        InputStream inputStream = System.in;
+        OutputStream outputStream = System.out;
 
         while (pm.running) {
-            InputStream inputStream = System.in;
-            pm.showMenu(inputStream);
+            pm.showMenu(inputStream, outputStream);
         }
         System.exit(0);
     }
@@ -21,7 +25,6 @@ public class PasswordManager implements PasswordManagerInterface {
 
     @Override
     public void listVaults() {
-
     }
 
     @Override
@@ -30,16 +33,21 @@ public class PasswordManager implements PasswordManagerInterface {
     }
 
     @Override
-    public void showMenu(InputStream inputStream) {
+    public void showMenu(InputStream inputStream, OutputStream outputStream) {
         StringBuilder sb = new StringBuilder();
         Scanner scan = new Scanner(inputStream);
+        running = true;
 
         sb.append("ciip Gruppe 8 - Password Manager\n\n");
 
         sb.append("Menu:\n");
         sb.append("- exit: e\n");
 
-        System.out.println(sb + "\n");
+        try {
+            outputStream.write((sb + "\n").getBytes(StandardCharsets.UTF_8));
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
 
         String input = scan.nextLine();
 

src/main/java/PasswordManagerInterface.java

@@ -1,9 +1,10 @@
 import java.io.InputStream;
+import java.io.OutputStream;
 
 public interface PasswordManagerInterface {
     public static void main(String[] args) {
     };
     public void listVaults();
     public void openVault();
-    public void showMenu(InputStream inputStream);
+    public void showMenu(InputStream inputStream, OutputStream outputStream);
 }

src/test/java/PasswordManagerTest.java

@@ -1,8 +1,7 @@
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
-import java.io.BufferedInputStream;
-import java.io.ByteArrayInputStream;
+import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.util.NoSuchElementException;
 
@@ -35,13 +34,28 @@ class PasswordManagerTest {
 
     @Test
     void showMenu() {
-        ByteArrayInputStream virtualConsoleInput = new ByteArrayInputStream("".getBytes(StandardCharsets.UTF_8));
-        assertThrowsExactly(NoSuchElementException.class, () -> pm.showMenu(virtualConsoleInput));
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        assertThrowsExactly(NoSuchElementException.class, () -> pm.showMenu(getEmptyStringInputStream(), outputStream));
+        assertTrue(outputStream.toString().startsWith("ciip Gruppe 8"));
     }
 
     @Test
     void exitMenu() {
-        pm.showMenu(new ByteArrayInputStream("e\n".getBytes(StandardCharsets.UTF_8)));
+        pm.showMenu(new ByteArrayInputStream("e\n".getBytes(StandardCharsets.UTF_8)), System.out);
         assertFalse(pm.running);
     }
+
+    @Test
+    void doNotExitMenuAfterWrongInput() {
+        pm.showMenu(new ByteArrayInputStream("__\n".getBytes(StandardCharsets.UTF_8)), System.out);
+        assertTrue(pm.running);
+
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        assertThrowsExactly(NoSuchElementException.class, () -> pm.showMenu(getEmptyStringInputStream(), outputStream));
+        assertTrue(outputStream.toString().startsWith("ciip Gruppe 8"));
+    }
+
+    private ByteArrayInputStream getEmptyStringInputStream() {
+        return new ByteArrayInputStream("".getBytes(StandardCharsets.UTF_8));
+    }
 }