control menu with custom InputStream

src/main/java/PasswordManager.java

@@ -1,7 +1,14 @@
+import java.io.BufferedInputStream;
+import java.io.InputStream;
+
 public class PasswordManager implements PasswordManagerInterface {
     public static void main(String[] args) {
         PasswordManager pm = new PasswordManager();
-        pm.showMenu();
+
+        while (true) {
+            InputStream inputStream = System.in;
+            pm.showMenu(inputStream);
+        }
     }
 
     public PasswordManager() {
@@ -19,7 +26,7 @@ public class PasswordManager implements PasswordManagerInterface {
     }
 
     @Override
-    public void showMenu() {
+    public void showMenu(InputStream inputStream) {
 
     }
 }

src/main/java/PasswordManagerInterface.java

@@ -1,7 +1,9 @@
+import java.io.InputStream;
+
 public interface PasswordManagerInterface {
     public static void main(String[] args) {
     };
     public void listVaults();
     public void openVault();
-    public void showMenu();
+    public void showMenu(InputStream inputStream);
 }

src/test/java/PasswordManagerTest.java

@@ -1,6 +1,10 @@
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+
 import static org.junit.jupiter.api.Assertions.*;
 
 
@@ -30,6 +34,6 @@ class PasswordManagerTest {
 
     @Test
     void showMenu() {
-        pm.showMenu();
+        pm.showMenu(new ByteArrayInputStream("".getBytes(StandardCharsets.UTF_8)));
     }
 }