[#141] handle default null and string for AppUserRole

src/main/java/de/bonndan/nivio/appuser/AppUserRole.java

@@ -2,5 +2,22 @@
 
 public enum AppUserRole {
     USER,
-    ADMIN
+    ADMIN;
+
+
+    // declare your defaults with constant values
+    private static final AppUserRole defaultValue = USER;
+
+    // `of` as a substitute for `valueOf` handling the default value
+    public static AppUserRole of(String value) {
+
+        if(!value.equals("ADMIN")) return defaultValue;
+        return AppUserRole.valueOf(value);
+    }
+
+    // `defaultOr` for handling default value for null
+    public static AppUserRole defaultOr(AppUserRole value) {
+        return value != null ? value : defaultValue;
+    }
+
 }

src/test/java/de/bonndan/nivio/appuser/AppUserRoleTest.java

@@ -3,6 +3,7 @@
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class AppUserRoleTest {
 
@@ -16,6 +17,8 @@ void valueOf() {
         // then
         assertEquals(AppUserRole.valueOf("ADMIN"), admin);
         assertEquals(AppUserRole.valueOf("USER"), user);
-
+        // handling default value for null and random string
+        assertEquals(AppUserRole.of("test"), user);
+        assertEquals(AppUserRole.defaultOr(null), user);
     }
 }