added test for converting externaluser to user

src/test/java/no/fintlabs/externalUser/ExternalUserServiceTest.java

@@ -0,0 +1,36 @@
+package no.fintlabs.externalUser;
+
+import no.fintlabs.user.User;
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ExternalUserServiceTest {
+    private ExternalUserService externalUserService;
+
+    @Test
+    public void shouldReturnUser() {
+        ExternalUser externalUser = ExternalUser
+                .builder()
+                .userName("titten@tei.no")
+                .identityProviderUserObjectId(UUID.fromString("f37f3048-637a-11ee-8c99-0242ac120002"))
+                .userType("EXTERNAL")
+                .build();
+
+        User userToBeConverted = User
+                .builder()
+                .userName("titten@tei.no")
+                .identityProviderUserObjectId(UUID.fromString("f37f3048-637a-11ee-8c99-0242ac120002"))
+                .userType("EXTERNAL")
+                .resourceId("f37f3048-637a-11ee-8c99-0242ac120002")
+                .build();
+
+        User convertedUser = externalUser.toUser();
+
+        assertEquals(userToBeConverted.getResourceId(),convertedUser.getResourceId());
+    }
+
+
+}