Add additional tests

immutables/src/main/java/com/baeldung/immutable/ValueObject.java

@@ -2,5 +2,7 @@ package com.baeldung.immutable;
 
 public class ValueObject {
     public ValueObject() {
+
+
     }
 }

immutables/src/main/java/com/baeldung/immutable/auxiliary/Person.java

@@ -0,0 +1,13 @@
+package com.baeldung.immutable.auxiliary;
+
+
+import org.immutables.value.Value;
+
+@Value.Immutable
+public abstract class Person {
+    abstract String getName();
+    abstract Integer getAge();
+
+    @Value.Auxiliary
+    abstract String getAuxiliaryField();
+}

immutables/src/test/java/com/baeldung/immutable/ImmutablePersonTest.java

@@ -17,6 +17,7 @@ public class ImmutablePersonTest {
 
         assertThat(john)
           .isNotSameAs(john43);
+
         assertThat(john.getAge())
           .isEqualTo(42);
     }

immutables/src/test/java/com/baeldung/immutable/auxiliary/ImmutablePersonAuxiliaryTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.immutable.auxiliary;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ImmutablePersonAuxiliaryTest {
+
+    @Test
+    public void whenComparing_shouldIgnore() throws Exception {
+        final com.baeldung.immutable.auxiliary.ImmutablePerson john1 = com.baeldung.immutable.auxiliary.ImmutablePerson.builder()
+          .name("John")
+          .age(42)
+          .auxiliaryField("Value1")
+          .build();
+
+        final com.baeldung.immutable.auxiliary.ImmutablePerson john2 = com.baeldung.immutable.auxiliary.ImmutablePerson.builder()
+          .name("John")
+          .age(42)
+          .auxiliaryField("Value2")
+          .build();
+
+
+        assertThat(john1.equals(john2))
+          .isTrue();
+
+        assertThat(john1.toString())
+          .isEqualTo(john2.toString());
+
+        assertThat(john1.hashCode())
+          .isEqualTo(john2.hashCode());
+    }
+}