unknown fields and null-values getting ignored

Author: dnltsk

src/main/java/com/dasburo/spring/cache/dynamo/rootattribute/RootAttributeReader.java

@@ -19,6 +19,9 @@ public class RootAttributeReader {
   public RootAttribute readRootAttribute(@NonNull RootAttributeConfig rootAttributeConfig, @NonNull Object object) {
     try {
       Object value = PropertyUtils.getProperty(object, rootAttributeConfig.getName());
+      if (value == null) {
+        return null;
+      }
       AttributeValue attributeValue = mapValueToAttributeValue(value, rootAttributeConfig.getType());
       return new RootAttribute(rootAttributeConfig.getName(), attributeValue);
     }
@@ -31,13 +34,13 @@ public RootAttribute readRootAttribute(@NonNull RootAttributeConfig rootAttribut
   @Nullable
   private AttributeValue mapValueToAttributeValue(@NonNull Object value, @NonNull ScalarAttributeType type) {
     switch (type) {
-      case S:
-        return new AttributeValue().withS(String.valueOf(value));
       case N:
         return new AttributeValue().withN(String.valueOf(value));
       case B:
         return new AttributeValue().withB((ByteBuffer) value);
+      case S:
+      default:
+        return new AttributeValue().withS(String.valueOf(value));
     }
-    return null;
   }
 }

src/test/java/com/dasburo/spring/cache/dynamo/rootattribute/RootAttributeReaderTest.java

@@ -9,6 +9,7 @@
 import java.util.LinkedHashMap;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 public class RootAttributeReaderTest {
 
@@ -138,4 +139,31 @@ public void testRootAttributeReader_LinkedHashMapCanBeHandled() {
     assertEquals("stringField", rootAttribute.getName());
     assertEquals("dummy-text", rootAttribute.getAttributeValue().getS());
   }
+
+  @Test
+  public void testRootAttributeReader_UnknownFieldIsGetsIgnored() {
+    //given
+    RootAttributeConfig rootAttributeConfig = new RootAttributeConfig("unknownField", ScalarAttributeType.S);
+    SampleTestClass sampleInstance = new SampleTestClass();
+
+    //when
+    RootAttribute rootAttribute = rootAttributeReader.readRootAttribute(rootAttributeConfig, sampleInstance);
+
+    //then
+    assertNull(rootAttribute);
+  }
+
+  @Test
+  public void testRootAttributeReader_NullValueOfKnownFieldsGetsIgnored() {
+    //given
+    RootAttributeConfig rootAttributeConfig = new RootAttributeConfig("stringField", ScalarAttributeType.S);
+    SampleTestClass sampleInstance = new SampleTestClass();
+    sampleInstance.setStringField(null);
+
+    //when
+    RootAttribute rootAttribute = rootAttributeReader.readRootAttribute(rootAttributeConfig, sampleInstance);
+
+    //then
+    assertNull(rootAttribute);
+  }
 }