NPE bug fixes in the DefaultLogstashPluginAttributesMapper

data-prepper-logstash-configuration/src/main/java/org/opensearch/dataprepper/logstash/mapping/DefaultLogstashPluginAttributesMapper.java

@@ -12,18 +12,26 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 class DefaultLogstashPluginAttributesMapper implements LogstashPluginAttributesMapper {
     private static final Logger LOG = LoggerFactory.getLogger(DefaultLogstashPluginAttributesMapper.class);
 
     @Override
     public Map<String, Object> mapAttributes(final List<LogstashAttribute> logstashAttributes, final LogstashAttributesMappings logstashAttributesMappings) {
+
+        Objects.requireNonNull(logstashAttributes);
+        Objects.requireNonNull(logstashAttributesMappings);
+        Objects.requireNonNull(logstashAttributesMappings.getMappedAttributeNames());
+        Objects.requireNonNull(logstashAttributesMappings.getAdditionalAttributes());
+
         final Map<String, Object> pluginSettings = new LinkedHashMap<>(logstashAttributesMappings.getAdditionalAttributes());
 
+        final Map<String, String> mappedAttributeNames = logstashAttributesMappings.getMappedAttributeNames();
         logstashAttributes.forEach(logstashAttribute -> {
-            if (logstashAttributesMappings.getMappedAttributeNames().containsKey(logstashAttribute.getAttributeName())) {
+            if (mappedAttributeNames.containsKey(logstashAttribute.getAttributeName())) {
                 pluginSettings.put(
-                        logstashAttributesMappings.getMappedAttributeNames().get(logstashAttribute.getAttributeName()),
+                        mappedAttributeNames.get(logstashAttribute.getAttributeName()),
                         logstashAttribute.getAttributeValue().getValue()
                 );
             }

data-prepper-logstash-configuration/src/main/java/org/opensearch/dataprepper/logstash/mapping/LogstashAttributesMappings.java

@@ -13,7 +13,25 @@
  * @since 1.2
  */
 public interface LogstashAttributesMappings {
+    /**
+     * A map of attribute names in the Logstash configuration to
+     * the correct property name in Data Prepper.
+     * <p>
+     * This should not return null and should return empty if not defined.
+     *
+     * @return A Map
+     * @since 1.2
+     */
     Map<String, String> getMappedAttributeNames();
 
+    /**
+     * A map of Data Prepper property names to values to set on those
+     * properties.
+     * <p>
+     * This should not return null and should return empty if not defined.
+     *
+     * @return A Map
+     * @since 1.2
+     */
     Map<String, Object> getAdditionalAttributes();
 }

data-prepper-logstash-configuration/src/main/java/org/opensearch/dataprepper/logstash/mapping/LogstashMappingModel.java

@@ -6,6 +6,8 @@
 package org.opensearch.dataprepper.logstash.mapping;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonSetter;
+import com.fasterxml.jackson.annotation.Nulls;
 
 import java.util.Map;
 
@@ -23,9 +25,11 @@ class LogstashMappingModel implements LogstashAttributesMappings {
     private String attributesMapperClass;
 
     @JsonProperty
+    @JsonSetter(nulls = Nulls.AS_EMPTY)
     private Map<String, String> mappedAttributeNames;
 
     @JsonProperty
+    @JsonSetter(nulls = Nulls.AS_EMPTY)
     private Map<String, Object> additionalAttributes;
 
     public String getPluginName() {

data-prepper-logstash-configuration/src/test/java/org/opensearch/dataprepper/logstash/mapping/DefaultLogstashPluginAttributesMapperTest.java

@@ -5,42 +5,94 @@
 
 package org.opensearch.dataprepper.logstash.mapping;
 
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.opensearch.dataprepper.logstash.model.LogstashAttribute;
 import org.opensearch.dataprepper.logstash.model.LogstashAttributeValue;
 
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.hasKey;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 class DefaultLogstashPluginAttributesMapperTest {
-    private DefaultLogstashPluginAttributesMapper createObjectUnderTest() {
-        return new DefaultLogstashPluginAttributesMapper();
-    }
 
-    @Test
-    void mapAttributes_sets_mapped_attributes() {
-        final String value = UUID.randomUUID().toString();
-        final String logstashAttributeName = UUID.randomUUID().toString();
+    private String logstashAttributeName;
+    private String value;
+    private List<LogstashAttribute> logstashAttributes;
+    private LogstashAttributesMappings mappings;
+
+    @BeforeEach
+    void setUp() {
+        value = UUID.randomUUID().toString();
+        logstashAttributeName = UUID.randomUUID().toString();
         final LogstashAttribute logstashAttribute = mock(LogstashAttribute.class);
         final LogstashAttributeValue logstashAttributeValue = mock(LogstashAttributeValue.class);
         when(logstashAttributeValue.getValue()).thenReturn(value);
         when(logstashAttribute.getAttributeName()).thenReturn(logstashAttributeName);
         when(logstashAttribute.getAttributeValue()).thenReturn(logstashAttributeValue);
 
+
+        logstashAttributes = Collections.singletonList(logstashAttribute);
+        mappings = mock(LogstashAttributesMappings.class);
+    }
+
+    private DefaultLogstashPluginAttributesMapper createObjectUnderTest() {
+        return new DefaultLogstashPluginAttributesMapper();
+    }
+
+    @Test
+    void mapAttributes_throws_with_null_Attributes() {
+        final DefaultLogstashPluginAttributesMapper objectUnderTest = createObjectUnderTest();
+
+        assertThrows(NullPointerException.class,
+                () -> objectUnderTest.mapAttributes(null, mappings));
+    }
+
+    @Test
+    void mapAttributes_throws_with_null_Mappings() {
+        final DefaultLogstashPluginAttributesMapper objectUnderTest = createObjectUnderTest();
+
+        assertThrows(NullPointerException.class,
+                () -> objectUnderTest.mapAttributes(logstashAttributes, null));
+    }
+
+    @Test
+    void mapAttributes_throws_with_null_Mappings_mappedAttributeNames() {
+        final DefaultLogstashPluginAttributesMapper objectUnderTest = createObjectUnderTest();
+
+        when(mappings.getMappedAttributeNames()).thenReturn(null);
+
+        assertThrows(NullPointerException.class,
+                () -> objectUnderTest.mapAttributes(logstashAttributes, mappings));
+    }
+
+    @Test
+    void mapAttributes_throws_with_null_Mappings_additionalAttributes() {
+        final DefaultLogstashPluginAttributesMapper objectUnderTest = createObjectUnderTest();
+
+        when(mappings.getAdditionalAttributes()).thenReturn(null);
+
+        assertThrows(NullPointerException.class,
+                () -> objectUnderTest.mapAttributes(logstashAttributes, mappings));
+    }
+
+    @Test
+    void mapAttributes_sets_mapped_attributes() {
         final String dataPrepperAttribute = UUID.randomUUID().toString();
-        final LogstashAttributesMappings mappings = mock(LogstashAttributesMappings.class);
+
         when(mappings.getMappedAttributeNames()).thenReturn(Collections.singletonMap(logstashAttributeName, dataPrepperAttribute));
 
         final Map<String, Object> actualPluginSettings =
-                createObjectUnderTest().mapAttributes(Collections.singletonList(logstashAttribute), mappings);
+                createObjectUnderTest().mapAttributes(logstashAttributes, mappings);
 
         assertThat(actualPluginSettings, notNullValue());
         assertThat(actualPluginSettings.size(), equalTo(1));
@@ -52,11 +104,10 @@ void mapAttributes_sets_mapped_attributes() {
     void mapAttributes_sets_additional_attributes_to_those_values() {
         final String additionalAttributeName = UUID.randomUUID().toString();
         final String additionalAttributeValue = UUID.randomUUID().toString();
-        final LogstashAttributesMappings mappings = mock(LogstashAttributesMappings.class);
         when(mappings.getAdditionalAttributes()).thenReturn(Collections.singletonMap(additionalAttributeName, additionalAttributeValue));
 
         final Map<String, Object> actualPluginSettings =
-                createObjectUnderTest().mapAttributes(Collections.emptyList(), mappings);
+                createObjectUnderTest().mapAttributes(logstashAttributes, mappings);
 
         assertThat(actualPluginSettings, notNullValue());
         assertThat(actualPluginSettings.size(), equalTo(1));

data-prepper-logstash-configuration/src/test/java/org/opensearch/dataprepper/logstash/mapping/LogstashMappingModelTest.java

@@ -41,4 +41,17 @@ void deserialize_from_JSON_should_have_expected_value() throws IOException {
         assertThat(logstashMappingModel.getAdditionalAttributes().get("addA"), equalTo(true));
         assertThat(logstashMappingModel.getAdditionalAttributes().get("addB"), equalTo("staticValueB"));
     }
+
+    @Test
+    void deserialize_from_JSON_with_null_values_has_empty_lists() throws IOException {
+
+        final LogstashMappingModel logstashMappingModel = objectMapper.readValue(this.getClass().getResourceAsStream("sample-with-nulls.mapping.yaml"), LogstashMappingModel.class);
+
+        assertThat(logstashMappingModel.getPluginName(), equalTo("samplePlugin"));
+        assertThat(logstashMappingModel.getAttributesMapperClass(), equalTo("org.opensearch.dataprepper.Placeholder"));
+        assertThat(logstashMappingModel.getMappedAttributeNames(), notNullValue());
+        assertThat(logstashMappingModel.getMappedAttributeNames().size(), equalTo(0));
+        assertThat(logstashMappingModel.getAdditionalAttributes(), notNullValue());
+        assertThat(logstashMappingModel.getAdditionalAttributes().size(), equalTo(0));
+    }
 }

data-prepper-logstash-configuration/src/test/resources/org/opensearch/dataprepper/logstash/mapping/sample-with-nulls.mapping.yaml

@@ -0,0 +1,4 @@
+pluginName: samplePlugin
+attributesMapperClass: org.opensearch.dataprepper.Placeholder
+mappedAttributeNames: null
+additionalAttributes: null