Validate user input for Feature

check whether input has valid index name, geospatial field
and GeoJSON data.

Signed-off-by: Vijayan Balasubramanian <balasvij@amazon.com>

src/main/java/org/opensearch/geospatial/GeospatialParser.java

@@ -39,13 +39,13 @@ public static Map<String, Object> toStringObjectMap(final Object input) {
     /**
      * User inputs are usually deserialized into Map. extractValueAsString will help caller to
      * extract value from the Map and cast it to string with validation.
-     * @param input User input of type Map
-     * @param key property we would like to extract value of
+     * @param input User input of type Map, cannot be null
+     * @param key property we would like to extract value of, cannot be null
      * @return null if key doesn't exist, value as String if it exists, throw exception otherwise
      */
     public static String extractValueAsString(final Map<String, Object> input, final String key) {
-        Objects.requireNonNull(key);
-        Objects.requireNonNull(input);
+        Objects.requireNonNull(key, "parameter 'key' cannot be null");
+        Objects.requireNonNull(input, "parameter 'input' cannot be null");
         Object value = input.get(key);
         if (value == null) {
             return null;

src/main/java/org/opensearch/geospatial/action/upload/geojson/UploadGeoJSONRequestContent.java

@@ -5,13 +5,17 @@
 
 package org.opensearch.geospatial.action.upload.geojson;
 
-import static java.util.Objects.requireNonNull;
 import static org.opensearch.geospatial.GeospatialParser.extractValueAsString;
 
 import java.util.Map;
+import java.util.Objects;
 
 import org.opensearch.common.ParseField;
+import org.opensearch.common.Strings;
 
+/**
+ * UploadGeoJSONRequestContent is the Data model for UploadGeoJSONRequest's body
+ */
 public final class UploadGeoJSONRequestContent {
 
     public static final ParseField FIELD_INDEX = new ParseField("index", new String[0]);
@@ -22,15 +26,26 @@ public final class UploadGeoJSONRequestContent {
     private final Object data;
 
     private UploadGeoJSONRequestContent(String indexName, String geospatialFieldName, Object data) {
-        this.indexName = requireNonNull(indexName);
-        this.geospatialFieldName = requireNonNull(geospatialFieldName);
-        this.data = requireNonNull(data);
+        this.indexName = indexName;
+        this.geospatialFieldName = geospatialFieldName;
+        this.data = data;
     }
 
     public static UploadGeoJSONRequestContent create(Map<String, Object> input) {
+        Objects.requireNonNull(input, "input cannot be null");
         String index = extractValueAsString(input, FIELD_INDEX.getPreferredName());
+        if (!Strings.hasText(index)) {
+            throw new IllegalArgumentException("field [ " + FIELD_INDEX.getPreferredName() + " ] cannot be empty");
+        }
         String geospatialField = extractValueAsString(input, FIELD_GEOSPATIAL.getPreferredName());
-        return new UploadGeoJSONRequestContent(index, geospatialField, input.get(FIELD_DATA.getPreferredName()));
+        if (!Strings.hasText(geospatialField)) {
+            throw new IllegalArgumentException("field [ " + FIELD_GEOSPATIAL.getPreferredName() + " ] cannot be empty");
+        }
+        Object geoJSONData = Objects.requireNonNull(
+            input.get(FIELD_DATA.getPreferredName()),
+            "field [ " + FIELD_DATA.getPreferredName() + " ] cannot be empty"
+        );
+        return new UploadGeoJSONRequestContent(index, geospatialField, geoJSONData);
     }
 
     public final String getIndexName() {

src/test/java/org/opensearch/geospatial/action/upload/geojson/UploadGeoJSONRequestContentTests.java

@@ -40,4 +40,20 @@ public void testCreate() {
         assertEquals(indexName, content.getIndexName());
         assertEquals(contents.get(FIELD_DATA.getPreferredName()), content.getData());
     }
+
+    public void testCreateEmptyIndexName() {
+        IllegalArgumentException invalidIndexName = assertThrows(
+            IllegalArgumentException.class,
+            () -> UploadGeoJSONRequestContent.create(buildRequestContent("", "location"))
+        );
+        assertTrue(invalidIndexName.getMessage().contains("cannot be empty"));
+    }
+
+    public void testCreateEmptyGeospatialFieldName() {
+        IllegalArgumentException invalidIndexName = assertThrows(
+            IllegalArgumentException.class,
+            () -> UploadGeoJSONRequestContent.create(buildRequestContent("some-index", ""))
+        );
+        assertTrue(invalidIndexName.getMessage().contains("cannot be empty"));
+    }
 }