Removed required index for Hit.java

java-client/src/main/java/org/opensearch/client/opensearch/core/search/Hit.java

@@ -107,7 +107,7 @@ public class Hit<TDocument> implements JsonpSerializable {
 
     private Hit(Builder<TDocument> builder) {
 
-        this.index = ApiTypeHelper.requireNonNull(builder.index, this, "index");
+        this.index = builder.index;
         this.id = builder.id;
         this.score = builder.score;
         this.explanation = builder.explanation;
@@ -134,7 +134,7 @@ public static <TDocument> Hit<TDocument> of(Function<Builder<TDocument>, ObjectB
     }
 
     /**
-     * Required - API name: {@code _index}
+     * API name: {@code _index}
      */
     public final String index() {
         return this.index;
@@ -281,8 +281,10 @@ public void serialize(JsonGenerator generator, JsonpMapper mapper) {
 
     protected void serializeInternal(JsonGenerator generator, JsonpMapper mapper) {
 
-        generator.writeKey("_index");
-        generator.write(this.index);
+        if (this.index != null) {
+            generator.writeKey("_index");
+            generator.write(this.index);
+        }
 
         if (this.id != null) {
             generator.writeKey("_id");
@@ -419,6 +421,8 @@ protected void serializeInternal(JsonGenerator generator, JsonpMapper mapper) {
      */
 
     public static class Builder<TDocument> extends ObjectBuilderBase implements ObjectBuilder<Hit<TDocument>> {
+
+        @Nullable
         private String index;
 
         @Nullable
@@ -478,7 +482,7 @@ public static class Builder<TDocument> extends ObjectBuilderBase implements Obje
         /**
          * Required - API name: {@code _index}
          */
-        public final Builder<TDocument> index(String value) {
+        public final Builder<TDocument> index(@Nullable String value) {
             this.index = value;
             return this;
         }

java-client/src/test/java/org/opensearch/client/opensearch/core/search/InnerHitsResultTest.java

@@ -0,0 +1,84 @@
+package org.opensearch.client.opensearch.core.search;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import java.io.StringReader;
+import org.junit.Test;
+import org.opensearch.client.json.JsonData;
+import org.opensearch.client.json.JsonpMapper;
+import org.opensearch.client.json.jsonb.JsonbJsonpMapper;
+
+public class InnerHitsResultTest {
+    private final JsonpMapper mapper = new JsonbJsonpMapper();
+    private final String storedSalary = "details.salary";
+    private final String storedJobId = "details.jobId";
+
+    /**
+     * test if the InnerHitsResult will build the Hit<JsonData>
+     */
+    @Test
+    public void testInnerHits() {
+
+        String classString = String.valueOf(hitResultWithIdIndex.innerHits().get("test_child").getClass());
+        assertEquals(classString, InnerHitsResult.class.toString());
+        // take hitResult and get the InnerHit
+        InnerHitsResult innerHitsResult = hitResultWithIdIndex.innerHits().get("test_child");
+        Hit<JsonData> innerHitResult = innerHitsResult.hits().hits().get(0);
+        assertNotNull(innerHitResult.index());
+        assertEquals(innerHitResult.index(), "_index");
+        assertNotNull(innerHitResult.id());
+        assertEquals(innerHitResult.id(), "child_id");
+    }
+
+    /**
+     * test if the InnerHitsResult will still build the Hit<JsonData> even if id and index is not specified
+     */
+    @Test
+    public void testInnerHitWithoutIdIndex() {
+
+        String classString = String.valueOf(hitResultNoIdIndex.innerHits().get("test_child").getClass());
+        assertEquals(classString, InnerHitsResult.class.toString());
+        // take hitResult and get the InnerHit
+        InnerHitsResult innerHitsResult = hitResultNoIdIndex.innerHits().get("test_child");
+        Hit<JsonData> innerHitResult = innerHitsResult.hits().hits().get(0);
+        // Id and index are now nullable.
+        assertNull(innerHitResult.index());
+        assertNull(innerHitResult.id());
+    }
+
+    private final String innerHitJsonWithNoIdOrIndex = "{\"key\":\"value\"}";
+    private final String innerHitJsonWithIdOrIndex = "{\"id\":\"value\",\"index\":\"value\"}";
+
+    private final Hit<JsonData> hitResultNoIdIndex = Hit.of(
+        it -> it.id("test_parent")
+            .index("_index")
+            .innerHits(
+                "test_child",
+                innerHitsResultBuilder -> innerHitsResultBuilder.hits(
+                    innerHitsMetadataBuilder -> innerHitsMetadataBuilder.total(total -> total.value(1).relation(TotalHitsRelation.Eq))
+                        .hits(
+                            innerHitsListMemberBuilder -> innerHitsListMemberBuilder.source(
+                                JsonData.from(mapper.jsonProvider().createParser(new StringReader(innerHitJsonWithNoIdOrIndex)), mapper)
+                            )
+                        )
+                )
+            )
+    );
+    private final Hit<JsonData> hitResultWithIdIndex = Hit.of(
+        it -> it.id("test_parent")
+            .index("_index")
+            .innerHits(
+                "test_child",
+                innerHitsResultBuilder -> innerHitsResultBuilder.hits(
+                    innerHitsMetadataBuilder -> innerHitsMetadataBuilder.total(total -> total.value(1).relation(TotalHitsRelation.Eq))
+                        .hits(
+                            innerHitsListMemberBuilder -> innerHitsListMemberBuilder.id("child_id").index("_index").source(
+                                JsonData.from(mapper.jsonProvider().createParser(new StringReader(innerHitJsonWithIdOrIndex)), mapper)
+                            )
+                        )
+                )
+            )
+    );
+}