Add missing SeqNo and PrimaryTerm fields in SearchHit

CHANGELOG.md

@@ -9,6 +9,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Adds the `SearchPipelines` field to `SearchParams` ([#532](https://github.com/opensearch-project/opensearch-go/pull/532))
 - Adds support for OpenSearch 2.14 ([#552](https://github.com/opensearch-project/opensearch-go/pull/552))
 - Adds the `Caches` field to Node stats ([#572](https://github.com/opensearch-project/opensearch-go/pull/572))
+- Adds the `SeqNo` and `PrimaryTerm` fields in `SearchHit` ([#574](https://github.com/opensearch-project/opensearch-go/pull/574))
 
 ### Changed
 - Security roles get response struct has its own sub structs without omitempty ([#572](https://github.com/opensearch-project/opensearch-go/pull/572))

opensearchapi/api_search.go

@@ -96,4 +96,6 @@ type SearchHit struct {
 	Type        string                  `json:"_type"` // Deprecated field
 	Sort        []any                   `json:"sort"`
 	Explanation *DocumentExplainDetails `json:"_explanation"`
+	SeqNo       *int                    `json:"_seq_no"`
+	PrimaryTerm *int                    `json:"_primary_term"`
 }

opensearchapi/api_search_test.go

@@ -128,4 +128,42 @@ func TestSearch(t *testing.T) {
 		assert.NotEmpty(t, resp.Hits.Hits[0].Routing)
 		assert.Equal(t, "foo", resp.Hits.Hits[0].Routing)
 	})
+
+	t.Run("with seq_no and primary_term", func(t *testing.T) {
+		seqNoPrimaryTerm := true
+		resp, err := client.Search(nil, &opensearchapi.SearchReq{
+			Indices: []string{index},
+			Body:    strings.NewReader(""),
+			Params: opensearchapi.SearchParams{
+				SeqNoPrimaryTerm: &seqNoPrimaryTerm,
+			},
+		})
+		require.Nil(t, err)
+		assert.NotNil(t, resp)
+		ostest.CompareRawJSONwithParsedJSON(t, resp, resp.Inspect().Response)
+		assert.NotEmpty(t, resp.Hits.Hits)
+		for _, hit := range resp.Hits.Hits {
+			assert.NotNil(t, hit.SeqNo)
+			assert.NotNil(t, hit.PrimaryTerm)
+		}
+	})
+
+	t.Run("without seq_no and primary_term", func(t *testing.T) {
+		seqNoPrimaryTerm := false
+		resp, err := client.Search(nil, &opensearchapi.SearchReq{
+			Indices: []string{index},
+			Body:    strings.NewReader(""),
+			Params: opensearchapi.SearchParams{
+				SeqNoPrimaryTerm: &seqNoPrimaryTerm,
+			},
+		})
+		require.Nil(t, err)
+		assert.NotNil(t, resp)
+		ostest.CompareRawJSONwithParsedJSON(t, resp, resp.Inspect().Response)
+		assert.NotEmpty(t, resp.Hits.Hits)
+		for _, hit := range resp.Hits.Hits {
+			assert.Nil(t, hit.SeqNo)
+			assert.Nil(t, hit.PrimaryTerm)
+		}
+	})
 }