add fields to document get api response (#526)

Signed-off-by: Bundit Jitkonghcuen <boybundit@hotmail.com>

CHANGELOG.md

@@ -14,6 +14,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Adds security plugin ([#507](https://github.com/opensearch-project/opensearch-go/pull/507))
 - Adds security settings to container for security testing ([#507](https://github.com/opensearch-project/opensearch-go/pull/507))
 - Adds cluster.get-certs to copy admin certs out of the container ([#507](https://github.com/opensearch-project/opensearch-go/pull/507))
+- Add the `Fields` field containing stored fields to the `DocumentGetResp` struct (#526)[https://github.com/opensearch-project/opensearch-go/pull/526]
 
 ### Changed
 - Uses docker compose v2 instead of v1 ([#506](https://github.com/opensearch-project/opensearch-go/pull/506))

opensearchapi/api_document-get.go

@@ -44,6 +44,7 @@ type DocumentGetResp struct {
 	Found       bool            `json:"found"`
 	Type        string          `json:"_type"` // Deprecated field
 	Source      json.RawMessage `json:"_source"`
+	Fields      json.RawMessage `json:"fields"`
 	response    *opensearch.Response
 }
 

opensearchapi/api_document_test.go

@@ -393,5 +393,44 @@ func TestDocumentClient(t *testing.T) {
 			assert.NotNil(t, res.Inspect().Response)
 			ostest.CompareRawJSONwithParsedJSON(t, res.Source, res.Inspect().Response)
 		})
+		t.Run("Fields", func(t *testing.T) {
+			_, err := client.Indices.Mapping.Put(nil,
+				opensearchapi.MappingPutReq{
+					Indices: []string{index},
+					Body: strings.NewReader(`{
+						"properties": {
+							"foo-stored": {
+								"type": "text",
+								"store":true
+							}
+						}
+					}`),
+				})
+			require.Nil(t, err)
+			_, err = client.Document.Create(
+				nil,
+				opensearchapi.DocumentCreateReq{
+					Index:      index,
+					Body:       strings.NewReader(`{"foo-stored": "bar"}`),
+					DocumentID: "test-stored-field",
+				},
+			)
+			require.Nil(t, err)
+			res, err := client.Document.Get(
+				nil,
+				opensearchapi.DocumentGetReq{
+					Index:      index,
+					DocumentID: "test-stored-field",
+					Params: opensearchapi.DocumentGetParams{
+						StoredFields: []string{"foo-stored"},
+					},
+				},
+			)
+			require.Nil(t, err)
+			require.NotNil(t, res)
+			assert.NotNil(t, res.Inspect().Response)
+			ostest.CompareRawJSONwithParsedJSON(t, res, res.Inspect().Response)
+			assert.NotEmpty(t, res.Fields)
+		})
 	})
 }