Fix field parameters in search request creation.

Original Pull Request #2739
Closes #2727

(cherry picked from commit f087d5a)

Author: sothawo

src/main/java/org/springframework/data/elasticsearch/client/elc/RequestConverter.java

@@ -30,6 +30,7 @@
 import co.elastic.clients.elasticsearch._types.mapping.RuntimeField;
 import co.elastic.clients.elasticsearch._types.mapping.RuntimeFieldType;
 import co.elastic.clients.elasticsearch._types.mapping.TypeMapping;
+import co.elastic.clients.elasticsearch._types.query_dsl.FieldAndFormat;
 import co.elastic.clients.elasticsearch._types.query_dsl.Like;
 import co.elastic.clients.elasticsearch.cluster.HealthRequest;
 import co.elastic.clients.elasticsearch.core.*;
@@ -1050,10 +1051,9 @@ public MsearchRequest searchMsearchRequest(
 							}
 
 							if (!isEmpty(query.getFields())) {
-								bb.fields(fb -> {
-									query.getFields().forEach(fb::field);
-									return fb;
-								});
+								var fieldAndFormats = query.getFields().stream()
+										.map(field -> FieldAndFormat.of(b -> b.field(field))).toList();
+								bb.fields(fieldAndFormats);
 							}
 
 							if (!isEmpty(query.getStoredFields())) {
@@ -1169,10 +1169,9 @@ private <T> void prepareSearchRequest(Query query, @Nullable Class<T> clazz, Ind
 		builder.source(getSourceConfig(query));
 
 		if (!isEmpty(query.getFields())) {
-			builder.fields(fb -> {
-				query.getFields().forEach(fb::field);
-				return fb;
-			});
+			var fieldAndFormats = query.getFields().stream()
+					.map(field -> FieldAndFormat.of(b -> b.field(field))).toList();
+			builder.fields(fieldAndFormats);
 		}
 
 		if (!isEmpty(query.getStoredFields())) {

src/test/java/org/springframework/data/elasticsearch/core/RuntimeFieldsIntegrationTests.java

@@ -31,6 +31,7 @@
 import org.springframework.data.elasticsearch.annotations.Field;
 import org.springframework.data.elasticsearch.annotations.FieldType;
 import org.springframework.data.elasticsearch.annotations.Mapping;
+import org.springframework.data.elasticsearch.annotations.ScriptedField;
 import org.springframework.data.elasticsearch.core.mapping.IndexCoordinates;
 import org.springframework.data.elasticsearch.core.query.Criteria;
 import org.springframework.data.elasticsearch.core.query.CriteriaQuery;
@@ -95,6 +96,88 @@ void shouldUseRuntimeFieldWithoutScript() {
 		assertThat(searchHits.getSearchHit(0).getId()).isEqualTo("1");
 	}
 
+	@Test // #2727
+	@DisplayName("should return runtime fields values")
+	void shouldReturnRuntimeFieldsValues() {
+
+		var entity = new SAREntity();
+		entity.setId("42");
+		entity.setValue(3);
+
+		operations.save(entity);
+
+		var runtimeField1 = getRuntimeField("scriptedValue1", 2);
+		var runtimeField2 = getRuntimeField("scriptedValue2", 3);
+
+		var query = CriteriaQuery.builder(Criteria.where("value").is(3)).build();
+		query.addRuntimeField(runtimeField1);
+		query.addRuntimeField(runtimeField2);
+		query.addSourceFilter(new FetchSourceFilterBuilder().withIncludes("*").build());
+		query.addFields("scriptedValue1", "scriptedValue2");
+		var searchHits = operations.search(query, SAREntity.class);
+
+		assertThat(searchHits.getTotalHits()).isEqualTo(1);
+		var foundEntity = searchHits.getSearchHit(0).getContent();
+		assertThat(foundEntity.value).isEqualTo(3);
+		assertThat(foundEntity.getScriptedValue1()).isEqualTo(6);
+		assertThat(foundEntity.getScriptedValue2()).isEqualTo(9);
+	}
+
+	@Document(indexName = "#{@indexNameProvider.indexName()}-sar")
+	public static class SAREntity {
+		@Nullable private String id;
+		@Field(type = FieldType.Integer)
+		@Nullable Integer value;
+		@ScriptedField
+		@Nullable Integer scriptedValue1;
+		@ScriptedField
+		@Nullable Integer scriptedValue2;
+		// getter and setter omitted
+
+		@Nullable
+		public String getId() {
+			return id;
+		}
+
+		public void setId(@Nullable String id) {
+			this.id = id;
+		}
+
+		@Nullable
+		public Integer getValue() {
+			return value;
+		}
+
+		public void setValue(@Nullable Integer value) {
+			this.value = value;
+		}
+
+		@Nullable
+		public Integer getScriptedValue1() {
+			return scriptedValue1;
+		}
+
+		public void setScriptedValue1(@Nullable Integer scriptedValue1) {
+			this.scriptedValue1 = scriptedValue1;
+		}
+
+		@Nullable
+		public Integer getScriptedValue2() {
+			return scriptedValue2;
+		}
+
+		public void setScriptedValue2(@Nullable Integer scriptedValue2) {
+			this.scriptedValue2 = scriptedValue2;
+		}
+	}
+
+	private static RuntimeField getRuntimeField(String fieldName, int factor) {
+		return new RuntimeField(
+				fieldName,
+				"long",
+				String.format("emit(doc['value'].size() > 0 ? doc['value'].value * %d : 0)", factor));
+	}
+
 	@Test // #2431
 	@DisplayName("should return value from runtime field defined in mapping")
 	void shouldReturnValueFromRuntimeFieldDefinedInMapping() {