[Backport 8.19] Source shortcut support

java-client/src/main/java/co/elastic/clients/elasticsearch/core/search/SourceConfig.java

@@ -25,15 +25,17 @@
 import co.elastic.clients.json.JsonpSerializable;
 import co.elastic.clients.json.JsonpUtils;
 import co.elastic.clients.json.ObjectDeserializer;
-import co.elastic.clients.json.UnionDeserializer;
 import co.elastic.clients.util.ApiTypeHelper;
 import co.elastic.clients.util.ObjectBuilder;
 import co.elastic.clients.util.ObjectBuilderBase;
 import co.elastic.clients.util.TaggedUnion;
 import co.elastic.clients.util.TaggedUnionUtils;
 import jakarta.json.stream.JsonGenerator;
+import jakarta.json.stream.JsonParser;
 import java.lang.Boolean;
 import java.lang.Object;
+import java.util.EnumSet;
+import java.util.List;
 import java.util.Objects;
 import java.util.function.Function;
 import javax.annotation.Nullable;
@@ -181,12 +183,23 @@ public SourceConfig build() {
 
 	}
 
-	private static JsonpDeserializer<SourceConfig> buildSourceConfigDeserializer() {
-		return new UnionDeserializer.Builder<SourceConfig, Kind, Object>(SourceConfig::new, false)
-				.addMember(Kind.Filter, SourceFilter._DESERIALIZER)
-				.addMember(Kind.Fetch, JsonpDeserializer.booleanDeserializer()).build();
-	}
-
 	public static final JsonpDeserializer<SourceConfig> _DESERIALIZER = JsonpDeserializer
-			.lazy(SourceConfig::buildSourceConfigDeserializer);
+			.lazy(() -> JsonpDeserializer.of(EnumSet.of(JsonParser.Event.START_OBJECT, JsonParser.Event.START_ARRAY,
+					JsonParser.Event.VALUE_TRUE, JsonParser.Event.VALUE_FALSE), (parser, mapper, event) -> {
+						return switch (event) {
+							case VALUE_TRUE -> SourceConfig.of(b -> b.fetch(true));
+							case VALUE_FALSE -> SourceConfig.of(b -> b.fetch(false));
+							case START_ARRAY -> {
+								List<String> includes = JsonpDeserializer
+										.arrayDeserializer(JsonpDeserializer.stringDeserializer())
+										.deserialize(parser, mapper, event);
+								yield SourceConfig.of(b -> b.filter(f -> f.includes(includes)));
+							}
+							case START_OBJECT -> {
+								SourceFilter filter = SourceFilter._DESERIALIZER.deserialize(parser, mapper, event);
+								yield SourceConfig.of(b -> b.filter(filter));
+							}
+							default -> null;
+						};
+					}));
 }

java-client/src/test/java/co/elastic/clients/elasticsearch/spec_issues/SpecIssuesTest.java

@@ -46,6 +46,8 @@
 
 import java.io.InputStream;
 import java.io.StringReader;
+import java.util.Arrays;
+import java.util.Collections;
 
 /**
  * Test issues related to the API specifications.
@@ -54,6 +56,28 @@
  */
 public class SpecIssuesTest extends ModelTestCase {
 
+    @Test
+    public void i1245_sourceAsArray() {
+        // "_source" also accepts an array of field names as a shortcut for SourceFilter.includes
+        SearchRequest array = fromJson("{\"_source\":[\"date\",\"distributor\"]}", SearchRequest.class);
+        assertTrue(array.source().isFilter());
+        assertEquals(Arrays.asList("date", "distributor"), array.source().filter().includes());
+
+        // The object form still works, with all SourceFilter fields set
+        SearchRequest object = fromJson(
+            "{\"_source\":{\"includes\":[\"date\",\"distributor\"],\"excludes\":[\"secret\"],\"exclude_vectors\":true}}",
+            SearchRequest.class);
+        assertTrue(object.source().isFilter());
+        assertEquals(Arrays.asList("date", "distributor"), object.source().filter().includes());
+        assertEquals(Collections.singletonList("secret"), object.source().filter().excludes());
+        assertTrue(object.source().filter().excludeVectors());
+
+        // The boolean form still works
+        SearchRequest bool = fromJson("{\"_source\":false}", SearchRequest.class);
+        assertTrue(bool.source().isFetch());
+        assertFalse(bool.source().fetch());
+    }
+
     @Test
     public void i0328_charFilter() throws Exception {
         // Both mappings and mappings_path are optional