DATAES-764 - StreamQueries#streamResults does not clear scroll context when finished.

Original PR: #406

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

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.elasticsearch.core;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.util.CloseableIterator;
+import org.springframework.lang.Nullable;
+
+/**
+ * @author Sascha Woo
+ */
+public class StreamQueriesTest {
+
+	@Test // DATAES-764
+	public void shouldCallClearScrollOnIteratorClose() {
+
+		// given
+		List<String> results = new ArrayList<>();
+		results.add("one");
+
+		ScrolledPage<String> page = new ScrolledPageImpl("1234", results);
+
+		AtomicBoolean clearScrollCalled = new AtomicBoolean(false);
+
+		// when
+		CloseableIterator<String> closeableIterator = StreamQueries.streamResults( //
+				page, //
+				scrollId -> new ScrolledPageImpl(scrollId, Collections.emptyList()), //
+				scrollId -> clearScrollCalled.set(true));
+
+		while (closeableIterator.hasNext()) {
+			closeableIterator.next();
+		}
+		closeableIterator.close();
+
+		// then
+		assertThat(clearScrollCalled).isTrue();
+
+	}
+
+	private static class ScrolledPageImpl extends PageImpl<String> implements ScrolledPage<String> {
+
+		private String scrollId;
+
+		public ScrolledPageImpl(String scrollId, List<String> content) {
+			super(content);
+			this.scrollId = scrollId;
+		}
+
+		@Override
+		@Nullable
+		public String getScrollId() {
+			return scrollId;
+		}
+	}
+}