Demonstrates that a default KeyValueTemplate with a standard MapKeyValueAdapter is not thread safe

KeyValueThreadSafety.java

import org.junit.Assert;
import org.junit.Test;
import org.springframework.data.annotation.Id;
import org.springframework.data.keyvalue.annotation.KeySpace;
import org.springframework.data.keyvalue.core.KeyValueTemplate;
import org.springframework.data.map.MapKeyValueAdapter;

import java.util.LinkedList;
import java.util.concurrent.CompletableFuture;

import static org.hamcrest.CoreMatchers.is;

public class KeyValueThreadSafety {
  @Test
  public void test() {
    KeyValueTemplate template = new KeyValueTemplate(new MapKeyValueAdapter());

    LinkedList<CompletableFuture<Void>> futures = new LinkedList<>();
    for (int index = 0; index < 10; index++) {
      TestEntity entity = new TestEntity(String.valueOf(index));
      futures.add(CompletableFuture.runAsync(() -> template.insert(entity)));
    }

    futures.forEach(CompletableFuture::join);
    Assert.assertThat(template.count(TestEntity.class), is(10L));
  }

  @KeySpace("test")
  public static class TestEntity {
    @Id
    final String value;

    public TestEntity(String value) {
      this.value = value;
    }
  }
}

output.txt

java.lang.AssertionError: 
Expected: is <10L>
     but: was <3L>
Expected :is <10L>
Actual   :<3L>