Fix testing for dense vectors and block loaders

Author: carlosdelest

server/src/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java

@@ -53,6 +53,7 @@
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.test.index.IndexVersionUtils;
 import org.elasticsearch.xcontent.XContentBuilder;
+import org.hamcrest.Matcher;
 import org.junit.AssumptionViolatedException;
 
 import java.io.IOException;
@@ -61,9 +62,11 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 
 import static org.apache.lucene.codecs.lucene99.Lucene99HnswVectorsFormat.DEFAULT_BEAM_WIDTH;
 import static org.apache.lucene.codecs.lucene99.Lucene99HnswVectorsFormat.DEFAULT_MAX_CONN;
+import static org.hamcrest.Matchers.closeTo;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
@@ -2244,6 +2247,26 @@ protected boolean supportsEmptyInputArray() {
         return false;
     }
 
+    @Override
+    protected BlockReaderSupport getSupportedReaders(MapperService mapper, String loaderFieldName) {
+        return new BlockReaderSupport(true, true, mapper, loaderFieldName);
+    }
+
+    @Override
+    protected Function<Object, Object> loadBlockExpected(BlockReaderSupport blockReaderSupport, boolean columnReader) {
+        DenseVectorFieldType ft = (DenseVectorFieldType) blockReaderSupport.mapper().fieldType(blockReaderSupport.loaderFieldName());
+        if (ft.getElementType() != ElementType.FLOAT) {
+            return null;
+        }
+
+        return Function.identity();
+    }
+
+    @Override
+    protected Matcher<?> blockItemMatcher(Object expected) {
+        return closeTo((double) expected, 0.000001);
+    }
+
     private static class DenseVectorSyntheticSourceSupport implements SyntheticSourceSupport {
         private final int dims = between(5, 1000);
         private final ElementType elementType = randomFrom(ElementType.BYTE, ElementType.FLOAT, ElementType.BIT);