Copy ES819TSDBDocValuesConsume into tests for version 0 bwc tests

Author: parkertimmins

server/src/main/java/org/elasticsearch/index/codec/tsdb/es819/ES819TSDBDocValuesFormat.java

@@ -118,7 +118,7 @@ private static boolean getOptimizedMergeEnabledDefault() {
 
     final int skipIndexIntervalSize;
     final int minDocsPerOrdinalForRangeEncoding;
-    private final boolean enableOptimizedMerge;
+    final boolean enableOptimizedMerge;
 
     /** Default constructor. */
     public ES819TSDBDocValuesFormat() {

server/src/test/java/org/elasticsearch/index/codec/tsdb/TsdbDocValueBwcTests.java

@@ -53,6 +53,7 @@
 import java.util.function.IntSupplier;
 
 import static org.hamcrest.Matchers.equalTo;
+import static org.elasticsearch.index.codec.tsdb.es819.ES819TSDBDocValuesFormatTests.TestES819TSDBDocValuesFormatVersion0;
 
 public class TsdbDocValueBwcTests extends ESTestCase {
 
@@ -62,6 +63,13 @@ public void testMixedIndex() throws Exception {
         testMixedIndex(oldCodec, newCodec);
     }
 
+    // TODO update Current to Version1 once version is incremented
+    public void testMixedIndexDocValueVersion0ToCurrent() throws Exception {
+        var oldCodec = TestUtil.alwaysDocValuesFormat(new TestES819TSDBDocValuesFormatVersion0());
+        var newCodec = TestUtil.alwaysDocValuesFormat(new ES819TSDBDocValuesFormat());
+        testMixedIndex(oldCodec, newCodec);
+    }
+
     public void testMixedIndex816To900Lucene101() throws Exception {
         var oldCodec = new Elasticsearch816Codec() {