LUCENE-8917: Fix Solr's TestCodecSupport to stop trying to use the now-removed Direct docValues format

solr/core/src/test-files/solr/collection1/conf/schema_codec.xml

@@ -16,7 +16,10 @@
  limitations under the License.
 -->
 <schema name="codec" version="1.2">
-  <fieldType name="string_direct" class="solr.StrField" postingsFormat="Direct" docValuesFormat="Direct"/>
+  <!-- NOTE: Direct (and Disk) DocValues formats were removed, so we use "Asserting" 
+       as a way to vet that the configuration actually matters.
+  -->
+  <fieldType name="string_direct" class="solr.StrField" postingsFormat="Direct" docValuesFormat="Asserting" />
   <fieldType name="string_standard" class="solr.StrField" postingsFormat="Lucene50"/>
 
   <fieldType name="string_disk" class="solr.StrField" docValuesFormat="Lucene80"/>

solr/core/src/test/org/apache/solr/core/TestCodecSupport.java

@@ -56,13 +56,15 @@ public class TestCodecSupport extends SolrTestCaseJ4 {
   }
 
   public void testDocValuesFormats() {
+    // NOTE: Direct (and Disk) DocValues formats were removed, so we use "Asserting" 
+    // as a way to vet that the configuration actually matters.
     Codec codec = h.getCore().getCodec();
     Map<String, SchemaField> fields = h.getCore().getLatestSchema().getFields();
     SchemaField schemaField = fields.get("string_disk_f");
     PerFieldDocValuesFormat format = (PerFieldDocValuesFormat) codec.docValuesFormat();
     assertEquals(TestUtil.getDefaultDocValuesFormat().getName(), format.getDocValuesFormatForField(schemaField.getName()).getName());
     schemaField = fields.get("string_direct_f");
-    assertEquals("Direct", format.getDocValuesFormatForField(schemaField.getName()).getName());
+    assertEquals("Asserting", format.getDocValuesFormatForField(schemaField.getName()).getName());
     schemaField = fields.get("string_f");
     assertEquals(TestUtil.getDefaultDocValuesFormat().getName(),
         format.getDocValuesFormatForField(schemaField.getName()).getName());
@@ -79,13 +81,15 @@ public class TestCodecSupport extends SolrTestCaseJ4 {
   }
 
   public void testDynamicFieldsDocValuesFormats() {
+    // NOTE: Direct (and Disk) DocValues formats were removed, so we use "Asserting" 
+    // as a way to vet that the configuration actually matters.
     Codec codec = h.getCore().getCodec();
     PerFieldDocValuesFormat format = (PerFieldDocValuesFormat) codec.docValuesFormat();
 
     assertEquals(TestUtil.getDefaultDocValuesFormat().getName(), format.getDocValuesFormatForField("foo_disk").getName());
     assertEquals(TestUtil.getDefaultDocValuesFormat().getName(), format.getDocValuesFormatForField("bar_disk").getName());
-    assertEquals("Direct", format.getDocValuesFormatForField("foo_direct").getName());
-    assertEquals("Direct", format.getDocValuesFormatForField("bar_direct").getName());
+    assertEquals("Asserting", format.getDocValuesFormatForField("foo_direct").getName());
+    assertEquals("Asserting", format.getDocValuesFormatForField("bar_direct").getName());
   }
   
   private void reloadCoreAndRecreateIndex() {