Improved assertion failure message and more logging, if the test fails again in CI.

Author: martijnvg

server/src/test/java/org/elasticsearch/index/mapper/blockloader/TextFieldBlockLoaderTests.java

@@ -27,6 +27,8 @@ public TextFieldBlockLoaderTests(Params params) {
 
     @Override
     protected Object expected(Map<String, Object> fieldMapping, Object value, TestContext testContext) {
+        logger.info("field mapping={}", fieldMapping);
+        logger.info("value={}", value);
         return expectedValue(fieldMapping, value, params, testContext);
     }
 

test/framework/src/main/java/org/elasticsearch/index/mapper/BlockLoaderTestRunner.java

@@ -13,6 +13,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.tests.index.RandomIndexWriter;
+import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.fieldvisitor.StoredFieldLoader;
@@ -24,6 +25,8 @@
 import org.junit.Assert;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -44,9 +47,25 @@ public void runTest(MapperService mapperService, Map<String, Object> document, O
         var documentXContent = XContentBuilder.builder(XContentType.JSON.xContent()).map(document);
 
         Object blockLoaderResult = setupAndInvokeBlockLoader(mapperService, documentXContent, blockLoaderFieldName);
+        expected = makeReadable(expected);
+        blockLoaderResult = makeReadable(blockLoaderResult);
         Assert.assertEquals(expected, blockLoaderResult);
     }
 
+    // Makes assertions readable:
+    private static Object makeReadable(Object expected) {
+        if (expected instanceof BytesRef bytesRef) {
+            expected = bytesRef.utf8ToString();
+        } else if (expected instanceof List<?> list && list.getFirst() instanceof BytesRef) {
+            List<String> expectedList = new ArrayList<>(list.size());
+            for (Object e : list) {
+                expectedList.add(((BytesRef) e).utf8ToString());
+            }
+            expected = expectedList;
+        }
+        return expected;
+    }
+
     private Object setupAndInvokeBlockLoader(MapperService mapperService, XContentBuilder document, String fieldName) throws IOException {
         try (Directory directory = newDirectory()) {
             RandomIndexWriter iw = new RandomIndexWriter(random(), directory);