Fix BulkItemResponse.Failure.toString

It was busted and causing intermittent test failures.

core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java

@@ -177,7 +177,7 @@ public class BulkItemResponse implements Streamable, StatusToXContent {
 
         @Override
         public String toString() {
-            return Strings.toString(this);
+            return Strings.toString(this, true);
         }
     }
 

core/src/main/java/org/elasticsearch/common/Strings.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.common;
 
 import org.apache.lucene.util.BytesRefBuilder;
+import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.FastStringReader;
 import org.elasticsearch.common.util.CollectionUtils;
@@ -1062,12 +1063,27 @@ public class Strings {
      * {@link ToXContent}.
      */
     public static String toString(ToXContent toXContent) {
+        return toString(toXContent, false);
+    }
+
+    /**
+     * Return a {@link String} that is the json representation of the provided
+     * {@link ToXContent}.
+     * @param wrapInObject set this to true if the ToXContent instance expects to be inside an object
+     */
+    public static String toString(ToXContent toXContent, boolean wrapInObject) {
         try {
             XContentBuilder builder = JsonXContent.contentBuilder();
+            if (wrapInObject) {
+                builder.startObject();
+            }
             toXContent.toXContent(builder, ToXContent.EMPTY_PARAMS);
+            if (wrapInObject) {
+                builder.endObject();
+            }
             return builder.string();
         } catch (IOException e) {
-            throw new AssertionError("Cannot happen", e);
+            return "Error building toString out of XContent: " + ExceptionsHelper.stackTrace(e);
         }
     }
 

core/src/test/java/org/elasticsearch/action/bulk/BulkItemResponseTests.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.action.bulk;
+
+import org.elasticsearch.action.bulk.BulkItemResponse.Failure;
+import org.elasticsearch.test.ESTestCase;
+
+import static org.hamcrest.Matchers.containsString;
+
+public class BulkItemResponseTests extends ESTestCase {
+    public void testFailureToString() {
+        Failure failure = new Failure("index", "type", "id", new RuntimeException("test"));
+        String toString = failure.toString();
+        assertThat(toString, containsString("\"type\":\"runtime_exception\""));
+        assertThat(toString, containsString("\"reason\":\"test\""));
+        assertThat(toString, containsString("\"status\":500"));
+    }
+}

core/src/test/java/org/elasticsearch/common/StringsTests.java

@@ -19,8 +19,14 @@
 
 package org.elasticsearch.common;
 
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.test.ESTestCase;
 
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.containsString;
+
 public class StringsTests extends ESTestCase {
     public void testToCamelCase() {
         assertEquals("foo", Strings.toCamelCase("foo"));
@@ -60,4 +66,21 @@ public class StringsTests extends ESTestCase {
         assertEquals("o", Strings.cleanTruncate("o\uD83D\uDEAB", 1));
         assertEquals("", Strings.cleanTruncate("foo", 0));
     }
+
+    public void testEvilToString() {
+        ToXContent needsEnclosingObject = new ToXContent() {
+            @Override
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+                return builder.field("ok", "here").field("catastrophe", "");
+            }
+        };
+        String toString = Strings.toString(needsEnclosingObject);
+        assertThat(toString, containsString("Error building toString out of XContent"));
+        assertThat(toString, containsString("Can not write a field name, expecting a value"));
+
+        // We can salvage it!
+        toString = Strings.toString(needsEnclosingObject, true);
+        assertThat(toString, containsString("\"ok\":\"here\""));
+        assertThat(toString, containsString("\"catastrophe\":\"\""));
+    }
 }