Add ReindexTaskStateDoc tests

Added xcontent serialization tests for ReindexTaskStateDoc

Related to elastic#42612
Depends on elastic#49278 (todo)

modules/reindex/src/main/java/org/elasticsearch/index/reindex/ReindexTaskStateDoc.java

@@ -31,7 +31,6 @@
 
 import java.io.IOException;
 
-// TODO: This class has become complicated enough that we should implement a xcontent serialization test
 public class ReindexTaskStateDoc implements ToXContentObject {
 
     public static final ConstructingObjectParser<ReindexTaskStateDoc, Void> PARSER =

modules/reindex/src/test/java/org/elasticsearch/index/reindex/ReindexTaskStateDocTests.java

@@ -0,0 +1,107 @@
+/*
+ * 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.index.reindex;
+
+import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.tasks.TaskId;
+import org.elasticsearch.test.AbstractXContentTestCase;
+
+import java.io.IOException;
+import java.util.Collections;
+
+public class ReindexTaskStateDocTests extends AbstractXContentTestCase<ReindexTaskStateDoc> {
+    @Override
+    protected ReindexTaskStateDoc createTestInstance() {
+        ReindexTaskStateDoc doc = new ReindexTaskStateDoc(new ReindexRequest().setSourceIndices("source").setDestIndex("dest"),
+            randomBoolean());
+
+        if (randomBoolean()) {
+            doc = doc.withNewAllocation(randomNonNegativeLong(), new TaskId(randomAlphaOfLength(10), randomNonNegativeLong()));
+        }
+
+        if (randomBoolean()) {
+            doc = doc.withCheckpoint(new ScrollableHitSource.Checkpoint(randomNonNegativeLong()),
+                randomStatus());
+        }
+
+        if (randomBoolean()) {
+            doc = doc.withRequestsPerSecond(randomFloat());
+        }
+
+        if (randomBoolean()) {
+            doc = doc.withFinishedState(new BulkByScrollResponse(TimeValue.timeValueMillis(randomLong()), randomStatus(),
+                Collections.emptyList(), Collections.emptyList(), randomBoolean()), null);
+        } else if (randomBoolean()) {
+            // todo: need fixing once #49278 is merged.
+//            doc = doc.withFinishedState(null, new ElasticsearchException("test"));
+        }
+
+        return  doc;
+    }
+
+    private BulkByScrollTask.Status randomStatus() {
+        return new BulkByScrollTask.Status(null, randomNonNegativeLong(), randomNonNegativeLong(), randomNonNegativeLong(),
+            randomNonNegativeLong(), randomIntBetween(0, 1000), randomNonNegativeLong(), randomNonNegativeLong(),
+            randomNonNegativeLong(), randomNonNegativeLong(), TimeValue.timeValueMillis(randomLong()),
+            randomFloat(), randomBoolean() ? randomAlphaOfLength(10) : null, TimeValue.timeValueMillis(randomLong()));
+    }
+
+    @Override
+    protected ReindexTaskStateDoc doParseInstance(XContentParser parser) throws IOException {
+        return ReindexTaskStateDoc.fromXContent(parser);
+    }
+
+    @Override
+    protected boolean supportsUnknownFields() {
+        return false;
+    }
+
+    @Override
+    protected void assertEqualInstances(ReindexTaskStateDoc expectedInstance, ReindexTaskStateDoc newInstance) {
+        assertNotSame(newInstance, expectedInstance);
+        assertArrayEquals(expectedInstance.getReindexRequest().getSearchRequest().indices(),
+            newInstance.getReindexRequest().getSearchRequest().indices());
+        // todo: once ReindexRequestTests are moved to reindex module, we can validate this properly.
+        assertEquals(expectedInstance.getReindexRequest().getDestination().index(),
+            newInstance.getReindexRequest().getDestination().index());
+        assertEquals(expectedInstance.getAllocationId(), newInstance.getAllocationId());
+        if (expectedInstance.getCheckpoint() != null) {
+            assertEquals(expectedInstance.getCheckpoint().getRestartFromValue(), newInstance.getCheckpoint().getRestartFromValue());
+        } else {
+            assertNull(newInstance.getCheckpoint());
+        }
+        assertEquals(expectedInstance.getEphemeralTaskId(), newInstance.getEphemeralTaskId());
+        if (expectedInstance.getException() != null) {
+            assertEquals(expectedInstance.getException().getMessage(), newInstance.getException().getMessage());
+        } else {
+            assertNull(newInstance.getException());
+        }
+        assertEquals(expectedInstance.getFailureStatusCode(), newInstance.getFailureStatusCode());
+        assertEquals(expectedInstance.getRequestsPerSecond(), newInstance.getRequestsPerSecond(), 0.0001d);
+        // todo: once BulkByScrollResponseTests is moved to reindex module, we can validate this properly.
+        if (expectedInstance.getReindexResponse() != null) {
+            assertEquals(expectedInstance.getReindexResponse().getCreated(), newInstance.getReindexResponse().getCreated());
+        } else {
+            assertNull(newInstance.getReindexResponse());
+        }
+        assertEquals(expectedInstance.isResilient(), newInstance.isResilient());
+    }
+}