Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/6189#discussion_r197073186
--- Diff:
flink-runtime/src/test/java/org/apache/flink/runtime/rest/MultipartUploadTestBase.java
---
@@ -0,0 +1,405 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF 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.apache.flink.runtime.rest;
+
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.api.java.tuple.Tuple2;
+import org.apache.flink.configuration.ConfigConstants;
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.configuration.RestOptions;
+import org.apache.flink.configuration.WebOptions;
+import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
+import org.apache.flink.runtime.rest.handler.HandlerRequest;
+import org.apache.flink.runtime.rest.handler.RestHandlerException;
+import org.apache.flink.runtime.rest.handler.RestHandlerSpecification;
+import org.apache.flink.runtime.rest.messages.EmptyMessageParameters;
+import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
+import org.apache.flink.runtime.rest.messages.EmptyResponseBody;
+import org.apache.flink.runtime.rest.messages.MessageHeaders;
+import org.apache.flink.runtime.rest.messages.RequestBody;
+import org.apache.flink.runtime.rpc.RpcUtils;
+import org.apache.flink.runtime.webmonitor.RestfulGateway;
+import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
+import org.apache.flink.util.TestLogger;
+
+import
org.apache.flink.shaded.jackson2.com.fasterxml.jackson.annotation.JsonCreator;
+import
org.apache.flink.shaded.jackson2.com.fasterxml.jackson.annotation.JsonProperty;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.rules.TemporaryFolder;
+
+import javax.annotation.Nonnull;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+import java.util.Random;
+import java.util.concurrent.CompletableFuture;
+
+import static java.util.Objects.requireNonNull;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Test base for verifying support of multipart uploads via REST.
+ */
+public abstract class MultipartUploadTestBase extends TestLogger {
--- End diff --
I'm not a huge fan of using inheritance in order to share code since it
makes understanding tests quite hard. Instead one could create a
`RestServerEndpointResource` or a `MultipartUploadResource` which extends
`ExternalResource` and can be added via a `@Rule` or `@ClassRule`. See
`MiniClusterResource` for an example.
---
