[GitHub] flink pull request #5836: [FLINK-9141][datastream] Fail early when using bot...

[fhueske <gi...@git.apache.org>]

Github user fhueske commented on a diff in the pull request:

    https://github.com/apache/flink/pull/5836#discussion_r185942147
  
    --- Diff: flink-streaming-java/src/test/java/org/apache/flink/streaming/api/datastream/SplitSideOutputTest.java ---
    @@ -0,0 +1,75 @@
    +/*
    + * 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.streaming.api.datastream;
    +
    +import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    +import org.apache.flink.streaming.api.functions.ProcessFunction;
    +import org.apache.flink.util.Collector;
    +import org.apache.flink.util.OutputTag;
    +
    +import org.junit.Test;
    +
    +import java.util.Collections;
    +
    +/**
    + * Tests that verify correct behavior when applying split/getSideOutput operations on one {@link DataStream}.
    + */
    +public class SplitSideOutputTest {
    +
    +	private static final OutputTag<String> outputTag = new OutputTag<String>("outputTag") {};
    +
    +	@Test
    +	public void testSideOutputAfterSelectIsForbidden() {
    +		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
    +
    +		SingleOutputStreamOperator<String> processInput = env.fromElements("foo")
    +			.process(new DummyProcessFunction());
    +
    +		processInput.split(Collections::singleton);
    +
    +		try {
    +			processInput.getSideOutput(outputTag);
    --- End diff --
    
    add `Assert.fail();` after `processInput.getSideOutput(outputTag);` to ensure that the test fails if no exception is thrown.


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