flink-tests/src/test/java/org/apache/flink/test/iterative/IdentityIterationITCase.java

/*
 * 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
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 */

package org.apache.flink.test.iterative;

import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.LocalCollectionOutputFormat;
import org.apache.flink.api.java.operators.IterativeDataSet;
import org.apache.flink.test.util.JavaProgramTestBase;

import java.util.ArrayList;
import java.util.List;

import static org.junit.Assert.assertEquals;

/** Test empty (identity) bulk iteration. */
public class IdentityIterationITCase extends JavaProgramTestBase {

    private List<Long> result = new ArrayList<Long>();

    @Override
    protected void testProgram() throws Exception {
        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        IterativeDataSet<Long> iteration = env.generateSequence(1, 10).iterate(100);
        iteration.closeWith(iteration).output(new LocalCollectionOutputFormat<Long>(result));

        env.execute();
    }

    @Override
    protected void postSubmit() {
        assertEquals(10, result.size());

        long sum = 0;
        for (Long l : result) {
            sum += l;
        }
        assertEquals(55, sum);
    }
}