package com.baeldung.flink; import com.baeldung.flink.operator.WordsCapitalizer; import org.apache.flink.api.java.DataSet; import org.apache.flink.api.java.ExecutionEnvironment; import org.junit.Assert; import org.junit.Test; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; public class WordCapitalizerIntegrationTest { @Test public void givenDataSet_whenExecuteWordCapitalizer_thenReturnCapitalizedWords() throws Exception { ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment(); List data = Arrays.asList("dog", "cat", "wolf", "pig"); DataSet testDataSet = env.fromCollection(data); List dataProcessed = testDataSet .map(new WordsCapitalizer()) .collect(); List testDataCapitalized = data.stream() .map(String::toUpperCase) .collect(Collectors.toList()); Assert.assertEquals(testDataCapitalized, dataProcessed); } }