pnowojski commented on a change in pull request #6367: [FLINK-9850] Add a string to the print method to identify output for DataStream URL: https://github.com/apache/flink/pull/6367#discussion_r210240596
########## File path: flink-java/src/test/java/org/apache/flink/api/java/io/PrintingOutputFormatTest.java ########## @@ -0,0 +1,130 @@ +/* + * 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.api.java.io; + +import org.junit.After; +import org.junit.Before; +import org.junit.Test; + +import java.io.ByteArrayOutputStream; +import java.io.PrintStream; + +import static org.junit.Assert.assertEquals; + +/** + * Tests for the {@link PrintingOutputFormat}. + */ +public class PrintingOutputFormatTest { + + private final PrintStream originalSystemOut = System.out; + private final PrintStream originalSystemErr = System.err; + + private final ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream(); + private final ByteArrayOutputStream arrayErrorStream = new ByteArrayOutputStream(); + + private final String line = System.lineSeparator(); + + @Before + public void setUp() { + System.setOut(new PrintStream(arrayOutputStream)); + System.setErr(new PrintStream(arrayErrorStream)); + } + + @After + public void tearDown() { + if (System.out != originalSystemOut) { + System.out.close(); + } + if (System.err != originalSystemErr) { + System.err.close(); + } + System.setOut(originalSystemOut); + System.setErr(originalSystemErr); + } + + @Test + public void testPrintOutputFormatStdOut() throws Exception { + PrintingOutputFormat<String> printSink = new PrintingOutputFormat<>(); + printSink.open(0, 1); + + printSink.writeRecord("hello world!"); + + assertEquals("Print to System.out", printSink.toString()); + assertEquals("hello world!" + line, arrayOutputStream.toString()); + printSink.close(); + } + + @Test + public void testPrintOutputFormatStdErr() throws Exception { + PrintingOutputFormat<String> printSink = new PrintingOutputFormat<>(true); + printSink.open(0, 1); + + printSink.writeRecord("hello world!"); + + assertEquals("Print to System.err", printSink.toString()); + assertEquals("hello world!" + line, arrayErrorStream.toString()); + printSink.close(); + } + + @Test + public void testPrintOutputFormatWithPrefix() throws Exception { + PrintingOutputFormat<String> printSink = new PrintingOutputFormat<>(); + printSink.open(1, 2); + + printSink.writeRecord("hello world!"); + + assertEquals("Print to System.out", printSink.toString()); + assertEquals("2> hello world!" + line, arrayOutputStream.toString()); + printSink.close(); + } + + @Test + public void testPrintOutputFormatWithIdentifierAndPrefix() throws Exception { + PrintingOutputFormat<String> printSink = new PrintingOutputFormat<>("mySink", false); + printSink.open(1, 2); + + printSink.writeRecord("hello world!"); + + assertEquals("Print to System.out", printSink.toString()); + assertEquals("mySink:2> hello world!" + line, arrayOutputStream.toString()); + + printSink = new PrintingOutputFormat<>("mySink", true); + assertEquals("Print to System.err", printSink.toString()); + assertEquals("mySink:2> hello world!" + line, arrayOutputStream.toString()); Review comment: Were you trying in those 3 lines test for stderr? If so, you haven't invoked anything on stderr instance of `printSink` and in this line, you are just asserting again the standard output. For asserting stderr you should check against `arrayErrorStream` instead of `arrayOutputStream`. However, I don't think it is necessary here to test for prefix AND for stderr together. So I would be actually in favour of dropping those 3 lines here (If you want you can keep those assertions after fixing the before mentioned bug). ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
