Add a simple test-case for XLSX2CSV

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1888432 13f79535-47bb-0310-9956-ffa450edef68

examples/src/test/java/org/apache/poi/integration/TestXLSX2CSV.java

@@ -0,0 +1,113 @@
+/* ====================================================================
+   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.poi.integration;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.apache.poi.examples.xssf.eventusermodel.XLSX2CSV;
+import org.apache.poi.openxml4j.opc.OPCPackage;
+import org.apache.poi.openxml4j.opc.PackageAccess;
+import org.apache.poi.xssf.XSSFTestDataSamples;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class TestXLSX2CSV {
+	private PrintStream err;
+	private final ByteArrayOutputStream errorBytes = new ByteArrayOutputStream();
+
+	@BeforeEach
+	public void setUp() {
+		// remember and replace default error streams
+		err = System.err;
+
+		PrintStream error = new PrintStream(errorBytes);
+		System.setErr(error);
+	}
+
+	@AfterEach
+	public void tearDown() throws Exception {
+		// restore output-streams again
+		System.setErr(err);
+
+		// Print out found error
+		if (errorBytes.size() > 0) {
+			System.err.println("Had stderr: " + errorBytes.toString("UTF-8"));
+		}
+	}
+
+	@Test
+	public void testNoArgument() throws Exception {
+		// returns with some System.err
+		XLSX2CSV.main(new String[0]);
+
+		String output = errorBytes.toString("UTF-8");
+		assertTrue(output.contains("XLSX2CSV <xlsx file>"), "Had: " + output);
+	}
+
+	@Test
+	public void testInvalidFile() throws Exception {
+		// returns with some System.err
+		XLSX2CSV.main(new String[] { "not-existing-file.xlsx" });
+
+		String output = errorBytes.toString("UTF-8");
+		assertTrue(output.contains("Not found or not a file: not-existing-file.xlsx"), "Had: " + output);
+	}
+
+	@Test
+	public void testSampleFile() throws Exception {
+		final ByteArrayOutputStream outputBytes = new ByteArrayOutputStream();
+		PrintStream out = new PrintStream(outputBytes);
+
+		// The package open is instantaneous, as it should be.
+		try (OPCPackage p = OPCPackage.open(XSSFTestDataSamples.getSampleFile("sample.xlsx").getAbsolutePath(), PackageAccess.READ)) {
+			XLSX2CSV xlsx2csv = new XLSX2CSV(p, out, -1);
+			xlsx2csv.process();
+		}
+
+		String errorOutput = errorBytes.toString("UTF-8");
+		assertEquals(errorOutput.length(), 0);
+
+		String output = outputBytes.toString("UTF-8");
+		assertTrue(output.contains("\"Lorem\",111"), "Had: " + output);
+		assertTrue(output.contains(",\"hello, xssf\",,\"hello, xssf\""), "Had: " + output);
+	}
+
+	@Test
+	public void testMinColumns() throws Exception {
+		final ByteArrayOutputStream outputBytes = new ByteArrayOutputStream();
+		PrintStream out = new PrintStream(outputBytes);
+
+		// The package open is instantaneous, as it should be.
+		try (OPCPackage p = OPCPackage.open(XSSFTestDataSamples.getSampleFile("sample.xlsx").getAbsolutePath(), PackageAccess.READ)) {
+			XLSX2CSV xlsx2csv = new XLSX2CSV(p, out, 5);
+			xlsx2csv.process();
+		}
+
+		String errorOutput = errorBytes.toString("UTF-8");
+		assertEquals(errorOutput.length(), 0);
+
+		String output = outputBytes.toString("UTF-8");
+		assertTrue(output.contains("\"Lorem\",111,,,"), "Had: " + output);
+		assertTrue(output.contains(",\"hello, xssf\",,\"hello, xssf\","), "Had: " + output);
+	}
+}