/*
    * 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.commons.io;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.nio.charset.StandardCharsets;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.commons.io.output.ByteArrayOutputStream;
  import org.apache.commons.io.test.TestUtils;
  import org.apache.commons.io.test.ThrowOnFlushAndCloseOutputStream;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests IOUtils write methods.
   *
   * @see IOUtils
   */
  @SuppressWarnings("deprecation") // includes tests for deprecated methods
  public class IOUtilsWriteTest {
  
      private static final int FILE_SIZE = 1024 * 4 + 1;
  
      private final byte[] inData = TestUtils.generateTestData(FILE_SIZE);
  
      @Test
      public void testWrite_byteArrayToOutputStream() throws Exception {
          final ByteArrayOutputStream baout = new ByteArrayOutputStream();
          final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
  
          IOUtils.write(inData, out);
          out.off();
          out.flush();
  
          assertEquals(inData.length, baout.size(), "Sizes differ");
          assertArrayEquals(inData, baout.toByteArray(), "Content differs");
      }
  
      @Test
      public void testWrite_byteArrayToOutputStream_nullData() throws Exception {
          final ByteArrayOutputStream baout = new ByteArrayOutputStream();
          final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
  
          IOUtils.write((byte[]) null, out);
          out.off();
          out.flush();
  
          assertEquals(0, baout.size(), "Sizes differ");
      }
  
      @Test
      public void testWrite_byteArrayToOutputStream_nullStream() throws Exception {
          assertThrows(NullPointerException.class, () -> IOUtils.write(inData, (OutputStream) null));
      }
  
      @Test
      public void testWrite_byteArrayToWriter() throws Exception {
          final ByteArrayOutputStream baout = new ByteArrayOutputStream();
          @SuppressWarnings("resource") // deliberately not closed
          final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
          final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
  
          IOUtils.write(inData, writer);
          out.off();
          writer.flush();
  
          assertEquals(inData.length, baout.size(), "Sizes differ");
          assertArrayEquals(inData, baout.toByteArray(), "Content differs");
      }
  
      @Test
      public void testWrite_byteArrayToWriter_Encoding() throws Exception {
          final ByteArrayOutputStream baout = new ByteArrayOutputStream();
          @SuppressWarnings("resource") // deliberately not closed
          final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
          final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
  
          IOUtils.write(inData, writer, "UTF8");
         out.off();
         writer.flush();
 
         byte[] bytes = baout.toByteArray();
         bytes = new String(bytes, StandardCharsets.UTF_8).getBytes(StandardCharsets.US_ASCII);
         assertArrayEquals(inData, bytes, "Content differs");
     }
 
     @Test
     public void testWrite_byteArrayToWriter_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write(null, writer, "UTF8");
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_byteArrayToWriter_Encoding_nullEncoding() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write(inData, writer, (String) null);
         out.off();
         writer.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_byteArrayToWriter_Encoding_nullWriter() throws Exception {
         assertThrows(NullPointerException.class, () -> IOUtils.write(inData, null, "UTF8"));
     }
 
     @Test
     public void testWrite_byteArrayToWriter_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write((byte[]) null, writer);
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_byteArrayToWriter_nullWriter() throws Exception {
         assertThrows(NullPointerException.class, () -> IOUtils.write(inData, (Writer) null));
     }
 
     @Test
     public void testWrite_charArrayToOutputStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str.toCharArray(), out);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_Encoding() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str.toCharArray(), out, "UTF16");
         out.off();
         out.flush();
 
         byte[] bytes = baout.toByteArray();
         bytes = new String(bytes, StandardCharsets.UTF_16).getBytes(StandardCharsets.US_ASCII);
         assertArrayEquals(inData, bytes, "Content differs");
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((char[]) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_Encoding_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str.toCharArray(), (OutputStream) null));
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((char[]) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_nullEncoding() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str.toCharArray(), out, (String) null);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charArrayToOutputStream_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str.toCharArray(), (OutputStream) null));
     }
 
     @Test
     public void testWrite_charArrayToWriter() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write(str.toCharArray(), writer);
         out.off();
         writer.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charArrayToWriter_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write((char[]) null, writer);
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charArrayToWriter_Encoding_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str.toCharArray(), (Writer) null));
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(csq, out);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_Encoding() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(csq, out, "UTF16");
         out.off();
         out.flush();
 
         byte[] bytes = baout.toByteArray();
         bytes = new String(bytes, StandardCharsets.UTF_16).getBytes(StandardCharsets.US_ASCII);
         assertArrayEquals(inData, bytes, "Content differs");
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((CharSequence) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_Encoding_nullStream() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
         assertThrows(NullPointerException.class, () -> IOUtils.write(csq, (OutputStream) null));
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((CharSequence) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_nullEncoding() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(csq, out, (String) null);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charSequenceToOutputStream_nullStream() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
         assertThrows(NullPointerException.class, () -> IOUtils.write(csq, (OutputStream) null));
     }
 
     @Test
     public void testWrite_charSequenceToWriter() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write(csq, writer);
         out.off();
         writer.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_charSequenceToWriter_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write((CharSequence) null, writer);
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_charSequenceToWriter_Encoding_nullStream() throws Exception {
         final CharSequence csq = new StringBuilder(new String(inData, StandardCharsets.US_ASCII));
         assertThrows(NullPointerException.class, () -> IOUtils.write(csq, (Writer) null));
     }
 
     @Test
     public void testWrite_stringToOutputStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str, out);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_stringToOutputStream_Encoding() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str, out, "UTF16");
         out.off();
         out.flush();
 
         byte[] bytes = baout.toByteArray();
         bytes = new String(bytes, StandardCharsets.UTF_16).getBytes(StandardCharsets.US_ASCII);
         assertArrayEquals(inData, bytes, "Content differs");
     }
 
     @Test
     public void testWrite_stringToOutputStream_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((String) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_stringToOutputStream_Encoding_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str, (OutputStream) null));
     }
 
     @Test
     public void testWrite_stringToOutputStream_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write((String) null, out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_stringToOutputStream_nullEncoding() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
 
         IOUtils.write(str, out, (String) null);
         out.off();
         out.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_stringToOutputStream_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str, (OutputStream) null));
     }
 
     @Test
     public void testWrite_stringToWriter() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write(str, writer);
         out.off();
         writer.flush();
 
         assertEquals(inData.length, baout.size(), "Sizes differ");
         assertArrayEquals(inData, baout.toByteArray(), "Content differs");
     }
 
     @Test
     public void testWrite_stringToWriter_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.write((String) null, writer);
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWrite_stringToWriter_Encoding_nullStream() throws Exception {
         final String str = new String(inData, StandardCharsets.US_ASCII);
         assertThrows(NullPointerException.class, () -> IOUtils.write(str, (Writer) null));
     }
 
     @Test
     public void testWriteLines_OutputStream() throws Exception {
         final Object[] data = {
                 "hello", new StringBuffer("world"), "", "this is", null, "some text"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(list, "*", out);
 
         out.off();
         out.flush();
 
         final String expected = "hello*world**this is**some text*";
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_OutputStream_Encoding() throws Exception {
         final Object[] data = {
                 "hello\u8364", new StringBuffer("world"), "", "this is", null, "some text"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(list, "*", out, StandardCharsets.UTF_8.name());
 
         out.off();
         out.flush();
 
         final String expected = "hello\u8364*world**this is**some text*";
         final String actual = baout.toString(StandardCharsets.UTF_8.name());
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_OutputStream_Encoding_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(null, "*", out, StandardCharsets.US_ASCII.name());
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWriteLines_OutputStream_Encoding_nullEncoding() throws Exception {
         final Object[] data = {
                 "hello", new StringBuffer("world"), "", "this is", null, "some text"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(list, "*", out, (String) null);
 
         out.off();
         out.flush();
 
         final String expected = "hello*world**this is**some text*";
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_OutputStream_Encoding_nullSeparator() throws Exception {
         final Object[] data = {"hello", "world"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(list, null, out, StandardCharsets.US_ASCII.name());
         out.off();
         out.flush();
 
         final String expected = "hello" + System.lineSeparator() + "world" + System.lineSeparator();
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_OutputStream_Encoding_nullStream() throws Exception {
         final Object[] data = { "hello", "world" };
         final List<Object> list = Arrays.asList(data);
         assertThrows(NullPointerException.class, () -> IOUtils.writeLines(list, "*", null, StandardCharsets.US_ASCII.name()));
     }
 
     @Test
     public void testWriteLines_OutputStream_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(null, "*", out);
         out.off();
         out.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWriteLines_OutputStream_nullSeparator() throws Exception {
         final Object[] data = {"hello", "world"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, false, true);
 
         IOUtils.writeLines(list, null, out);
         out.off();
         out.flush();
 
         final String expected = "hello" + System.lineSeparator() + "world" + System.lineSeparator();
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_OutputStream_nullStream() throws Exception {
         final Object[] data = {"hello", "world"};
         final List<Object> list = Arrays.asList(data);
         assertThrows(NullPointerException.class, () -> IOUtils.writeLines(list, "*", (OutputStream) null));
     }
 
     @Test
     public void testWriteLines_Writer() throws Exception {
         final Object[] data = {
                 "hello", new StringBuffer("world"), "", "this is", null, "some text"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.writeLines(list, "*", writer);
 
         out.off();
         writer.flush();
 
         final String expected = "hello*world**this is**some text*";
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_Writer_nullData() throws Exception {
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.writeLines(null, "*", writer);
         out.off();
         writer.flush();
 
         assertEquals(0, baout.size(), "Sizes differ");
     }
 
     @Test
     public void testWriteLines_Writer_nullSeparator() throws Exception {
         final Object[] data = {"hello", "world"};
         final List<Object> list = Arrays.asList(data);
 
         final ByteArrayOutputStream baout = new ByteArrayOutputStream();
         @SuppressWarnings("resource") // deliberately not closed
         final ThrowOnFlushAndCloseOutputStream out = new ThrowOnFlushAndCloseOutputStream(baout, true, true);
         final Writer writer = new OutputStreamWriter(baout, StandardCharsets.US_ASCII);
 
         IOUtils.writeLines(list, null, writer);
         out.off();
         writer.flush();
 
         final String expected = "hello" + System.lineSeparator() + "world" + System.lineSeparator();
         final String actual = baout.toString();
         assertEquals(expected, actual);
     }
 
     @Test
     public void testWriteLines_Writer_nullStream() throws Exception {
         final Object[] data = {"hello", "world"};
         final List<Object> list = Arrays.asList(data);
         assertThrows(NullPointerException.class, () -> IOUtils.writeLines(list, "*", (Writer) null));
     }
 
 }