src/test/java/org/apache/commons/codec/binary/Base64OutputStreamTest.java - commons-codec - Git at Google

 /*
  * 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
  *
  *      https://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.codec.binary;

 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;

 import java.io.ByteArrayOutputStream;
 import java.io.OutputStream;

 import org.apache.commons.codec.CodecPolicy;
 import org.junit.jupiter.api.Test;

 /**
  * Tests {@link Base64OutputStream}.
  */
 class Base64OutputStreamTest {

     private static final byte[] CR_LF = {(byte) '\r', (byte) '\n'};

     private static final byte[] LF = {(byte) '\n'};

     private static final String STRING_FIXTURE = "Hello World";

     private void testBase64EmptyOutputStream(final int chunkSize) throws Exception {
         final byte[] emptyEncoded = {};
         final byte[] emptyDecoded = {};
         testByteByByte(emptyEncoded, emptyDecoded, chunkSize, CR_LF);
         testByChunk(emptyEncoded, emptyDecoded, chunkSize, CR_LF);
     }

     /**
      * Test the Base64OutputStream implementation against empty input.
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testBase64EmptyOutputStreamMimeChunkSize() throws Exception {
         testBase64EmptyOutputStream(BaseNCodec.MIME_CHUNK_SIZE);
     }

     /**
      * Test the Base64OutputStream implementation against empty input.
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testBase64EmptyOutputStreamPemChunkSize() throws Exception {
         testBase64EmptyOutputStream(BaseNCodec.PEM_CHUNK_SIZE);
     }

     /**
      * Test the Base64OutputStream implementation
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testBase64OutputStreamByChunk() throws Exception {
         // Hello World test.
         byte[] encoded = StringUtils.getBytesUtf8("SGVsbG8gV29ybGQ=\r\n");
         byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         testByChunk(encoded, decoded, BaseNCodec.MIME_CHUNK_SIZE, CR_LF);

         // Single Byte test.
         encoded = StringUtils.getBytesUtf8("AA==\r\n");
         decoded = new byte[]{(byte) 0};
         testByChunk(encoded, decoded, BaseNCodec.MIME_CHUNK_SIZE, CR_LF);

         // OpenSSL interop test.
         encoded = StringUtils.getBytesUtf8(Base64TestData.ENCODED_64_CHARS_PER_LINE);
         decoded = BaseNTestData.DECODED;
         testByChunk(encoded, decoded, BaseNCodec.PEM_CHUNK_SIZE, LF);

         // Single Line test.
         final String singleLine = Base64TestData.ENCODED_64_CHARS_PER_LINE.replace("\n", "");
         encoded = StringUtils.getBytesUtf8(singleLine);
         decoded = BaseNTestData.DECODED;
         testByChunk(encoded, decoded, 0, LF);

         // test random data of sizes 0 through 150
         final BaseNCodec codec = new Base64(0, null, false);
         for (int i = 0; i <= 150; i++) {
             final byte[][] randomData = BaseNTestData.randomData(codec, i);
             encoded = randomData[1];
             decoded = randomData[0];
             testByChunk(encoded, decoded, 0, LF);
         }
     }

     /**
      * Test the Base64OutputStream implementation
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testBase64OutputStreamByteByByte() throws Exception {
         // Hello World test.
         byte[] encoded = StringUtils.getBytesUtf8("SGVsbG8gV29ybGQ=\r\n");
         byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
         testByteByByte(encoded, decoded, 76, CR_LF);

         // Single Byte test.
         encoded = StringUtils.getBytesUtf8("AA==\r\n");
         decoded = new byte[]{(byte) 0};
         testByteByByte(encoded, decoded, 76, CR_LF);

         // OpenSSL interop test.
         encoded = StringUtils.getBytesUtf8(Base64TestData.ENCODED_64_CHARS_PER_LINE);
         decoded = BaseNTestData.DECODED;
         testByteByByte(encoded, decoded, 64, LF);

         // Single Line test.
         final String singleLine = Base64TestData.ENCODED_64_CHARS_PER_LINE.replace("\n", "");
         encoded = StringUtils.getBytesUtf8(singleLine);
         decoded = BaseNTestData.DECODED;
         testByteByByte(encoded, decoded, 0, LF);

         // test random data of sizes 0 through 150
         final BaseNCodec codec = new Base64(0, null, false);
         for (int i = 0; i <= 150; i++) {
             final byte[][] randomData = BaseNTestData.randomData(codec, i);
             encoded = randomData[1];
             decoded = randomData[0];
             testByteByByte(encoded, decoded, 0, LF);
         }
     }

     @Test
     void testBuilder() {
         assertNotNull(Base64OutputStream.builder().getBaseNCodec());
     }

     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base64OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded
      *            base64 encoded data
      * @param decoded
      *            the data from above, but decoded
      * @param chunkSize
      *            chunk size (line-length) of the base64 encoded data.
      * @param separator
      *            Line separator in the base64 encoded data.
      * @throws Exception
      *             Usually signifies a bug in the Base64 commons-codec implementation.
      */
     private void testByChunk(final byte[] encoded, final byte[] decoded, final int chunkSize, final byte[] separator) throws Exception {

         // Start with encode.
         ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
         try (OutputStream out = new Base64OutputStream(byteOut, true, chunkSize, separator)) {
             out.write(decoded);
         }
         byte[] output = byteOut.toByteArray();
         assertArrayEquals(encoded, output, "Streaming chunked base64 encode");

         // Now let's try to decode.
         byteOut = new ByteArrayOutputStream();
         try (OutputStream out = new Base64OutputStream(byteOut, false)) {
             out.write(encoded);
         }
         output = byteOut.toByteArray();
         assertArrayEquals(decoded, output, "Streaming chunked base64 decode");

         // I always wanted to do this! (wrap encoder with decoder etc.).
         byteOut = new ByteArrayOutputStream();
         OutputStream out = byteOut;
         for (int i = 0; i < 10; i++) {
             out = new Base64OutputStream(out, false);
             out = new Base64OutputStream(out, true, chunkSize, separator);
         }
         out.write(decoded);
         out.close();
         output = byteOut.toByteArray();

         assertArrayEquals(decoded, output, "Streaming chunked base64 wrap-wrap-wrap!");
     }

     /**
      * Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
      * encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
      * <p/>
      * By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base64OutputStream wraps itself in encode and decode
      * mode over and over again.
      *
      * @param encoded
      *            base64 encoded data
      * @param decoded
      *            the data from above, but decoded
      * @param chunkSize
      *            chunk size (line-length) of the base64 encoded data.
      * @param separator
      *            Line separator in the base64 encoded data.
      * @throws Exception
      *             Usually signifies a bug in the Base64 commons-codec implementation.
      */
     private void testByteByByte(final byte[] encoded, final byte[] decoded, final int chunkSize, final byte[] separator) throws Exception {

         // Start with encode.
         ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
         try (OutputStream out = new Base64OutputStream(byteOut, true, chunkSize, separator)) {
             for (final byte element : decoded) {
                 out.write(element);
             }
         }
         byte[] output = byteOut.toByteArray();
         assertArrayEquals(encoded, output, "Streaming byte-by-byte base64 encode");

         // Now let's try to decode.
         byteOut = new ByteArrayOutputStream();
         try (OutputStream out = new Base64OutputStream(byteOut, false)) {
             for (final byte element : encoded) {
                 out.write(element);
             }
         }
         output = byteOut.toByteArray();
         assertArrayEquals(decoded, output, "Streaming byte-by-byte base64 decode");

         // Now let's try to decode with tonnes of flushes.
         byteOut = new ByteArrayOutputStream();
         try (OutputStream out = new Base64OutputStream(byteOut, false)) {
             for (final byte element : encoded) {
                 out.write(element);
                 out.flush();
             }
         }
         output = byteOut.toByteArray();
         assertArrayEquals(decoded, output, "Streaming byte-by-byte flush() base64 decode");

         // I always wanted to do this! (wrap encoder with decoder etc.).
         byteOut = new ByteArrayOutputStream();
         OutputStream out = byteOut;
         for (int i = 0; i < 10; i++) {
             out = new Base64OutputStream(out, false);
             out = new Base64OutputStream(out, true, chunkSize, separator);
         }
         for (final byte element : decoded) {
             out.write(element);
         }
         out.close();
         output = byteOut.toByteArray();

         assertArrayEquals(decoded, output, "Streaming byte-by-byte base64 wrap-wrap-wrap!");
     }

     /**
      * Test the Base64OutputStream implementation against the special NPE inducing input
      * identified in the CODEC-98 bug.
      *
      * @throws Exception for some failure scenarios.
      */
     @Test
     void testCodec98NPE() throws Exception {
         final byte[] codec98 = StringUtils.getBytesUtf8(Base64TestData.CODEC_98_NPE);
         final byte[] codec98_1024 = new byte[1024];
         System.arraycopy(codec98, 0, codec98_1024, 0, codec98.length);
         final ByteArrayOutputStream data = new ByteArrayOutputStream(1024);
         try (Base64OutputStream stream = new Base64OutputStream(data, false)) {
             stream.write(codec98_1024, 0, 1024);
         }

         final byte[] decodedBytes = data.toByteArray();
         final String decoded = StringUtils.newStringUtf8(decodedBytes);
         assertEquals(Base64TestData.CODEC_98_NPE_DECODED, decoded, "codec-98 NPE Base64OutputStream");
     }

     /**
      * Test strict decoding.
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testStrictDecoding() throws Exception {
         for (final String impossibleStr : Base64Test.BASE64_IMPOSSIBLE_CASES) {
             final byte[] impossibleEncoded = StringUtils.getBytesUtf8(impossibleStr);
             ByteArrayOutputStream bout = new ByteArrayOutputStream();
             try (Base64OutputStream out = new Base64OutputStream(bout, false)) {
                 // Default is lenient decoding; it should not throw
                 assertFalse(out.isStrictDecoding());
                 out.write(impossibleEncoded);
             }
             assertTrue(bout.size() > 0);
             // Strict decoding should throw
             bout = new ByteArrayOutputStream();
             try (Base64OutputStream out = new Base64OutputStream(bout, false, 0, null, CodecPolicy.STRICT)) {
                 // May throw on write or on close depending on the position of the
                 // impossible last character in the output block size
                 assertThrows(IllegalArgumentException.class, () -> {
                     out.write(impossibleEncoded);
                     out.close();
                 });
             }
             try (Base64OutputStream out = Base64OutputStream.builder()
                     .setOutputStream(bout).setEncode(false)
                     .setBaseNCodec(Base64.builder().setLineLength(0).setLineSeparator(null).setDecodingPolicy(CodecPolicy.STRICT).get())
                     .get()) {
                 assertTrue(out.isStrictDecoding());
                 assertThrows(IllegalArgumentException.class, () -> {
                     out.write(impossibleEncoded);
                     out.close();
                 });
             }
             try (Base64OutputStream out = Base64OutputStream.builder()
                     .setOutputStream(bout).setEncode(false)
                     .setBaseNCodec(Base64.builder().setDecodingPolicy(CodecPolicy.STRICT).get())
                     .get()) {
                 // May throw on write or on close depending on the position of the
                 // impossible last character in the output block size
                 assertThrows(IllegalArgumentException.class, () -> {
                     out.write(impossibleEncoded);
                     out.close();
                 });
             }
         }
     }

     /**
      * Tests Base64OutputStream.write for expected IndexOutOfBoundsException conditions.
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testWriteOutOfBounds() throws Exception {
         final byte[] buf = new byte[1024];
         final ByteArrayOutputStream bout = new ByteArrayOutputStream();
         try (Base64OutputStream out = new Base64OutputStream(bout)) {
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, -1, 1), "Base64OutputStream.write(buf, -1, 1)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, 1, -1), "Base64OutputStream.write(buf, 1, -1)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length + 1, 0), "Base64OutputStream.write(buf, buf.length + 1, 0)");
             assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length - 1, 2), "Base64OutputStream.write(buf, buf.length - 1, 2)");
         }
     }

     /**
      * Tests Base64OutputStream.write(null).
      *
      * @throws Exception
      *             for some failure scenarios.
      */
     @Test
     void testWriteToNullCoverage() throws Exception {
         final ByteArrayOutputStream bout = new ByteArrayOutputStream();
         try (Base64OutputStream out = new Base64OutputStream(bout)) {
             assertThrows(NullPointerException.class, () -> out.write(null, 0, 0));
         }
     }
 }
	/*
	* 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
	*
	* https://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.codec.binary;

	import static org.junit.jupiter.api.Assertions.assertArrayEquals;
	import static org.junit.jupiter.api.Assertions.assertEquals;
	import static org.junit.jupiter.api.Assertions.assertFalse;
	import static org.junit.jupiter.api.Assertions.assertNotNull;
	import static org.junit.jupiter.api.Assertions.assertThrows;
	import static org.junit.jupiter.api.Assertions.assertTrue;

	import java.io.ByteArrayOutputStream;
	import java.io.OutputStream;

	import org.apache.commons.codec.CodecPolicy;
	import org.junit.jupiter.api.Test;

	/**
	* Tests {@link Base64OutputStream}.
	*/
	class Base64OutputStreamTest {

	private static final byte[] CR_LF = {(byte) '\r', (byte) '\n'};

	private static final byte[] LF = {(byte) '\n'};

	private static final String STRING_FIXTURE = "Hello World";

	private void testBase64EmptyOutputStream(final int chunkSize) throws Exception {
	final byte[] emptyEncoded = {};
	final byte[] emptyDecoded = {};
	testByteByByte(emptyEncoded, emptyDecoded, chunkSize, CR_LF);
	testByChunk(emptyEncoded, emptyDecoded, chunkSize, CR_LF);
	}

	/**
	* Test the Base64OutputStream implementation against empty input.
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testBase64EmptyOutputStreamMimeChunkSize() throws Exception {
	testBase64EmptyOutputStream(BaseNCodec.MIME_CHUNK_SIZE);
	}

	/**
	* Test the Base64OutputStream implementation against empty input.
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testBase64EmptyOutputStreamPemChunkSize() throws Exception {
	testBase64EmptyOutputStream(BaseNCodec.PEM_CHUNK_SIZE);
	}

	/**
	* Test the Base64OutputStream implementation
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testBase64OutputStreamByChunk() throws Exception {
	// Hello World test.
	byte[] encoded = StringUtils.getBytesUtf8("SGVsbG8gV29ybGQ=\r\n");
	byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
	testByChunk(encoded, decoded, BaseNCodec.MIME_CHUNK_SIZE, CR_LF);

	// Single Byte test.
	encoded = StringUtils.getBytesUtf8("AA==\r\n");
	decoded = new byte[]{(byte) 0};
	testByChunk(encoded, decoded, BaseNCodec.MIME_CHUNK_SIZE, CR_LF);

	// OpenSSL interop test.
	encoded = StringUtils.getBytesUtf8(Base64TestData.ENCODED_64_CHARS_PER_LINE);
	decoded = BaseNTestData.DECODED;
	testByChunk(encoded, decoded, BaseNCodec.PEM_CHUNK_SIZE, LF);

	// Single Line test.
	final String singleLine = Base64TestData.ENCODED_64_CHARS_PER_LINE.replace("\n", "");
	encoded = StringUtils.getBytesUtf8(singleLine);
	decoded = BaseNTestData.DECODED;
	testByChunk(encoded, decoded, 0, LF);

	// test random data of sizes 0 through 150
	final BaseNCodec codec = new Base64(0, null, false);
	for (int i = 0; i <= 150; i++) {
	final byte[][] randomData = BaseNTestData.randomData(codec, i);
	encoded = randomData[1];
	decoded = randomData[0];
	testByChunk(encoded, decoded, 0, LF);
	}
	}

	/**
	* Test the Base64OutputStream implementation
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testBase64OutputStreamByteByByte() throws Exception {
	// Hello World test.
	byte[] encoded = StringUtils.getBytesUtf8("SGVsbG8gV29ybGQ=\r\n");
	byte[] decoded = StringUtils.getBytesUtf8(STRING_FIXTURE);
	testByteByByte(encoded, decoded, 76, CR_LF);

	// Single Byte test.
	encoded = StringUtils.getBytesUtf8("AA==\r\n");
	decoded = new byte[]{(byte) 0};
	testByteByByte(encoded, decoded, 76, CR_LF);

	// OpenSSL interop test.
	encoded = StringUtils.getBytesUtf8(Base64TestData.ENCODED_64_CHARS_PER_LINE);
	decoded = BaseNTestData.DECODED;
	testByteByByte(encoded, decoded, 64, LF);

	// Single Line test.
	final String singleLine = Base64TestData.ENCODED_64_CHARS_PER_LINE.replace("\n", "");
	encoded = StringUtils.getBytesUtf8(singleLine);
	decoded = BaseNTestData.DECODED;
	testByteByByte(encoded, decoded, 0, LF);

	// test random data of sizes 0 through 150
	final BaseNCodec codec = new Base64(0, null, false);
	for (int i = 0; i <= 150; i++) {
	final byte[][] randomData = BaseNTestData.randomData(codec, i);
	encoded = randomData[1];
	decoded = randomData[0];
	testByteByByte(encoded, decoded, 0, LF);
	}
	}

	@Test
	void testBuilder() {
	assertNotNull(Base64OutputStream.builder().getBaseNCodec());
	}

	/**
	* Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
	* encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
	* <p/>
	* By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base64OutputStream wraps itself in encode and decode
	* mode over and over again.
	*
	* @param encoded
	* base64 encoded data
	* @param decoded
	* the data from above, but decoded
	* @param chunkSize
	* chunk size (line-length) of the base64 encoded data.
	* @param separator
	* Line separator in the base64 encoded data.
	* @throws Exception
	* Usually signifies a bug in the Base64 commons-codec implementation.
	*/
	private void testByChunk(final byte[] encoded, final byte[] decoded, final int chunkSize, final byte[] separator) throws Exception {

	// Start with encode.
	ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
	try (OutputStream out = new Base64OutputStream(byteOut, true, chunkSize, separator)) {
	out.write(decoded);
	}
	byte[] output = byteOut.toByteArray();
	assertArrayEquals(encoded, output, "Streaming chunked base64 encode");

	// Now let's try to decode.
	byteOut = new ByteArrayOutputStream();
	try (OutputStream out = new Base64OutputStream(byteOut, false)) {
	out.write(encoded);
	}
	output = byteOut.toByteArray();
	assertArrayEquals(decoded, output, "Streaming chunked base64 decode");

	// I always wanted to do this! (wrap encoder with decoder etc.).
	byteOut = new ByteArrayOutputStream();
	OutputStream out = byteOut;
	for (int i = 0; i < 10; i++) {
	out = new Base64OutputStream(out, false);
	out = new Base64OutputStream(out, true, chunkSize, separator);
	}
	out.write(decoded);
	out.close();
	output = byteOut.toByteArray();

	assertArrayEquals(decoded, output, "Streaming chunked base64 wrap-wrap-wrap!");
	}

	/**
	* Test method does three tests on the supplied data: 1. encoded ---[DECODE]--> decoded 2. decoded ---[ENCODE]-->
	* encoded 3. decoded ---[WRAP-WRAP-WRAP-etc...] --> decoded
	* <p/>
	* By "[WRAP-WRAP-WRAP-etc...]" we mean situation where the Base64OutputStream wraps itself in encode and decode
	* mode over and over again.
	*
	* @param encoded
	* base64 encoded data
	* @param decoded
	* the data from above, but decoded
	* @param chunkSize
	* chunk size (line-length) of the base64 encoded data.
	* @param separator
	* Line separator in the base64 encoded data.
	* @throws Exception
	* Usually signifies a bug in the Base64 commons-codec implementation.
	*/
	private void testByteByByte(final byte[] encoded, final byte[] decoded, final int chunkSize, final byte[] separator) throws Exception {

	// Start with encode.
	ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
	try (OutputStream out = new Base64OutputStream(byteOut, true, chunkSize, separator)) {
	for (final byte element : decoded) {
	out.write(element);
	}
	}
	byte[] output = byteOut.toByteArray();
	assertArrayEquals(encoded, output, "Streaming byte-by-byte base64 encode");

	// Now let's try to decode.
	byteOut = new ByteArrayOutputStream();
	try (OutputStream out = new Base64OutputStream(byteOut, false)) {
	for (final byte element : encoded) {
	out.write(element);
	}
	}
	output = byteOut.toByteArray();
	assertArrayEquals(decoded, output, "Streaming byte-by-byte base64 decode");

	// Now let's try to decode with tonnes of flushes.
	byteOut = new ByteArrayOutputStream();
	try (OutputStream out = new Base64OutputStream(byteOut, false)) {
	for (final byte element : encoded) {
	out.write(element);
	out.flush();
	}
	}
	output = byteOut.toByteArray();
	assertArrayEquals(decoded, output, "Streaming byte-by-byte flush() base64 decode");

	// I always wanted to do this! (wrap encoder with decoder etc.).
	byteOut = new ByteArrayOutputStream();
	OutputStream out = byteOut;
	for (int i = 0; i < 10; i++) {
	out = new Base64OutputStream(out, false);
	out = new Base64OutputStream(out, true, chunkSize, separator);
	}
	for (final byte element : decoded) {
	out.write(element);
	}
	out.close();
	output = byteOut.toByteArray();

	assertArrayEquals(decoded, output, "Streaming byte-by-byte base64 wrap-wrap-wrap!");
	}

	/**
	* Test the Base64OutputStream implementation against the special NPE inducing input
	* identified in the CODEC-98 bug.
	*
	* @throws Exception for some failure scenarios.
	*/
	@Test
	void testCodec98NPE() throws Exception {
	final byte[] codec98 = StringUtils.getBytesUtf8(Base64TestData.CODEC_98_NPE);
	final byte[] codec98_1024 = new byte[1024];
	System.arraycopy(codec98, 0, codec98_1024, 0, codec98.length);
	final ByteArrayOutputStream data = new ByteArrayOutputStream(1024);
	try (Base64OutputStream stream = new Base64OutputStream(data, false)) {
	stream.write(codec98_1024, 0, 1024);
	}

	final byte[] decodedBytes = data.toByteArray();
	final String decoded = StringUtils.newStringUtf8(decodedBytes);
	assertEquals(Base64TestData.CODEC_98_NPE_DECODED, decoded, "codec-98 NPE Base64OutputStream");
	}

	/**
	* Test strict decoding.
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testStrictDecoding() throws Exception {
	for (final String impossibleStr : Base64Test.BASE64_IMPOSSIBLE_CASES) {
	final byte[] impossibleEncoded = StringUtils.getBytesUtf8(impossibleStr);
	ByteArrayOutputStream bout = new ByteArrayOutputStream();
	try (Base64OutputStream out = new Base64OutputStream(bout, false)) {
	// Default is lenient decoding; it should not throw
	assertFalse(out.isStrictDecoding());
	out.write(impossibleEncoded);
	}
	assertTrue(bout.size() > 0);
	// Strict decoding should throw
	bout = new ByteArrayOutputStream();
	try (Base64OutputStream out = new Base64OutputStream(bout, false, 0, null, CodecPolicy.STRICT)) {
	// May throw on write or on close depending on the position of the
	// impossible last character in the output block size
	assertThrows(IllegalArgumentException.class, () -> {
	out.write(impossibleEncoded);
	out.close();
	});
	}
	try (Base64OutputStream out = Base64OutputStream.builder()
	.setOutputStream(bout).setEncode(false)
	.setBaseNCodec(Base64.builder().setLineLength(0).setLineSeparator(null).setDecodingPolicy(CodecPolicy.STRICT).get())
	.get()) {
	assertTrue(out.isStrictDecoding());
	assertThrows(IllegalArgumentException.class, () -> {
	out.write(impossibleEncoded);
	out.close();
	});
	}
	try (Base64OutputStream out = Base64OutputStream.builder()
	.setOutputStream(bout).setEncode(false)
	.setBaseNCodec(Base64.builder().setDecodingPolicy(CodecPolicy.STRICT).get())
	.get()) {
	// May throw on write or on close depending on the position of the
	// impossible last character in the output block size
	assertThrows(IllegalArgumentException.class, () -> {
	out.write(impossibleEncoded);
	out.close();
	});
	}
	}
	}

	/**
	* Tests Base64OutputStream.write for expected IndexOutOfBoundsException conditions.
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testWriteOutOfBounds() throws Exception {
	final byte[] buf = new byte[1024];
	final ByteArrayOutputStream bout = new ByteArrayOutputStream();
	try (Base64OutputStream out = new Base64OutputStream(bout)) {
	assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, -1, 1), "Base64OutputStream.write(buf, -1, 1)");
	assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, 1, -1), "Base64OutputStream.write(buf, 1, -1)");
	assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length + 1, 0), "Base64OutputStream.write(buf, buf.length + 1, 0)");
	assertThrows(IndexOutOfBoundsException.class, () -> out.write(buf, buf.length - 1, 2), "Base64OutputStream.write(buf, buf.length - 1, 2)");
	}
	}

	/**
	* Tests Base64OutputStream.write(null).
	*
	* @throws Exception
	* for some failure scenarios.
	*/
	@Test
	void testWriteToNullCoverage() throws Exception {
	final ByteArrayOutputStream bout = new ByteArrayOutputStream();
	try (Base64OutputStream out = new Base64OutputStream(bout)) {
	assertThrows(NullPointerException.class, () -> out.write(null, 0, 0));
	}
	}
	}