content: /*
   * 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.beam.sdk.util;
  
  import static org.junit.Assert.assertArrayEquals;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotSame;
  import static org.junit.Assert.assertSame;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.nio.charset.StandardCharsets;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Unit tests for {@link ExposedByteArrayOutputStream}. */
  @RunWith(JUnit4.class)
  public class ExposedByteArrayOutputStreamTest {
  
    private static final byte[] TEST_DATA = "Hello World!".getBytes(StandardCharsets.UTF_8);
  
    private ExposedByteArrayOutputStream exposedStream = new ExposedByteArrayOutputStream();
    private ByteArrayOutputStream stream = new ByteArrayOutputStream();
  
    @Test
    public void testNoWrite() {
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteZeroLengthArray() throws IOException {
      writeToBoth(new byte[0]);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteZeroLengthArrayWithOffset() {
      writeToBoth(new byte[0], 0, 0);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleByte() {
      writeToBoth(32);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleByteTwice() {
      writeToBoth(32);
      writeToBoth(32);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleArray() throws IOException {
      writeToBoth(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
      assertNotSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWriteSingleArrayFast() throws IOException {
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
      assertSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWriteSingleArrayTwice() throws IOException {
      writeToBoth(TEST_DATA);
      writeToBoth(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleArrayTwiceFast() throws IOException {
      writeToBothFast(TEST_DATA);
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleArrayTwiceFast1() throws IOException {
      writeToBothFast(TEST_DATA);
      writeToBoth(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleArrayTwiceFast2() throws IOException {
      writeToBoth(TEST_DATA);
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteSingleArrayWithLength() {
      writeToBoth(TEST_DATA, 0, TEST_DATA.length);
      assertStreamContentsEquals(stream, exposedStream);
      assertNotSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWritePartial() {
      writeToBoth(TEST_DATA, 0, TEST_DATA.length - 1);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWritePartialWithNonZeroBegin() {
      writeToBoth(TEST_DATA, 1, TEST_DATA.length - 1);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteByteAfterWriteArrayFast() throws IOException {
      writeToBothFast(TEST_DATA);
      writeToBoth(32);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteArrayFastAfterByte() throws IOException {
      writeToBoth(32);
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testResetAfterWriteFast() throws IOException {
      writeToBothFast(TEST_DATA);
      resetBoth();
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteArrayFastAfterReset() throws IOException {
      writeToBothFast(TEST_DATA);
      resetBoth();
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
      assertSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWriteArrayFastAfterReset1() throws IOException {
      writeToBothFast(TEST_DATA);
      writeToBothFast(TEST_DATA);
      resetBoth();
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
      assertSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWriteArrayFastAfterReset2() throws IOException {
      resetBoth();
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
      assertSame(TEST_DATA, exposedStream.toByteArray());
    }
  
    @Test
    public void testWriteArrayFastTwiceAfterReset() throws IOException {
      writeToBothFast(TEST_DATA);
      resetBoth();
      writeToBothFast(TEST_DATA);
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteArrayFastTwiceAfterReset1() throws IOException {
      writeToBothFast(TEST_DATA);
      writeToBothFast(TEST_DATA);
      resetBoth();
      writeToBothFast(TEST_DATA);
      writeToBothFast(TEST_DATA);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteByteAfterReset() {
      writeToBoth(32);
      resetBoth();
      writeToBoth(32);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    @Test
    public void testWriteByteAfterReset1() {
      resetBoth();
      writeToBoth(32);
      assertStreamContentsEquals(stream, exposedStream);
    }
  
    private void assertStreamContentsEquals(
        ByteArrayOutputStream stream1, ByteArrayOutputStream stream2) {
      assertArrayEquals(stream1.toByteArray(), stream2.toByteArray());
      try {
        assertEquals(stream1.toString("UTF-8"), stream2.toString("UTF-8"));
      } catch (UnsupportedEncodingException e) {
        throw new RuntimeException(e);
      }
      assertEquals(stream1.size(), stream2.size());
    }
  
    private void writeToBoth(int b) {
      exposedStream.write(b);
      stream.write(b);
    }
  
    private void writeToBoth(byte[] b) throws IOException {
      exposedStream.write(b);
      stream.write(b);
    }
  
    private void writeToBothFast(byte[] b) throws IOException {
      exposedStream.writeAndOwn(b);
      stream.write(b);
    }
  
    private void writeToBoth(byte[] b, int off, int length) {
      exposedStream.write(b, off, length);
      stream.write(b, off, length);
    }
  
    private void resetBoth() {
      exposedStream.reset();
      stream.reset();
    }
  }
  