gt:         ByteArrayOutputStream in = new ByteArrayOutputStream(20);
context: /*
   * 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.sshd.server.shell;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.EOFException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.charset.StandardCharsets;
  
  import org.apache.sshd.server.Environment;
  import org.apache.sshd.server.session.ServerSession;
  import org.apache.sshd.util.test.BaseTestSupport;
  import org.apache.sshd.util.test.BogusEnvironment;
  import org.apache.sshd.util.test.BogusExitCallback;
  import org.apache.sshd.util.test.BogusInvertedShell;
  import org.junit.FixMethodOrder;
  import org.junit.Test;
  import org.junit.runners.MethodSorters;
  
  @FixMethodOrder(MethodSorters.NAME_ASCENDING)
  public class InvertedShellWrapperTest extends BaseTestSupport {
      public InvertedShellWrapperTest() {
          super();
      }
  
      @Test
      public void testStreamsAreFlushedBeforeClosing() throws Exception {
          BogusInvertedShell shell = newShell("out", "err");
          shell.setAlive(false);
  
          try (ByteArrayInputStream in = new ByteArrayInputStream("in".getBytes(StandardCharsets.UTF_8));
               ByteArrayOutputStream out = new ByteArrayOutputStream(50);
               ByteArrayOutputStream err = new ByteArrayOutputStream()) {
  
              InvertedShellWrapper wrapper = new InvertedShellWrapper(shell);
              try {
                  wrapper.setInputStream(in);
                  wrapper.setOutputStream(out);
                  wrapper.setErrorStream(err);
                  wrapper.setExitCallback(new BogusExitCallback());
                  wrapper.start(new BogusEnvironment());
  
                  wrapper.pumpStreams();
  
                  // check the streams were flushed before exiting
                  assertEquals("stdin", "in", shell.getInputStream().toString());
                  assertEquals("stdout", "out", out.toString());
                  assertEquals("stderr", "err", err.toString());
              } finally {
                  wrapper.destroy();
              }
          }
      }
  
      @Test   // see SSHD-570
      public void testExceptionWhilePumpStreams() throws Exception {
          final BogusInvertedShell bogusShell = newShell("out", "err");
          bogusShell.setAlive(false);
  
          final int destroyedExitValue = 7365;
          InvertedShell shell = new InvertedShell() {
              private boolean destroyed;
  
              @Override
              public void start(Environment env) throws IOException {
                  bogusShell.start(env);
              }
  
              @Override
              public void setSession(ServerSession session) {
                  bogusShell.setSession(session);
              }
  
              @Override
              public boolean isAlive() {
                  return bogusShell.isAlive();
              }
  
              @Override
              public InputStream getOutputStream() {
                  return bogusShell.getOutputStream();
              }
  
              @Override
              public OutputStream getInputStream() {
                  return bogusShell.getInputStream();
              }
  
              @Override
              public InputStream getErrorStream() {
                  return bogusShell.getErrorStream();
              }
  
              @Override
              public int exitValue() {
                  return destroyed ? destroyedExitValue : bogusShell.exitValue();
              }
  
              @Override
              public void destroy() {
                  bogusShell.destroy();
                  bogusShell.setAlive(false);
                  destroyed = true;
              }
          };
  
          try (ByteArrayOutputStream out = new ByteArrayOutputStream();
               ByteArrayOutputStream err = new ByteArrayOutputStream();
               InputStream stdin = new InputStream() {
                   private final byte[] data = getCurrentTestName().getBytes(StandardCharsets.UTF_8);
                   private int readPos;
  
                   @Override
                   public int read() throws IOException {
                       if (readPos >= data.length) {
                           throw new EOFException("Data exhausted");
                       }
  
                       return data[readPos++];
                   }
  
                   @Override
                   public int available() throws IOException {
                       return data.length;
                   }
               }) {
  
              BogusExitCallback exitCallback = new BogusExitCallback();
              InvertedShellWrapper wrapper = new InvertedShellWrapper(shell);
              try {
                  wrapper.setInputStream(stdin);
                  wrapper.setOutputStream(out);
                  wrapper.setErrorStream(err);
  
                  wrapper.setExitCallback(exitCallback);
                  wrapper.start(new BogusEnvironment());
  
                  wrapper.pumpStreams();
              } finally {
                  wrapper.destroy();
              }
  
              assertEquals("Mismatched exit value", destroyedExitValue, exitCallback.getExitValue());
              assertEquals("Mismatched exit message", EOFException.class.getSimpleName(), exitCallback.getExitMessage());
          }
      }
  
      @Test // see SSHD-576
      public void testShellDiesBeforeAllDataExhausted() throws Exception {
          final String inputContent = "shellInput";
          final String outputContent = "shellOutput";
          final String errorContent = "shellError";
          try (final InputStream stdin = newDelayedInputStream(Long.SIZE, inputContent);
               final ByteArrayOutputStream shellIn = new ByteArrayOutputStream(Byte.MAX_VALUE);
               final InputStream shellOut = newDelayedInputStream(Byte.SIZE, outputContent);
               ByteArrayOutputStream stdout = new ByteArrayOutputStream(outputContent.length() + Byte.SIZE);
               final InputStream shellErr = newDelayedInputStream(Short.SIZE, errorContent);
               ByteArrayOutputStream stderr = new ByteArrayOutputStream(errorContent.length() + Byte.SIZE)) {
  
              InvertedShell shell = new InvertedShell() {
                  @Override
                  public void start(Environment env) throws IOException {
                      // ignored
                  }
  
                  @Override
                  public void setSession(ServerSession session) {
                      // ignored
                  }
  
                  @Override
                  public boolean isAlive() {
                      return false;
                  }
  
                  @Override
                  public InputStream getOutputStream() {
                      return shellOut;
                  }
  
                  @Override
                  public OutputStream getInputStream() {
                      return shellIn;
                  }
  
                  @Override
                  public InputStream getErrorStream() {
                      return shellErr;
                  }
  
                  @Override
                  public int exitValue() {
                      return -1;
                  }
  
                  @Override
                  public void destroy() {
                      // ignored
                  }
              };
  
              BogusExitCallback exitCallback = new BogusExitCallback();
              InvertedShellWrapper wrapper = new InvertedShellWrapper(shell);
              try {
                  wrapper.setInputStream(stdin);
                  wrapper.setOutputStream(stdout);
                  wrapper.setErrorStream(stderr);
  
                  wrapper.setExitCallback(exitCallback);
                  wrapper.start(new BogusEnvironment());
  
                  wrapper.pumpStreams();
              } finally {
                  wrapper.destroy();
              }
  
              assertEquals("Mismatched STDIN value", inputContent, shellIn.toString(StandardCharsets.UTF_8.name()));
              assertEquals("Mismatched STDOUT value", outputContent, stdout.toString(StandardCharsets.UTF_8.name()));
              assertEquals("Mismatched STDERR value", errorContent, stderr.toString(StandardCharsets.UTF_8.name()));
          }
      }
  
      private static InputStream newDelayedInputStream(int callsCount, String data) {
          return newDelayedInputStream(callsCount, data.getBytes(StandardCharsets.UTF_8));
      }
  
      private static InputStream newDelayedInputStream(final int callsCount, byte ... data) {
          return new ByteArrayInputStream(data) {
              private int delayCount;
  
              @Override
              public synchronized int read() {
                  throw new UnsupportedOperationException("Unexpected single byte read call");
              }
  
              @Override
              public synchronized int read(byte[] b, int off, int len) {
                  if (delayCount < callsCount) {
                      delayCount++;
                      return 0;
                  }
  
                  return super.read(b, off, len);
              }
          };
      }
  
      private static BogusInvertedShell newShell(String contentOut, String contentErr) {
  