import java.io.IOException;
import java.io.OutputStreamWriter;

/** @author Colin Decker */
public class TestWriter extends FilterWriter {

  private final TestOutputStream out;

  public TestWriter(TestOption... options) throws IOException {
    this(new TestOutputStream(ByteStreams.nullOutputStream(), options));
  }

  public TestWriter(TestOutputStream out) {
    super(new OutputStreamWriter(checkNotNull(out), UTF_8));
    this.out = out;

    assertTrue(source.wasStreamOpened());
    assertTrue(source.wasStreamClosed());
  }

  public void testCopyToAppendable_doesNotCloseIfWriter() throws IOException {
    TestWriter writer = new TestWriter();
    assertFalse(writer.closed());
    source.copyTo(writer);
    assertFalse(writer.closed());
  }

  public void testClosesOnErrors_copyingToCharSinkThatThrows() {

    assertTrue(source.wasStreamOpened());
    assertTrue(source.wasStreamClosed());
  }

  public void testCopyToAppendable_doesNotCloseIfWriter() throws IOException {
    TestWriter writer = new TestWriter();
    assertFalse(writer.closed());
    source.copyTo(writer);
    assertFalse(writer.closed());
  }

  public void testClosesOnErrors_copyingToCharSinkThatThrows() {

public class UncaughtExceptionHandlersTest extends TestCase {

  private Runtime runtimeMock;

  @Override
  protected void setUp() {
    runtimeMock = mock(Runtime.class);
  }

  public void testExiter() {
    new Exiter(runtimeMock).uncaughtException(new Thread(), new Exception());
    verify(runtimeMock).exit(1);
  }

    try {
      ByteStreams.copy(new ByteArrayInputStream(data), out);
    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

  public void testWrite() throws IOException {
    sink.write(data);

    assertContainsExpectedBytes();
  }

  public void testWriteFrom_inputStream() throws IOException {
    sink.writeFrom(new ByteArrayInputStream(data));

    try {
      ByteStreams.copy(new ByteArrayInputStream(data), out);
    } finally {
      out.close();
    }

    assertContainsExpectedBytes();
  }

  public void testWrite() throws IOException {
    sink.write(data);

    assertContainsExpectedBytes();
  }

  public void testWriteFrom_inputStream() throws IOException {
    sink.writeFrom(new ByteArrayInputStream(data));

* the test/e2e/e2e.test binary can test arbitrary storage drivers, see the `-storage.testdriver` parameter ([#72836](https://github.com/kubernetes/kubernetes/pull/72836), [@pohly](https://github.com/pohly))