import org.jspecify.annotations.Nullable;

/**
 * Tests may use this to intercept messages that are logged by the code under test. Example:
 *
 * <pre>
 *   TestLogHandler handler;
 *
 *   protected void setUp() throws Exception {
 *     super.setUp();
 *     handler = new TestLogHandler();
 *     SomeClass.logger.addHandler(handler);
 *     addTearDown(new TearDown() {
 *       public void tearDown() throws Exception {

import org.jspecify.annotations.Nullable;

/**
 * Tests may use this to intercept messages that are logged by the code under test. Example:
 *
 * <pre>
 *   TestLogHandler handler;
 *
 *   protected void setUp() throws Exception {
 *     super.setUp();
 *     handler = new TestLogHandler();
 *     SomeClass.logger.addHandler(handler);
 *     addTearDown(new TearDown() {
 *       public void tearDown() throws Exception {

import org.junit.runner.Description
import org.junit.runners.model.Statement

/**
 * A log handler that records which log messages were published so that a calling test can make
 * assertions about them.
 */
class TestLogHandler(
  private val logger: Logger,
) : TestRule,
  BeforeEachCallback,
  AfterEachCallback {
  constructor(loggerName: Class<*>) : this(Logger.getLogger(loggerName.getName()))

/**
 * Unit test for {@link TestLogHandler}.
 *
 * @author kevinb
 */
@NullUnmarked
public class TestLogHandlerTest extends TestCase {

  private TestLogHandler handler;
  private final TearDownStack stack = new TearDownStack();

  @Override
  protected void setUp() throws Exception {
    super.setUp();

    handler = new TestLogHandler();

    queue.enqueue(THROWING_EVENT, "custom-label");

    Logger logger = Logger.getLogger(ListenerCallQueue.class.getName());
    logger.setLevel(Level.SEVERE);
    TestLogHandler logHandler = new TestLogHandler();
    logger.addHandler(logHandler);
    try {
      queue.dispatch();
    } finally {
      logger.removeHandler(logHandler);
    }

    queue.enqueue(THROWING_EVENT, "custom-label");

    Logger logger = Logger.getLogger(ListenerCallQueue.class.getName());
    logger.setLevel(Level.SEVERE);
    TestLogHandler logHandler = new TestLogHandler();
    logger.addHandler(logHandler);
    try {
      queue.dispatch();
    } finally {
      logger.removeHandler(logHandler);
    }