import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit tests for any listenable future that chains other listenable futures. Unit tests need only
 * override buildChainingFuture and getSuccessfulResult, but they can add custom tests as needed.
 *
 * @author Nishant Thakkar
 */
@NullUnmarked
public abstract class AbstractChainedListenableFutureTest<T> extends TestCase {

  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);

  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);

  private static final UndeclaredThrowableException WRAPPED_EXCEPTION =
      new UndeclaredThrowableException(EXCEPTION);

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    return transform(inputFuture, new ComposeFunction(), directExecutor());
  }

  @Override
  protected String getSuccessfulResult() {
    return RESULT_DATA;
  }